• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Intensif afr

Intensif afr



presentation slides

presentation slides



Total Views
Views on SlideShare
Embed Views



1 Embed 4

https://twitter.com 4



Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment

    Intensif afr Intensif afr Presentation Transcript

    • Conference AbstractsChallenges and Opportunities forAgricultural Intensification of theHumid Highland Systems of sub- Saharan Africa Fertility Soil Biology banana 2008
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 2
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 4
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa INTRODUCTORY KEYNOTES 5
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 6
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa1. Sustainable intensification and the food security challenge Brian Keating1 and Peter Carberry1 Commonwealth Scientific and Industrial Research Organisation (CSIRO), 1 Canberra, Australia.AbstractGlobal food demand is estimated to increase between 50 and 80 percent between2010 and 2050 – with the range driven by variation in the key drivers such aspopulation growth, per capita consumption trends, diversion to biofuels and foodwastage rates. Pathways by which this challenge can be met include; reducingthe demand trajectory, filling the production gap and avoiding losses of currentproductive capacity. This paper focuses on the opportunity to expand food supplyto fill this projected increase in demand. Challenges of this scale have been metin the past – between 1961 and 2008, agricultural output increased by 179 percentglobally. In many parts of the world, these production increases were achievedby intensification of agricultural practices, in particular via combining inorganicfertiliser and agri-chemical inputs with intensive tillage and improved varieties. Thelonger term sustainability of such intensive systems remains a concern, but thereis little doubt that without the higher yields now being achieved in much of thedeveloping world, the numbers of undernourished would be much higher than thecurrent (still unacceptable) levels. While yields were rising in response to agriculturalintensification in other parts of the world, sub Saharan Africa maintained (just) foodproduction per capita by expanding the land footprint and productivity levels perunit land remain low. While there is still scope for further expansion of agriculturalland, particularly in sub Saharan Africa and in parts of South America, the clearingof forests and woodlands and cultivation of grasslands is going to generate asignificant load of greenhouse gases on an already overloaded atmosphere – withconsequences for climate change and potential for negative feedback on agriculturalproductivity. Given the food demand pressures and the environmental constraints(carbon, water, biodiversity), there seems little alternative to an intensificationpathway for agriculture – but it needs to be a sustainable one (i.e. eco-efficient) interms of nutrient and water cycles and agro-ecological functions. This conclusionapplies generally, but the potential upside is greatest in Africa where inputs arevery low and productivity is coming off a low baseline. In this paper we argue for astrong evidence base to help guide interventions towards sustainable intensification.We present a diagnostic framework applicable at the field and farm scale, but alsoargue that progress in productivity growth will be slow without concerted effortsto embed agricultural R&D in a wider innovation effort. Such an effort needs tosupport the evolution of a system of enabling institutions (input and output markets,public policy settings, private sector activity, trade and regulation) that are a precondition for any transformation in the African farm sector. 7
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa2. Paradigm Change for African Agriculture: why and how to make the transition Hans R Herren Millennium Institute, Washington DC, USAAbstractAgriculture needs to transition from being a major problem for climate change, to thesolution, while at the same time it also needs to become the true engine of sustainabledevelopment. The International Assessment of Agricultural Knowledge, Science andTechnology for Development (IAASTD) is a unique and comprehensive assessment ofAgricultural Knowledge, Science and Technology, which outlined the path for such atransition. It started with requests from the private sector and NGOs to the World Bank,to look at new ways for agriculture and food systems to assure sufficient and qualityfood, fiber and feed production for the long term under the challenges of increased andchanging demand, shrinking natural resources and climate change, while also dealingwith the more immediate perennial hunger and poverty nexus. The IAASTD waslaunched by the major UN agencies at the Johannesburg World Summit on SustainableDevelopment in 2002, and subsequently officially endorsed by the OECD and othercountries at a Plenary meeting in Nairobi in 2004. A Bureau made up of representativesfrom government, multilateral agencies and civil society groups, including the privatesector, guided all the steps of the assessment and endorsed over 400 authors, fromdeveloped and developing nations covering agricultural and related disciplines. Ina first step, some 800 stakeholders framed the key questions to be addressed by thereport’s authors at workshops held in the five regions covered by the assessment (NorthAmerica and Europe, Latin America and the Caribbean, Sub-Saharan Africa, Centraland West Asia and North Africa and South Asia and the Pacific). Of main interestwas how the AKSTs of the past 50 years influenced where we are today in terms ofagricultural production and food systems and how to reshape these for reducing hungerand poverty; improving rural livelihoods; improving nutrition and human health;and facilitating environmentally, socially, equitable and economically sustainabledevelopment. In the report series “Agriculture at a Crossroads”, the IAASTD authorsemphasized the need for a new paradigm in AKST that will lead to food systems,that are in harmony with the environment, i.e., agroecology, organic agriculture, thatmitigates rather than contribute to climate change, that has reduced external energyinputs in terms of synthetic fertilizers and pesticides, that is high in genetic and systemdiversity, that targets the small and family farms and one that assures food security andsovereignty at national level. It also emphasized the multi-functionality of agriculture,and in particular its social, environmental and economic aspects, which are all linkedand key in moving to a socially, environmentally and economically sustainable andproductive agriculture in the medium and long term. It suggest among others thatecosystem services be remunerated for all farmers instead of providing market distortingproduction and export support to the industrialized country farmers. The feasibilityof a green agriculture to meet the sustainability and millennium development goalsis presented, based on modeling results from the Millennium Institute, utilizing theoptions for action from the IAASTD report. 8
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEMATIC ORAL SESSIONS 9
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 10
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEME 1: SYSTEM COMPONENTS 11
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 12
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa3. Below- and aboveground organic inputs and the sustainability of agriculture: productivity and supply of ecosystem services Meine van Noordwijk1, Kurniatun Hairiah2, Bernard Vanlauwe3, Sileshi Weldesemayat4, Edmundo Barrios5, Bob Boddey6 and Georg Cadisch7 1 Ecosystem Services for Poverty Alleviation (ESPA), Scotland, UK; 2Faculty of Agriculture, University of Brawijaya, Indonesia; 3Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 4 World Agroforestry Centre (ICRAF), Nairobi, Kenya; 5Centre for International Development, Harvard University, Cambridge, USA; 6Embrapa-Agrobiologia, Rio de Janeiro, Brazil; 7University of Hohenheim, Stuttgart, GermanyAbstractOrganic inputs to the soil can derive within the field from aboveground plantresidue left at harvest time, from belowground inputs (roots, rhizosphere foodwebsand mycorrhizal hyphae) and externally, from recycled waste products (includingmanure and compost). Organic inputs serve functions at the surface, includingprotection of the soil from erosion, reduction of soil evaporation and regulation oftopsoil microclimate, as well as after incorporation to the soil, including maintenanceof soil structure, buffering of nutrients and supply of nutrients by mineralization.The tradeoff between these above and belowground functions is modulated bysoil tillage and presence of soil fauna. We review the literature on a number ofhypotheses: I. In the absence of soil tillage or active worm fauna, aboveground littercontributes little to soil organic matter, most of which derives from root turnover,II. Nutrients mineralized from aboveground litter decomposition are available toplants , as superficial roots develop where surface litter is (semi)permanent and/or nutrients leach into the root zone. III. In the presence of permanent surface litter,the dependence of soil function on soil organic matter for soil physical properties isreduced as well as the rate of soil organic matter decomposition, IV. ’Low-quality’litter, with e.g. high polyphenol contents, is to be preferred over material with higherrates of decomposition where agricultural sustainability on slopes is an issue. 13
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa4. CIALCA interventions for productivity increase of cropping system components in the African Great Lakes zone. P. Pypers1, W. Bimponda2, E. Birachi3, K. Bishikwabo4, G. Blomme5, S. Carpentier6, A. Gahigi7, S. Gaidashova7, J. Jefwa1, S. Kantengwa4, J.P. Kanyaruguru8, P. Lepoint9, J.P. Lodi-Lama4, M. Manzekele2, S. Mapatano10, R. Merckx6, T. Ndabamenye7, T. Ngoga7, J.J. Nitumfuidi2, C. Niyuhire11, J. Ntamwira2, E. Ouma12, J.M. Sanginga4, C. Sivirihauma13, R. Swennen6, P. van Asten14, B. Vanlauwe1, N. Vigheri15, and J.M. Walangululu16 1 TSBF-CIAT (Kenya), 2 INERA (DR Congo), 3 CIAT (DR Congo), 4 TSBF-CIAT (DR Congo), 5 Bioversity (Uganda), 6 KULeuven (Belgium), 7 ISAR (Rwanda), 8 CIALCA (Burundi), 9 Biover- sity (Burundi), 10 DIOBASS (DR Congo), 11 ISABU (Burundi), 12 IITA (Burundi), 13 Bioversity (DR Congo), 14 IITA (Uganda), 15 UCG (DR Congo), 16 UCB (DR Congo).Abstract: In the African Great Lakes zone, farmers are confronted by declining soil fertility, low crop yieldsand food insecurity. The local crop cultivation practice entails the use of local varieties in mixedsystems with often high crop densities, and little or no application of inputs. To improve pro-ductivity, the Consortium for Improving Agricultural Livelihoods in Central Africa (CIALCA)implements a strategy with improved banana and grain legume germplasm as the entry pointand key component of natural resource and disease management options. Successful introductionrequires that new varieties perform superiorly in terms of yield and resistance to biotic and abi-otic stresses in comparison with local varieties, but also match farmer expectations for traits suchas e.g., duration, taste and tradability. In addition, CIALCA sought to introduce varieties withtraits favourable for soil fertility and human nutrition. Large germplasm evaluation trials wereconducted on-station with research partners in the region, and selected varieties were evaluatedin on-farm demonstration trials to assess genotype x environment interactions and obtain farmerfeedback. Examples are given of the performance of the performance of newly introduced variet-ies. Preferred varieties were then made available to farmers through investments in community-led macropropation of banana germplasm, and legume seed multiplication schemes. Durableproductivity improvements however require further investment. CIALCA is promoting technol-ogy packages that combine improved germplasm with fertilizer use, organic matter managementand/or agronomic measures. Although farmers correctly recognize low soil fertility and droughtas the major abiotic crop constraints, they rarely make use of technologies to overcome these. Fer-tilizer is little used because of its cost and limited availability. The price of fertilizer is characteristi-cally high due to a poorly developed agro-input sector and infrastructural constraints, but pricesof crop produce are likewise high, resulting in favourable benefit-cost ratios. This has been dem-onstrated in all countries, in grain legumes as well as in cassava and maize intercrops, and createdinterest and opportunities for fertilizer use. CIALCA further advocates appropriate organic mat-ter management in conjunction with fertilizer use. Examples are given how quality and methodof application affect fertilizer use efficiency in climbing beans. In banana systems, mulching andzero-tillage have positive effects on moisture retention, nutrient recycling and weed suppression,which results in increased bunch yield even without application of external nutrients. In cassavasystems, combined application of fertilizer and green manure results in greater profitability thanthe sole application of either resource. Agronomic measures can further improve yields. Optimiz-ing the plant density and plantation management can increase banana bunch weights, but mayprolong the cropping cycle and conflict with other farmer objectives. An evaluation of water-harvesting options suggested that benefits can be obtained from tied ridging in drought-proneregions, but poor soil fertility is a more important constraint in maize-based systems. CIALCAhas a substantial evidence base on how the productivity of individual crop components can beimproved, but challenges remain to integrate these at system and farm level, and adjust these tothe diverse agro-ecological and socio-economic conditions of smallholder farmers. Also, the avail-ability and affordability of fertilizer, the economic durability of community-led seed multiplica-tion schemes, as well as the knowledge intensity of technology packages remain limitations forlarge-scale dissemination and adoption. 14
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa5. Mitigating the impact of biotic constraints to build resilient banana systems in Central and Eastern Africa Rony Swennen1, Guy Blomme2, Piet van Asten3, Pascale Lepoint4, Eldad Karamura2, Emmanuel Njukwe3 and Jim Lorenzen3 1 Katholieke Universiteit Leuven, Leuven, Belgium; 2Bioversity International, Uganda office, Kampala, Uganda; 3International Institute of Tropical Agriculture (IITA), Uganda office, Kampala, Uganda; 4Bioversity International, Bujumbura, BurundiAbstractBanana and plantain are a major food staple and source of income for food-insecuresmallholders across Central and Eastern Africa. Banana diseases and pests continueto threaten the region’s banana production. Xanthomonas and Fusarium wilt arewidely spread across the region. Banana bunchy top disease, spread by an aphidvector with a preference for warmer temperatures, is currently mainly presentin the Congo basin and the Rusizi valley. However, the movement of plantingmaterials and climate change may speed up the spread of this disease to highlandbanana producing regions. Black leaf streak, nematodes and weevils, so far onlyimportant in regions below 1,500 masl,could also potentially move to higherelevations with climate change. Population movements during years of war/socialunrest or resettlement of refugees have often been associated with banana plantingmaterial movement and possible disease and pest introduction. A wide range ofintegrated pest and disease management (IPM) technologies has been developedover the past years, including the introduction of resistant Musa germplasm, pesttrapping, male bud removal, disinfection of garden tools and improved canopyand soil management. Significant progress has been achieved through research onpest and disease epidemiology. High yielding exotic and improved varieties wereintroduced via the International Transit Centre (ITC), Leuven, Belgium and the firsthighland banana hybrids originating from IITA/NARO Uganda were tested acrossthe region. These varieties combine higher resistance with higher yields. Rapidand healthy multiplication of banana planting material is key to a vigorous andhealthy banana sector. Farmers mostlyuse suckers, from their own or a neighbor’sfield, which are often infected by pests and diseases.Technologies for clean seedproduction have been developed and disseminated, including paring of corms,boiling water treatment, the use of macro-propagation units, and to a lesser extenttissue culture plants. Improved linkages between research, extension, the privatesector, and policy makers from farm to regional level is required to improve theproductivity and resilience of banana systems; a critical contribution to sustainablefood systems in the region. 15
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa6. Do commercial biological and chemical products increase crop yields and economic returns under smallholder farmer conditions? Jefwa, J.M.1, Asrat, A.2, Hermann, L.1, Jemo, M.3, Kavoo, A.1, Lesueur, D.4, Majengo, C.5, Mucheru, M.6, Mukhongo1, R., Mulet6, F., Munyahali1, W., Mutegi1, E., Mwangi1, E., Ncho3, C., Nwoke, O.C.7, Okalebo, R.5, Pypers, P.1, Were, B.5, and Yusuf, A.8 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 2Ethiopian Institute of Agricultural Research (EIAR), Ethiopia; 3 International Institute of Tropical Agriculture, Ibadan, Nigeria; 2Ahmadu Bello University, Zaria, Nigeria; 4Agricultural Research for Development (CIRAD), Indonesia; 5Moi University, Eldoret, Kenya; 6Kenyatta University, Nairobi, Kenya; 7Department of Agronomy, Osun State University, Osogbo, Nigeria; 8Ahmadu Bello University, Zaria, NigeriaAbstractSmallholder farmers in sub-Saharan Africa are confronted by low crop yields due to poor soilfertility, and only have a limited capacity to invest in inputs. During recent decennia, newcommercial products have appeared on the market as alternatives to common fertilizers. Whilesome of these products are based on well-established technologies, such as e.g., Rhizobiuminoculation, others have not been subjected to scientific scrutiny. During 3 years, we evaluatedover 80 of these new products, including microbial inoculants and chemical products on majorlegume, cereal and banana crops across diverse agro-ecological conditions in Ethiopia, Nigeriaand Kenya. Amongst the Rhizobium inoculants, several products from different companies werefound very effective, but generally only on soybean. In Ethiopia, for example, over 30% increasein soybean yield was found as a result of increased nodulation and N fixation. In the Nigeriansavannah zone, a similar improvement in productivity was found with three commercial strains,which was relatively independent of soybean variety and soil type, if the soil had a low indigenousRhizobium population. In groundnut, contrarily, the commercial Rhizobium inoculants testedwere not only ineffective but appeared to be inferior to the indigenous soil population, independentof the rate and source of P applied. In Kenya, inoculation increased average soybean grain yieldup to 30%, with a benefit-cost ratio up to 5.0. Responses were largest when control yields rangedbetween 0.5-1.0 t ha-1, and when the soil N content varied between 0.05 and 0.15 % N. The effectof arbuscular mycorrhizal inoculants (AMF) was less evident. No effect was observed in wheatin Ethiopia, or on maize or soybean in Kenya. In tissue culture (TC) banana, in contrast, positivebut soil-dependent effects were found of several AMF inoculants on growth at the plantlets andthe potting stage, a crucial stage in the production process of planting material. Other productscontaining Trichoderma or Bacillus spp. also had positive effects on growth. When transplantedto the field, soil-dependent growth improvements of over 40% were observed, demonstratingthat TC bananas can indeed benefit from commercial biological products. On-going work iselucidating the interactions with pathogenic rhizosphere organisms, particularly Fusarium, onwhich the inoculants have variable and soil-dependent effects. Amongst the chemical productsevaluated, special attention was given to alternative P fertilizers such as leaf sprays, seed coatingsand conditioners with humic acids. The effect on cereals depended on the crop, the soil andaccompanying agronomic measures. In Ethiopia, positive effects in wheat were only found withthe humic acid conditioner. In Nigeria, both humic acid conditioners and leaf sprays increasedmaize grain yield, but the effect of the leaf sprays was highly site-dependent and the cost of thehumic acid conditioner was not compensated by the benefits on yield. In Kenya, positive effectswere found only if products were combined with fertilizer at a sub-optimal rate, and only in themost P-deficient soils. Benefit-cost ratios were only favourable for seed P coating because this is afairly inexpensive treatment (3 USD ha-1). In conclusion, results demonstrate that there is potentialfor biological and chemical commercial products, but there is need for continued evaluation.Smallholders may benefit from some of these products, on the condition that a good-qualityproduct is correctly applied to the appropriate crop with appropriate soil and crop management. 16
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa7. Enhanced utilization of biotechnology research and development innovations in eastern and central Africa Masiga, C. W.1, Ketema S.1 and Mugoya C.1 1 Associationfor Strengthening Agricultural Research in East and Central Africa (ASARECA), Entebbe, UgandaAbstractThe association for strengthening agricultural research in east and central Africa(ASARECA) through its Agrobiodiversity and biotechnology programme isenhancing utilization of biotechnology research and development innovations inECA. This is achieved through support to national agricultural research systems.The programme supports generation and uptake of biotechnology innovations,capacity strengthening, and availability of information. The successes so far areimpressive. Cassava transformation platforms in Kenya, Uganda and Tanzania havebeen established to Biosafety level II status and have become regional research andtraining epicentres in biotechnology. Low cost tissue culture protocols for cassavaand sweetpotato have been developed for banana, sweetpotatoes and cassava.Virus indexing tools have been developed for screening banana, cassava andsweetpotatoe planting materials against the common diseases and pests. Productionand dissemination of clean banana tissue culture has been strengthened. A regionalgenebank utilizing conservation biotechnology for conservation of cassava andsweetpotatoes is being rehabilitated and refurbished at the National Gene bankof Kenya. A parallel research activity involving development of a genetic linkagemap to map the location of the genes that confer resistance to cassava brown streakdisease (CBSD) is underway. Drought tolerant transgenic maize has been developedfor seven farmer preferred maize lines for Kenya, Sudan, Tanzania and Ethiopia.Marker assisted selection has been used to generate 51 sorghum lines resistant tostriga. Fine mapping of sorghum for striga resistance is almost completed. A pen-side diagnostic kit for detection of Taenia solium cysticercosis has been developedin ECA and the vaccine is under going trial. A number of post graduate trainingshave been supported. Information on these technological breakthroughs is beingdeveloped and will be published through books, journals and workshops. 17
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa8. Production of virus free sweetpotato planting materials using horticultural fleece Schulte-Geldermann, E. 1, Omuse, O.P.2, Agili, S. 1 and Low, J.1 International Potato Center (CIP), Nairobi, Kenya; 2Moi University, School of 1 Agricultural sciences, Eldoret, KenyaAbstractSweetpotato (Ipomea batatas) is one of the most important staple crops in denselypopulated parts of Eastern Africa and is quickly becoming an importantsupplementary staple in the southern part of the continent. It is vital to small scalefarmers with limited land, labor and capital. One of the major yield limiting factorsin sweetpotato production are lack of clean planting material owing to infection ofSweetpotato virus diseases (SPVD). Therefore there is a need to provide farmerswith better technologies for rapidly multiplying clean planting materials andmaintaining a clean stock for a long period on-farm without compromising on thequality. An experiment was set at Kakamega agriculture research station, in Kenyafrom June 2009 to March 2011. Three varieties of sweet potato free from virus butsusceptible to SPVD have been evaluated in three methods of vine multiplication a)control -exposed, b) Fleece-cover and c) Fleece-tunnel. In an interval of 5 monthscuttings have been taken and tested for virus incidence. Furthermore, cuttings werereplanted to measure the effect on field performance. Results indicate significantreduction in aphid, white fly population and virus levels, and a significant higherproduction of vine cuttings from the second cutting onwards. However, direct fleececover led to heat damage on vines which couldn’t be observed in the tunnel. Yieldsfrom vines obtained from both covering treatments have been significantly higherthan from vines out of the exposed treatment with all varieties. Preliminary datareveal that the use of horticulture fleece could act as a cheap measure to maintainvirus free foundation seed. 18
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa9. Lessons from Upstream Soil Conservation Measures to Mitigate Soil Erosion and Improve Land Productivity in the Humid Highlands of Northwestern Ethiopia Mengesha, Y.G.S.1 and Tadele, A.2 Department of Natural Resources Management, College of Agriculture and Environ- 1 mental Science Bahir Dar University, Bahir Dar, Ethiopia; 2 Department of Natural Resources Management, College of Agriculture and Natural Resources, Debremarkos University, Debremarkos, EthiopiaAbstractA study was conducted in Absela site, Banja Shikudad district, Awi administrativeZone of the Amhara National Regional State (ANRS), Northwestern Ethiopia locatedin the Blue Nile Basin to evaluate the effects of soil bunds stabilized with vetiver grass(V. zizanioides) and tree lucerne (C. palmensis) on selected soil physical and chemicalproperties, bund height, inter-terrace slope and barley (Hordeum vulgare L.) yield. Theexperiment had five treatments that included non-conserved land (control), a 9-yearold soil bund stabilized with tree lucerne, a 9-year old soil bund stabilized with vetivergrass, a 9-year old sole soil bund, and a 6-year old soil bund stabilized with tree lucerne.Data were analyzed using one-way analysis of variance (ANOVA) and mean valuesfor the treatments were separated using Duncan Multiple Range Test. Results of theexperiment indicated that OC, total N, bulk density, infiltration rate, bund height, andinter-terrace slope are significantly (p≤0.05) affected by soil conservation measures.The non-conserved fields had significantly lower OC, total N, infiltration rate; whereashigher bulk density as compared to the conserved fields with different conservationmeasures. However, no significant differences in bulk density were observed among theconservation methods. The field treated with 9-year old soil bund stabilized with treelucerne or sole soil bund had significantly higher OC content than all other treatments.Fields having 6-year old soil bunds had lower OM and total N when compared to fieldshaving 9-year old soil bunds irrespective of their method of stabilization. Fields with soilbunds stabilized with vetiver grass had the highest bund height and the lowest inter-terrace slope than fields with the remaining conservation measures. Barley grain andstraw yields were significantly (P<0.05) greater in both the soil accumulation and losszones of the conserved fields than the non-conserved (control) ones. In the accumulationzone, fields with the 9-year old soilbund stabilized with tree lucerne and with the9-year old sole soil bund gave higher grain yields (1878.5 kg ha-1 and 1712.5 kg ha-1,respectively) than fields having 9-year old soil bund stabilized with vetiver grass (1187kg ha-1) and 6-year old soil bund stabilized with tree lucerne (1284.25 kg ha-1). Whenwe compare the accumulation and the loss zones, the average grain yield obtained fromthe accumulation zones (averaged over all the treatments) was by 29.8% higher than theaverage grain yield obtained from the loss zones. The causes of soil erosion in the regioncould be rugged nature of the topography, high and erratic rainfall pattern, extensivedeforestation, continues cultivation and complete removal of crop residues from thefield, over and free grazing, improper farming practices and development efforts, overpopulation and poverty, socio- economic problems, lack of awareness on the effect oferosion and poor land use policy enforcement. 19
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 20
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEME 2: SYSTEM COMPONENTS 21
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 22
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa10. Tradeoffs analysis in the design of integrated resource management strategies for smallholder farming systems in the African highlands Pablo Tittonell Agricultural Research for Development (CIRAD), Montpellier, FranceAbstractSmallholder farming systems are diverse, spatially heterogeneous and dynamic. Theyoperate in uncertain and changing environments to which they need to adapt constantly.Resources and investments are often limited, and their strategic allocation in space andtime impacts on system attributes such as efficiency, vulnerability and resilience in theshort and long terms. Any technological strategy aiming to improve system performanceand sustainability should be designed considering the integrated nature of smallholderfarming systems, particularly in the case of mixed crop-livestock farming. Relativelyhigh agroecological potential and moderate tropical climate attracted preferential humansettling in the African highlands, often resulting in mixed smallholdings in which thecrop subsystem may be annual, perennial or both, and the livestock subsystem mayrange from communal grazing to cut-and-carry practices. Dense human population,coupled with lack of resources and sometimes inadequate agricultural practices oftenresulted in resource degradation at farm and landscape levels, and conflict over thecontrol and utilization of communally owned resources. The design of managementstrategies should consider resource interactions at different scales, from farms, tolandscapes or territories. Yet, interactions at the scale of field plots or livestock unitsare central, as biophysical responses and affordability and are key determinants oftechnology adoption. Beyond their impact on the system as a whole, technologies mustbe effective, exhibit a positive impact on the subsystem they target, and fit within localsocio-economic contexts and livelihood systems (self-subsistence, market-orientation,off-farm employment, etc.). Decisions on the allocation of scarce resources within thefarming system entail tradeoffs of different nature, which must be quantified to betterinform the design of integrated resource management strategies. While smallholderfarmers are system managers by nature, system integration remains a major challengein the field of agricultural research. Disciplinary standpoints, institutional interests anddifferent scales of analysis may often lead to competing research efforts, disaggregatedresults, replication of old experiences and/or impractical recommendations. Althoughintegrative approaches have been proposed in the field of agronomy over the last twodecades: Integrated Pest Management (IPM), Soil Fertility Management (ISFM), or CropManagement (ICM), their acronym has been frequently misused. Taking ISFM as anexample, we may find a long list of examples in which the term is used to describedisciplinary research that ignores the integrated nature of smallholder farming systems.This presentation will discuss examples of system integration in agricultural researchthrough tradeoffs analysis at different scales, with the aid of participatory field researchand bio-economic simulation modeling, placing emphasis on ISFM technologies.Whole-system properties of interest that emerge in integrated analyses (e.g., systemorganisation, complexity and throughflows) will also be examined. 23
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa11. CIALCA’s efforts on integrating farming system components and exploring related trade-offs P. van Asten1, B. Vanlauwe2, E. Ouma1, P. Pypers2, J. Van Damme3, G. Blomme4, P. Lepoint5, J. Ntamwira6, H. Bouwmeester7, E. Birachi8, L. Jassogne3, T. Muliele9, S. Bi- zimana10, A. Nibasumba10, S. Delstanche3, P. Baret3, J. Sanginga11, F. Bafunyembaka11, M. Manzekele6 1 IITA, Kampala, Uganda; 2TSBF-CIAT, Nairobi, Kenya; 3Université Catholique de Louvain, Louvain-la-neuve; 4Bioversity International, Kampala, Uganda; 5Bioversity International, Bujumbura, Burundi; 6INERA/CIALCA, Mulungu, DR Congo; 7IITA, Dar es Salaam, Tanzania; 8CIAT, Kigali, Rwanda; 9INERA/CIALCA/UCL, Mulungu, DR Congo; 10ISABU/CIALCA/UCL, Bujumbura, Burundi Belgium; 11TSBF-CIAT, Bukavu, DR CongoAbstractThe densely populated humid East African highlands of East DRC, Rwanda, andBurundi are characterized by small farms (<1ha), large families (7 people), few livestock(0.4 TLU), high illiteracy, and a large dependence on a few staple food crops such ascassava, bananas, and beans. Farmers wish to improve their food security and income,but have limited resources to achieve this. Farming system components interact,especially in environments where resources (e.g land, labour, capital, nutrient inputs)are in short supply. To better understand constraints and opportunities to improvethe farming systems, farmers can be clustered in farm typologies with similar traits.In the CIALCA area, few farmers belong to the “resource-rich entrepreneurs” andmost farmers are “resource-constrained”, particularly in East DRC and Burundi. The“natural-resource rich” farmers have relatively large land holdings and livestock unitsbut are often remotely located and subsistence oriented. CIALCA has made an effortto improve the resource use efficiency at farm level, by exploring and improving theinteractions between some of the dominant farming system crop components. The aim isto achieve triple-wins of improved food production, income, and natural resource base.For the annual crops, new planting arrangements have been developed for cassava-legume and maize-legume systems. When combined with judicious applications ofmineral fertilizers and organic matter inputs, production and income is often doubled.However, the ‘best’ combination depends on the agro-ecological region and within farmsoil fertility gradients. For the perennial-based systems, we improved legume intercropproduction by reducing the banana leaf numbers. This is particularly needed for themore light-demanding legumes such as climbing beans and soybean in the high rainfall,better soil fertility areas near the Albertine rift. Our studies on intercropping banana andcoffee suggest large agronomic benefits at farm level and the technology is appealing forfarmers who wish to combine food and cash crops to cover their needs. In general, theintegrated technologies proposed are knowledge intensive and the applicability showsstrong spatial variation. In addition, investments related to soil and water conservationand use of perennials do often not offer much short-term benefit, which makes adoptiondifficult for the resource-poor and risk-averse farmers. As a result, achieving impactthrough the proposed integration packages requires a favorable policy, extension, andmarket environment. Constraints in these environments are often a constraint for thescaling out of improvements at the farm level 24
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa12. Trade Costs reduction in the Congo Basin: Impact on crop land expansion and agricultural productivity growth Mosnier, A. 1, 2, Havlik, P.1,3, Obersteiner, M.1, Aoki, K.1, Schmid, E. 2 1 International Institure for Applied Systems Analysis (IIASA), Laxenburg, Austria; 2 University of Natural Resources and Applied Life Sciences (BOKU), Vienna, Austria; 3 International Livestock research Institute (ILRI), Nairobi, KenyaAbstractIf most of the Congo basin benefits from very suitable conditions for agriculture, yields aremuch lower than in other tropical regions as Brazil or Indonesia and subsistence farming isstill dominant. One major bottleneck of agriculture development is the poor availability andquality of infrastructure. Many studies suggest that the importance of subsistence agricultureis partly due to high transaction costs which make the sales out of the farm not profitableand limit the possibilities to get food from other sources (A. Ruijs et al., 2003; P. Buys et al.,2006). Furthermore, better transportation infrastructure can facilitate access to inputs andcapital and improve labor productivity through a better access to social infrastructures asschools and health centers (Thirtle et al., 2003; Oshikoya and Hussain, 2002). But at thesame time, the strong impact of road expansion on deforestation has been highlighted (Geistand Lambin, 2002; Freitas et al., 2009; Pfaff, 1999). Forest covers approximately 80 % of thebasin (GLC2000) with more than half classified as dense forest. In a context of fast growingpopulation – population of Congo basin could reach 170 million inhabitants in 2030 (IIASA-SRES) – and high international commodity prices, agricultural sector faces strong incentivesto grow. For the next decades food security, economic development and forests protectionare high in the agenda and the increase in agricultural productivity is often viewed as theonly way to reconcile these objectives. We use GLOBIOM, a global partial equilibrium modelwhich integrates the main land based sectors i.e. agriculture, forestry and bioenergies (Havlíket al., 2010) to simulate the impact of future investments in transportation infrastructureson the development of the agricultural sector in the Congo Basin. Land use modeling isbased on land characteristics with a very detailed representation -more than 6000 simulationunits- in the Congo basin. This allows us to spatially differentiate the impact of infrastructuredevelopment on agriculture and land use change through two channels of transmission: theprice of the fertilizers and the price of the farm products. Moreover, GLOBIOM is a globalmodel where Congo Basin region is connected to the other regions through internationaltrade. Then, the reduction of the price of locally produced goods change the tradeoff betweenimports and local goods for domestic consumption and the competitiveness of Congo Basinexports on international markets. Simulations are made by 2030. We include in our databasethe transportation infrastructure projects in the Congo Basin for which a funding is alreadyplanned and recompute the internal transportation costs on this new basis. We run the modelfor two variants: 1) there is no limit on deforestation; 2) a limit on GHG emissions fromdeforestation is introduced. Finally, a sensitivity analysis is made on the transportation costsreduction due to the uncertainty related to the effective transmission of the reduction ofthe costs to the customer price. Infrastructure improvement is especially beneficial for cropswith high yields in areas which were very remote before. This is especially true in the case ofcassava and sugarcane in the Democratic Republic of Congo. The preliminary results -withoutthe transmission of reduced transportation costs on fertilizers- show that agricultural sectoris fostered but that productivity increase is very limited. Most of the increase in agriculturalproduction is achieved through cropland expansion: the total deforested area is multipliedby three. The introduction of limits on deforestation considerably reduces the positive impactof infrastructure improvement on agriculture and leads to higher food imports and food prices. Theseresults imply that costs associated with more productive systems are currently very high inthe Congo Basin and that the only market forces will lead to higher deforestation and limitedproductivity increase. 25
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa13. Using the ‘livestock ladder’ to exit poverty for poor crop-livestock farmers in South Kivu, eastern DR Congo Brigitte L. Maass1, Wanjiku L. Chiuri2, Rachel Zozo3, Dieudonné Katunga-Musale3 and Eliud Birachi2 CIAT (Centro Internacional de Agricultura Tropical), Nairobi, Kenya; 2CIAT/CIALCA, 1 Kigali, Rwanda; 3 CIAT/CIALCA, Kasongo, Commune d’Ibanda, Bukavu, DR Congo;AbstractSmall animals dominate in South Kivu, DR Congo after decades of war and unrest.We applied different survey instruments to assess the current situation of livestockproduction in the region such as a diagnostic survey, participatory rural appraisal(PRA) and value chain (VC) analysis along a North-South and Southwestern axisaround the provincial capital Bukavu. Mean livestock was only 1.84 TLU per livestockholder. Monogastric animals in smallholder farms are produced in very flexiblebackyard systems. They are characterized by small numbers of chicken and/or caviesor pigs. Monogastric animals are traditionally fed by household wastes and other feedssourced by scavenging around the homestead (e.g., seeds, insects, worms); only 10% ofthe chicken and even less of pigs received small complements of maize. Monogastricanimals are usually underfed under these conditions. Thus, productivity is low butthe system provides a steady source of high quality animal protein in the form of eggsand meat for household consumption and, consequently, helps to enhance nutritionsecurity. The majority of peasants does not produce sufficient livestock throughout theyear to have surplus for regular sales, thus, local production is even too low to satisfysubsistence. Farmers only sell when needs arise. Sales take place on local or regionalmarkets, but rarely reach Bukavu, at a distance of 20-80 km. However, the current roadinfrastructure is not conducive to gain access to this urban population of more than500,000 inhabitants. Recently, trans-border provision of products has become significantin South Kivu; the urban meat market is supplied by producers from nearby Rwanda oreven Uganda and Kenya. Humanitarian assistance during the past decades of war andunrest seems to have discouraged peasants from taking own initiatives; they are ratherreceptive to any kind of donation. The challenge under these conditions is to start toenhance production. We suggest to invest and investigate into the lowest rung of the‘livestock ladder’ by improving the small animal systems emphasizing the provisionof dry season feed, which was raised as a major issue. Applying participatory varietyselection (PVS) on small plots in four locations, farmers chose forages with visible dryseason-tolerance, but also those palatable for their small animals, like the herbaceouslegume Canavalia brasiliensis. By including leguminous forages in farming systems, soilfertility will improve. Soil fertility management was traditionally based on manure.Increasing livestock stocking rates will also help to improve crop productivity. Thepotential role of forages needs to be assessed in a systems context by identifying spatialand temporal niches in addition to their potential acceptability by local farmers. Wesuggest to use a participatory scenario modelling approach focusing on small animalsand feed systems to re-connect South Kivu farmers to the market. The final outcome will,hence, be better nutrition of family members, provision of cash income and, eventually,support for the acquisition of larger animals. 26
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa14. N2Africa: Putting nitrogen fixation to work for smallholder farmers in Africa Giller Ken1, Vanlauwe B2, Baijukya F2, Franke L1 and Bala A3 Plant Production Systems, Wageningen University, Wageningen, The 1 Netherlands; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 3International Institute of Tropical Agriculture (IITA), Ibadan, NigeriaAbstractMaximal rates of N2-fixation recorded in the tropics reach an astonishing 5 kg Nha-1 day-1. We have measured more than 250 kg N ha-1 of fixed N2 in soyabeanin southern Africa with associated grain yields of more than 4 t ha-1. But often lessthan 5 kg N ha-1 year-1 is fixed by legumes at farm scale in African smallholdersystems. Increase of inputs from nitrogen fixation is required to achieve theincreases in productivity required as part of the African green revolution that isgaining momentum. Successful N2-fixation by legumes in the field depends on theinteraction: (GL × GR) × E × M that is (legume genotype × rhizobium genotype)× environment × management. Environment encompasses climate (temperature,rainfall, daylength etc) and soil stresses (acidity, aluminium toxicity, limitingnutrients etc). Management includes aspects of agronomic management (use ofmineral fertilizers, sowing dates, plant density, weeding). Although much researchis focused on identifying best combinations of GL and GR, the E and M factorsoften override the potential of the legume/rhizobium symbiosis for N2-fixation.Attention will be focused on identifying new socioecological niches for fitting grain,forage and tree legumes into existing farming systems, and the conditions necessaryto achieve successful N2-fixation. The N2Africa project aims to increase inputsfrom N2-fixation on more than 225,000 smallholder farms across eight Africancountries within four years through: a) Increasing the area of land cropped withlegumes; b) Increasing legume productivity through better agronomy and basal(P, K etc) fertilizer; c) Selecting and disseminating legume varieties with increasedN2-fixation; d) Selecting better rhizobium strains and promoting high qualityinoculants; e) Linking farmers to markets and creating new enterprises to increasedemand for legumes. N2Africa has already reached more than 25,000 farmers andthe latest learnings will be discussed. 27
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa15. The 4R Nutrient Stewardship in the context of smallholder agriculture in Africa Zingore Shamie1 and Johnston Adrian2 1 International Plant Nutrition Institute, Africa Program, Nairobi, Kenya; 2 International Plant Nutrition Institute, CanadaAbstractIn the face declining crop productivity and a growing food insecurity, there arerenewed efforts to support smallholder farmers in sub-Saharan Africa (SSA)intensify crop production, in particular by increased fertilizer use. Successfulagricultural intensification will depend to a large extent on proper managementof plant nutrients to increase fertilizer use efficiency (agronomic N use efficiencyvalue are often less than 15 kg grain /kg N for maize in farmers’ fields). The 4RNutrient Stewardship Framework developed by the fertilizer industry worldwideaims to provide the context for efficient on‐farm nutrient management practiceswith irreducible simplicity focused on four central components: applying the rightfertilizer source at the right rate, at the right time in the growing season, and inthe right place. Smallholder farms in SSA exhibit substantial heterogeneity in soilfertility within short distances, and the 4R Nutrient Stewardship should address thisvariability to increase nutrient use efficiencies. Although fertilizer recommendationsin SSA mostly cover N and P only, analysis of nutrient deficiencies show an increaseof constraints to crop production with decreasing soil fertility status. Depleted soilsthat cover wide areas are associated with multiple nutrient deficiencies and additionof the ‘right’ fertilizer sources that provide base cations (K and Ca) and micronutrients(Zn and B) in addition to N and P is required to significantly increase yields. The‘right rate’ of fertilizer application has also been found to have profound effectson nutrient use efficiency, with on farm experiments showing that agronomic andeconomic returns diminish rapidly on most poor soils when nutrient applicationsrates exceed 60 kg N/ha and 10 kg P/ha. In addition to the standard timing of basaland top dressing fertilizer application, ‘right time’ of fertilizer application in SSAshould be flexible and adjustable to the highly variable inter- and intra-seasonalrainfall as a risk mitigation strategy. The ‘right place’ is often critical when lowrates of fertilizer are used, with spot-application more effective at placing nutrientswhere crops can use them effectively. Each of the four “rights” is directly related tothe other three in at least one way, interconnected into a unified, effective system.When viewed holistically, 4R Nutrient Stewardship can have far-reaching effects onthe sustainability of agricultural systems in SSA beyond the immediate benefits interms of crop productivity. 28
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa16. Building “climate smart” East African coffee production systems Henk van Rikxoort1,2, Laurence Jassogne3, Peter Laderach1 and Piet van Asten3 1 Wageningen University and Research Centre (WUR), Development and Rural In- novation, The Netherlands; 2International Center for Tropical Agriculture (CIAT), De- cision and Policy Analysis Program (DAPA), Nicaragua; 3International Institute of Tropical Agriculture (IITA), Kampala, UgandaCoffee is a major cash crop in the tropical humid highlands of East Africa and is mostlycultivated by smallholder farmers. Here, it contributes significantly to their income se-curity but also to the national economies of the region. Coffee can be found cultivatedin different agricultural systems ranging from monocultures to polycultures with shadetrees and additional food crops. Global Circulation Models (GCM) generally predict anincrease in temperature and more rainfall in the region. Rainfall is predicted to becomemore erratic and as a consequence, short periods of drought will be more common, pos-sibly with less distinct dry seasons. These predictions can have drastic consequenceson coffee production and coffee quality because coffee relies on very distinct dry andwet seasons for flowering and cherry maturation. Therefore, climate change will havea direct impact on the productivity of the coffee system and therefore on the farmerslivelihoods. For smallholder coffee farmers, polyculture systems often are more resilientthan monocrop systems, this is through a reduction of income and food risks, whileadapting at the same time to extreme climate events such as drought and high tempera-tures. A carbon footprint analysis also shows that besides coffee suffering from a chang-ing climate it also contributes to climate change itself. Carbon footprint standards haveemerged as new market requirements for producers of agri-food products to retailers indeveloped countries and are likely to become a comparative advantage. Based on thesetwo dynamics we compared both the adaptive capacity and the carbon footprint of sev-eral East African coffee production systems. First, coffee systems in East Africa are de-scribed and characterized by comparing them with coffee systems in Central America.Following this, the productivity, resilience and adaptation potential to climate changeof these systems are analyzed. Finally, the carbon footprint of the various systems basedon data from East Africa and Latin America is estimated and discussed. The resultshighlight the importance of sound adaptation strategies along the coffee value chain inorder to come to a sustainable coffee production in East Africa in short, medium andlong term. 29
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 30
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEME 3: DRIVERS FOR ADOPTION 31
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 32
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa17. Drivers of productivity growth in Africa: implications for enhancing adoption of improved technologies Langyintuo Augustine, Alliance for a Green Revolution in Africa (AGRA), Nairobi, KenyaAbstractThe contribution of technological change to agricultural productivity and ruraltransformation in many developing countries sometimes by-passes many ruralpopulations in Africa due to institutional and technical constraints. Consequently,the dream of improving the livelihoods of rural farm households in Africa dependenton agriculture would remain an illusion if the adoption rates of proven technologiesremain low. While highlighting the main causes of the poor performance ofagricultural productivity in Africa to be a combination of low use of improvedtechnologies (mainly seeds and fertilizers), historical factors such as structuraladjustment, poorly developed markets, lack of political support, among others, thispaper argues for strong private-public partnership to drive productivity growth,transform rural economies and improve household livelihood and incomes. 33
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa18. Drivers of technology adoption in the banana-legume systems in the East and Central Africa region E. Ouma1, E. Birachi2, V. Kasereka3, H. Garming4, I. Macharia5, P. Van Asten6, A.Chifizi7, M. Nyagaya8, B. Ekesa9, J. Van Damme10, B. Vanlauwe11, G. Blomme9, M.C. Niyuhire12, L. Ndimurirwo12, J. Ochieng1, T. Dubois6, P.Pypers11, L. Wairegi6, C. Ruraduma12, A. Bizoza7, and M. Maertens13 1 International Institute of Tropical Agriculture, Bujumbura, Burundi; 2TSBF-CIAT, Kigali, Rwanda; 3CIALCA, Bukavu; 4Bioversity International, Costa Rica; 5Jomo Kenyatta University of Agriculture and Technology, Kenya; 6International Institute of Tropical Agriculture, Kampala, Uganda; 7Rwanda Agricultural Board, Rwanda; 8TSBF-CIAT, Kampala Uganda; 9Bioversity In- ternational, Kampala, Uganda; 10Universite Catholique de Louvain-la-Neuve, Belgium; 11TSBF- CIAT, Nairobi, Kenya; 12Institut des Sciences Agronomiques du Burundi (ISABU), Burundi; 13 Katholieke Universiteit Leuven (KU Leuven)AbstractMany interventions to improve productivity of agricultural systems have been promotedin the Great Lakes Region of Africa through technological change. The expected benefitsof such technologies however remain limited and in some cases do not reach theintended beneficiaries due to technical and institutional constraints. The Consortium forImproving Agricultural Livelihoods in Central Africa (CIALCA) promotes productivityenhancing technologies in the region with components of improved banana and legumegermplasm coupled with natural resource and disease management strategies basedon participatory approaches. CIALCA has applied the Production-Consumptioncontinuum to link system value chain actors, from inputs required for production todelivery to the consumers, while addressing key drivers that affect the process. Themarket linkage approach has been used to drive the uptake of banana and legumetechnologies through collective efforts among smallholder farmers. The result hasbeen a marked increase in potential productivity of the production systems based ondemonstration and control field trials. The interventions if adopted have positive effecton the overall goals of alleviating poverty and improving nutritional health among thepopulation. CIALCA has conducted a comprehensive study to map out the pathwaysfor technology uptake and dissemination as well as factors that are likely to drive orenhance the uptake of technologies in the region. Results show that in order to achieve acritical mass in agricultural technology adoption, social factors, policy and institutionalenvironment need to be favorable. Local institutions, grassroot level collective actionand agricultural development partners play a critical role in technology dissemination.Accessibility by farmers to appropriate inputs for production has also been assessed inthe region and results indicate that input prices, tax levies and level of development ofdistribution networks influence input use. The need for government support throughappropriate policies is thus emphasized. Results further reveal that market access andsupport services in the form of extension services and credit access through functionalfinancial markets influences technology adoption. This shows that certain institutionalfactors as well as transaction cost factors need to be addressed to motivate uptake oftechnologies. Potentials of large scale private sector linkages that can fill identified gapsto enhance technology adoption is highlighted. 34
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa19. The agro-ecological solution!? Food security and poverty reduction in sub-Saharan Africa, with an emphasis on the East African Highlands Henk Breman International Fertilizer Development Centre (IFDC), CATALIST project, BurundiAbstractIn a recent report, Olivier de Schutter, “Special UN Reporter on the Right to Food”,insists that the adoption of the agro-ecological approach can double food productionby smallholders in poor and vulnerable regions of our world. He considers themsuperior to conventional agriculture based on chemicals and proposes measures forGovernments leading to the development and adoption of such approaches. Thebasis for this opinion is weak. The average relative production increase is misleadingwhen the effect is far the highest for original yields between 0 - 0.5 t/ha, seriouserrors are made in key background papers, and the contribution to agriculturalsustainability will be undermined by increasingly negative soil nutrient balances.The risk exists that the UN report will become co-responsible for increasing famineand poverty in sub-Saharan Africa. If, however, a recommendation is added,promoting the adoption of agro-ecological approaches for improving the efficiencyand the accessibility of inorganic fertilizers, instead of suggesting replacing the latter,an entirely different perspective is created. The chance of seeing a rapid adoptionof more productive, more remunerative and more sustainable production systemsin sub-Saharan Africa increases considerable. In particular when the inherentagronomic recommendations become part of value chain development efforts, foodsecurity can be rapidly obtained in the region. Even for Somalia there is hope. Tosubstantiate the above statement, the analyses of the De Schutter report and some ofthe background studies, will be combined with results of the promotion of integratedsoil fertility management in a value chain development context in Central Africa’sGreat Lakes region. A rapid diffusion of agriculture intensification technologies isobserved, and those applying inorganic fertilizers in combination with organic andother soil amendments produce even in dry years. 35
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa20. Exploring the scope of fertilizer use in the East African region Wairegi, L.W.1, van Asten, P.J.A.2 Centre for Agriculture and Biosciences International (CABI), Africa Regional Centre, 1 Nairobi, Kenya; 2International Institute of Tropical Agriculture, Kampala, UgandaAbstractNutrient removal exceeds nutrient replenishment in much of sub-Saharan Africa’s ag-riculture. Furthermore, use of mineral fertilizers is low as fertilizers are often consid-ered expensive and not accessible to smallholder farmers. The diversity of the crops andcropping systems in sub-Saharan Africa further complicate farmer decisions on inputuse. Decision support tools for use by farmers in deciding types of crops to grow andamount and type of soil inputs required are in most cases not available to farmers. Thispaper explores the expected benefits of fertilizer by relating value of yield to the valueof fertilizer equivalent of nutrients removed for selected crops (maize, beans, bananas,cassava and coffee), in the East African region. It further explores how changes in farm-gate prices and fertilizer costs can affect the expected benefits. Between mid 2010 to mid2011, fertilizer was least expensive in Rwanda (e.g. Urea 540 USD/t), Kenya (e.g. Urea541 USD/t) and Tanzania (e.g. Urea 558 USD/t) compared with other countries in theregion (Urea ≥712 USD/t). Farm-gate prices varied up to 80% among regions withincountries. Assuming nutrient recovery efficiencies of 50%, 15% and 60% for N, P andK, respectively, the amount of single-nutrient fertilizers (Urea, Triple Super Phoshate,Muriate of Potash) required to increase yield by one ton edible dry matter is estimatedto range between 214kg (for rice) and 900 kg (for banana). The ratio between averageprice of one ton of yield and average cost of fertilizer required to increase yield by onetonne ranged between 1.1 (banana) and 5.0 (rice) in Burundi, 0.8 (cassava) to 8.1 (coffee)in Kenya, 1.0 (maize) to 6.7 (rice) in Rwanda, 0.7 (cassava) to 7.6 (coffee) in Tanzania, 0.6(cassava) to 4.3 (rice) in Uganda, 1.1 (banana) to 4.7 (rice) in the Democratic Republic ofCongo. These ratios increased by between 100% and 896 when calculations were basedon nutrients removed in edible yield and not on total above ground biomass. The ratiosfor beans ranged between 2.9 (Rwanda) and 4.0 (Burundi and Tanzania ) and increasedto between 3.9 (Rwanda) to 5.5 (Burundi) when 50% of the N requirements were as-sumed to be met through biological nitrogen fixation. We conclude there is need andscope for fertilizer use in the East African region, but choice of crop for intensification,and decision on amount and type of fertilizer should depend on input/output prices,residue management, and crop response. We also conclude that in cropping systemswhere more than one crop is grown, intensification in one crop can be beneficial to othercrops in the system. 36
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa21. Supply and demand drivers of grain legumes in highlands of central and southern Africa: Implications for targeting agricultural research investments Rusike Joseph1, Boahen Steve K.2, Dashiell Kenton3, Kantengwa Speciose4 and Ongoma Josephine5 1 International Institute of Tropical Agriculture, Lilongwe, Malawi; 2International Institute of Tropical Agriculture, Nampula, Mozambique; 3Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 4CIALCA, Kigali, Rwanda; 5Kleen Homes and Gardens, Migori, KenyaAbstractThe highland areas of central and southern Africa are endowed with favorableagro-ecological conditions for production of grain legumes. There is increasingevidence that rapid population growth is increasing population densities and theseare resulting in Boserupian changes. These include soil fertility mining, soil erosion,land degradation, deforestation and poverty traps. Smallholders are failing toexploit the opportunities. There is a growing interest in expanding the share acreageannually planted to legumes for sustainable intensification and diversification whilemaintaining soil health. This study uses rapid assessment value chain surveys toanalyze the supply and demand drivers driving changes, identify opportunities andconstraints for expanding production and draw implications for targeting researchinvestments. We find that significant opportunities lie in supplying grain legumes todomestic urban markets and export to regional and international markets. Differentcountries are at different stages of development. The major constraints on expandingproduction and marketing of the grains include low yields, production and qualityof products; uncompetitive farm gate prices; poor market coordination; the lack ofagro-processing, storage, and microfinance; and poor government policies. Theincidence and severity of constraints and priority research interventions to resolvethem vary with the stage of development of the value chains of grain legumes in thecountry. 37
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa22. Assessing nutritional diversity of cropping systems in Africa Remans Roseline1, Flynn Dan3, DeClerck Fabrice3, Nziguheba Generose1 and Palm Cheryl4 1 Earth Institute, Columbia University, New York, USA; 2Leuven Sustainable Earth, Katholieke Universiteit Leuven, Belgium; 3Department of Ecology, Evolution, and En- vironmental Biology, Columbia University, New York, USAAbstractBackground: In Sub-Saharan Africa, 40% of children under five years in age arechronically undernourished. As new investments and attention galvanize actionon African agriculture to reduce hunger, there is an urgent need for metrics thatmonitor agricultural progress beyond calories produced per capita and addressnutritional diversity essential for human health. In this study we demonstrate howan ecological tool, functional diversity (FD), has potential to address this need andprovide new insights on nutritional diversity of cropping systems in rural Africa.Methods and findings: Data on edible plant species diversity, food security and dietdiversity were collected for 170 farms in three Millennium Villages in Sub-SaharanAfrica. Nutritional FD metrics were calculated for macronutrients, vitamins, andminerals, based on farm species composition and species nutritional composition.Iron and vitamin A deficiency were determined PalmNutritional FD metricssummarized the diversity of nutrients provided by farms and gives unique insightsin nutrient differences across farms and villages. Regression of FD against speciesrichness and expected FD allowed identification of key species adding nutrientdiversity to the system and assessment of the degree of redundancy for nutritionaltraits across farms and villages. Nutrition FD metrics further showed that dependingon the original composition of species on farm or village, adding or removing anindividual species can have radically different outcomes for nutritional diversity.Analysis of the relationship between nutrition FD metrics and household nutritionindicators proposes new hypotheses on the link between agro-diversity, foodsecurity and human nutrition as well as strategies for future research that emphasizelandscape-scale interdisciplinary approaches. This study delivers a novel metric toaddress nutritional diversity in agricultural systems and provides a set of examplesthat can help guide agricultural interventions towards more balanced and diversenutritional outputs. New questions are raised that call for integration of agriculture,ecology, nutrition, and socio-economic studies, particularly at the landscape scale. 38
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa23. Disseminating Agro forestry Innovations in Cameroon: Are Relay Organizations Effective? Degrande Ann1, Yeptiet Siohdjie Yannick2, Tsobeng Alain1, Asaah Ebenezer1 and Takoutsing Bertin1 1 World Agroforestry Centre, ICRAF-West and Central Africa, Yaoundé, Cameroon; 2 University of Dschang, Faculty of Agronomy and Agricultural Sciences, CameroonAbstractIneffective dissemination methods have been partially responsible for low adoptionof agricultural innovations in Africa and consequently have failed to improve farmers’livelihoods. Therefore, innovative and low cost ways of disseminating agriculturalinnovations, especially farmer to farmer dissemination, are now gaining interest.However, there is limited or conflicting evidence as to their effect on productivityand poverty, as well as on financial sustainability. The present paper evaluates theperformance of relay organisations (community-based organisations that make thebridge between research and farmers) in disseminating agroforestry innovationsin Cameroon and identifies factors that affect this performance. Overall, the 8 relayorganisations studied were successfully diffusing agroforestry innovations tofarmer groups. Though differences were not statistically significant, results suggestthat relay organisations which operate under favourable internal and externalfactors perform best for most of the performance indicators. Also, the study putsforward that external factors such as existing opportunities for agroforestry, strongfarmer associations and good road and communication networks, might affect theeffectiveness of relay organisations more than their internal capacity, reflected bytheir human, material and financial resources. Further research involving morerelay organisations should focus on evaluating the sustainability and financialviability of the approach and look at appropriate support mechanisms to enhancerelay organisations’ capacities to disseminate agroforestry innovations. 39
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 40
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEME 4: COMMUNICATING COMPLEX KNOWLEDGE 41
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 42
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa24. Knowledge and technology transfer within an Evolving R4D Framework in East Africa Lynam, J Independent Consultant, Nairobi KenyaAbstractThe evolution of research themes and methods with the focus on sustainableintensification of smallholder farming systems in the East African highlands aremoving well head of the state of the art in technology transfer methodologies and thesuccessful adoption of more knowledge intensive techniques by farmers.  The paperbriefly reviews the methods inherent in research on production systems, particularlywithin the context of the heterogeneity characterizing farming systems in the EastAfrican highlands.   The paper locates these with alternative trajectories for landuse intensification in the region.  The current state of extension methods are thenreviewed in relation to the shift to more knowledge intensive techniques deployedwithin a production systems framework. Given a increasing disparity betweenresearch and extension approaches, the paper reviews more innovative approachesto closing that gap.  Finally, the paper analyzes our lack of understanding in thesteps from knowledge transfer to farmer learning to farmer change in managementpractices with suggestions on how research on production systems must encompassunderstanding how farmers change and adapt their farming system. 43
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa25. Walking the Impact Pathway: The CIALCA Experience in Mobilising Agricultural Knowledge for the African Great Lakes Region Van Schagen Boudy1, Njukwe Emmanuel2, Katharina Paul Birthe3, Sengele Ndani4, Mazibo Foma5, Blomme Guy6, Vanlauwe Bernard7, Van Asten Piet8. 1 Bioversity International, Bujumbura, Burundi; 2International Institute of Tropical Agriculture, Bujumbura, Kampala; 3Wageningen University, Netherlands; 4Institut de Recherche Agronomique et Zootechnique, Gitega, Burundi; 5Institut de Recherche Agronomique et Zootechnique, Gitega, Burundi; 6Bioversity International, Kampala, Uganda; 7Tropical Soil and Biology Institute of the International Center for Tropical Agriculture, Nairobi, Kenya; 8International Institute of Tropical Agriculture, Uganda, Kampala.AbstractAn impact-oriented AR4D approach requires considerable investments in extensionand information capacity to ensure new agricultural technologies are adopted forlivelihood benefits. The Consortium for Improving Agriculture-based Livelihoodsin Central Africa (CIALCA) espouses a partner-oriented outreach strategy toactivate impact pathways for the scaling out of validated, science-based agriculturalinformation in ‘mandate areas’ in Burundi, Rwanda and the Democratic Republicof Congo. The decentralized, geographically dispersed and multi-partner natureof the Consortium poses unique challenges for effective knowledge flow and theability to deliver ‘knowledge into use’. The challenge is compounded by difficultiesin communicating complex technical solutions to farming communities with limitedadaptive capacity. Experience shows there is a strong need for extended facilitationand follow-up by CIALCA extension specialists and trained partners to ensureadequate understanding and adoption. Cascade training of partners can be effectivelysupported through the provision of adequate resource materials such as factsheets,video, and rural radio programming adapted for context, language and locality.This paper will discuss the CIALCA knowledge-into-use praxis and elucidate someof the challenges to and opportunities for agricultural science communication in thiscontext. We address the vital role of strong outreach partnerships, and how improvedpartnership arrangements in a well-coordinated policy environment can reducethe apparent trade-off between knowledge-intensive technologies and the abilityto reach scale. We further explore how the CIALCA Knowledge Resource Centreoperates as a knowledge broker and platform for the production and disseminationof audience-specific resource materials. The current and potential role of ICT toolsfor extension support, such as the CIALCA website, is discussed. Finally, thispaper reflects upon emerging opportunities for new, innovative approaches for therepackaging and dissemination of scientific information, and options for ensuringthe long-term sustainability of CIALCA-generated knowledge. 44
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa26. Integrated Agricultural Research for Development (IAR4D) an Approach to Enhance Small-holder Farmers’ Livelihood: Experiences from Lake Kivu Region. Buruchara, R.1, M. Tenywa2, J.G.M. Majaliwa2, W. Chiuri3, J. Mugabo4, S.O. Nyamwaro5, Adewale A.6 1 CIAT (Centro Internacional de Agricultura Tropical)-AFRICA, Kampala, Uganda; 2 Makerere University, Faculty of Agriculture, Kampala, Uganda; 3CIAT (Centro In- ternacional de Agricultura Tropical)/CIALCA, Kigali, Rwanda; 4Rwanda Agricultural Board (RAB), Rwanda; 5Trypanosomiasis Research Centre, Kenya Agricultural Re- search Institute, Kikuyu, Kenya; 6Merck Research Laboratories, North Wales, Pennsyl- vania, United StatesAbstractDespite the resource endowment in the Lake Kivu region and research successesregistered in several projects implemented so far to improve food security,income, and nutrition, poverty is yet to be significantly reduced. It is hypothesizedthat the sectoral nature of conventional linear research approach in addressingthe interlinked productivity, natural resource management, market and policychallenges / constraints in isolation is one of the most critical causes underlyingthe agricultural under-performance. A new paradigm in agricultural research,technology, innovation and knowledge system is required to break the paradox,steer and accelerate the targeted development. Integrated Agricultural Research forDevelopment Approach (IAR4D) is a new approach that holds promise to reversethe trend and enhance smallholder livelihood. The approach builds on previousapproaches such as Integrated Natural Resource Management; and addressesproductivity, market, natural resource management and policy and their interfaceissues. This paper highlights key results in the “Proof of the IAR4D concept” andits contribution to the small-holder farmers’ livelihood enhancement based onInnovation Platforms (IPs) in the Lake Kivu Pilot Learning Site (LKPLS); one ofthe three sites selected across Africa, to test this concept under the Sub-SaharanAfrica Challenge Programme. Strategic partnerships and 12 IPs were formedand operationalised in the LK PLS. Farmers’ challenges and solutions to priorityissues were identified through facilitation and research. Linkages with researchinstitutions, NGOs and private sectors were established for value addition andcapacity building; while warrantee, credit and market links were done primarily tosustain production and income. The operationalisation of the four elements of IAR4Drequires establishment of functional and strong linkages where farmers’ interests,needs and/or opportunities are core to the participating stakeholders’ forum [aninnovation platform (IP)]. Farmers were motivated to produce, were involved incrop diversification and value addition. It was observed that in situations whereproductivity, market and NRM issues were addressed together, better IAR4Dresults on small farmers’ livelihood were registered. Facilitation of IAR4D requires,however, functional and efficient linkage and monitoring mechanism(s) akin to acentral processing unit to address emerging dynamic facilitation and research issues. 45
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa27. Communication channels used in dissemination of soil fertility management practices in the Central Highlands of Kenya Kimaru-Muchai S.W1, Mucheru-MunaM.W1, Mugwe J.M1, Mugendi D.N.1 and Mairura F.S.2 1 Kenyatta University, Nairobi, Kenya; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, KenyaAbstractIncreased recognition of soil fertility depletion as the main biophysical factorlimiting crop production in many African small holder farms has renewed interestin the dissemination of soil fertility management practices. Despite soil technologydevelopment and research outputs, few of the recommendations from soil fertilitymanagement research have been put into use by the target end users. The biggestchallenge to the accessibility and utilization of the existing knowledge lies withthe inadequacies in the communication methods and tools used in disseminationand up scaling of soil fertility management practices. The objective of the studywas to investigate communication channels used in dissemination of soil fertilitymanagement (SFM) practices inthe Central highlands of Kenya. Interview scheduleswere used to collect information from 240 randomly selected farmers. Data wasanalyzed using statistical package for social sciences (SPSS) programme. Resultsshowed that, other farmers were perceived as the most available and reliable sourceof information. Demonstration and farmer to farmer extension methods were themost preferred methods in dissemination of most of the SFM practices. Significantpositive relationship was found to exist between education and individual contactapproach (r=0.154, P=0.01, while farm size and gender positively correlated withpreference of group approach at (r=0.123, P=0.05) and (r=0.124, P=0.05), respectively.Gender, education, farm size and number of times a farmer had been visited by anextension agent were significant predictors in preference of field days in training ofanimal manure. It was recommended that agricultural stakeholders should considerfarmers’ socio-economic factors in designing extension intervention strategies. 46
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa28. A global information and knowledge sharing approach to facilitate the use of Musa genetic resources Roux, N.1, Van den Bergh, I.1, Ruas, M.2 and Vezina, A.3 1 Bioversity International, Montpellier, France ; 2Department of Pharmacology, Univer- sity of Oxford,  Oxford, UK; 3Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, NS, CanadaAbstractIntraspecific crop diversification is a crucial component of any strategy to makeagricultural production systems more sustainable, and bananas/plantains areno exception. Growing a mix of cultivars can contribute to safeguarding the cropagainst pests and diseases, and make it more resilient in adverse environmentalconditions. In addition, different cultivars can bring different nutritional benefitsto poor populations, and offer a broader range of processing and marketingopportunities. A comprehensive understanding of the existing Musa diversity, andits potential uses, is therefore crucial, not only to genebank curators, molecularbiologists, breeders, phytopathologists and other Musa researchers, but also tothe rural households most dependent on the crop for their food and income.Bioversity International is coordinating the implementation of the global Musagenetic resources conservation and use strategy, and has recently launched theglobal Musa genetic resources network, MusaNet. The network not only strivesto improve the conservation and safe dissemination of Musa genetic resources,but it also seeks to fill the gaps in our knowledge of the Musa genepool throughincreased characterization and multilocational evaluation efforts. The network willinvest further in the documentation of accessions held in genebanks and link theMusa Germplasm Information System (MGIS) with global multi-crops systemslike Genesys. It will also soon be possible to order, through the MusaNet website,clean in vitro Musa germplasm from the International Transit Centre (ITC), Belgium.MusaNet will facilitate access to Musa genetic resources held at the regional leveland information about their characteristics through strong links with the Bioversity-coordinated four regional Musa R4D networks. It is through these partnershipsthat demonstration trials at the farm level, like those already existing in certainAsian countries within the framework of National Repository, Multiplication andDissemination Centres (NRMDCs), will be set up. A recent study of the impactof the ITC showed that strengthening germplasm evaluation will allow a greaterfocus on users’ needs. Farmers’ experiences on traits of popular cultivars, and othercultivar-level information, will be summarized in the online banana compendiumon the ProMusa website. This paper discusses these global partnerships and thisnetworking approach for reaching farmers with information about Musa geneticresources. 47
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa29. Targeting farmer’s priorities for effective agricultural intensification in the humid highlands of eastern Africa Mowo Jeremias1, Tanui Joseph1, Masuki Kenneth2 and Mukuralinda Athanase3 1 World Agroforestry Centre (ICRAF), Nairobi, Kenya; 2Mlingano Agricultural Re- search Institute, Tanga, Tanzania; 3World Agroforestry Center (ICRAF), RwandaAbstractExperience by the African Highlands Initiative in Eastern Africa has shown thatfailure to attract farmer’s interest in most proven natural resource managementtechnologies is mainly due to lack of approaches that tackles the interrelated factorsresponsible for poor resource management and most importantly failure to considerthe priorities of the farmers hence leading to loss of interest in the introducedtechnologies. Ranking of farmers constraints in agricultural production has oftencome up with priorities that are contrary to the aims of the agricultural researchand development organizations. Constraints like poor soil fertility and soil erosionare mainly ranked low compared to issues like water, financial capital, and energy.The later are not necessarily under the mandate of research and developmentorganizations yet, without addressing them it is difficult to attract farmer’s interestin the introduced technologies. Using integrated approaches, it was a hypothesizedthat that addressing a high-priority constraint such as domestic water availability orenergy as part of an integrated catchment management approach leads to multiplesystem benefits and greater local commitment to natural resource management. Thishypothesis was tested in the humid highlands of Tanzania, Ethiopia and Ugandausing action research. Results showed that when farmers’ priorities are given dueconsideration, their interest in managing land and water resources increase leadingto multiple benefits including improvement in soil conservation, and increasedwater recharge and agricultural productivity. 48
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa30. Reintroducing Vicia faba beans in resource-poor farming systems – adoption of a participatory farmer-led initiative Karltun Erik1, Gichamo Tesfanesh2, Chiwona-Karltun Linley3, Lemenih Mulugeta4 and Tolera Motuma4 1 Swedish University of Agricultural Sciences, Department of Forest Soils, Uppsala, Sweden; 2Swedish University of Agricultural Sciences, Department of Urban and Ru- ral Department, Uppsala, Sweden; 3Division for International Health Care Research, Department of Public Health, Karolinska Institute, Stockholm, Sweden; 4 Wondo Genet College Forestry and Natural Resources, Shashamane, EthiopiaAbstractThe theft of fresh bean pods from the field has been identified as one of the majorreason for farmers abandoning the cultivation of beans in the Beseku-Ilala peasantassociation, Ethiopia. To avoid conflicts over theft accusations, and to preservehuman security and community integrity farmers simply stopped cultivating beans.The abandonment led to (i) a negative impact on household nutrition and health,(ii) deterioration in household economy, (iii) conflicts in households between wivesand husbands and (iv) negative consequences on soil fertility since the beans was theonly nitrogen fixing legume in the crop rotation. Iterative discussions with farmerscame up with the suggestion that one of the traditional institutions in the village,Idir, could formulate local by-laws to control bean theft. Within a space of one yearwe observed farmers growing bean in some of the villages and not in some. Twoof the villages Shibeshi Gasha 1 and Shibeshi Gasha 2 had not reintroduced beancultivation while the third village, Boye had successfully reintroduced beans. This ledus to ask; Why had two of the villages adjacent to the one that had reintroduced beancultivation not done so? The results revealed that where the village Idirs comprisedof men bean cultivation was reintroduced. Farming households that could afford torent farmland away from their village were also starting to grow beans. Householdsheaded by women and households where the man was the one who attended thevillage meeting did not grow beans. Upon closer investigation and probing, it wasrevealed that the men in those households did not share the information with theirwomen or wives, for fear of continued theft despite the formulation of by-laws.Information from focus group discussions on attitudes towards and perceptionsof theft identified a range of feelings and interpretations. The over-riding feelingwas that it was difficult to control bean theft because security and legal means todo so were very rudimentary. In addition, the mix of different socio-cultural andsocio-economic conditions provided an environment that was rife with conflict.Further research is required to acquire a deeper understanding of these issues andthe challenges of scaling-up bean cultivation in rural Ethiopia. 49
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 50
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa POSTER SESSIONS 51
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 52
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEME 1: SYSTEM COMPONENTS 53
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 54
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa31. The Position of the Lake Chad and Its Related Agricultural Activities Abubakar Babagana1, Laila Deribe Abubakar1, Ak Tijjaniwakil2, Dungus Mohammed- 3 and Babagana Rufai4 1 Kanuri Development Association, Alhaji Bukar, Kuya/United Nations Conference of Non-governmental Organization (United Nations-CONGO), Kanuri Development Association; 2Universal Basic Education Board, Maiduguri, Nigeria; 3Dumams Ni- greria Limited, Damboa Road, Maiduguri,Nigeria; 4Borno State Water Corporation, Maiduguri, NigeriaAbstractThe “Lake Chad” is one of the worlds largest and most historical lakes located inthe Sahelian region of Africa (lat. 12:30 N to 14:30 N and long. 13:00E to 15:30 E)bordering the Sahara desert in the North and in between the borders of the West andCentral African regions (North-Eastern Nigeria, North-Western Cameroon, South-Eastern Niger and South Western Chad republics) which was once 0ver 25,000 KMsquare as indicated by some geo- archaeological and historical evidences, the recentof which was the accidental discovery of an ancient Canoe dating back to over threethousand years (3000) located in about Six hundred kilometers (600) away from thepresent day bank or shores of the Lake in the Nigerian Territory of the Lake Chadbasin area, in the year 1992 by a peasant farmer from the Kanuri inhabited desertareas of Damaturu-Nigeria, while digging a well in quest of water for his domesticactivities as reported by Abubakar, B. (IJNA 37.2,2008), but due to the impacts ofthe on-going climate change which is leading to the continues reduction in thesizes of the feeder rivers of the Lake Chad as a result of shortage in the annualrainfall, blockages of the major feeder rivers as a result of damming and irrigationalactivities along the major feeder rivers of the Lake by some African governments;like the blockage of the river “Shari’’ flowing through Cameroon from the republicof Chad as a result of the construction of a Dam by the Cameroonian governmentalong the river to generate hydro electric power and as adaptation measures to theclimate change in order to boost irrigational activities has presently reduced theLake to just one tenth (1/10) of its original size of 25000 KM square and still keepshrinking over time, but yet the Lake is still sustaining the livelihood of over 8(eight) million peoples in Africa living within the Lake Chad basin areas of Nigeria,Niger, Chad and Cameroon by providing water for their domestic activities such asdrinking and cooking and for their economic activities such as fishing, farming andIndustrial as well as mining activities; potassium extractions from the shores andbed of the Lake and more recently petroleum prospectors have been continuouslydiscovering and re-discovering new oil fields which was of course made possible asa result of the decomposition of dead marine sediments of the lake over thousandsor millions of years . In fact this Lake has provided jobs opportunities for over sixtypercent (20%) of the population residing in Nigeria, Niger, Cameroon and Nigeria. 55
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa32. Banana and plantain diversity and uses in the North Eastern Democratic Republic of Congo Adheka J.1, D.B. Dhed’a1, Karamura, E.2, De Langhe, R.3, Swennen3 and G. Blomme2 1 University of Kisangani, DR Congo; 2Bioversity International, Uganda; 3Katholieke Universiteit Leuven, Belgium;AbstractThe Congo basin is a centre of diversity for plantains, while the east African highlandbananas dominate the production landscape in the eastern DR Congo highlandsalong the Albertine rift. Studies on Musa diversity and distribution have beencarried out in the DR Congo since the 1950s. However, there is still insufficient dataon diversity in large sections of the Congo basin and eastern highlands. The presentstudy focused on the morphological diversity and uses of bananas and plantains in114 villages in 33 territories across OrientalProvince, South Kivu, ManiemaProvinceand part of Equateur. Participatory Musa germplasm surveys were conducted with1,140 households. An ad hoc characterization of Musa germplasm was carried outusing morphological descriptor sets as well as by taking photos of different plantparts for each representative sampled cultivar. On that base, synonymy assessmentwas carried out by comparing the cultivars with the accessions at the University ofKisangani field collection.A total of 127 cultivars including 99 plantains [Musa AAB](67 French, 22 False Horn and 10 Horn) and 28 bananas (13 dessert bananas [AAA], 10cooking bananas [AAA-EA] and 5 brewing bananas [AAA-EA]) were described andidentified. Synonymy could not be established for 45 out of the 99 identified plantains.Comparative study of their description with past and present other collection datawill likely identify several never-recorded cultivars, thus covering the entire diversityin the Congo basin. The most common plantain cultivars in farmers’ fields wererespectively ‘Libanga Likale’ or ‘Ambulu’ (23.4%), ‘Tchwatchwa’ (9.1%), ‘Litete’ (5.3%)and ‘Libanga Lifombo’ (5.1%), while ‘Yangambi Km5’ (6.8%), ‘Gros Michel’ (4.2%)and ‘Kamaramasenge’ (2.9%) were the most preferred dessert bananas.The mostcommon and widespread plantain cultivar ‘Libanga Likale’ (‘Ambulu’) was foundto have 17 synonyms. In contrast, no synonyms were found for ‘Mangweangwea’, aplantain cultivar with a very limited distribution, a probable indication that it couldbe a new cultivar (mutant) in the region. Generic names are used to describe bananaand plantain cultivars. For example, the word ‘Ambulu’ is used to describe all FalseHorn plantains with large fingers. Special names like ‘Kola’ (Snail shell), ‘LibangaLiboelabokoyi’ or ‘Ukali Okoy’ (Leopard tail) and ‘Nganganga’ (loose hands) areused to describe cultivars with particular bunch traits.Fruit pulp quality, availabilityof planting material, bunch size, sustainability of production and marketing potentialwere the main criteria used by farmers when selecting cultivars. On the utilizationaspects, unripe plantains are cooked or roasted, while ripe plantains are boiled andpound into a paste called Lituma. Plantain fruits are also processed into fritters orflour. Unripe cooking bananas (AAA-EA) on the other hand are boiled, while ripeones are eaten as dessert. The beer bananas (AAA-EA) are mainly used to producebeer in South Kivu. However, in certain regions, the cooking bananas (AAA-EA),the dessert (AAA), and even the plantains, are also used to produce a local distilledalcoholic liquor (lotoko). It’s not only fruits which are used as food, as the Bua andManga ethnical groups in the Banalia region of Oriental province boil and eat themale flower buds of French type plantains as a vegetable. Musa characterizationstudies will be further expanded to North Kivu, Bandundu, eastern and westernKasai as well as northern Katanga province in order to capture all diversity across theCongo basin and eastern highlands. Efforts should also be focusing on agronomic,post harvest and molecular aspects for enhanced knowledge, use and conservation ofMusa diversity across the DR Congo. 56
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa33. The role of soils and landscape on banana growth in Muleba District, Kagera Region, Tanzania Araki, S.1 and SARR, P.S.2 1 Graduate School of Asian and African AreaStudies, Kyoto University, Japan; 2 Center for African Area Studies, KyotoUniversity, JapanAbstractBukoba and Muleba Districts in Kagera Region of Tanzania are one of the centersof highland banana cultivation in the East Africa where Haya people developedintensive banana home gardens called Kibanja that include common beans, maize,yam, cocoyam and coffee, etc. Replenishment of soil fertility has been accelerateddue to the increased export of bananas to urban areas and the break-down of nutrienttransfer from surrounding grassland (Rweya) to Kibanja. To clarify the effect ofsoils and landscape on banana growth, the following studies were conducted in asub-village of Bubuya, Muleba District. 1) Six Kibanja were selected and bananaheight was measured along transects that follow a slope. 2) Accordingly, soils werecollected in three depths (0-10, 40-50, and 90-100 cm) and chemical soil analysiswas conducted. 3) Estimation of biomass and yield of banana was conducted in 12quadrates out of the six Kibanja. Results showed that the height of banana decreasedalong transects towards Kibanja-Rweya boundary, within a range of between 2.9and 3.9 m. Soil characteristics associated to the height of banana were primarily basesaturation and pH of surface soils ( 0-10 cm ), followed by carbon contents, showingthat Kibanja soils (Rhodic Haplustults) are strongly affected both by landscapepositions and intensive farm management by farmers through incorporationof plant residues and manures to the soil. Estimation of biomass and yield ofbanana resulted in the productivity of 16 - 43 t/ha/year of fresh banana, which iscomparable to cereal production with medium input (1.8-4.8t/ha/year). Carryingcapacity of banana based systems was estimated by combining such productiondata with village population statistics, and measurement of Kibanja areas. 57
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa34. Intensification of cassava production in Nigeria: Adoption of improved cassava varieties and access to processing technologies Ayedun, B.1, Abdoulaye B., Rusike J.3, Alene A.1 and Manyong V.4 1 International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria; 3International Institute of Tropical Agriculture, Lilongwe, Malawi; 4International Institute of Tropical Agriculture (IITA),Dar es Salaam, TanzaniaAbstract:Over the period of 2002-2008, cassava production increased annually by anaverage of 4.9% in Nigeria. Demand for Nigeria’s cassava tuber has increasedappreciably in recent years due to increased awareness on cassava utilisation. Astudy was conducted by IITA and the goal of the study is to explore and explainthe potential role of access to cassava processing technologies on uptake by farmersof improved cassava technologies. The study also analysed factors that influenceintensification of cassava production in Nigeria. A total of 952 farming householdrespondents (from IITA intervention and non-intervention villages) were randomlyselected and interviewed in 2010 using multistage sampling techniques. Data wereanalyzed using stochastic frontier production function to determine input-outputrelationship in cassava production and logit model was fitted on the data to find outdeterminants of improved cassava variety and the processing machine adoption inthe study households.Results showed that mean value of cassava farm output wasestimated to be positively influenced by land area cultivated in hectares, quantityof improved cassava planted in bundles, quantity of herbicide used in litters, andquantity of manure applied in kilograms; thus an increase in any or in all of thesevariables would enhance the level of technical efficiency in cassava production andsystem intensity, and that technical inefficiency is reduced by household villagelocation, house head being educated, and house head been a cassava processor.Result indicated that four variables significantly influenced adoption of improvedcassava cultivars: they are its awareness, being a member of grower association,the use of improved management techniques, and the use of cassava graters forcassava processing. Alternative adoption analysis to identify determinants ofgraters’ adoption indicated that the use of improved cassava variety also influencedadoption of cassava greater. However, the effect of improved varieties on graters’adoption was greater than the opposite effect. One of the drivers for higher cassavaproduction output is the use of improved cassava cultivars by farmers and theefficiency of the production is better improved on when such a farmer processescassava as well. In addition introducing of the improved varieties and graters to anarea should be done one after the other with improved cassava first.. However, tosustain cultivation of improved cassava varieties, access to graters usage is a must.Thus as expected demand expansion improves adoption of intensive productiontechnologies. 58
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa35. Evaluation de l’efficacité d’usage des engrais dans les sols degradés de Walungu Bagula, E.1, Pypers, P.2, Nachigera, M.G.1, Kulimushi F.3and Sanginga J.M.4 1 Université Evangelique en Afrique (UEA), DR Congo; 2Tropical Soil and Biology Insti- tute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 3 Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIAL- CA), Bukavu, DRC; 4Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Bukavu, DRCAbstractL’épuisement des nutriments dans le Sud-Kivu constitue un véritable problème àla productivité des terres. L’une des causes de cet épuisement est la faiblesse dessols à retenir les nutriments, ce qui les exposent à la lixiviation et au lessivage.Cela fait que la plupart des engrais appliqués ne sont pas efficaces. D’où pourassurer une meilleure une meilleure efficacité des engrais, il est impérieux dans cesconditions d’utiliser efficacement la matière organique en jouant sur des facteurscomme la qualité, le taux et le mode d’application. L’objectif de ce travail étaitd’évaluer l’efficacité des engrais dans les sols dégradés de Walungu en jouant surla stratégie d’application de la matière organique (MO).Dans le cadre du projet degestion intégrée de la fertilité des sols du CIAT - TSBF, Des essais ont été installésà Burhale et à Lurhala en saisosn A et B dans deux types de sol dont le Kalongo etle Civu. De ce fait, le rendement du maïs était fortement influencé par la qualité, ladose et le mode d’application la MO, soit une augmentation de 20%, de 24% et 53%respectivement, l’augmentation liée à l’application des engrais étant de 95 à 190%dans le Kalongo et de 54 à 94% dans le Civu. Par contre pour le haricot seule le moded’épandage a influencé le rendement soit une augmentation de 41%, l’augmentationlié au engrais étant de 79 à 133%. Le Civu a donné le double de rendement queceux obtenus dans le Kalongo. L’efficacité agronomique et le rapport valeur coût(RVC) étaient bons pour les traitements où on a appliqué la MO de bonne qualitéen poquet et en dose élevée (12,12 par NPK appliqué et en terme d’azote 71,3 et pourle RVC 2,4) pour le maïs et en dose moyenne pour le haricot (6,9pour le NPK et enterme de phosphore 40,58. et pour le RVC 2,3). 59
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa36. Analysis of farmer preferred traits as a basis for participatory improvement of East African highland bananas in Uganda Baryeke A.1, P. Tongoona2, J. Derera2, M.D. Laing3 and W.K. Tushemereirwe1 National Agricultural Research Organisation (NARO), Kampala, Uganda; 2African 1 Centre for Crop Improvement, Univ. of KwaZulu-Natal, Pietermaritzburg, South Africa; 3School of Agricultural Sciences and Agribusiness, University of KwaZulu- Natal, Pietermaritzburg, South AfricaAbstractThe survey reported aimed to establish farmers’ knowledge of black Sigatokadisease, farmers’ and consumer preferences for East African highland bananas,and the qualities desired in new disease resistant banana genotypes. A structuredquestionnaire was deployed on 59 households during October to December 2007. InJune 2008, a farmers’ group in Gombe subcounty, Wakiso district validated the newbanana materials and their parents for farmer preferred traits. Seven percent and3% of farmers in medium and low production zones, respectively, were aware ofblack Sigatoka disease. The East African highland bananas were preferred becauseof superior taste, softness, and yellow colour when cooked. These bananas maturedearly and were marketable. However, the East African highland bananas producedsmall bunches, lacked pest and disease resistance, and did not tolerate poor soilsand drought. Farmers desired to have new banana materials with heavy bunches,resistance to pests and diseases, tolerance to drought, fast maturing, and marketabletraits. Farmers indicated that before accepting new materials, the most importantattributes they would consider were pleasant taste, soft texture, aroma and yellowcolour of food in that order. Farmers ranked food quality aspects higher thanproduction traits in adoption of new banana materials, because they grow bananasmainly for home consumption. These findings highlighted the importance of farmerinvolvement in the identification of traits which have not been directly targeted forbreeding. 60
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa37. Soil constraints evaluation and maping using infrared scanning and digital map in east of Democratic Republic of Congo Bashagaluke Janvier1, Pypers Pieter2, Boeckx Pascal3, Walangululu Jean4 and Vanlauwe Bernard2 1 Kenyatta University, Nairobi, Kenya; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; Ghent University, Belgium; 4UCB(Catholic University of Bukavu), Bukavu, DRCAbstractNear infrared reflectance (NIR) and mid-infrared (MIR) spectroscopy techniquesare rapid, convenient and simple non-destructive techniques for quantifying severalsoil properties. This study uses MIR method to predict pH, soil organic C, total N,exchangeable Al, Ca, Mg, and K, CEC and soil texture for soil samples collected inSud-Kivu, Democratic Republic of Congo. A total of 534 composite soil sampleswere taken from two locations (Burhale and Luhihi) at two depths (0-20 and 20-40 cm) using a spatially-stratified random sampling design within an area of 100km2. Differences in characteristics were evaluated between the two locations,land use (cultivated vs. non-agricultural land) and soil depth. A random subsetof the samples (10%) were analyzed using standard wet chemistry methods, andcalibration models developed using MIR data to estimate soil properties for thefull soil sample set. Partial least squares regression (PLS) method gave acceptablecoefficients of determination between 0.71 and 0.93 for all parameters.Soil organicmatter levels were higher in cultivated plots in Luhihi (3.9% C) than in Burhale (3.0%C), suggesting lower levels of soil fertility in the latter area. The average topsoilpH equalled 4.6 in agricultural land in both sites, and was about 0.2 units lower innon-agricultural land. This indicates high levels of acidity, which are likely to limitcrop production in the area. Phosphorus deficiency is acute for Burhale (2.4 mg Pkg-1) but less for Luhihi (5.4 mg P kg-1). In both locations, low levels of Ca and Mgindicate that soils may be susceptible to deficiencies in both elements. The soil datacollected will be extrapolated to the entire province by using digital map of Kivu.These findings provide new opportunities for monitoring soil quality in the regionwhich can benefit multiple actors in the agricultural and environmental sectors. 61
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa38. Methods for cost-effective monitoring of soil organic carbon as a key indicator of soil condition across landscapes Betemariam E.1, Vagen T.1, Sila A.2, Winowiecki L.2and Shepherd K.1 1 World Agroforestry Centre (ICRAF), Nairobi, Kenya; 2Earth Institute, Columbia Uni- versity, NY, USA AbstractSoil degradation and decreasing soil fertility has been identified as a majorconstraint to agriculture in sub-Saharan Africa (SSA). Increasing demand for foodas a consequence of ever- growing populations in SSA has resulted in rapid increasein land under agriculture and agricultural intensification. To better understand theimpacts of agricultural expansion and intensification on soil condition, systematicmonitoring across landscapes is necessary. This is challenging, particularly in areaswhere resources are limited and infrastructure generally poor. The objective of thisstudy is to evaluate the applicability of near-and mid-infrared soil spectroscopy asa low cost and repeatable measure of soil organic carbon (SOC), which is a keyindicator of soil condition. This study investigates soil organic carbon stocks atlandscape-scale using data from five sites (100 km2 each) across western Kenya.Samples were collected from 240 locations to a depth of 120 cm, at 20 cm depthintervals. The SOC estimates were made from a PLS calibration model usingspectral data and log transformed SOC reference data for 459 samples, which wascross-validated using leave one out procedure. The results indicate that both NIR(R2 = 0.80; RMSE = 0.37) and MIR (R2 = 0.94; RMSE = 0.31) are good estimators ofsoil organic carbon. The topsoil (0-20 cm) has highest carbon concentration, but alow soil carbon stock due to low soil mass (bulk density) (mean ± SE: 21.53 ± 1.75 tha-1). Therefore, to avoid bias in quantifying soil carbon stocks using a single bulkdensity from a fixed depth, it is important to consider differences in bulk densitywith depth. In conclusion, infrared spectroscopy offers promise for a rapid, reliableand cost effective measurement of soil organic carbon, which is a key parameter inmonitoring ecosystem health in the humid tropics. 62
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa39. Banana-beans intercropping in Burundi: effect of mulch application and mulch type Bizimana Syldie1, Baret Phillipe V2, Jassogne Laurence3, Van Asten Piet4 1 Institut des Sciences Agronomiques du Burundi (ISABU), Burundi 2Université Catho- lique de Louvain (UCL), Belgium; 3Université Catholique de Louvain-la-Neuve/Inter- national Institute of Tropical Agriculture (UCL-IITA), Belgium; 4International Insti- tute of Tropical Agriculture (IITA), Kampala, UgandaAbstractIntercropping beans and bananas is a traditional practice in the African Great Lakesregion. It provides security in terms of food and revenue. However, the traditionalmanagement method of tillage to prepare the plot for bean cultivation destroys thebanana root system and therefore has an impact on banana yield. Moreover, theexportation of banana mulch to coffee may influence negatively soil fertility in theseagricultural systems. The objective of this study was to compare the application of 3different mulch types with the traditional tillage practice. In order to do so, the sametrial was organized in 5 different agro-ecological sites (2 in RDC and 3 in Burundi).Four treatments were compared : tillage, no tillage + banana mulch, Hyppareniamulch and Tripsacum mulch. Banana yield was assessed during the first cycle andbean yields were followed during three consecutive seasons. Soil nutrients andfoliar elements were analysed. The impacts of the different agricultural practicesare dependent on the agro-ecological conditions and vary from one location to theother. Across all trials, tillage had a negative impact on banana yield. Bean yieldwas decreasing when banana was growing. This is probably due to competition forlight, water and nutrients. Some differences were observed between the differenttypes of mulch but were not fully consistent across conditions. It seems that whenconsidering the banana-bean association, a specific attention should be paid tobanana shade and therefore banana density or canopy pruning. 63
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa40. Introduction and adoption of improved cassava varieties by smallholder farmers on the island Idjwi Bolonge Epampuka1, Winter Stephan2, Kamondo Bertin S.3 1 Coordonnateur PIDR/CBFC-HF, Kisangani, RDCongo; 2Plant Virus Department, Leibniz-Institut DSMZ - Deutsche Sammlung von Mikroorganismen und Zellkultu- ren, Braunschweig, Germany; 3Directeur du CPR Afrique, Gisenyi, RwandaAbstractThe island Idjwi in Lake Kivu is a densely populated area where 260 000 inhabitantslive on 310 km2 land area. Cassava is the main diet for the rural population and thuscassava based cropping systems predominate in an agriculture of smallholders (<0.5ha) farming on remote and marginal lands with almost no access to agriculturalinputs. Crop improvement and resource management are essential for increasingcrop productivity and since cassava cultivation on the island is seriously menacedby Cassava mosaic disease (CMD), introduction of improved cultivars was themost immediate intervention to enhance cassava production at Idjwi. To reflectfarmers’ needs and awareness the rural communities were involved from start ofthe activities. Adaptation trials with 11 improved cultivars selected on the basis oftheir CMD resistance and other agronomic traits were set up at 3 sites on the island.Farmers associations were implicated in multiplication and varietal evaluationsof the cassava cv. Mayombe, Nsansi, Mvuazi, Namale, Butamu, Disanka, Liyayi,TMS 96/0730, Sadisa, Sawasawa, TME419 and the local cultivar Nambiombio. Theassessment of the harvest after the first year of cultivation showed that the cultivarMayombe outperformed other cassava lines at all sites, essentially remaining free ofvirus symptoms, showing vigorous growth and high yield. Remarkable differences(root number & weight) were recorded for the cultivars indicating differences in soilfertility. Interestingly the local cultivar Nambiombio also performed well confirmingthat the health status of planting material strongly determines productivity of cassavacultivation. This model of community involvement in vulgarisation of improvedvarieties will continue and scaled to reach more farmers. However already at thisstage it can be concluded that the yield potential of the new cassava cultivars cannotbe attained by subsistence farming thus successful adoption of improved cultivarsrequire agronomic inputs, good farming practices and resource management. 64
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa41. Dispersal and establishment of Habrobracon hebetor Say (Hymenoptera: Braconidae) ectoparasitoid of the millet head borer Heliocheilus albipunctella de Joannis (Lepidoptera: Noctuidae) following experimental releases in Niger Boukary Baoua Ibrahim1, Manuel Tamo2, Malick Ba3, Clementine Dabiré3 and Mama- dou N’Diaye4 1 Institut National de la Recherche Agronomique du Niger (INRAN), Niger; 2Interna- tional Institute of Tropical Agriculture (IITA), Cotonou, Benin; 3INERA, Burkina Faso; 4 IER, MaliAbstractAgriculture in the Sahel region of Africa is subjet to various constraints whichsubstantially reduce its performance. The production of millet, Pennisetum glaucum(L) R. BR, a staple food, is severely undermined by biotic and abiotic stress factors.Among them, the millet head borer Heliocheilus albipunctella De Joannis is one ofthe key pests attacking this crop. The damage in the field is only observed towardsthe end of the cropping season, thus preventing an early detection, for which onlyvery limited intervention possibilities exist. In recent years, biological control usingrelease bags for the millet head borer parasitoid Habrobracon hebetor Say has beensuccessfully developed. This study wants to assess the dispersal of H. hebetor fromrelease points. On two different sites, four series of observations have enabled theassessment of H. hebetor dispersal using a network of 40 monitoring station in aradius of 5km around each village. A total of 9600 millet head were collected andassessed for borer damage and the presence of the parasitoid. At the Danja site,0.37 borer larvae per millet head were parasitized 45 days after initial release, whileat Bamo the number of parasitized larvae were 0.52. It is concluded that a total of16 release bags per village can cover some 7850 ha of millet crop with an averagedistruction of nearly 80% of borer larvae. The cost of this biocontrol operation isestimated to be 2.03 CFA francs (0.004 US$) for ha of millet crop. 65
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa42. Mapping of Banana Xanthomonas Wilt Status in Tanzania S. Bulili1, J. Nkuba1, J. Mukandala1, I. Ndyetabula1, S. Mkulila1, W. Tinzaara2, E. Karamura2, T. Mugireneza3, W.Jogo2 and A. Rietveld2 1 Agricultural Research and Development Institute, Tanzania; 2Bioversity International- Uganda, Kampala, Uganda; 3National University of Rwanda, Centre for Geographical Information System, Huye District, South Province, RwandaAbstractBanana Xanthomonas wilt (BXW) which is caused by Xanthomonas campestris pvmusacearum is one of the most devastating epidemic on bananas in Tanzania. It wasconfirmed present in the country in 2006 in Muleba district and it has since spread toother districts in the country. The objective of this study was to map the distribution andincidence of the disease in Tanzania. In addition, the level of awareness by stakeholdersin the different districts was determined. The study was conducted in Missenyi,Bukoba and Muleba districts between December 2009 and January 2010. A total of 120households were interviewed using a structured questionnaire and GIS readings weretaken which were later used in mapping. Of the farms which were surveyed 60% hadthe disease while 16% had the disease but controlled. The proportion of farms affectedvaried from district to district, with the highest incidence in Muleba District (50%)and lowest incidence in Bukoba (12%). Proportion of infected mats with BXW wasassessed by farmers ranging from less than 10% to 100% of the total mats owned by afarmer. Awareness of BXW symptoms varied from 60 to 90% while awareness of modesof spread ranged between 30 and 80%. Although awareness of control measures washigh (80%) use of control measures was low (<40%). Majority of farmers (60%) used de-budding and fewer (36%) used clean planting materials. There is a need to review BXWcontrol strategy which will involve all stakeholders at different levels. 66
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa43. Banana and plantain research at the University of Kisangani (UNIKIS), DR Congo Dhed’a, B.D.1, Adheka, J.G.1, Moango, A.M.1, Ngama, F.B.y2, Lepoint, P.3, Blomme, G.3, Langhe, De E.4 and Swennen, R.4 1 University of Kisangani (UNIKIS), Kisangani, DR Congo; 2International Fertilizer Industry Association (IFA)-Yangambi, DR Congo; 3Bioversity International, Kampala, Uganda; 4 Katholieke Universiteit Leueven, Leueven, BelgiumAbstractBanana and plantain are a key component of food security in DR Congo (2,700million tons/year) and then particularly in the OrientalProvince (e.g. TshopoDistrict with 444,435 tons in 2009) which covers a large part of the Congo basin. Theeastern Congolese highlands along the Albertine riftvalley are considered a meetingplace of the east African highland bananas (Musa AAA-EA) and the plantains (MusaAAB). A wide variety of plantain cultivars can be found in the Congo basin. By 1960,56 plantain cultivars had been collected and characterized by Edmond De Langhe(INEAC, Yangambi).Social unrest, civil war and political instability prevented thecontinuation of the Musa characterization work during several decades. Since 2005,UNIKIS, Kisangani in collaboration with Bioversity and K.U.Leuven revived theMusa collection, characterization and conservation work. To date, Musa germplasmsurveys have been carried out in Oriental province, Maniema, South Kivu andEquateur. Musa production constraints were also assessed during these surveys.In addition, research has focused on assessing the incidence and spread of BBTDacross the Congo basin and eastern highlands. The production of BBTV free plantingmaterials using TAS-ELISA tests is ongoing. Finally, research on plantain post-harvest transformation (e.g. flour) has started. So far 129 Musa cultivars including96 plantains have been collected. 44 are putative new cultivars, mainly plantains.The main constraints to Musa production identified during the surveys are: lowyield, low soil fertility, cultivarspoorly characterized by farmers, presence of pestsand diseases (e.g., BBTD, black leaf streak, banana weevil and nematodes), poormarket access, low market prices and lack of clean seed. The BBTD incidence is veryhigh (70.2 % in Ituri and 87.7 % in Tshopo district). However, BBTD severity is lowand the main symptoms are streaks on the leaf sheaths, petioles and midribs. TheBBTV vector (Pentalonia nigronervosa) is widely present throughout the study area(on 58.3 % of mats in Ituri and 87.1 % in Tshopo district). Musa research at UNIKISwill continue to have a strong focus on Musa surveys, collection, characterization(morphological, agronomic, nutritional and molecular), conservation and use ofthe available germplasm. New collaborative efforts on clean seed systems/bestperforming germplasm and post-harvest transformation (e.g. plantain dried slices,banana flour, banana paste or Fufu) are envisaged. UNIKIS will also focus its futureresearch on enhancing soil fertility through AMF, organic matter, soil coveringcrops and agro-forestry techniques. 67
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa44. Effects of soil amendments with cattle manure on soil hydraulic properties and crop yields of two contrasting soils in Murewa, Zimbabwe Dunjana Nothando1, Nyamugafata Philip2, Nyamangara Justice2 and Zingore Shamie3 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Harare, Zimbabwe; 2Department of Soil Science and Agricultural En- gineering, University of Zimbabwe, Harare, Zimbabwe 3International Plant Nutrition Institute (IPNI), Nairobi, KenyaAbstractA study was conducted in Murewa smallholder farming of Zimbabwe (17o 38΄ 49˝S and31o46΄ 39˝ E, altitude 1270 m) to determine the effects of adding cattle manure in combinationwith mineral fertilizer on soil hydraulic properties and crop yields of fields of differentmanagement histories. Four fields displaying fertility gradients (homefields, typically morefertile and closer to the homestead and outfields which are less fertile than homefields) wereselected on clay and sandy soils and subjected to four treatments, control (no fertilizer andmanure), 5, 15 and 25 tha-1 cattle manure + 100 kgha-1 N over 6 years. Two other fields, ahomefield and an outfield were also established on the clay soil to investigate the effectsof application of cattle manure at 5, 15 and 20 tha-1 and mineral fertilizer on soil hydraulicproperties over 2 years. Soil hydraulic properties including steady state infiltration rates,pore density, total effective porosity, unsaturated hydraulic conductivity, mean pore sizesand soil moisture characteristics were measured using double ring infiltrometers, tensioninfiltrometers, tension tables and pressure chambers in the control, 20 and 25 tha-1 manuretreatments. Steady state infiltration rates were significantly higher (p < 0.05) in the manuretreatments than control in both long-term and short-term clay fields. On sandy fields therewere no significant differences between fertility treatments (p > 0.05) after 6 years. Pore densityand total effective porosity of pores < 600 µm measured at 5cm tension were significantlyhigher with cattle manure application and they ranged between 429-1130 and 1164-3228 m-2on clay long- and short-term fields respectively, while being significantly lower in sandy soils.At 10 cm tension the trend for pore density and total effective porosity was similar with 5 cmbut values were higher implying that smaller sized pores (< 300 µm) were more dominantin the clay soils. Unsaturated hydraulic conductivity at 5 cm was highest (3.00 cmhr-1) in the25 tha-1 manure treatment in the clay long term homefield and significantly higher than thecontrol (1.83 cmhr-1) and the outfield conductivities. Cattle manure application at 25 tha-1 also significantly improved macroscopic capillary length (λ ) and microscopic capillary cradius (λm) of pores at 5 cm in the long-term clay fields compared to control. Hydraulicconductivity on short-term clay fields was 1.57 cmhr-1 in 20 tha-1 cattle manure treatmentat 5 cm and significantly higher than the control but there was no change in λc and λm.Cattle manure also resulted in improved water retention in manure treatments at 5 and 10kPa in the clay long-term fields. Maize grain yields were 3 times higher than control withcattle manure application at 5 tha-1 and at least 4 times higher with 25 tha-1 cattle manureand inorganic fertilizer in all field types. Significant and positive linear relationships with anR2 value of at least 0.52 were observed between grain yield, steady state infiltration rates,pore density, total effective porosity, unsaturated hydraulic conductivity and total availablewater. It was concluded that cattle manure application at 25 tha-1improves soil hydraulicproperties of clayey homefields and outfields but not sandy fields after 6 years. In addition,application of at least 5 tha-1 cattle manure with inorganic fertilizer improves crop yieldsboth in sandy and clayey soils in the short-term and long-term. 68
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa45. Musa cultivar preference, local processing/cooking techniques and consumption patterns among small-holder communities in South-Western Uganda Ekesa Beatrice1, Christien Miroir2, Davey Mark2, Van den Bergh Inge3, Karamura Deborah1and Blomme Guy1 1 Bioversity International, Kampala, Uganda; 2Lab Fruit Breeding and Biotechnology, Department of Biosystems, Katholieke University of Leuven (KUL), Leuven, Belgium; 3Bioversity International, Montpellier, France.AbstractA cross-sectional study was carried out in Bushenyi district, South-Western Ugandain August 2009. The objective was to identify the most preferred Musa cultivars,the Musa processing/cooking methods practiced and consumption patterns amongsmall-holder households. Data was collected through six focus group discussionswith local male farmers and women of child-bearing age. In addition, 172 householdinterviews with mainly mothers with children of less than five years as respondentswere carried out. Findings indicated that >10 different Musa cultivars are availableto community members in South-Western Uganda. Prescreening of fruit pulp ofthese Musa cultivars was carried out using a standardized HarvestPlus color stripto identify potential carotenoid rich cultivars. Results indicated that the pulp colorof the 3 most popular cultivars ranged from creamish-yellow (AAA-EAs) to lightorange (AAB-French horn plantain). The most preferred AAA-EA cultivars were‘Entaragaza’ and ‘Mbwazirume’ amongst, respectively, 46% and 43% of interviewedhouseholds. Reasons for their popularity were: short maturation period, goodcooking qualities and high yield. The most preferred plantain cultivar was ‘Manjaya-Gonja’ (AAB-French horn) as this cultivar has a large bunch and a high market price/value. Eighty eight percent (n=155) of the interviewed households had consumedcooking banana (AAA-EA) over the last 24 hours, while 84% of these 155 householdshad obtained the cooking bananas from their own farms. Consumption of dessertbanana and plantain was 8.7% and <5% respectively in the 24 hours preceding thesurvey. Most plantain is sold to middlemen/traders at a high market price, resultingin a low home consumption. Although banana and plantain in Uganda are boiled,steamed, roasted, deep fried, processed into flour and made into pancakes, a 7-daysfood frequency questionnaire showed that most of the households (86%) had eitherconsumed steamed or boiled bananas with rates of between 2 and 4 times in a week.This study could give valuable information to researchers wanting to screen Musacultivars for carotenoid content (pVACs). Varieties with high pVAC content couldsubsequently be used in a fast-tracking approach to reduce Vitamin A deficiencywhich is omnipresent in the local communities in South-Western Uganda. 69
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa46. Effect of banana leaf pruning on banana growth and legume yield in banana-legume intercropping systems in Burundi Emera Willy, Lepoint Pascale2, Blomme Guy3, Van Asten Piet4 and Pypers Pieter5 Bioversity International, Bujumbura, Burundi 3Bioversity International, Kampala, 2 Uganda; 4International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 5Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, KenyaAbstract:Intercropping is a common practice amongst farmers in the region, especially incountries such as Burundi, where demographic pressure is high and arable landssparse. Farmers have been using this system for generations to maximize utilizationof land, minimize labor and food insecurity risk and to concentrate and recyclebanana organic matter. Beans, and other leguminous crops, are a major sourceof protein in the region and are grown in all agro-ecological zones of Burundiwith a consumption reaching 50kg/capita/year. Similarly, banana cultivation isalso widespread, primarily as a cash crop (beer and dessert banana), reaching aconsumption of 89 kg/capita/year. An on-station banana-legume intercroppingtrial assessing cooking banana ‘Incakara’ (AAA-EA, cooking) and leguminous cropyields (bush beans MLB49-89/ISO201513, AND10/G13706 and soybean SB24/Yezumutima) under three shading levels created by de-leafing (4, 7 and all bananaleaves remaining) was followed for three consecutive cropping seasons (2010B, 2011Aand 2011B) in Moso ISABU Research station (Rutana Province). Mono-crop controlplots (banana and leguminous crop varieties) were included in the trial, resultingin a full factorial design with fifteen treatments. Due to a non-established bananacanopy, data collected during the first cropping season indicated that shading levelsdid not significantly influence legume yield. A similar observation was made thefollowing season, this time attributed to erratic climatic conditions (sparse rains),which did not favor a vigorous banana canopy and legume development. On theother hand, a significant negative effect on legume biomass, especially for highshading levels (all banana leaves and 7 leaves), was observed during the third beancropping season (2011B). Moreover, significant differences in tolerance to shadingwere observed on leguminous crops with soybean suffering the most under high-density canopy. Bush bean produced significantly more biomass in intercroppingtreatments (7 and all banana leaves retained) in comparison to climbing bean,boding well for grain yield. Findings indicate that legume yield is highest undermono-cropping conditions and that banana growth is proportional to the numberof functional leaves retained. 70
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa47. Crop – livestock Interaction for Improved productivity: Effect of Selected Varieties of Field Pea (Pisum Sativum L.) on grain and straw parameters Gebru Yetimwork Gebremeskel1, Gebre Awet Estifanos2, and Melaku Solomon3 1 DebreBirhan University (DBU), Amhara, Ethiopia; 2Tigray Agricultural Research In- stitute (TARI), Tigray, Ethiopia; 3Haramaya University (HU), Diredawa, EthiopiaAbstractThe study was conducted at Alemaya University Campus and Hirna ExperimentalStations, Ethiopia, during 2004 cropping season with the objective of determing leafto stem ratio (L:S), straw dry matter yield (SDMY), harvest index (HI), potentialutility index (PUI), chemical composition, invitro dry matter yield (IVDMY) andinsacco dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF)degradability. The experiment was conducted at both sites using five selected varitiesof field pea in Randomized Complete Block Design (RCBD) with four replications.The overall result showed that varietal differences in grain yield, SDMY and strawquality and this indicated that the possibility of selecting for field pea varietiesthat combine high grain yield and desirable straw characteristic. According to theresult of the experiment Tegenech were identified to have high grain yield andSDMY. Moreover, Local pea at Alemaya and Tegenech at Hirna were significantly(P<0.05) higher in potential utility index than the remaining varieties. The valueof PUI ranged from 29.2 to 41.7. The field pea varieties were significantly differentin IVDMD value at Alemaya whereas there was no significant difference at Hirna.At Alemaya the variety G22763-2C had significantly higher IVDMD than Tegenechand Adi. There were significant differences among the field pea varieties for theplant cell wall. Except for the rate of degradability there was significant difference(P<0.001) among the field pea varieties for dry matter degradability both at Alemayaand Hirna, Organic matter and Neutral detergent fiber degradability at Alemaya. 71
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa48. Arbuscular mycorrhizal fungi colonization, plant parasitic nematodes and their impact on East African highland banana performance in Rwanda Gaidashova Svetlana1, Van Asten Piet2, Delvaux Bruno3, De Waele Dirk4 and Declerck Stephane3 1 RAB-ISAR (Institut des Sciences Agronomiques du Rwanda), Rwanda; 2 International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 3 Université catholique de Louvain (UCL), Belgium; 4 Katholieke Universiteit Leueven (KUL), BelgiumAbstractEast African Highland bananas are associated with arbuscular mycorrhizal (AM)fungi. Such fungi are generally known to improve water and nutrient uptake, whilestrengthening plant tolerance to nematode pests. However, field relationshipsbetween highland bananas, AM fungi, and nematodes are still poorly understood.We assessed root colonization of arbuscular mycorrhizal (AM) fungi, nematodeinfestation and banana plant growth in 188 banana fields in five eco-regions inRwanda. AM fungi root colonization was observed in all banana plants at all sites.However, root colonization levels and population density and diversity of AM fungistrongly varied according to edapho-climatic conditions (i.e. rainfall, soil textureand P content) and soil management practices (tillage). Nematode parasitic speciesidentified were in order of importance (i) Pratylenchus goodeyi, (ii) Helicotylenchusmulticinctus, (iii) Meloidogyne spp., (iv) Radopholus similis and (v) Hoplolaimuspararobustus. P. goodeyi was the dominant species in all eco-regions except in thelowland (<1000m) site Bugarama. Only P. goodeyi significantly (p<0.001) correlated(r=0.61) with root necroses. Colonization frequency was negatively correlated withroot necroses (r = -0.24, P < 0.01) and with P. goodeyi population densities (r = -0.13,P < 0.10). Banana plants with poor vigor showed stronger associations with AMfungi. This suggests that these plants depended more strongly on AM fungi fortheir nutrient uptake. Tillage intensity rank was negatively correlated to frequency(r = -0.30, P < 0.001) and intensity of root colonization (r = -0.20, P < 0.01). AMfungi friendly practices such as zero-tillage soil management practices should bepromoted, particularly in areas with sub-optimal soil fertility. 72
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa49. Adoption of technologies disseminated for the control of banana xanthomonas wilt in Rwanda Gaidashova S1, Night G1, Rurangwa E1, Gahakwa D1, Mukandinda A1, Uwimpuhwe B1, Karemera F1, Mugiraneza T1, Kajuga J1, Murekezi, C2, Tinzaara W3, Karamura E3 & Jogo W3 1 Institut des Sciences Agronomiques du Rwanda, Kigali, Rwanda ; 2Rwanda Agriculture Development Authority (RADA), Kigali, Rwanda ; 3Bioversity International, Katalima Road, P.O. Box 24834, Kampala, UgandaAbstractBanana Xanthomonas wilt caused by Xanthomonas campestris pv. musacearum was firstconfirmed present in the East and Central Africa region in 2001 and has since beenconfirmed in all the countries of the region. In Rwanda, the disease was first confirmedin 2005, in Rubavu district. Following the outbreak of the disease in the district, severalmeasures were put in place to contain the disease that had reached epidemic levels.Promotion of cultural control technologies coupled with awareness raising for farmers/stakeholders were carried by extension and research institutions of Rwanda and theirregional partners. Raising stakeholders’ awareness involved sensitization activities,training of trainers, and formation and implementation of task forces. A number oftechnologies were disseminated to farmers, including the uprooting and destruction ofinfected plants/mats, de-budding, use of clean planting materials, the decontaminationof field tools and quarantine. This study was conducted to assess adoption of thedisseminated management technologies and to determine their effects on BXWdistribution and incidence in Rubavu district. Using a structured questionnaire, tenhouseholds were interviewed from each of the 9 sectors that had the disease, makinga total of 90 farmers. Adoption of technologies varied from 7% for quarantine to 61%for removal of male buds, and was influenced by socioeconomic factors, includingawareness of disease dynamics at the farm level, effectiveness of surveillance strategiesadopted and labour costs and availability. There was a general observation that farmerswho used technologies had much lower incidence of the disease than those that werenot applying them. 73
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa50. Soil-related effects of arbuscular mycorrhizal fungi performance on banana (Musa spp.) Gaidashova Svetlana1, Van Asten Piet2, Delvaux Bruno3, Elsen Annemie4 and Declerck Stephane3 1 RAB-ISAR (Institut des Sciences Agronomiques du Rwanda), Rwanda; 2 International Institute of Tropical Agriculture (IITA), Uganda, 3Université catholique de Louvain (UCL), Belgium; 4BDB, BelgiumAbstractArbuscular mycorrhizal (AM) fungi are known to improve plant growth,particularly when plants are young and root systems still poorly developed. Thiseffect may depend on soil type. Here we reported the effect of inoculation withindigenous AM fungi isolated from a Nitisol in Kibungo (Rwanda) on the growthand root characteristics of three banana genotypes: FHIA 17 (AAAA), Musakala(AAA-EA) and Sukali Ndiizi (AAB), grown in pasteurized and non-pasteurizedAcrisol, Ferralsol and Nitisol. Root characteristics differed significantly between soiltypes (P < 0.001) and banana genotype (P < 0.05). The poorest root development wasobserved on Acrisol and the largest on Nitisol whatever the genotypes. Musakalahad a smaller root system compared to FHIA 17 and Sukali Ndiizi. Inoculationresulted in highly significant (P < 0.001) differences in frequency of arbuscules (FA)between soil types in all genotypes and treatments. The highest FA was observedin Nitisol and the lowest in Acrisol. Inoculation significantly (P < 0.001) increasedplant growth (12-103 %) and dry shoot biomass (23.3-450% %) but its effect wasless marked in non-pasteurized treatments as compared to pasteurized treatmentsin all soils and genotypes. The exception was Ferralsol where pasteurization didnot result in significant increase of plant growth. Inoculation increased plantgrowth most in poor Acrisol. This was observed in all genotypes and treatments.This was most probably linked to greater limitations in root growth in Acrisol.Poorer root development of Musakala coincided with its highest response to theAM fungi inoculation compared to other genotypes, which suggested higher AMFdependency. Our results suggest that use of inoculums source originated from thesame soil type as where inoculation is done may be more beneficial and have higherimpact on plants than use of AMF strains developed on different soil types. 74
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa51. Effect and Performance of Relay Cropping Mucuna (Mucuna pruriens) Green Manure Cover Crop with Maize (Zea mays) in the Central Highlands of Kenya Gitari J.1, J. G. Mureithi2, C.K.K. Gachene3, D.N. Mugendi4, and J.B. Kung’u4 1 Kenya Agricultural Research Institute (KARI), Embu, Kenya; 2Kenya Agricultural Research Institute (KARI) HQ, Nairobi, Kenya; 3University of Nairobi, Faculty of Ag- riculture, Department of Land Resources Management and Agricultural Technology, Nairobi, Kenya; 4Kenyatta University, Nairobi, KenyaAbstractLand productivity in many parts of the eastern African highlands, particularlythe central highlands of Kenya, is constrained by low and declining soil fertility.In the maize-based farming systems, continuous cultivation without adequate soilfertility enhancement measures has led to a deterioration of land quality resultingin low agricultural yields and degraded soils. Herbaceous legumes can provide analternative to commercial fertilizers and animal manures. This study explored thepossibility of intercropping or relay cropping mucuna [Mucuna pruriens (L.) DC.Var. utilis (Wright) Bruck] which is a good candidate for green manuring/covercropping in the maize-based cropping systems of the sub humid central Kenyahighlands. Results of the field experiments showed that it is feasible to intercropmaize with mucuna green manure legume (GML) so that the resultant biomass maybe used as an organic fertilizer in the subsequent maize crop. Relay-cropping thisGML beyond the second week after maize emergence had a significant reductionon legume biomass production possibly due to reduced photosynthetically activeradiation (PAR) under the maize canopy. Intercropped GML intercepted less than30 per cent of the total incident radiation. Nonetheless, intercropping of maize andmucuna GML greatly improved land productivity giving relative yield total (RYT)values of between 1.0 and 1.5 75
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa52. Macropropagation: Adapting the technology to the Burundian context Iradukunda Francois1, Blomme Guy2, Lepoint Pascale1 and Ndarubayemwo Gaspard3 Bioversity International, Bujumbura, Burundi; 2Bioversity International, Kampala, 1 Uganda; 3University of Burundi, BurundiAbstractMacropropagation is considered as a rapid means of producing, at a local level,numerous Musa spp. disease-free plantlets of preferred and/or improved varietiesat a putative low cost. The technology was evaluated in an on-station research-ledtrial covering two contrasting agro-ecological sites in Burundi, Bujumbura (818masl, mean temperature 25°C) and Gitega (1,655 masl, mean temperature 19°C).Two humidity chambers (a ‘standard’ unit made out of wooden planks and plasticsheeting versus a ‘prototype’ unit made out of locally available Eucalyptus wood andpapyrus [Cyperus] mats covering sides and top) placed under 50% natural shading,three non-sterilized substrates (sawdust, rice hull and coffee husks) and four Musavarieties (‘Kamaramasenge’ [AAB], ‘Igisahira’ [AAA-EA cooking], ‘FHIA17’ [AAAA]and a plantain cultivar [AAB]) were evaluated in two successive trials at each site.Corm viability, number of days till emergence of the first shoot (latency period), andnumber of shoots produced per corm after secondary scarification (productivity)was recorded. Results show that independently from genotype, type of unit and/or substrate, a cooler climate such as in Gitega is not suitable for macropropagation,reducing corm viability and productivity significantly and doubling the latencyperiod. Despite lower temperatures observed in the prototype unit, corm viability,latency period and productivity were not significantly altered. Sawdust and rice hullperformed equally and significantly better as initiation substrates than coffee husks.Significant differences linked to genotype were observed with regards to viabilityof corms, latency period and number of plantlets produced per corm. Out of thefour varieties tested, ‘Kamaramasenge’ performed poorly with reduced viabilityof mother corms and productivity. In contrast, ‘Igisahira’ / ’FHIA17’ and plantainresponded well to the technique with moderate to high viability of mother cormsand a production of up to 20 and 24 suckers per corm, respectively. The present trialhas identified a prototype unit made out of local materials using non-sterilized ricehull as initiation media as an alternative low-cost option (75% cost reduction) forskilled and motivated resource-poor farmers, farmer groups or associations lookingto multiply banana and/or plantain locally at lower altitudes in Burundi. 76
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa53. An economic analysis of dairy production systems in Nyamira District, Kenya J. Isaboke1, H. Nyongesa2, G. Amusala1, P. Nyangweso1 and C .O. Kenyanito3 1 Moi University, Department of Agricultural Economics, Eldoret, Kenya; 2Masinde Muliro University Of Science And Technology, Kakamega, Kenya; 3Bukura Agricul- tural College, Bukura  AbstractThis study was conducted to find out whether dairy farmers could increase theirprofits through intensification of input use. The data used in the study was collectedfrom 150 farmers in three dairy production system practiced by farmers in NyamiraDistrict, Kenya. The data collected included the resources used in milk production,yields obtained, prices of inputs and output and the problems faced by farmers indairy production. Gross margin analysis was done for each system of productionand the means compared. The results indicated that the gross margin for the threesystems of dairy production is currently not significantly different from each other.Quadratic and Cobb-Douglas functions were fitted using the inputs used in dairyproduction and marginal products equated to inverse price ratios. The resultsshowed that the highest scope for increasing milk yield and profit exists in zerograzing where it is possible to increase milk yield by 94.4% (2538.6 kg/cow/yearabove current levels) through increased use of concentrates and farm by-products.For semi-zero and extensive grazing systems, farmers could increase milk yield by57.5% (from 2517.9 to 3964.8kg/cow/year) to reach economic optimum by usingmore concentrates and forages. The important conclusion which can be drawnfrom this study is that there is unexploited potential in the three dairy productionsystems. The study recommends that farmers should be encouraged to use moreconcentrates and by-products by addressing problems which lead to limited use ofconcentrates andby-products. These would include efforts such as: farmer training,paying farmers promptly for their milk so that they have sufficient cash to buyconcentrates, making roads more passable especially during the rainy season foreasy transportation of feeds, and assisting farmers to acquire credit. 77
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa54. Improvement of sweet potato (Ipomoea batatas (L.) Lam) production with fertiliser and organic inputs in Rwanda Janssens Marc1, Rutunga Venant2, Mukamugenga Joyce3, Mukantagengwa Spéciose3 and Marijnissen Roland4 1 Bonn University, INRES-Unit of Tropical Crops, Bonn, Germany; 2ISRIC- World Soil Information/ WUR, Wageningen, The Netherlands; 3Female Agricultural Technical School of Nyagahanga, Rwanda; 4Ministry of Health, Division of Food Security, Brus- sels, BelgiumAbstractSweet potato is among the staple food crops for Rwandese population. In Rwanda,s. potato yields vary from 7 to 8 Mg ha-1 and as all arable land is continuouslycropped hence depleted, the production increase is only possible through theuse of various inputs including nutrients. New s. potato cultivars highly yieldingwere screened and tested for their response to mineral (N, P, K, lime) and organicinputs in the main agro-ecological zones of Rwanda. Results from years 1980 to1982 showed that each agro-ecological zone has its most adapted cultivar(s) andthat the use of fertiliser/organic inputs improves yields. However, the high rates offertiliser/organic inputs applied on the selected s. potato cultivars had not led to themaximum yield. The effect of these inputs was highly influenced by crop husbandryand health, climatic conditions during the growth period and soil properties of theexperimental plots. The influence of agro-ecological conditions contributed to maskthe cultivars capacity to respond to fertiliser/organic inputs. In Rwanda it would behighly recommended that types and rates of fertiliser/organic inputs be determinedaccording to the types and levels of soil fertility. 78
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa55. Integrating commercial biological products into management of tissue culture (TC) banana and plantain Jefwa Joyce1, Kavoo Agnes1, Mwangi Elias1, Pypers Pieter1 and Lesueur Didier2 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 2Agricultural Research for Development (CIRAD), IndonesiaAbstractTissue culture (TC) banana and plantain face challenges in survival and establishmentparticularly at the transfer and nursery stage. Integrating soil biodiversity into soilfertility interventions has potential to alleviate nutrient, pests and disease constraints.A study funded by BMGF is being conducted by CIAT-Tropical Soil Biology andFertility (TSBF) institute to evaluate commercial biological and chemical productsfor suitability in crop production. A study on effect of fungal (Rhizatech, Mycorand EcoT) and bacterial (PHC Biopak, PHC Colonize and Subtilex) based productson growth of TC bananas in eutric nitosol (Coast), vertisol (Nyanza) and humicnitisol (Central) was undertaken. At the potting stage, a comparison of productswith non-inoculated control and conventional practices showed products to haveeffect on growth in vertisol and eutric nitosol and none in humic nitisol. In vertisol,all products increased height of plantlets with increase significant (p <.001) in onlyPHC Biopak (39.27%) and Rizatech (20.05%). Eutric nitosol showed increase inheight with PHC Biopak (107.05%) and a slight increase with EcoT (17.30%) andSubtilex (4.83%). The products significantly affected (p = 0.013) shoot dry weight(SDWT), with plantlets grown in soils without products having the least SDWT.The PHC products had the highest shoot dry weight followed by Rhizatech andMycor. The performance of products was slightly dependent on soil types (p =0.107). The products enhanced SDWT in all three soils, although the effect was morepronounced in eutric nitosol and vertisol for PHC biopak and from only vertisolfor PHC colonize. The increase in SDWT was slight with Rhizatech for all soiltypes with the least effect in soils from humic nitisol. The PHC products, althoughwith the best growth effect under greenhouse, had low survival rates, hence weresubstituted with Subtilex under field evaluation. Similar trends were observed ongrowth with plant response evident in vertisols and eutric nitosols. An increase ofmore than30% was observed with inoculation in both soils with Rhizatech (141.1-59.7%), EcoT (103.6-36.6%), Subtilex (62.4-48.4%). The performance of plantlets withthe Rhizatech and EcoT far exceeded the conventional practice in vertisols by over40%. Tissue culture bananas can benefit from commercial biological products butthe effect of products is soil dependent. 79
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa56. Dynamics of infective AMF propagules and phosphorus uptake of maize in three land use soils in southern Cameroon Martin Jemo1,2* Adamou Souleymanou3, Robert Clement Abaidoo2, Christian Nolte4, Emmanuel Frossard1, and Jan Jansa1 1 ETH Zurich, Institute of Plant, Animal and Agroecosystems Sciences (IPAS), Lindau, Switzerland; 2 International Institute of Tropical Agriculture (IITA), Oyo Road, Ibadan, Nigeria; 3 Department of Plant biology, Faculty of Science, University of Yaoundé I, Cameroon; 4FAO, Plant Production and Protection Division (AGP) Viale delle Terme di Caracalla 1; Rome, Italy; formerly International Institute of Tropical Agriculture (IITA), Humid forest Ecoregional Center, Yaoundé, Cameroon.AbstractPhosphorus uptake of maize was assessed in three land use soils of southernCameroon differing in arbuscular mycorrhizal fungi (AMF) inoculums potential intwo greenhouse experiments with the aims to assess whether simultaneous rootcolonization by several AMF species differently affect its acquisition . In the firstexperiment, substrate was treated with 0 or 100 kg ha-1 of benlate. Maize was grownon substrate soil from forest, fallowed, and cultivated land, and fertilizer with 0 or30 kg P ha-1 as triple super phosphate (TSP). Benlate application highly significantlyreduced P uptake, root length colonization and shoots dry matter of maize in the inthe respective land use system. P uptake and shoot dry matter significantly increasedfollowing P- application, and the root length colonization and P uptake weresignificantly related (P< 0.05). In the second experiment, 80 % of soil substrate wassterilized with Gamma-irradiation and 20 % of fresh substrate used to re-inoculatethe same or another soil substrate. The AMF species composition in the roots ofmaize assessed by the real-time PCR to determine the copy numbers of the largesubunit (LSU) ribosomal genes and to relate to P uptake was dominated by Glomusintraradices in theforest and fallow, while G. claroideum dominates in the cultivatedland soils. The transfer of P is facilitated by the involvement of G intraradices in theforest soils. Both fungi G. intraradices and G. claroideum synergistically contribute toP transfer to the maize roots in the fallow and cultivated soils. 80
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa57. Response of grain legumes to commercial rhizobia inoculants under different agro-ecological zones of West Africa Martin Jemo 1, Aliyu Ibrahim2, Ado Yusuf 2, Chike Nwoke 3, Robert Clement Abaidoo1 1 International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria; 2Department of Soil Science, Faculty of Agriculture, Institute for Agricultural Research, Ahmadu Bello University, Samaru-Zaria    Kaduna State  Nigeria; 3Department of Agronomy, Osun State University, Osogbo, Nigeria.AbstractGrain legume crops such as cowpea, soybean, and groundnut are conserved as animportant component of cropping systems in several ago-ecological zones of WestAfrica (WA). They constitute important sources of dietary proteins to small-scalefarmers and have substantial contribution to soil fertility restoration. However,in growing areas of WC, legumes are cultivated often in unfavourable conditions,and are affected by several abiotic and biotic stresses such as lack of adequateand efficient rhizobial population, resulting in that legumes yields are only 45 %of the potential achievable yield in WC. We conducted field experiments in fourago-ecologies of WC to test whether rhizobial inoculants from commercial sourcescan improve is N2 fixation potential and increase yields of different grain legumesin WC agro ecological zones. The agro-ecological zones were the Sahel Savanna(Maradi, Niger republic), the Sudan Savanna (Shanono), northern Guinea Savanna(Kaya), and southern Guinea Savanna (Mokwa), all in Nigeria. Eight rhizobialinoculants: USDA-110, TSBF 560, Mix 531+442+560, 1495MAR, IRJ2180A, RACA6, Legume fix, His tick soybean. The design of the experiment was a split-plot,organized in randomized complete block with ten replicates. The results indicateda significantly higher nodule dry matter of soybean, groundnut and cowpeafollowing inoculation (P<0.05). Different responses to inoculation in relation tocrop species were observed. At Kaya, Legumes fix, 1495MAR, IRJ 2189A and TSBFmix significantly increased nodule dry matter of soybean compared to the controlwithout inoculation. At Shanono, Histick and RACA6 significantly increased thenodule dry matter of groundnut plants. The grain yield of the respective legumecrops significantly increased after inoculation in the four locations, except Maradi.Consistent yield increase across locations was observed following RACA6 product,which was a combination of several rhizobia strains from several host partners. TheRACA6 was further selected for the dissemination at a wider scale. 81
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa58. Securing sources of phosphorus: Alternative sources and improved management options of phosphorus in the humid tropics - A survey. Jeng Alhaji Bioforsk -Norwegian Institute for Agricultural and Environmental Research, NorwayAbstractAgriculture in Sub-Saharan Africa cannot succeed without a secured supply ofmineral fertilizers. This is particularly true of phosphorus, one of the key essentialmacronutrients. In most tropical soils, P is one of the main limiting plant nutrientsand its deficiency is a major constraint for better crop production. This is mainlyattributable to: (i) the low total P content in soil, (ii) the relative unavailability ofinherent soil P for plant uptake, and lastly, (iii) the relative speed at which appliedsoluble sources of P such as inorganic P fertilizers and manures become fixed orchanged to unavailable forms. It is clear that mining P minerals and spreading Pfertilizers over the landscape is not sustainable in the long run. Cultural practiceswhich can secure P sources and which conserve P should be made use of. Someof the measures necessary to adequately address the P problem include nutrientcycling through the recycling of crop residues, green manures, animal manures,domestic and industrial wastes integration into the cropping system of P-mobilizingplant species which show the ability to improve P uptake even from less labile Pforms and store P in the aboveground biomass even in excess of their needs; andbiological means by making use of mycorrhiza to help extract fixed P from deepsoils under low pH conditions.Sub-Saharan African agriculture must put a lotof emphasis on integrated soil fertility management (ISFM), which combines theuse of plant residues and inorganic P fertilizers exploiting their high potential forincreasing crop production and ensuring sustainability. Increased production andproductivity should never be based on addressing the constraints surroundinginorganic (mineral) fertilizers alone. 82
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa59. Evaluation of exotic, improved and local Musa germplasm in contrasting agro-ecological zones across Central Africa Kamira Muller1, Jules Ntamwira2, Svetlana Gaidashova3, Jean-Prosper Kanyaruguru4, Charles Sivirihauma5, Ndungo Vigheri6, Piet van Asten1, Guy Blomme7, Jim Lorenzen1, Inge Van den Bergh8, Emily Ouma1, Tony Muliele9 and Perez Mucunguzi10 1 International Institute of Tropical Agriculture, Kampala, Uganda; 2Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA), DRC ; 3RAB- ISAR (Institut des Sciences Agronomiques du Rwanda), Rwanda; 4Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA), CIALCA Bu- rundi; 5Bioversity International, CIALCA Project, Butembo, North Kivu, DR Congo; 6 Université Catholique du Graben, Butembo, NorthKivu, DR Congo; 7Bioversity Inter- national, Kampala, Uganda; 8Bioversity International, Montpellier, France; 9INERA, Rwanda; 10International Institute of Tropical Agriculture, Bujumbura, BurundiAbstract: The introduction of new banana (Musa) germplasm has been central to CIALCA’sintervention strategy in banana-based systems in Central Africa. It forms an integral partof technology packages aimed at overcoming a number of biotic and abiotic challengesthat face banana production. The abiotic constraints include low soil fertility anddrought stress, while the biotic constraints include pests (e.g. weevils and nematodes)and diseases (e.g. Xanthomonas wilt, banana bunchy top virus, Fusarium wilt and blackSigatoka). Musa field trials have been established since March 2007 at 20 locations acrossRwanda, Burundi, and North Kivu and South Kivu in DR Congo where the CIALCAR4D project has its action sites. The sites are located in different agro-ecological zoneswith contrasting altitudes, soils (fertility) and rainfall. Fifteen plants per variety (in 3 repsof 5 plants) are planted out per trial site. The genotypes tested include: exotic varietiessourced from the International Transit Centre (ITC), Leuven, Belgium (multipliedthrough the Agrobiotech lab in Burundi), NSH hybrids produced by the InternationalInstitute of Tropical Agriculture (IITA)/National Agricultural Research Organization(NARO) in Uganda (multiplied through the IRAZ lab in Burundi), and best local varietiesselected by the National Agriculture Research Systems in each respective country. TheITC-sourced varieties include tetraploid FHIA hybrids (‘FHIA-03’ and ‘FHIA-21’), whilethe triploid AAA-EA IITA hybrids include two cooking types (‘9750S- 13’/‘NSH-20’ and‘8386S-19’/’NSH-22’) and a juice/beer type (‘9518S-12’/’NSH-42’). Plantain genotypesadapted to high altitudes (e.g. ‘Obubit’ from Papua-New-Guinea) are also beingevaluated. These newlyintroduced varieties are tested against a large number of locallyavailable Musa genome groups (e.g., AAB plantain, AAA-EA beer, AAA-EA cookingand AAA dessert). Plantlet hardening was done at INERA, Mulungu, South Kivu, DRCongo; ISAR, Rubona, Rwanda, and the Agrobiotech and IRAZ nurseries in Burundi.Data from three cropping cycles were collected, comprising data on: plant performanceindicators at flowering and harvest, soil and leaf sample analysis, pest and diseaseincidence and severity, and sensory acceptability data. The first farmer participatoryevaluations saw particularly ‘FHIA- 21’, NSH (‘NSH20’ and ‘NSH42’) varieties and‘Obubit’ (AAB-plantain) selected. However, appreciation and performance of thesecultivars were strongly depending on region and the performance of the farmer selectedlocal cultivars that were used to compare against. 83
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa60. Fertilization of legume - maize sequences for improved productivity under variable rainfall conditions on resource poor farms in Eastern Zimbabwe Kanonge Grace1, Manzeke Grace1, Chikowo Regis1, Mtambanengwe Florence1 and Mapfumo Paul1,2 1 University of Zimbabwe, Harare, Zimbabwe; 2International Centre of Maize and Wheat Re- search (CIMMYT), Harare, ZimbabweAbstractLow yields of < 0.5 Mg ha-1 for staple maize have become synonymous withsmallholder farming systems in southern Africa. Major underlining causes includeinfertile soils, lack of external nutrient inputs and unreliable rainfall. A study wasconducted between 2008 and 2010 in Wedza district of eastern Zimbabwe, to evaluateoptions for fertilization of maize through grain legume rotations and combinationsof organic and inorganic nutrient sources. Maize yields of up to 5 Mg ha-1 wereobtained when an NPK compound fertilizer (7% N, 14% P2O5, 7% K2O) was co-applied with either cattle manure or woodland litter during the first season (2008/09).Sole application of a basal PKS blend (32% P2O5, 16% K2O, 5% S), NPK fertilizer orthe organic materials resulted in maize grain yields of ~2 Mg ha-1. When the differentfertilizer combinations were applied to cowpea, similar trends were observed onboth cowpea and the succeeding maize crop. Combinations of NPK fertilizer or thePKS blend with organic nutrient sources produced high yields of above 2.8 Mg ha-1during the 2009/10 season, despite poor rainfall distribution during that season,compared to <1.2 Mg ha-1 obtained when the nutrient sources were applied solely.When the fertilization options were tested by farmers on cowpea in their own fields,grain yields exceeding 1.5 Mg ha-1 were achieved, with the farmers managing to sellsurplus grain to a local private company. Positive gross margins were obtained forall tested options, with the exception of continuous fertilized maize and maize afterunfertilized cowpea. We concluded that co-application of P-based fertilizers andlocally available organic nutrient sources improve legume and maize productivityhence food security at local level, and assures farmers of much needed income, evenunder variable rainfall conditions. 84
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa61. Dynamics of Banana Xanthomonas Wilt in Burundi: Case study of Cankuzo and Makamba Province Kantungeko Déo1, Guy Blomme2 and Pascale Lepoint3 1 Université du Burundi, Faculté des Sciences Agronomiques, Bujumbura, Burundi; 2 Bioversity International, Kampala, Uganda ; 3 Bioversity International, Bujumbura, BurundiAbstractSince December 2010, cases of Xanthomonas wilt of banana (caused by Xanthomonascampestris pv. musacearum) are being reported every month to local authorities fromthe four corners of Burundi. This devastating bacterial disease, causing major losses inproduction and rendering bunches unfit for human consumption, has been reportedin numerous communes of Bubanza, Cankuzo, Makamba, Muyinga and Ruyigiprovinces. Plants can be infected either by insects via the inflorescence, contaminatedgarden tools or soil-borne inoculum. In addition, animals such as birds, bats andruminants may transmit bacteria from plant to plant. Burundi’s farming systems,recent political crisis, topography and associated contrasting agro-ecologies are achallenge to the implementation of efficient and adapted management strategies.Farmer’s awareness, putative routes of introduction, varieties affected, and incidenceof the disease were recorded through one-on-one farmer discussions in two contrastingprovinces bordering Tanzania (Cankuzo, 1,800 masl, versus Makamba, 1,350 masl).First observations reveal that the disease has hit the most vulnerable stratum of thepopulation consisting of isolated, illiterate (30%), widowed (11%) and large (mean6.6 individuals) households living off their agricultural production, where bananaplays a key role as a subsistence and cash crop. Results indicate that farmers areunfamiliar with the modes of transmission and management options of the disease;sometimes confounding Xanthomonas wilt and Fusarium wilt. Banana is typicallycultivated in a season-dependant intercropping system (with taro, beans, sweet potatoand maize depending on site) with ‘Igisahira’ (AAA-EA, cooking), ‘Igitsiri’ (AAA-EA, cooking) and ‘Kayinja’ (ABB, beer) grown as the most common varieties in allsites surveyed. Farmers date the first cases of bacterial wilt back to 2008 and 2010 inCankuzo and Makamba, respectively; with losses in production ranging from 30%(Cankuzo province, Gisagara commune, colline Ramba, sous-colline Kigoti) to 65%(Makamba province, Gisenyi commune, sous-colline Nyamatugu), and all varietiesbeing affected. Cases of insect-vectored infection (observation of symptoms on male-bud and/or bunch) were significantly higher at lower altitudes and on ‘Kayinja’. Nocoping mechanisms were observed, and farmers were concerned for their future. Atimely response from government authorities, NGOs and donors is urgently requiredto raise awareness via appropriate channels at all stakeholder levels, and to provideadapted management strategies and coping mechanisms if the impact of the diseaseis to be minimized. Early de-budding, prompt removal of pseudostems with earlyinflorescence infections, and a no-tool policy are simple, cost-effective measures thatcan be put into place pending more labor intensive and time-consuming uprooting ofmats when disease incidence and severity increase. 85
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa62. Quality Assessments of Banana Beverages in Rwanda Kanyana Immaculate1, Ouma Emily1 and Van Asten Piet1 1 International Institute of Tropical Agriculture, Bujumbura, BurundiAbstractBananas play a key role in Rwanda, contributing to rural populations’ householdfood security and revenue. The beer banana cultivars are a common sourceof household income as it is transformed into beverages which is then sold toconsumers or used for social and ceremonial events. Per capita consumptionof banana beverages in 2000 in Rwanda was estimated at 1.2Lts per day. Theprocessing and handling of these beverages is dominated by smallholdersusing artisanal methods. No standards and control measures have been setup by the government regulatory authorities yet hygiene and sanitation ofprocessing equipments and personnel are often very poor. A few processorsexist at association/cooperative and small scale industrial levels utilizing semi-mechanised and mechanized equipment. This paper examines the quality ofbanana juice and beer by undertaking a microbiological assessment of 46 samplescollected at different levels along the market chain in Kigali, Butare, Gisenyi andRwamagana districts in Rwanda. The microbial and physical chemical aspectsassessed include total plate count (PCA), lactic acid bacteria (LAB), mould andyeast, coliforms, pH, total acidity (TA) and total soluble solids (TSS). The resultsshow high total bacteria and coliform counts for juice samples associated withartisanal processing and those drawn from plastic jerrycans. High counts of totalbacteria and coliforms were also observed for the banana beer samples, indicatingpoor sanitation during processing and handling with the possibility of sewagecontamination and therefore salmonellae or other intestinal microorganismsmight be present. Coliforms were however not detected for juice and beersamples drawn from the industrial processor. Recommendations; documentationof procedures to improve the quality of banana beverageand how these can beimplemented by processors and the regulatory authorities are then highlighted. 86
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa63. Rapid and easy molecular detection of Cassava Mosaic Disease ACMV agent and preliminary optimisation of a chemotherapy treatment to sanitise cassava infected genotypes Kanyange M.C.1 and Busogoro J.P.2 Institut des Sciences Agronomiques du Rwanda (ISAR), Kigali, Rwanda 2Belgium 1 Technical Cooperation, IPM project, Kigali, RwandAbstractUsing cassava planting materials free of begomovirus infection constitutes a principalcomponent of the cassava mosaic disease control strategy. This management strategyrequires availability of sensitive detection methods to identify and discard infectedplanting materials. By the present work, it was undertaken to optimise simplifiedmolecular detection methods directed to CMD causing begomoviruses. Preparationof the template materials was performed by scraping the PhytoPASS on cassava leavesto harvest plant debris before suspending them in a KAJI buffer. The obtained crudeextracts’ suspension was directly used as the template material for PCR reactionsperformed to detect CMD begomoviruses into cassava tissues. Amplification ofDNA fragment corresponding to ACMV pathogen was realised very easily by usingthis newly developed system. Moreover, this detection possibility was also obtainedwith in vitro propagated cassava plantlets even no specific symptoms of cassavamosaic disease were visible on young plantlets. For sanitation of cassava infectedwith CMD agents, explants of ACMV infected cassava plants were treated bychemotherapy through tissue culture on in vitro medium amended with ribavirinas antiviral molecule. After 5 weeks incubation underchemotherapy conditions,application of the molecular detection method revealed that the so treated plantletswere free of ACMV infection while the control in vitro plantlets remained infectedas revealed by the PCR amplification of the virus specific DNA fragment. 87
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa64. L’insecurite alimentaire Chronique au Burundi: La banane et les legumineuses comme filieres porteuses. Kanyaruguru Jean Prosper1, Niyongere Clestin2, Niyuhire Marie Chantal2, Emmanuel Njukwe1, Bernard Vanlauwe3, Piet VanAsten4 and Guy Blomme5 1 Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA), CIALCA Burundi; 2Institut des Sciences Agronomiques du Burundi (ISABU), Burundi; 3 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 4International Institute of Tropical Agriculture, Kampala, Uganda; 5Bioversity International, Kampala, UgandaAbstract :L’insécurité alimentaire chronique au Burundi : La banane et les légumineuses commefilières porteuses promues par le Consortium CIALCA. J.P. Kanyaruguru, C.NiyongereEn pleine région des Grands Lacs Africains, le Burundi est un pays des tropiques aucœur de l’Afrique avec une population dépassant légèrement les 8 Millions d’habitantssur une superficie de 27 834 Km2 (environ 81 fois la RDC voisine). Ancienne colonieBelge, il vit essentiellement de l’agriculture qui est la principale source de revenues.Les cultures d’exportation faisant entrer des devises pour le pays sont le café et lethé introduites dès la période coloniale. Il reste faiblement industrialisé. La rechercheagronomique est essentiellement assurée par l’Institut des Sciences agronomiques duBurundi (crée du temps colonial) et la Faculté d’Agronomie de l’Université du Burundi.Il existe aussi un Institut de Recherche Agronomique et Zootechnique (IRAZ) ayant lamission de coordonner la recherche dans la Communauté Economique des Pays desGrands Lacs (CEPGL) réunissant le Burundi ; le Rwanda et la République Démocratiquedu Congo.Plongé dans la crise socio économique depuis 1993 (18 ans), le Burundiconnait des déficits alimentaires chroniques bien qu’il soit potentiellement productif. Leburundais est réputé grand consommateur du haricot et de la banane qui sont d’ailleursles principales cultures du monde rural.Cependant, la population burundaise estconstamment confrontée au manque de semences de qualité et de matériel de plantationen quantité et en qualité suffisantes. Pour la banane, les 2 seuls laboratoires privés devitro culture ne parviennent pas à satisfaire les besoins et souvent on a recours aux rejetsconventionnels avec tout le cortège de risques d’introduction de maladies que ce matérielde plantation comporte. CIALCA a introduit la technique de macropropagation qui estefficace dans le contexte burundais et à portée des agriculteurs réunis en associationou individuellement.Parallèlement à cette technique, CIALCA intensifie la recherchesur le GIFS pour une amélioration de la fertilité des sols d’une part et de la promotionde la nutrition d’autre part. Ainsi, des associations culturales bénéfiques à base delégumineuses (manioc, maïs,…) sont vulgarisées dans les ménages encadrés dans leszones mandataires de CIALCA. La carence d’intrants organiques et minéraux restecependant une difficulté majeure. Les causes majeures à la base des déficits alimentairesau Burundi sont de 4 ordres :Le manque de semences de qualité ,la faible fertilité des sols,les aléas climatiques et la pression des maladies et pestes.CIALCA essaie d’apporterdes solutions en proposant une série de ses produits aux agriculteurs à travers despartenariats avec des organisations ayant des assises communautaires solides (sitessatellitaires) pour la vulgarisation des technologies en milieux paysans. 88
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa65. Banana genotype composition along the Uganda-D R Congo Border: a gene pool mix for plantain and highland bananas Karamura Deborah1, Ocimati Walter1, Tendo Reuben2, Jogo Wellington1, Walyawula Stephen4 and Karamura Eldad1 1 Bioversity International, Kampala, Uganda; 2Makerere University, Faculty of Sci- ence, Kampala, Uganda; 4National Agricultural Research Laboratories, Kawanda, UgandaAbstractLandraces contain many genotypes which makes them a good source of genes forcrop improvement and hence the need for sourcing and conserving it. Bananasampling and collection was carried out along the Uganda-Congo border whichis homes to the largest insitu diversity collection of Musa AAA ’Lujugira-Mutika’(Uganda) and Musa AAB ‘plantains’ (DRC). The objectives of the collectingmission were to capture Musa genetic resources border districts, sample and collectunique Musa germplasm and assess the cross-border genotype composition. Acombination of stratified purposive sampling and respondent-driven snowballsampling were employed. Sub counties, parishes and villages with high Musaproduction were purposively sampled in the 3 districts. A descriptor, checklistsand the germplasm catalogue for Mbarara regional collection were used to studythe existing banana diversity insitu. The minimum set of descriptors for Musatechnique was applied to the ‘unique’ collected materials to assess its capacity todiscriminate cultivars at the subgroup level. GPS data was obtained for reference.Results showed that 44% of bananas found in Arua and Zombo were cooking types(Musa AAA ‘ Lujugira-Mutika’), 44 % dessert (Musa AAA, AAB), 9% roasting types(Musa AAB ‘plantains’ ) and 3% beer bananas (MusaAB, ABB). Musa diversityinBundibugyo was 49% cooking types, 27% roasting types, 13% dessert and 11%beer and juice types. Eighteen new genotypes were collected and among themwere two suspected diploids collected from Arua, ‘Bura’ and ‘Menvu’. From the 31minimum descriptors, only 25 were used with an addition of two other descriptorssince they were able to discriminate the clones which had been collected. Of the sixdescriptors which were not used, two of them were not discriminative enough todifferentiate the clones. The descriptors were useful in separating the Musa genomegroups and to a less extent the subgroups. 89
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa66. Effects of separate and combined additions of compost and fertilizer on crop yields in Arsi Negele, south-central Ethiopia Karltun Erik1, Mulugeta Lemenih2 and Motuma Tolera3 1 Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden; 2International Water Management Institute, Addis Ababa, Ethiopia; 3Wondo Genet College of Forestry and Natural Resources, Shashemene, Ethio- piaAbstractLocally made compost presents an alternative to compensate for reduced fertilizerapplications. The objective of this study was to assess the potential of compost as analternative soil nutrient amendment and it’s effect on crop yield in agro-ecosystemin the highlands of Ethiopia. The experiments were conducted in Arsi-NegeleDistrict, in a sub-humid agro-ecosystem. Soils of the area are Humic Andosols.The experiment involved four treatments: compost (C) (farmer made compost),fertilizer, i.e. DAP + urea (F), control (Co) and half compost and half fertilizer (CF).The experiment was replicated across farm fields of four households intended tocapture variations in soil status- and farm household management practices. Oneach field, a randomized complete block design with three replications was used.The experiment was monitored for four subsequent years by applying the sametreatment each year. Maize was grown on three out of the four years, while beanson two fields, potato and wheat on one field each were grown during year two ofthe experiment. Yield and soil related data were collected and part of the data isreported here. During the first year of the experiment, maize yield performancefollowed the order CF > F > C >Co. This was consistently reversed to the order CF> C > F > Co during the latter two years. Maize yield gains relative to the control ofup to 97% was recorded for the CF combination, and the minimum relative yieldgain during the three years was 38%. The compost treatment resulted in up to 46%yield increment relative to the control. Similarly, bean yields followed the order CF>C>F> Co, with 44% relative yield gain in the CF experiment over the control. Potatoand wheat yields were higher for the compost followed by fertilizer treatments. Ourdata show an evident synergy between compost and fertilizer applications on cropyields. The effect on soil properties, however, appear to be strongest in the composttreatment. 90
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa67. Effect of Lime and Nitrogenous fertilizer Rates on Yield Components, Grain Yield and Nitrogen Use Efficiency of Malt Barley (Hordeum vulgare L.) in Bekoji, Oromiya Regional State, Ethiopia Kebede Fassil1 and Belay Yebo2 1 Department of Land Resource Management and Environmental Protection Mekelle University, Mekelle, Ethiopia; 2Bekoji Agricultural, Technical, Vocational Edu- cation and Training College, Oromiya Regional State, EthiopiaAbstractA research was conducted in KulumsaAgriculturalResearchCenter, Bekoji subcenter in June 2009 with the objectives of studying the effects of nitrogenous fertilizerand lime rates on yield components, grain yield and nitrogen use efficiency of maltbarley (Hordeum vulgarae L.). Four lime and four nitrogenous fertilizer rates werearranged in a randomized complete block design in three replications. Agronomicparameters were collected and analyzed. The results indicated significant (P < 0.05)difference in grain yield, number of tillers, and harvest index among the nitrogenousfertilizer rates and the lime rates. Thousand kernel weight and population weresignificantly different for nitrogenous fertilizer rates but non-significant for limerates.The highest yield (4.67 t/ha) was obtained at 69 kg ha-1 and lowest (3.83 t/ha) was obtained at 23 kg ha-1. Furthermore, the highest marginal profit (7644 Birr)was obtained at rates of 69 kg N ha-1 and 2.5 t CaCO3 ha-1. The highest benefit tocost ratio (1.42) was obtained from 23 kg N ha-1 and 2.5 t CaCO3 ha-1; followed by 69kg N ha-1 and 2 t CaCO3 ha-1 with benefit to cost ratio of 1.41 Birr/Birr and the thirdbenefit to cost ratio (1.29) was obtained from 46 kg N ha-1 and 2.5 t CaCO3 ha-1. Thetreatment with high benefit cost produced relatively cheaper cost as compared tothe rest treatments. Therefore; the nitrogenous fertilizer and lime rates of 23 kg Nha-1 and 2.5 t CaCO3 ha-1 were the best in terms of the economic efficiency. Hence,this study recommends 23 kg N ha-1 and 2.5 t CaCO3 ha-1. 91
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa68. Determination of limiting nutrients using a spatially explicit approach Kihara J.1, Nziguheba G.2, Huising J.1, Vanlauwe B.1, Palm C.2, Kabambe V.3, Sayula G.4, Coulibaly A5., Amapu I.6 and Esilaba A.7 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 2Earth Institute, Columbia University, NY, USA  3 Bunda College of Agriculture, University of Malawi, Lilongwe, Malawi; 4Selian Agricultural Research Institute, Arusha, Tanzania; 5Institut d’Economie Rurale, Bamako, Mali;  6Institute for Agricultural Research, Ahmadu Bello University, Department of Soil Science, Zaria, Nigeria; 7Kenya AgriculturalResearch Institute, KARI H/Q, Nairobi,Kenya AbstractTheAfrican Soils Information Service (AfSIS) implemented diagnostic trialsin 10different sites within 5 countries of sub-Saharan Africa namely Kenya, Malawi,Mali, Nigeria and Tanzania to identify soil fertility constraints to crop production.In each site, 23 to 32 trials were conducted within 10 km by 10 km sentinel sites. Thetreatments tested included a control, a full NPK treatment, 3 treatments in which theN, P and K nutrient were omitted at a time from the full NPK treatment, and onetreatment in which multinutrients (Ca, Mg, micronutrients) were added to the fullNPK. Two optional treatments, manure or lime were included depending on theavailability and pH level in case of lime. Test crop were maize and sorghum. In mostsites, nutrient limitation was in the order N>P>K except in more acidic soils (KontelaMali for example) where P was more limiting than N. Nutrient omission resulted insignificant yield reductions of 30% for N and 20% for P on average, relative to fullNPK while K showed no effect in most sites. For maize growing sites, applicationof lime (500 kg/ha) increased grain yield by up to 500 kg/ha in acidic sites whilemanure resulted in even higher increases (600 kg/ha) in comparison to the full NPKtreatment. The effect of multi-nutrients was low and insignificant in most cases.In each site, amendment treatments (lime, manure and multi-nutrients) that hadat least 300 kg/ha more grain than in NPK treatments constituted 40 to 75% of allcases indicating wide existence of non-responsive soils that can be improved withsimple management. Similarly to other mapped soil constraints, the magnitude ofthe yield differences between control and NPK was high in high erosion risk areasas compared to lower erosion risk ones. These results are compared with data fromsimilar trials conducted beyond AfSIS sentinel sites, such as those from CIALCAproject. Suggestions for minimum treatments needed to diagnose soil constraints,and analysis framework for such trials are made. 92
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa69. Determination of appropriate rate and mode of applying lime to acid soils of western kenya “targeting small scale farmers Kiplagat J.1, Okalebo J.R.2, Serrem C.K.2, Mbakaya D.S.3 and Jama B.4 1 Moi University, Eldoret, Kenya; 2Department of Soil Science, School of Agriculture and Biotechnology, Chepkoilel University College, Eldoret, Kenya; 3Kenya Agricultural Research Institute (KARI), Kakamega, Kenya; 4Alliance for a Green Revolution in Af- rica, Nairobi, KenyaAbstractWestern Kenya is experiencing declining food production as a result of increased Soilacidity in smallholder farms. To counteract this, KARI Kakamega and MoiUniversityhave demonstrated the potential of using agricultural lime, inorganic fertilizers andMinjingu rock phosphates to address the food security problem. Despite this, the use oflime is still low due to: unawareness on lime effectiveness, and importance and modeof application by small holder farmers. The study aimed at comparing three possiblemethods of applying lime (spot, band and broadcast methods) to acid soils at 4 differentrates of application (0, 2, 4 and 6 t/ha) in terms of maize performance in the twotarget districts of Western Kenya. On farm experiment was conducted in two sites inSiaya district and two sites in North Kakamega district, laid out in a 3x4 factorial inRCBD with 4 replications. Lime was applied but with phosphorus as (TSP) and nitrogenas (CAN) applied as blankets at the rate of 26kg/ha P and 75kg/ha N. Highest grainyield increased on average from 1.67 t/ha in control to 4.37 t/ha from application of6 t/ha lime by broadcast method in Siaya district for two seasons (2010 long rains andshort rains). While in Kakamega north district it increased from 1.49 t/ha to 3.14 t/ha with 6 t/ha lime applied by band methodThe labour costs per hectare required forthe application of lime differed with method, the broadcast method was costly becausea farmer has to incorporate lime in the entire plot, while for the other methods, onlythe applied areas i.e. band rows and hills are tilth. Therefore, with the current resultsit can be inferred that the methods of applying lime for the two districts vary due todifferences in soil type and climatic conditions. 93
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa70. Dissemination and use of Cassava Chippers in Cameroon Kirscht Holger1 and Njukwe Emmanuel2 1 International Institute of Tropical Agriculture (IITA), Cameroon; 2International Insti- tute of Tropical Agriculture (IITA), Uganda office, Kampala, UgandaAbstractIn 2007 the International Institute of Tropical Agriculture (IITA-Cameroon) andthe IFAD funded Roots and Tuber Program of Cameroon (Programme Nationalde Développement des Racineset Tubercules - PNDRT) started to promote anddisseminate cassava chipping machines in the main cassava production zones ofCameroon. Beneficiaries of the programme were rural agricultural associations towhom the machines were assigned. They are supposed to store and maintain thechipper and they control the access of their members to the machines. In the regionsof action, women account for about two thirds of all members rural agriculturalassociations. Women are the main cassava producers and transformers in Cameroonand are playing important roles as ordinary members or part of the board. Togetherwith or preceding the dissemination of the chipping machines, improved cassavavarieties, which carry certain resistance against pests and diseases, and thereforeallow higher yields, were introduced by IITA and its partners. It was one of theprograms targets to especially facilitate the transformation of this improved cassavavarieties. It was aimed at producing storable and marketable products with agood price to weight ratio, thus increasing the storage options and reducing costsfor transport to the local and regional markets. It was assumed, that particularlywomen would like to benefit from the chipping machines because of the relativelylow labourinput necessary for the processing and the small operational costs.Nevertheless, the survey revealed, that men show a considerable interest in themachines, which was reflected in the high number of male beneficiaries in the survey.In 2010 the distribution of the chipping machines was completed and 25 villagesreceived about 100 manual machines, developed by IITA and produced by localfabricators. In addition motor driven machines were delivered to selected villages.This poster presents results of a socio-economic survey about the acceptance ofthe cassava chipping machines by the local population and the benefits they havebrought to the participating village communities. 94
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa71. Maize Yield and Striga Emergence Response to Varying Desmodium Trimming Regime in the “Push- Pull” Intercropping System in Western Kenya Koech-Njeri, M.1, J.R. Okalebo1, C.O. Othieno1, P. Pypers2, B.Vanlauwe2, Z. Khan3 and J.A. Pickett4 1 Moi University, Eldoret, Kenya; 2Tropical Soil and Biology Institute of the Interna- tional Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 3International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya; 4Rothamsted Re- search, Harpenden, Hertfordshire, United KingdomAbstractLow soil fertility, cereal stem borers and Striga weeds are the major constraints tothe production of maize which is the major staple food in western Kenya. “Push-pull” technology (PPT) defined as maize intercropped with a stem borer moth –repellent legume, Desmodium, and surrounded with an attractant host plant, Napiergrass planted as a trap plant for stem borers has been described as an appropriateinnovative technology capable of addressing maize yield losses caused by theabove constraints in this region. This study tested the hypothesis that inclusion ofDesmodium spp into maize cropping system and varying its trimming regime mayprovide a substitute for inorganic nitrogen fertilizers and control striga whichwould result to enhanced crop growth and yield. The tested technologies includedtwo Desmodium spp [Desmodium uncinatum Jacq and Desmodium intortum Urb.)intercropped with maize, mono maize with urea (90 kg N /ha), mono maize withouturea and three Desmodium trimming regimes (9, 12 and 18 weeks after planting maize(WAPM) in two sites in western Kenya with contrasting soil fertility levels during4 consecutive seasons. Maize grain yields obtained from three consecutive seasonswere independent of Desmodium trimming regimes. Desmodium spp increased maizegrain yield above mono maize without urea from the second and third season in theless (Busia) and more fertile (Siaya) sites respectively. Desmodium uncinatum resultedto higher maize grain yields compared to Desmodium intortum but both Desmodiumspp reduced striga emergence from the second season in both sites. 95
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa72. Irrigation Livelihoods Heterogeneity and Water Management in Bua Watershed, Central Malawi: Policy Implications for Irrigation Development Kopa-Kamanga Tawina Jane1 and Jose Kjosavik Darley2 Research & Development Section; Department of Irrigation, Mzuzu, Malawi; 1 Noragric-Department of International Environment and Development Studies 2 Norwegian University of Life Sciences, NorwayAbstract:A study was conducted in Nkhotakota, Malawi, among Bua watershed irrigationhouseholds to determine the economic importance of irrigation in relation to otherlivelihood activities, and examine institutional arrangements for irrigation and watermanagement. The study also explored the determinants of household livelihooddiversity and factors that affected performance of single production or livelihoodcomponents. A livelihoods approach was adopted for the study. The results indicate that`irrigation livelihoods’ are heterogeneous in that some are more irrigation based thanothers, as reflected in varying benefits accrued from irrigation as a single productioncomponent. They further show that most irrigation households venture into diverselivelihood activities, notably, livestock production, rain-fed crop production, sellingdried fish. The study suggests that some livelihood components are water dependentunlike others, e.g. livestock production is water dependent while selling of groceriesis not. Thus water was noted to be a major constraint to production of the livelihoodcomponents, among other constraints such as access to credit, land, labour and capital.Therefore, dichotomising these livelihood activities between water-dependency andnon-water dependency provides a useful framework for analysing inter- and intra-household competing water uses. The study reveals that irrigation, like most water-dependent activities, is less profitable to non-water dependent households contributingonly 24 % to their livelihoods than it is to water-dependent households with 62 %contribution. The study further suggests that as households make decisions on resourceallocation, rationally more resources are allocated to more profitable activities. It alsoshows that water-dependent households have more diversified income sources andrelatively less income than non-water dependent households who are better off by 29%. Furthermore, irrigation seems to play a role in reducing income inequalities amongthe water-dependent households but it has no significant effect among non-waterdependent households. The results of this study argue against the common view thatirrigation households are dependent on irrigation-based livelihoods. It shows that thisview overshadows the water-dependency dichotomy of livelihood activities whichhas implications for water management. The study concludes that integrated waterresource management starts at household level as households efficiently allocatewater to diverse uses. Therefore, placing irrigation within the livelihood frameworkwill promote the integrated approach as well as ensure effective and result-orientedpolicies. Additionally, a household approach would yield positive results in improvingrural livelihoods and presumably performance of each single production component.However, as this is piloted in some sites within my research area, it would be prematureto propose and let alone evaluate interventions that would improve the efficiency,profitability, quality and productivity of the production components. 96
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa73. Impact of agroforestry and other land uses on microbial communities and functional capacity of soil bacteria in Kenyan highland soils Lagerlöf Jan1, Lena Adolfsson1, Gunnar Börjesson2, Knut Ehlers3, Glòria Pallarès Vinyoles1 and Ingvar Sundh1 1 Swedish University of Agricultural Sciences, Sweden; 2Department of Water and En- vironmental Studies, Linköping University, Linköping, Sweden; 3Institute of Plant Sci- ences, Swiss Federal Institute of Technology (ETH), Zürich, SwitzerlandAbstractThe objective of this study was to compare the microbial community and potentialfunctional capacity of soils under different land uses and to correlate this to otherchemical and biological soil properties. The hypotheses were: 1) Microbial biomassand diversity as well as the functional capacity of the soil decreases with intensifiedcultivation. 2) Microbial biomass, diversity and functional capacity can be restoredby active soil and land management in agroforestry practices. Replicated samplesfrom undisturbed natural forest, forest plantations, agroforestry fields, agriculturalfields and eroded soil were taken from farms on the slopes of Mount Elgon inwestern Kenya. Agroforestry fields had earlier been agricultural fields without trees.Agroforestry practise was introduced during the latest 20 years with support from theSwedish NGO Vi Agroforestry Programme. Functional capacity of soil bacteria wasmeasured as potential substrate utilization studied by Biolog Ecoplates, where theutilisation of 31 different substrates is measured. Microorganism communities werecharacterised by PLFA analysis and by determination of microbial C and N. Othersoil properties measured were soil texture, moisture, pH, total N and C, extractableP and nitrate.The results followed a pattern with eroded and agricultural land onthe low end of the scale and agroforestry and planted and natural forest on thehigh end concerning bacterial substrate utilisation capacity measured by EcoPlate.All 31 substrates were metabolised in all treatments, i.e. functional diversity didnot differ among treatments but so did substrate utilisation rate. Soil pH and Nand C contents, as well as microbial C and N and total PFLA had similar patternamong treatments; the values increased with decreasing disturbance and increasedsoil organic matter content. A PCA analysis showed a significant difference betweennatural forest and the other land uses for chemical and microbial properties, whileagroforestry overlapped with both agriculture and forest plantation but wasdifferent from eroded land. These results indicate that the substrate utilisationcapacity of soil bacteria was similar in land with similar vegetation and thus thatthe functional capacity of the soil can be restored by active soil management, suchas agroforestry practices. The advantages and limitations of the methods used andmicrobial community composition are discussed. 97
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa74. La qualité de la chaux, le chaulage une nécessité pour l’intensification agricole en sols acides des RGLACs. Lindiro Revelien1, Breman Henk1, Nzohabonayo Zacharie1 and Hatangimana Thomas1 1 International Fertilizer Development Centre (IFDC), CATALIST project, BurundiAbstractLe projet CATALIST est  exécuté au Rwanda, au Burundi et la RD Congo (Provincesde Kivu). L’approche de la Gestion Intégré de la Fertilité des Sols (GIFS) qu’utiliseCATALIST pour déclencher l’intensification agricole dans la RGLAC, fait entreautres attention aux sols acides.  Le problème le plus sérieux de ces sols acidesconcerne la toxicité aluminique, où la présence des (hydr)oxydes d’Al et de Fe faitque la structure physique du sol acide est bonne. La bonne gestion des sols acidesdans les tropiques, fait appel au chaulage, aux engrais non acidifiant et au respectdes principes et technologies de la GIFS pour un système de production durable. Nosétudes et nos expériences nous ont convaincu qu’il suffit de corriger le pH à un niveaude 5.2. Des tests participatifs de contrôle d’acidité ont été conduits par CATALISTavec des organisations de développement et de producteurs. Les résultats montrentune augmentation des rendements de 5 à 12 % avec l’utilisation saisonnière de CAN(Carbonate Ammonium Nitrate) au lieu d’urée dans des formules d’engrais, parrapport aux mêmes formules ayant urée comme composant. L’augmentation grâceaux derniers engrais est de 15 à 23 % avec une dose unique de chaux pour unepériode de 3 à 4 ans. Ainsi, l’efficacité agronomique (EA) et la Ration Valeur Coût(RVC) des engrais s’améliorent.  Un problème sérieux est le manque des normesstandard de la chaux et un manque de liaison entre prix et qualité. La correctiond’une acidité donnée visant à ramener le pH du sol à 5.2 demande des quantités trèsdifférentes de chaux en dépendance des sources, et le prix de chaulage peut devenirexorbitant. Les résultats avec la meilleure chaux obtenue est bien supérieure auxvaleurs moyennes : une augmentation de 30% pour le rendement, 72% pour l’EA et60% pour la RCV des engrais.  98
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa75. Evaluation of pre-screened sweet potato germplasm for biomass production under different cropping regimes and their potential as dual-purpose varieties in Kenya Lukuyu B.1, J. Kinyua2, S. Agili3, C.K. Gachuiri4 and J. Low3 1 International Livestock Research Institute (ILRI), Nairobi, Kenya; 2School of Informa- tion Communication Technology, Central University of Technology, Free State, South Africa; 3International Potato Center (CIP), Nairobi, Kenya; 4University of Nairobi, Nairobi, KenyaAbstractSix cultivars of sweet potato were grown on farms in five sites located in central,south and north rift valley regions of Kenya under rain fed conditions. Two siteseach were located in the high and medium altitude areas while one was located inthe low altitude area. All sites have warm climates except one in the high altitude thatexperiences cold climate. The cultivars included 103001, Gweri, Kemb 23, Kemb 36,Naspot 1 and Wagabolige. The vines of each variety were harvested at two differentstages (75 and 150 days) post planting. The 75-day treatment was ratooned again at150 day post planting. Agronomical observations were carried during the long rainsseason 2010. Harvesting vines twice significantly (P<001) increased forage yields butsignificantly (P<001) reduced root yield in all varieties. The Gweri variety realizedthe highest forage but lowest storage root yields indicating its potential as a foragevariety. Kemb 23, Kemb 36 and Napsot 1 produced appreciable amount of vines andhighest root storage yield making them potential dual purpose varieties. The effectof agro ecological zone (AEZ) varied with time of harvest. There was less interactionbetween the cultivars and the AEZ at 75 day harvest. Gweri, Kemb 23 and Kemb36 showed some level of interaction with AEZ at 150 day harvest. Across AEZs dryvine yields (t DM/ha) ranged from 2.3,5.3 in 103001, 2.4,8.5 in Gweri, 1.9,8.4 in Kemb23, 1.4,7.8 in Kemb 36, 1.8,7.4 in Naspot 1 and 1.2,7.4 in Wagabolige and dry storageroot yields (t DM/ha) ranged from 0.7,2 in 103001, 0.3,1.2 in Gweri, 0.4,2.5 in Kemb23, 0.9,1.5 in Kemb 36, 1.7,2.3 in Naspot 1 and 0.5,1.8 in Wagabolige. The storage rootyield: vine (R/V) ratio was determined by dividing the total root by vine dry matteryield). The R/V ratios significantly (P<005) varied between cultivar and harvestingstage. The mean R/V were 1.8 in 103001, 0.2 in Gweri, 0.6 in Kemb 23, 0.5 in Kemb36, 1.5 in Naspot 1 and 0.7 in Wagabolige. The R/V ratios obtained classifies 103001and NASPOT 1 as low forage-high root production varieties, Wagabolige and Kemb36 as low dual purpose and Kemb 36 and Gweri as forage varieties. Preference ofdifferent growers for forage vs. dual purpose types appears to vary by location. 99
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa76. Improving Soil Fertility, Productivity and Livelihoods of Smallholder Farmers in Tanzania through Intensification and Diversification of Pigeon pea Cropping Systems Lyimo, S.D.1, Ubwe, R.M.1, Mligo, J.K.2, Mushi, P.P.1, and Owenya, M.Z.1 Selian Agricultural Research Institute (SARI) Arusha Tanzania; 1 2 Ilonga Agricultural Research Institute (Ilonga ARI) Kilosa, TanzaniaAbstractSmall scale farmers in Tanzania are constrained by declining soil fertility, landdegradation and poor seed resulting into decreased food productivity and lowincome. The project aims at improving productivity of the maize-based croppingsystem through intensification of pigeonpea in three zones of Tanzania. A keyfeature of the systems intensification was the use of P-micro-dosing by using P-basedfertilizers to both the maize and pigeonpeas which would increase the pigeonpeasbiological nitrogen fixation ability resulting into increased productivity of bothcrops, and thus contributing to food security, income and improved livelihood ofthe farmers.The project started in 2010 season where 100 mother trials each withfour sub-plots measuring 10mx 10m each were planted to maize intercropped withpigeonpeas at a spacing of 100 cm x 50cm with two plants per hill. Three plots ateach site were applied to P- fertilizers at planting from either Minjingu granular (0%N, 13%P, 0% K), Minjingu Mazao (10%N, 9%P, 0%K), or Di-ammonium Phosphate(DAP) (18%N, 20 %P, 0%K), at the rate of 20 kg P/ha. The fourth plot was plantedwithout fertilizer as farmer’s practice.Overall, use of P micro-dosing doubled yieldsof both maize and pigeonpeas from 1.5 tons to 3.5 tons/ha and 0.6 tons to 1.5 tons/harespectively. The average net income from the fertilized treatments was 1,272,000/=Tshs per ha compared to 380,300/= Tshs per ha from the farmers’ practice. Morethan 5,000 farmers/stakeholders were reached through various promotionalactivities. The above results sensitized farmers to adopt the technology this seasonthrough Going Beyond Demos Initiative (GBDI) where farmers bought 11,000 kgsof pigeonpeas seed and used about 30,700 tons of fertilizers. The preliminary resultsindicated that the Minjingu fertilizers showed more or less similar responses asDAP and hence their use should be promoted in the country. 100
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa77. Risk and Hazards Assessment during the Production of Bananas and Plantains Seedlings Derived from Stem Bits or Fragments (PIF-Technique) Agnes Lyonga1 and Cletus C. Fonbah1 1 African Research Center on Bananas and Plantains (CARBAP), CameroonAbstractOne of the pressures of agriculture in sub-Saharan Africa is the weak productivenessdue to the lack of adoption of technologies and techniques of production withhigh output by small-scale agrarian farmers. For example, the production ofclean planting materials in large quantity constitutes the major problems farmersfaced during the putting in place of plantain plantations. For several years, theproduction of clean plantain planting materials has preoccupied researchers of theAfrican Research Centre on Bananas and Plantains (CARBAP).Conscious of thesedifficulties, CARBAP developed in the 90s and put in place a horticultural techniquefor the rapid multiplication of clean banana and plantain planting materials. Thistechnique, known as PIF (Plants Issus de Fragments de tige), is widely adoptedby farmers and producers of banana and plantain. This paper throws more lightinto one of the adopted agrarian innovations of macro-propagation techniqueby CARBAP for banana-plantain production applicable to small and large-scalefarm holders in rural regions in Cameroon. The paper also assesses the risk andverifies the presence of pending hazards that may cause low productivity andquality during the production of planting materials using the PIF Technique.Withincreased knowledge of research and train-the-trainers approach by CARBAP, thePIF technique is not only used for the generation and multiplication of clean bananaand plantain plantlets for increase production (food security or to enhanced the self-sufficiency of banana-plantain production). The availability of PIF technique, fromthe training outcomes, helps on promoting agricultural growth for social protection;thereby, promoting agricultural growth above subsistence farming with smallsurpluses for cash that enhances the economic well-being for the poorest segmentsof the population. 101
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa78. The domestic cavy (Cavia porcellus L.) – a small animal carrying great hope for nutrition security and as a source of income for poor households in South Kivu, eastern DR Congo Maass Brigitte1 and Thierry K. Metre2 CIAT (Centro Internacional de Agricultura Tropical), Nairobi, Kenya; 2 Association 1 Villages Cobayes (VICO asbl) (Village Guinea-Pig Association), South-Kivu, Democratic Republic of CongoAbstractIn South Kivu, one of DRC’s 11 provinces experiencing several wars and civil unrestin past decades, pillage of larger livestock species has been the rural population’sdaily experience. Today, the domestic cavy (i.e., Guinea pig; Cavia porcellus L.),a mini-livestock species of South American origin, constitutes the only sourceof animal protein accessible to poor households. It is virtually consumed by thewhole population regardless of age and sex. This explains the proliferation of smallrestaurants specialized in cavy meat in several village markets. In surveys carriedout around the provincial capital Bukavu in 2009 and 2010, every second intervieweeheld cavies. However, two thirds of the smallholders held 10 animals and less, withprobably low productivity. Typically, they held cavies in the kitchen, feed them onkitchen scraps and collected forages, some of which have low digestibility. Mostcavy holders admitted their lack of husbandry knowledge, reflected in unspecificfeeding, low levels of hygiene, and not applying any mating control. Adult animalsweigh about 500 g. When improving husbandry pursuing the enhanced Peruvianmodel by keeping animals in 1 x 1 m2 boxes with 8-10 females per male, avoidinginbreeding and regular feeding based on Napier grass, adult animals reach 800g. In an improved cavy culture at Walungu, 45 km West of Bukavu, with around250 animals kept per stable, local cavy breeds have greatly increased productivity.In South Kivu, cavies are not only used to supply the family with meat; they alsoprovide a noteworthy source of household cash income directed towards children’seducation, basic sanitation, and purchase of clothes, among others. Demand for cavymeat is constantlyincreasing and not always matching the weak supply. Finally,vegetable gardens or plots with improved forages benefit from the application of itshigh quality manure. 102
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa79. Evaluating Zinc containing fertilizers for improved crop and human nutrition under cereal based farming systems in Zimbabwe Manzeke Grace1, Mtambanengwe Florence1, Mapfumo Paul1,2, Kanonge Grace1, Chikowo Regis1 and Cakmak Ismail University of Zimbabwe, Harare, Zimbabwe; 2International Centre of Maize and Wheat 1 Research (CIMMYT), Harare, ZimbabweAbstractFertilization of staple cereal crops in smallholder farming systems of sub-SaharanAfrica has mostly been focused on supply of nitrogen (N), phosphorus (P) andpotassium (K), despite widespread deficiencies of micronutrients that include Zinc(Zn). On granitic sandy soils, Zn deficiency limits crop productivity and as a result,the nutritional value of food crops originating from such soils is compromised. Astudy was conducted on smallholder farms in Wedza district of eastern Zimbabwe,to evaluate different Zn fertilizer formulations on maize (Zea mays L.) yieldsand subsequently Zn concentration in the grain. Results from the 2008/09 seasonshowed that sole application of basal or in combination with foliar Zn fertilizers tomaize increased grain yields by up to 62%. Significant maize grain yield differences(p < 0.05) among treatments were observed with high yields of ~ 5.2 t ha-1 attainedwith co-application of basal Zn and NPK fertilizer. Such yields are rarely achievedin smallholder farms where sub-optimal fertilizer rates are often applied. Up to228% increase in Zn uptake by maize (p<0.01) was measured against the control.Highest uptake of 118 g Zn ha-1 was achieved after application of basal CompoundZ (7N:14P2O5:7K20:1Zn) at 3 kg Zn ha-1. Ear leaf samples collected at tasselling,before application of foliar fertilizers (0.3% Zn solution), had Zn concentrationsranging from 16 - 51 mg kg-1, about -11.1 to 183% increase against the control.The Zn concentrations in maize grain ranged from 16 - 30 mg kg-1, with a highestincrease of 87% against the control realized after application of foliar Zn as ZnSO4.The results indicated that, irrespective of method of application, Zn fertilizers wereessential in improving maize productivity, grain nutrition, with potential positiveimpacts on human nutrition. 103
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa80. ETUDE FLORISTIQUE ET PHYTOSOCIOLOGIQUE DE LA VEGETATION DU HAUT PLATEAU D’UVIRA: CAS DES LOCALITES AGROPASTORALES DE MARUNGU, KITEMBE ET KAHOLOHOLO (SUD-KIVU/ R.D.CONGO) Mapenzi Assani Neville1 and KATUNGA Musale Diudonne2 1 Centre de Recherche en Science Naturelle (CRSN/LWIRO); 2Institut National d’Etude et de Recherche Agronomique(INERA/MULUNGU) Abstract :La végétation alpine et touristique du haut plateau d’Uvira, dans les localitésde Marungu, Kitembe et Kaholoholo est menacée de disparition suite à unemauvaise exploitation (usage des feux de brousse incontrôlés, coupe de boiseffrénée sans reboisement, défrichage pour les cultures, surpâturage, faiblesse desservices de vulgarisation etc). La caractérisation de cette flore a été faite du 21au 28 Septembre 2010. Les méthodes utilisées étaient celle de Braun-Blanquetpour la strate herbacée et Van der Maarel pour la strate ligneuse. Le résultat decette étude a révélé que dans la strate herbacée et notamment dans les pâturages,l’espèce Pennisetum clandestinum, tend à la disparition totale selon sa rareté dansles relevés phytosociologiques pendant qu’elle était d’une importance capitale surle plan fourrage. Dans la strate ligneuses, les espèces tels que Hagenia abyssinica,Sinarundinaria alpina(Bambou) et Erica arborea, devraient avoir une grande surfaceterrière mais elles présentent une faible dominance et sont remplacées peu à peu parles espèces de jachères. Ce qui prouve une grande destruction de cette forêt. Malgrécette dégradation, cette contrée engorge encore une végétation ayant:114 espècesréparties dans 50 familles.L’étude phytosociologique a prouvé l’existence de cinqcommunauté végétale :La végétation forestière avec trois groupements végétaux à savoir : *Groupement à Hagenia abyssinica *Groupement à Erica arborea et *Groupement à Sinarundinaria alpina.·La végétation marécageuse avec un seul groupement : * Groupement à Juncusdregeanus et Cyperus latifolius. ·Et la végétation des pâturages avec un groupement :* Groupement à Paspalum sp. Nous aimerions à ce que la population de ce milieu soit sensibilisée à l’importancede cette forêt afin de la gérer rationnellement sans perturber les activités agro-pastorales.Mots clé:-Disparution des espèces fourragères. -Destruction de la forêt. -Introduction d’autres espèces fouragères. 104
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa81. The floristic and phytosociological vegetation study of top shelf of uvira: case of pastoral localities of marungu, kitembe and kahololo (South Kivu /Dr Congo) Mapenzi Assani Neville1 and Katunga Musale Diudonne2 1 Centre de Recherche en Science Naturelle (CRSN/LWIRO); 2Institut National d’Etude et de Recherche Agronomique(INERA/MULUNGU) Abstract:South of the province of South Kivu, alpine vegetation and tourism butanthropized has awakened the curiosity of scientific researchers. Their goal hasfocused on the characterization of the flora and vegetation of the top shelf ofUvira, in the localities of Marungu, Kitembe Kahololo and before it is destroyedcompletely.This study revealed that this region has a vegetation rich in species: 114species in 50 families.  Five plant communities were identified as follows: Forestvegetation with three plant groups including:   * Hagenia abyssinica grouping * Erica arborea grouping* Sinarundinaria alpina grouping. • The marsh vegetationwith a single group: * Juncus dregeanus and Cyperus latifolius grouping• And thevegetation of pasture with one group:  * Paspalum sp grouping. 105
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa82. Structure and conduct of cross-border bean (Phaseolus Vulgaris) marketing in east africa: the case of Western Kenya and Eastern Uganda Mauyo Lianda1, Kirgby R.A.2, Buruchara R2 and Ugen M3 1 Masinde Muliro University of Science and Technology, Kakamega, Kenya; 2CIAT (Centro Internacional de Agricultura Tropical)-AFRICA, Kampala, Uganda; 3 Namulonge Agricultural and Animal Production Research Institute (NAARI), Kampala, UgandaAbstractThis study was conducted to assess the current status of cross-border bean(Phaseolusvulgaris) marketing patterns in the border districts of Kenya and Uganda, with aview to improving the marketing system in the region. Common bean is the mostimportant pulse in Kenya and Uganda. It is a major source of food and income.Smallholder farmers in both countries have adopted improved bean varieties.However, there is inadequate empirical evidence on the bean grain characteristicsprefered by consumers, the geographical distribution of the bean cultivars andmarketing patterns. The objectives of this study were to identify and assess thebean marketing channels and structure in the study area. It was hypothesised thatthere are no barriers to entry in the bean business in the study area. Purposive,multistage and systematic random sampling methods were used to select the studydistricts, bean farmers and traders respectively. Two hundred and ten respondentswere interviewed using structured questionnaires. Structure-conduct-performance(S-C-P) model was used to describe the bean marketing system. The study revealedfour marketing channels in both Kenya and Uganda. The degree of concentration atthe retail and wholesale levels show that markets are competitive. There are barriersto entry into the bean business in the study area. No collusive or predatory tacticswere observed in the bean marketing system. However, the study revealed thatthere is poor market information flow in the marketing system. 106
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa83. Using lime and multi nutrient fertilizers to improve soil health and productivity of acidic soils of smallholder farming systems of Western Kenya Mbakaya D.1, J. R. Okalebo2, F. N. Muyekho3, C. Serem2, R. Ochebo1, AND B. Jama5 1 Kenya Agricultural Research Institute (KARI), Kakamega, Kenya; 2Department of Soil Science, School of Agriculture and Biotechnology, Chepkoilel University College, Eldoret, Kenya; 5Alliance for a Green Revolution in Africa, Nairobi, Kenya; 3National Agricultural Research Centre (NARC), Kitale, KenyaAbstractSoil fertility depletion on smallholder farms is one of the biophysical root causes ofdeclining food production in Africa. Previous studies indicate that soils in westernKenya are severely depleted of phosphorus (P) and nitrogen (N) and in additionacidic. Past soil survey showed that 7.5 million hectares (13%) of high agriculturalpotential land of Kenya is acidic (pH<5.5) and out of these 57,670 ha are in westernKenya. The objective of the study was to assess the effects of integrated soil fertilitymanagement technologies (ISFM) on soil fertility, Striga and maize yields in Ugenyaand Kakamega North districts of western Kenya. The study was conducted on 40representative farms for three seasons 2009 short rains to 2010 long and short rainsusing a randomized complete block design with six treatments Lime, Diamoniumphosphate, Mavuno, Lime + Diamonium phosphates, Lime + Mavuno andconventional farmers practice as control using two maize varieties DK 8031 andHybrid 513 to evaluate the technologies. Soils were sampled for chemical analysis.Results (p<0.05), overall rating of technologies based on maize yields at harvestingwere significantly different, with Mavuno alone being higher followed by Lime +DAP, Lime + Mavuno, DAP, Lime alone and control last The soil chemical analysisresults showed most parts of Kakamega North and Ugenya were moderately tostrongly acidic with pH ranging from 4.63 to 5.81. Liming was highly appreciated byall farmers in the two sites due to reduction in the Striga population and appreciablemaize yield increase realized compared to farmers practice. 107
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa84. Improving High Quality Food of Staple Crops in the Democratic Republic of Congo Mbikayi Jean Albert Institut National pour l’Etude et la Recherche Agronomique(INERA), Bukavu, DR CongoAbstractIn the world, the people are starving of hunger because they have not enough foodand the quality is poor. The Democratic Republic of Cong multiplication et les variétésdont vous devez augmenter le noyau des semences.o is among the developingcountries where the people are facing this nutritional problem. The statistics haveshown that 72% of the Congolese people are starving of hunger. They gain 1.610cal/person/day which is lower than the requirement. To improve this situation,the DR. Congo, in collaboration with the CGIAR are improving three of main cropsmostly produced and eiten par the people.These main crops are: 1) Yellow fleshcassava rich in Pro-vitamin A 2) Micro-nutrient rich bean (iron and zinc) 3) QualityProtein Maize rich in protein. The promising varieties of these crops are availablefor production and dissemination. The purpose of this Poster is to create awarenessamong partners who are willing to sustain Congolese agriculture and avail qualityfoods, mostly for vulnerable people, children and pregnant women. 108
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa85. Effect of Bio-inorganic Fertilizer on soil fertility and Maize production improvement Mfune Peter1, Munthali M.W.2, and Makumba W.I2 Bvumbwe Agricultural Research Station, Blantyre, Malawi; 2Chitedze Agricultural 1 Research Station, Lilongwe, MalawiAbstractEvaluation of bio-inorganic fertilizer made from integration of tobacco stems, maizestover using yeast microbites and chemical fertilizers additives on soil fertility andmaize grain yield production was done at Chitedze Agricultural Research Stationin Malawi. Fertilizer field experiments were conducted. There were 3 sources ofN with 5 different rates (0, 30, 60, 90 and 120 N kg/ha) in a RCBD replicated 3times. Each plot size was made up of 6ridges spaced at 0.75m and each 5m long.One Maize seed was planted per station spaced at 25cm apart. The results indicatedthat there were significant maize grain yield differences (P<0.001) among the Nsources and fertilizer rates. The mean grain yield for bio-inorganic fertilizer (5017Kg/ha) was higher than bio-organic fertilizer (3467 Kg/ha) and inorganic fertilizer(4069 Kg/ha). The rate of 120kg N/ha gave the optimum maize grain yields forthe three fertilizer sources. The results also indicated an increase in soil pH, OMand K availability as compared to the control. Fe and Mn ions were suggested tobe complexed to the organic matter which resulted into reduced soil soluble toxiclevels. Bio-inorganic fertilizer was more effective at improving soil fertility than theother two fertilizer types. 109
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa86. Effects of Tillage and Cropping Systems on Yield and Economic Returns of Maize and Cowpea in Eastern Kenya Miriti Joseph1, Kironchi G.2, Gachene C.C.K2, Esilaba A.O.3 and Mwangi D.M.4 1 Kenya Agricultural Research Institute (KARI), Kenya; 2The University of Nairobi, Nairobi, Kenya; 3Kenya Agricultural Research Institute, KARI H/Q, Nairobi, Kenya; 4 International Livestock Research Institute (ILRI), Nairobi, KenyaAbstractCrop yields and financial returns are important criteria for the adoption ofconservation tillage by farmers. A study was carried out between 2007-2010 tocompare the financial profitability of subsoiling and ripping (SR) and tied-ridging(TR) tillage relative to the conventional ox-ploughing (OP) in the production of themaize (Zea mays L.) and cowpea (Vigna unguiculata L.) under subsistence farmingconditions in Eastern Kenya. The treatments arrangement was a split-plot with tillagepractices as the main plots and cropping systems as the sub-plots in a CompletelyRandomized Block Design (CRBD) replicated four times. Cropping systems weremaize sole crop (SM), cowpea sole crop (SC), maize-cowpea intercrop (MC) andmaize sole crop + 5 Mg ha-1 manure (MM). The yields of maize and cowpea inevery season were determined at harvest for 4 seasons. Prevailing market pricesof cowpea and maize grains, labour, inputs and other relevant socio-economicdata were collected for gross margin analysis. Tillage effect on maize grain yieldwas not significant for SM and MM. Compared to OP, SR did not have significantimprovement on maize grain yields. Manure increased average maize grain yieldsby 36% (from 0.90 to 1.23 Mg ha-1). Intercropping significantly (P<0.05) reducedmaize grain yields by a third (32%). Cowpea grain yields under SR were 15% lessthan the yields under OP tillage. Tied ridges increased land preparation labour costsby 190% while subsoiling-ripping on the other hand reduced labour cost by 53%relative to ploughing. Net returns from maize production ranged from a loss of200.3 to a profit of 166.2 US$ ha-1 and were profit was realized in only two outof four seasons. Although sowing maize with manure improved maize yields andnet returns, positive net returns were obtained in relatively wet seasons. Cowpeaproduction was more profitable than the production of maize but farmerspreferredgrowing maize to cowpea. 110
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa87. Mitigating P sorption for enhanced P availability and maize yield in the acid soils of Southern Rwanda Mukuralinda A.1, Nabahungu, N.L.2, Mowo, J.G.3, Miyuki I. 4 and Masuki, K.F.5 1 World Agroforestry Center (ICRAF), Rwanda; 2Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 3World Agroforestry Centre (ICRAF), Nairobi, Kenya; 4 Graduate School of Economics, University of Tokyo, Japan; 5African Highland Initia- tive, Kampala, UgandaAbstractAcidic soils poses a major management problem due to the high phosphorus (P)sorption, often leading to poor crop yields. This study aims at identifying the bestmanagement options of the acidic soils of Southern Rwanda that will reduce Psorption to increase its availability and crop productivity. The effects of organicand inorganic fertilisers applied either alone or in combination on soil phosphorussorption and P availability to maize were evaluated on an Ultisol in the SouthernProvince of Rwanda. A randomized complete block design with three replicateswas used. Treatments included a control, lime, TSP, green manure from Calliandra,Tephrosia and Tithonia and combinations of the organic and inorganic fertilisersources. The isotherm parameters (sorption affinity (k), sorption maxima (b) andsorption at equilibrium solution (q)) were determined using Langmuir equation.Results showed that P sorption varied between 436.8 and 504.6 mg P kg-1. Generally,the control exhibited the highest P sorption compared to the other treatments.Tithonia combined with TSP reduced P sorption by 20.8% while lime appliedonce for 4 seasons at (2.5 t/ha-1 ) reduced P sorption by 13.3% compared to thecontrol and the other treatments. The combination of Tithonia with TSP reducedk significantly compared to lime (P < 0.05) and the control treatments. Calliandra,Tephrosia and their combination with TSP reduced k in the same proportion as thatof lime. Tithonia combinedwith TSP showed low amount of P sorption (188.2 mgP kg-1) at equilibrium P solution (q) with a P concentration of 0.2 mg P kg -1. Thecombination of Tithonia with TSP increased available inorganic P fractions by 1.6 to52.2% compared to the control. The combination of green manure treatments withTSP in the proportion of 25% of P requirement significantly increased maize yieldsfrom 24 to 508% for 4 seasons . Plant quality residues and labile inorganic P fractionswere strongly correlated with maize yield, confirming the beneficial role of plantresidues quality on P desorption, P availability and maize yield. 111
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa88. The potential of trees and shrubs to improve banana productivity and production in Central Uganda – an analysis of the current situation Mpiira S.1, Staver C.2, Kagezi, GH.1, Wesiga, J.3, Nakyeyune, C.4, Ssebulime, G.5, Kabi- rizi, J.1, Nowakunda, K1, Karamura, E.2, Tushemereirwe, W.K.1 1 National Agricultural Research Organisation, Uganda; 2Bioversity International, Kampala, Uganda; 3VEDCO (Volunteer effort for development concern), Uganda; 4 SCC_VI, Uganda; 5Kiboga Local Government, UgandaAbstractIn Central Uganda, in spite of poor soils and high pest pressure, bananas are aprimary source of household food and income. Farmers are increasingly challengedby how to maintain banana productivity and to expand production for nearbymarkets. Traditional inputs - grass mulch, crop residue, and animal manure – havebecome scarce and expensive. We posed the question whether on-farm trees andshrubs as a source of fodder and mulch and for an improved microclimate couldbe harnessed to improve banana productivity. A survey was conducted in threedistricts of Uganda – Kiboga, Ssembabule and Nakaseke - to characterize the currentstatus of and linkages among bananas, livestock, trees and shrubs. Per district 70households were interviewed and field sampling was conducted on 30 of these.For Kiboga, Ssembabule and Nakaseke respectively land holding on average was6.5, 10.9 and 9.7 acres with 291, 517, and 355 banana mats and 15, 11 and 23 treesand shrubs per farm with 69, 71 and 32% owning no ruminants. Of households24, 56 and 57 % hired labor, while 24, 37 and 36% sold their labor. 18, 24 and 17 %applied manure to bananas, and 6.7, 1.6 and 4.7% of bananas were found under treeshade respectively. A total of 49 tree species were counted with jackfruit, Ficus,Albizia, Markhamia, mango and avocado being the most common. From the surveywe concluded that bananas and trees co-exist on farm. Farmers readily identifygood neighbor trees for bananas (Ficus and Albizia spp), tree-friendly bananacultivars Kibuzi, Ndibwabalangira, Nakitembe, Mbwazirume and Nakabululu andnumerous fodder trees and shrubs. Certain households are endowed with moreland, livestock and on-farm trees to undertake agroforestry strategies to improvebanana productivity. However, no households make systematic use of trees andshrubs as mulch or animal fodder to increase manure supplies and do not managetree canopies to improve the microclimate for bananas. 112
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa89. Effect of Using Inorganic and Cattle Manure with Different Topdressing Rates of Ammonium Nitrate on Yield of Maize Under Wetland Conditions in Zimbabwe. Mtetwa Godwin Department of Research and Specialist Serviecs, Chiredzi Research Station, Chiredzi, ZimbabweAbstractMaize is sensitive to both biotic and abiotic stress competition for nutrients anddrought resulting in large variations in yields occurring both within and betweenareas of production. Smallholder farmers are facing problems of low soil fertilitycausing yield reduction up to1.5 t/ha compared to five tones per hectare in thecommercial sector. A trial was conducted under wetland conditions in NaturalRegion IV of Zimbabwe at Zungwi vlei (200 25` S and 300 25` E) in ZvishavaneDistrict on two wetlands located in the same vicinity. Four basal applications wereapplied in the trial as treatments for two seasons (Zero kg/ha, 150kg/ha, 300kg/hacompound D (8:14:7: N:P:K)and 5t/ha of cattle manure from farmers). Four differentlevels of nitrogen were applied as subplots factor :( 0 kg/ha N, 50kg/ha N, 100kg/ha N, and 150kg/ha N in the form of ammonium nitrate (34.5% N)). A two-wayearly maturing hybrid developed by Seed Co. for marginal areas was used (SC513).The objective of the study was to determine effects of different rates of compound Dand cattle manure as basal dressing with different rates of ammonium nitrate as topdressing under vlei conditions. Results show that grain yield increased significantly(p<0.05) when 300kg/ha of compound D was applied with 150kg/ha N topdressing. There was a significant yield advantage when the nitrogen was increasedafter applying a basal dressing in both sites for the two seasons. When manure wasapplied as basal the response on different levels of nitrogen was positive showingsignificant difference p<0.05 in both schemes for the two seasons. There were nosignificant yield advantages in applying basal dressing without top dressing at bothschemes for the two seasons. 113
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa90. The Impact of leguminous culture system and semis dates on the maize yield in mountainous South-Kivu Mubasi Casinga1, Bagula Mukengere E1, Sanginga Jean Marie3, Mushagalusa Nachigera G.1 and Pypers Pieter5 1 Université Evangilique en Afrique (UEA), DRC, Bukavu; 3Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), DRC; 5 Tropical Soil and Biology Institute of the International Center for Tropical Agricul- ture (CIAT-TSBF), Nairobi, KenyaAbstractDespite its potential yield, the culture of climbing beans in the mountainuous Kivuis limited lack of tools. Thus, appropriate technologies corresponding to the poorfarmer’s incomes should be adapted in terms of labour, soil and investment in capitalsuch as intercropping that would substitute the use of stakes and allow a better soilcover. A study had been carried out at Burhale during two cultural seasons A2009and B2010. Conducted in four sites in 9 trials using Maize(WH 403); Soya(SB 19) andbeans(AND 10). NPK 17-17-17 and organic fertilizers were used. The MOJA culturalsystem( A row of beans between two rows of maize) was applied in the 1A and 2trials and the MBILI(two successive rows of beans between two rows of maize)inthe 2 and 4 trials; also, the monoculture was practiced in the 6, 7, 8 and 9 trials. Beanswere sawn at 10 to 15 days after maize in the 1 and 3 trials. However, in the 2, 4 and7 trials were at 20 to 30 days after maize. The soya beans had simultaneously beensawn with maize in the MBILI system of the 5 trial and in the monoculture of 8 trials.Maize was sawn the day of the installation of the experiment. Firstly, leguminousplants yield had been inferior(respectively 259,26 ; 271,88 ;0 and 0 kg.ha-1 for the 1,2, 3 and 4 trials) as for the monoculture( Respectively 2711,11et 1100,18kg.ha-1 forthe 6 and 7 trials). Secondly, the maize yield was inferior( respectively 7564,4; 5397,0;10279,61 and 842,91kg.ha-1 for the 1, 2, 3 and 4 trials) for the monoculture of 9 trial(7957,4kg.ha-1). Good LER of 1,01 and 1,25 were found for the 1 and 3; they were bad0,76; 0,92 and 0,69 for the 2, 4 and 5 trials. 114
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa91. On-farm evaluation of newly introduced east african highland banana hybrids in Burundi and North Kivu Muchunguzi, P.1, Tushemereirwe, W.3, Vigheri, N.4, Lwanga, C.2, Kanyaruguru, J.2, Ouma, E.1, Blomme, G.2, van Asten, P.1, Kezumutima, M.5, Kimana, C.1, and Lorenzen, J.1 International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 1 Bioversity International, Kampala, Uganda; 3National Agricultural Research 2 Organization, Uganda; 4Catholic university of Graben; 5Hope university of BurundiAbstractThe East African Highland bananas are a major source of both food and income in theGreat Lakes region. The crop is faced by a number of biotic and abiotic challenges.The biotic challenges include pests like weevils and nematodes, and diseases such asXanthomonas wilt, Banana bunchy top virus, Fusarium, and black Sigatoka amongmany others. Breeding for host plant resistance was identified as an appropriatemeans of managing the above production related challenges. Hybrids from a jointbreeding program between the International Institute of Tropical Agriculture (IITA)and the Uganda National Banana Program of the National Agricultural ResearchOrganization (NARO) were selected on-station and on farmers’ fields according totheir black Sigatoka resistance, maturity period, high yield and pulp color. Severalof these hybrids were evaluated at a regional level against local checks and high-yielding imported lines in collaboration with the National Agricultural Researchsystems of Burundi, and north Kivu. IITA/NARO hybrids included ‘9750S-13’(‘NSH-20’) and ‘8386S-19’ (‘NSH-22’) for cooking and ‘9518S-12’ (‘NSH-42’) for juiceproduction. Five action sites in both Burundi and Nord-Kivu were used to plantfifteen plants each of fifteen newly introduced varieties that included plantains,beer bananas, dessert bananas and their respective local checks. The performance ofplants was monitored and data for yield and sensory acceptability were collected.Yield was obtained by measuring bunch weights and number of hands per bunch.Sensory acceptability by farmers was rated on a 1- 5 point hedonic scale for pulpcolor, pulp texture, food aroma, taste and general acceptability traits in comparisonto the local check. While agronomic data collection and processing are still ongoing,hybrids 9750S-13 and 9518S-12 produced higher yields than the local check. Sensoryevaluations by farmers of steamed banana revealed that hybrid 9750S-13 hada similar acceptability as the local checks was acceptably close to local checks insome areas and was in some places preferred, while hybrid 9518S-12 was highlypromising for juice production. These results show the promise of breeding forimproved hybrids with resistance to biotic threats and good consumer acceptability. 115
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa92. Returns to production of common beans, soybeans and groundnuts in Rwanda Mugabo J.1, Chianu J.2, Tollens E.3 And Vanlauwe B.4 1 Rwanda Agricultural Board (RAB), Rwanda; 2African Development Bank, Tunis, Tunisia; 3Catholic University of Leuven (KUL)/Belgium; 4Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, KenyaAbstractCommon bean and soybean are among the key crops for which specific actions areplanned in the Plan for Agricultural Transformation in Rwanda (SPAT). Legume-based systems provide high quality food, cash to farmers and contribute tosustainable agricultural production systems. The aim of this study was to evaluateand compare the profitability of common bean, soybean and groundnuts croppingsystems and examine the change in soybean profitability in response to variationin market price and yield. To achieve this goal, the data collected through focusgroup discussions (FGD), interviews with key informants and formal questionnairesurvey were organized and analyzed using the enterprise gross margins approach.Results showed that soybean sole cropping systems are associated with low to highprofitability both in terms of returns to land and returns to labor, low returns beingpredominant. A careful analysis of sensitivity analysis results led to two importantconclusions. First, the increase in producer price will mostly benefit farmers whocan achieve higher yields while having limited impact on the profitability of thoselagging behind in soybean yield. Second, a price increase, although essential in theprocess of boosting soybean profitability, is not the best solution in the presence oflow yield levels, if the necessary conditions are not present to permit a subsequentincrease in yields. Common bean cropping systems are also characterized by low tohigh returns to land and labor with moderate returns being more frequent. Althoughclimbing beans cropping systems have higher yields compared to bush beans, thetwo types of common bean have comparable returns to land due to high extracosts on labor and stakes associated with climbing beans. Compared to soybeanand common bean production, groundnut production values better land and labormostly due to higher local market prices. 116
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa93. Maize yields response to intercropping and application of manure, tithonia and fertilizer in the central highlands of Kenya Mugwe, J.1, Mugendi, D.N.1, Mwebia, F.W.1, Kimaru, S.1 and Muna M.M.1 1 Kenyatta University, Nairobi, KenyaAbstractDeclining soil fertility remains a key problem in smallholder farms of centralKenya mainly due to use of inadequate organic and mineral fertilizers. A field trialto evaluate performance of intercrops, Tithonia diversifolia, manure and mineralfertilizer was carried out in the central highlands of Kenya for two cropping seasons(2010 and 2011-2011 seasons). The intercrops had two treatments; conventionalmaize-bean intercrop and a staggered two-by-two bean maize intercrop (MBILI),either alone or with mineral fertilizer, while the tithonia and manure were eitherapplied solely or combined with fertilizer, sole application of mineral fertilizer wasin two rates; at 60kg N ha-1 and 90 kg N ha-1 , commercial soil conditioner (AGRISOC), and a control. The treatments were arranged in a complete randomizedblock design, with four replicates. Performance was evaluated through grain yieldmeasurements and also by farmers participating in field days at the experimentalusing visual observation. Farmers were also encouraged to select inputs that theywished to use on their farms. Cattle manure and Tithonia sole or with mineralfertilizer recorded the highest maize grain yields of 5.8 t ha-1, while the intercropsgave the lowest yields of 2.6 t ha-1. Using cob size, farmers’ ratings scored fertilizerat 90 kg N ha-1 as the best followed by Tithonia and Agrisoc treatments. There was88% correlation between measured yields from the treatments and farmers ratingsof the treatments using cob size. Manure and fertilizer was selected by most farmers(65%) while the least selected was intercrop treatments. These results confirmsthe superiority of organic inputs or their combinations with mineral fertilizer inincreasing yields. 117
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa94. Meta-Analysis to Determine Effect of Nutrient Management Options on Maize Yield Responses in African Small-scale Production Systems. Muhati Stephen Ichami Plant Production Systems, Wageningen University, Wageningen, The Netherlands/ Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, KenyaAbstractFertilizer recommendations currently designed in sub-Sahara (SSA) rarely considerstandardized soil-testing procedures. Values result soil test values can be interpretedin terms of nutrient availability for crop requirement. Although site-specific soilcharacteristics (e.g., clay and carbon content, pH) influence the relation betweensoil nutrient content and fertilizer effectiveness, most of these factors are notquantitatively considered when assessing fertilizer demand. Recent re-evaluations offield observations suggests of field observation suggest that even for highly deficientsoils, fertilizer applications often resulted in no yield increase. In this study, resultsfrom agronomic trials conducted during the past three decades in SSA were analysedusing meta-analysis technique. The meta- analysis consisted of segmentation of thedata pool in order to elaborate a modified fertilizer recommendation scheme. Soilnutrient content, fertilizer-application, nutrient-use efficiency, and soil test attributevalues for pH, clay content, and soil organic carbon (SOC), increased maize yieldincrease compared to an unfertilized control. Nutrient-use efficiency had the largestinfluence, followed by soil-test potassium (K) content, whereas for phosphorus (P),the influence of soil-test P content was largest, followed by pH and SOC content.The results may be used in a novel approach to predict the probability of maizeyield increase for a specified combination of fertilizer-application and site-specificdata. 118
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa95. ETUDE DU CONTROLE DE L’EROSION HYDRIQUE ET D’AMELIORATION DE LA PRODUCTION SUR LES VERSANTS AU SUD KIVU MONTAGNEUX Muke Audry1, Pieter Pypers2, Jean-Marie Sanginga3 and Bernard Vanlauwe2 ¹Institut National pour l’Etude et la Recherche Agronomique(INERA), Bukavu, DR Congo; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 3Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), DRCAbstractL’érosion hydrique est responsable de l’improductivité des sols sur les versantsagricoles du Sud Kivu. A l’échelle des champs, elle conduit à une infertilitégénéralisée des sols et à une baisse de la production des cultures pour la subsistancedes petits agriculteurs. Une étude, dont le but était de contribuer au développementdes techniques antiérosives au Sud Kivu, a été conduite à Mudaka près de l’INERA-Mulungu. Les effets antiérosifs combinés d’une technique dénommée « fanyajuu »ou des haies constituées de Calliandra callothursus et du zéro labour sur la perte dessols et sur les rendements, ont été évalués sur un versant de pente de 43%. Troisans plus tard, nous avons observé que, 24 kg m⁻² des sols étaient perdus dans lesparcelles sans aucune mesure antiérosive, représentant presque 2,4cm des solsfertiles perdus. En pratiquant le zéro-labour, cette valeur a augmenté à 30 kg m⁻²alors que quand on a combiné avec les autres mesures antiérosives, le zéro-laboura eu peu d’effet sur la perte des sols. Dans les terrasses qui ont été formées par latechnique de fanyajuu et par une haie de calliandra, les pertes des sols ont été réduitesà 70 et 24% respectivement. En effet, la technique de fanyajuu parait suffisante pourcontrôler l’érosion que celle de haie constituée de calliandra. Durant la premièresaison, la technique de fanyajuu a réduit 40% des rendements contre seulement 16%pour l’utilisation des haies de calliandra. Ceci se justifie par la perte de la surfacecultivable induite par la haie de callindra (13%) alors que pour fanyajuu la réductiondes rendements se justifient à la fois par la perte de surface cultivable (21%) et parl’effet du terrassement qui a mis à jour le sol acide de profondeur. Trois annéesplus tard, les rendements de soja étaient toujours supérieurs dans les terrassessans mesure antiérosive seulement sous labour traditionnel. Le zéro-labour avaitun léger effet positif sur les rendements, seulement en absence des autres mesuresantiérosives. Cependant, malgré l’amélioration en perte des sols, l’utilisation defanyajuu et de haie antiérosive de calliandra ont réduit les rendements à 24 et 32%respectivement. De ces résultats, il ressort qu’il est évident que la promotion destechniques antiérosives, aux agriculteurs du Sud Kivu, reste une tâche ardue, dufait qu’elles n’entrainent pas des bénéfices en terme de production des récoltesen moyen ou en court terme. Néanmoins, les investissements consentis trouvesignification dans la mesure où les haies antiérosives sont, par exemple, destinées àproduire du fourrage pour les batails et/ou des tuteurs pour les haricots volubile. 119
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa96. Integrated use of TwinN-Nitrogen fixing microbes and fertilizers for improving soil fertility and maize production in humid highlands of Malawi Munthali Moses W.1 and E.D. Mazuma1 1 Chitedze Agricultural Research Station, Lilongwe, MalawiAbstractResearch was conducted at Bvumbwe and Bembeke Agricultural Research Stationsituated in the humid highlands of Southern and Central Regions of Malawirespectively. The objective was to evaluate the effect of integrated use of TwinN-Nitrogen fixing microbes plus fertilizers on improving soil fertility and Maize grainyield production for resource constrained smallholder farmers. The experimentaldesign was RCBD with 11 treatments in either sole or different combinations ofTwinN and chemical fertilizers. TwinN-Nitrogen fixing microbes were inoculatedon the Maize leaves and roots. Soil samples were collected before and after theimplementation of the experiment. Collected soil samples were analysed for soiltexture, pH, OM, N, P, K and presence of TwinN microbes. Collected Maize plantsamples were analysed for N, P, K and presence of TwinN microbes. The resultsindicated that the inoculated TwinN microbes were present in the inoculated soiland maize plants during the experiment. Soil OM mineralisation was enhancedincluding P and K uptake by the Maize plants from the soil by TwinN microbes.There were significant differences (P=0.05) in Maize grain yields among thetreatments. The inoculated Maize with TwinN microbes gave higher Maize grainyields of 3830Kg/Ha than the zero treatment (1855Kg/Ha). The combination ofTwinN microbes with half rate of chemical fertilizer gave the highest Maize grainyields and profit margin among the 11 treatments. The grain yield (6271Kg/ha)was higher than either the sole TwinN microbes (3830Kg/Ha) treatment or full ratechemical fertilizer (4836Kg/Ha) treatment. 120
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa97. Evaluation of commercial chemical products for increased maize production through the use efficiency of applied P under smallholder farmers’ conditions in different agro-ecological zones of Kenya Munyahali Wivine1, Mutegi Edwin1, Mucheru Monicah2, Lesueur Didier3 and Pypers Pieter1 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 2Kenyatta University, Nairobi, Kenya; 3 Agricultural Research for Development (CIRAD), IndonesiaAbstractSmallholder farmers in sub-Saharan Africa are confronted by low crop productiondue to phosphorus (P) deficiency and a limited investment capacity in P inputs.Alternative P fertilizer types are being commercialized which aim at improved Puse efficiency through specialized formulations. These products include, amongstothers, leaf sprays, seed coatings and conditioners with humic acids. We evaluatedthese products in pot trials under greenhouse conditions and in multi-locationalparticipatory field trials with farmer groups in three distinct agro-ecological zonesin Kenya. The products were applied in combination with TSP fertilizer at 13 kgP ha-1, as the P supplied through the products was assumed insufficient to attainadequate crop yields. Response to P was assessed by including treatments with Paddition at 0, 13 and 26 kg P ha-1. In the pot trial, none of the products significantly(P<0.05) increased the shoot dry matter yield of 6-weeks old maize. Seed coating,however, resulted in increased root yield and root-shoot ratio. In the field trials, TSPapplication resulted in average grain yield increases of 0.2 - 0.7 and 0.7 - 1.0 t ha-1 atrates of 13 and 26 kg P ha-1, respectively. None of the treatments with the differentproducts significantly increased maize yields, but significant (P<0.05) positivecorrelations (R² = 0.45 - 0.51) were found when yield increase due to application ofthe seed coating or conditioning with humic acids (in combination with TSP at 13 kgP ha-1) was plotted in function of the difference in yield obtained with TSP appliedat 26 and 13 kg P ha-1. This suggests that these products only increase yields in themost P-deficient soils with a significant response to fertilizer beyond 13 kg P ha-1.As seed P coating is a fairly inexpensive treatment (3 USD ha-1), benefit-cost ratiosare favourable, especially when the technology is targeted to responsive fields withagronomic efficiencies of at least 45 kg grain per kg fertilizer P applied. 121
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa98. Organic versus Conventional farming: First season maize performance in consecutive rotation cycles, Central Kenya Muriuki A.1, Musyoka M.W.2, Cobo J.3, Zundel C.4 and Vanlauwe B.2 1 Kenya Agricultural Research Institute (KARI), Nairobi, Kenya; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 3Institute of Plant Production and Agroecology in the Tropic and Sub- tropics, University of Hohenheim, Stuttgart, Germany; 4Swiss College of Agriculture, Zollikofen, SwitzerlandAbstractIn Sub-Saharan Africa, crop production is largely carried out by smallholderfarmers, in a mixed farming non-commercialized setting where application ofsynthetic fertilizers and pesticides is minimal, necessitating reliance on increasinglyscarce organic resources to improve soil fertility and control pests. By contrast,northern hemisphere farmers rely heavily on synthetic inputs to sustain highyields. Comparative studies in the northern hemisphere have proven that organicagriculture is superior to conventional agriculture in ecosystem services deliveryand economic viability, therefore has potential to make yields more stable in risk-prone environments, achieve higher yields than traditional farming systems andgive farmers greater access to attractive markets and participation in crop valuechains, but disparities in soils, socio-economic environments and climate forbiddirect transfer of technologies to tropical countries. In 2007, a long-term project wasestablished in central Kenya to compare organic and conventional farming systemsat commercial and local farmer input levels using agronomic, environmentaland social economic data and to disseminate the findings to stakeholders. Thetrial features 4 treatments (Conventional High, Conventional Low, Organic Highand Organic Low) in a Randomized Complete Block Design (RCBD). Nutrientsin ‘Conventional’ treatments are supplied by farmyard manure, diammoniumphosphate and calcium ammonium nitrate and by compost, Tithonia diversifolia,and rock phosphate in ‘Organic’ treatments. Pests are controlled using biopesticidesand chemical products in `Organic’ and ‘Conventional’ treatments respectively.A three-year, treatment-specific maize-based rotation system is followed. Therewere no treatment differences in grain yield (p=0.101) in 2007, but stover weightsinConventional High were superior to Organic Low and indistinguishable fromConventional Low and Organic High (p=0.034). No differences were observedbetween the conventional and organic system at similar levels of nutrient input in2010 (grain yield, p=0.109; stover, p=0.622) suggesting that organic farming may bea viable option for tropical Africa. 122
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa99. Evidence of correlation of ENSO events and climate variations in Northern Rwanda: toward seasonal forecasting for humid mountainous tropics Musana Bernard1, Ngoga T. Gislain1, Nabahungu N. Léon1, Kababo Desiré1 1 Institut des Sciences Agronomiques du Rwanda (ISAR), RwandaAbstractClimate forecasting even in non changing climate scenario is a big challengeconsidering the temporal and spatial variability of climate. Predictive tools areinsufficient in Rwanda with often no consideration of agrometeorological informationdue to difficulty of translating it in ready to use information for agriculturalists.Prediction for mountainous tropics is needed considering their importance in EastAfrica region where they are important breadbasket area considering quantityand/or quality of agriculture produce. El Nino and la Nina Southern Oscillationeffects has been investigate in Australian and Zimbabwe in past decade and shownpromising result in managing drought affected areas. The relation between ElNino Southern Oscillation and the rainfall, coupled to the relation between rainfall,temperature and relative humidity was used to improve simple predictive yield andcrop failure risk models. Actual climatic data were completed by Historical data,and remotely generated data.Based 2002 to 2009 data, analysis has shown the central Rwanda has almost a neutralresponse to El Ninõ Southern Oscillation. The responses are clearer for Nyamagabeand Gicumbi districts where the Southern Oscillation Index explains 30 to 50 % ofrainfall variations i.e more than 200 mm. The spatial clustering of those responseareas may improve seasonal crop priority setting in Rwanda. The effects of rainfallincrease on temperature depend on the time resolution of the analysis. In mediumaltitude in Rwanda (1560 m) a reduction of more than 1 Celsius degree on Maximumand minimum temperature is observed when the rain increases by 70mm. Cloudcover, precipitation are important drivers of change in temperature, vapor pressureand relative humidity. Two Celsius degrees increase and 2 hPa reduction can reduceby 20% relative humidity. Below 75% of relative humidity at the beginning of thedry season a third season of potatoes is uncertain. 123
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa100. Spatially traceable indicators of agriculture income and land degradation in Northern Rwanda Musana Bernard1, Majaliwa M. Jackson2, Kagabo Desire1, Josaphat Mugabo3, Nabahun- gu N. Leon3, Jonas Mugabe4, Badege Peter1 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 2Makerere Univer- sity, Faculty of Agriculture, Kampala, Uganda; 3Rwanda Agricultural Board (RAB), Rwanda; 4Forum for Agricultural Research in Africa (FARA), Ghana;AbstractMonitoring poverty and natural resource degradation has become a highly rankedpriority toward Millennium Development Goals realization and improvingresilience of rural people of least developed countries against climate variabilitychange, food crisis and social stability. This study uses socio-economic and naturalresource management surveys to trace indicators that are related to crop andlivestock productivity, profitability and the relation with other spatially continuousvariables. From indicators definition a typology of households and non spatialvariables that require attention have been made and vulnerable areas identified.Considering income generated by cropping activities, spatial variables explained30 to 50 % of yield variation in the Northern Rwanda. It has shown that evapo-transpiration, soil fertility and rainfall regime are the strongest driving factors forland reclamation and crop intensification. Often evapo-transpiration explainedby itself more than 20% of the yield spatially variability in Rwanda. Non spatialindicators of agriculture income are soil conservation, farmyard manure, chemicalfertilizers and seed availability. Quantity of Farm yard manure used by unit ofarea is not related directly linked to number of animals while Commodity prices,Land size, cost of labour, and farm assets, can be clustered spatially. ConsideringLivestock income results have shown that farmers near grazing land have lessreturn to investment but higher living standards. This is due to known resilience ofcows keepers to natural hazard compare to crop farming. Generally, there is a trade-off between return per animal, milk price, cost of fodder production and alternativecropping activities. Below 0.2 USD per liter zero grazing may not be considered ascommercial farming. 124
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa101. Validation of New Innovations to Overcome Staking Constraints of Climbing Beans in Rwanda Musoni Augustine1, Butare L.2, Murwanashyake E., Gasigwabe and Gahakwa D.3 1 Institut des Sciencies Agronomiques du Rwanda (ISAR), Rwanda; 2Crop Protection Unit, Rwanda Agricultural Research Institute, Kigali, Rwanda; 3Rwanda Agriculture Board (RAB), Kigali , RwandaAbstractBeans (Phaseolus vulgaris L.) constitute 85% of vegetable and 65% of all dietaryproteins in Rwanda. Climbing beans are important for intensified production dueto superior yields of 3.5 – 5.0 T/Ha in Rwanda, where arable is scarce. Shortage ofstaking wood has been a major challenge limiting wider adoption of climbing beans.Economic losses resulting from poorly or none staking of climbing beans rangesfrom 50 – 90%.. The study was undertaken to generate cost-effective innovationsof staking climbing beans. Six treatments combining varying wood staking densityat 0% (none-staked), 15,000, 16,670, 20,000 (farmers’ practice), 23,000 and 50,000poles per ha (normal check) with knitting thread, sisal or plastic string trelliseswere evaluated with farmers. RCBD with two replications and 6 rows on a 6m x6m plot were planted on six locations at Rubona, Muhanga (1700 masl); Rwerere(2100 masl); Nyagatare, Ngoma and Karama (1400 masl). Two adapted climbingbean varieties ISAR-CB-105 (MAC 9) and ISAR-CB-102 (RWV 1129) were used.The experiment was replicated over locations and 3 seasons in 2009 and 2010.Sixty farmers participated in evaluation and selection of preferred innovationsat physiological maturity stages. ANOVA of grain yields was performed. Therewere highly significant differences between treatments, locations and seasons,while differences due to interactions were insignificant (P = 0.001 – 0.005). Normalwood staking produced the highest yields 87% of the times, but differences wereinsignificant from yields from other treatments except where no staking was done.Farmers consistently selected treatment with 16,670 stakes per ha and 20,000 stakesper ha in a cone (farmers’ practice). Normal and no staking were rated 5th and 6th(last) respectively. Choice of staking innovations depended on reduction in poledensity, firmness of canopy and envisaged labour and costs associated with trelliseswhen grain yields were similar. 125
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa102. Utilisation of non food parts of cassava for production of bio- ethanol and biofuels Nuwamanya Ephraim1, BagumaYona1, Kawuki Robert1, Chiwona-Karltun Linley2 and Bua Anton1 National crops resources research institute (NaCRRI), Kampala-Uganda; 2Swedish 1 University of Agricultural Sciences (SLU), Uppsala, SwedenAbstractAgriculture, the most important tool for poverty reduction and food security hascome under intense pressure given the effects of climate change. In Sub SaharanAfrica (SSA) where the poor and resource limited reside, agriculture is the mostpromising with crops like cassava taking centre stage although they have beenaffected by current changes in climate leading to poor productivity in addition to alooming energy crisis. Thus the solution to climate change in SSA lies in improvedand sustainable agricultural systems with special emphasis on crops for fuel andfor food. Therefore addressing issues of climate change in light of food agricultureis a practical and integrated approach that is duly sustainable and beneficial to theecosystem. Since climate adaptation and mitigation measures must have multiplesustainable development benefits, growing crops such as cassava and using themto produce food and energy is a realistic means to get people out of hunger andpoverty without compromising the environment. Thus we embarked on a studyto determine the feasibility of using non-food parts of cassava in production ofenergy (ethanol), leaving the root for food. It was realised that cassava peels andstems have high dry matter contents (over 28%) with considerable amounts ofcellulose comparable to the dry matter of the starchy roots. These were hydrolysedto produce over 8.5 g sugar per 10 g of feed stock. After fermentation, over 60%ethanol was produced with an average PH of 2.85, clarity of 74-84% transmittanceand conductivity of 368 mV. The results show how promising the non food parts ofcassava are for production of ethanol. Thus instead of wastage, these plant parts canbe utilised to provide income, and mitigate the effects of climate change. 126
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa103. Biochemical and morphological properties of Cassava as selection indicators for drought tolerance Nuwamanya Ephraim1, BagumaYona2 and Rubaihayo Patrick3 National Agriculture Research Organisation (NARO), Uganda; 2Namulonge Crops 1 Resources Research Institute, Kampala, Uganda; 3Department of Crop Science, Maker- ere University, Kampala, UgandaAbstractElevated heat and low moisture stresses are the main deterrents of crop productivityworldwide. Their effects on plant morphology and physiological behavoir resultinto severe yield losses and unitended effects on yield components of the plant.In the search for varieties tolerant to the above stresses, a field experiment wasset up in the drought prone area of Kasese in western Uganda. The area receivesminimal rainfall and experiences higher than normal average temperature rangingfrom 33-360C during the day and about 22-280C at night. A randomised completeblock design was used with two replications for the stressed and non stressedplots. Twenty (20) disease free accessions collected from different parts of Ugandawere used in screening experiments. Tolerance to stress was assesed by studies onplant morphology by including growth parameters on the leaves, stems and roots.Biochemical studies were done on the level of low molecular weight carbohydratesand sugars, protein contents, levels of amino acids, chlorophyll content andcarotenoids. Preliminary results for six months already show the importance ofusing phenotype related properties in selection for drought tolerance. Variationswere observed for plant growth parameters such as plant height, height of leaflessstem, leaf length and leaf width, petiole length and leaf retention properties amongthe different varieties used and for the stressed and non stressed plots. Chlorophyllcontent significantly varied and was low for stressed plants compared to theirunstressed counterparts. The level of non-structural carbohydrates and sugars washigh in the stressed plots while the starch content was low in the stressed plotsalthough it didnt vary significantly among different experimental conditions. Theresults show that much as cassava is percieved to be a drought tolerant crop, severemoisture and heat stress has debilitating effects on the plant and thus varietiestolerant to these stresses should be sought for. In addition, it is important to notethat morphological and biochemical properties which can be easily determinedare important selection tools for tolerance to a number of stresses even at fieldlevel. Comprehensive molecular and genetic analyses however need to be done toascertain observed phenotypic differences. 127
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa104. Contribution to the availability of fertilizers by transforming cow’s horns, cow’s bones, cow rumen content, rice’s peels ashes and sawdust into local fertilizer in bukavu. (DRC South Kivu). Mwabi Ngama Alexandre 1 Societe Cooperative Umoja, DR CongoAbstractAgricultural activities is the main way to fight against poverty in the humidhighlands in Sub Saharan Africa. Unfortunately the population have manyagricultural constraints to have access to means in order to improve its livehood.For increasing crop production, most of Sub Sahara countries have to use fertilizerbut to find factories which are leading to manufacture fertilizer is so difficult in thispart of Africa. Aware with this situation, a peasants cooperative named SOCOOPU( Société Coopérative Umoja) is transforming in Bukavu some unvalorized wasteslike cow’s horns, cow’s bones, cow rumen content, rice’s peels ashes and sawdustinto a fertilizer named «Engrais Biotropical R.D.Congo» which is produced underpowder form. The objective of this research is develop and establish the infrastructurewhich is necessary to produce an organic, eco-friendly and sustainable fertilizerfrom agricultural and animal biomass in large quantities. The following positiveimpacts of the project are expected:- Introduce a new technology and contribute to the fight against poverty by moving towards modern agriculture in highly professional and sustainable way.- Considering the environment, the research will contribute to improve the surroundings of certain socio-economic infrastructures like: slaughter houses, rice and wood processing plants.Results found after comparison of the effect of this fertilizer with NPK(17.17.17)on some crops like tomatoes, potatoes and maize crops respectively in 2004 and2010 in Rwanda, have shown that this local fertilizer has improved crops yield morethan this imported fertilizer NPK(17.17.17) which is manufactured abroad, then notavailable in Rwanda and D.R.Congo 128
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa105. Pyretrum Residues on Maize Dry Matter Yield and Improved Phosphate Responses in Andisols in Northern Region, Rwanda Nabahungu L.1, Nuwumeremyi J.1, Mukuralinda A.2 and Ngenzi G.1 1 Rwanda Agriculture Boad (RAB), Kigali, Rwanda; 2World Agroforestry Center (ICRAF), RwandaAbstractThis study was conducted under green house of the Agronomic university ofRwanda with the aim to study the effect of pyrethrums residues combined withTSP on the improvement of phosphorus response and maize dry matter yield inan Andisol of Kinigi, Ruhengeri, Rwanda. The Katumani variety of maize has beenused as crop test. The methodology was a randomized completely blocks designwith three replicated. Fertilizers used were TSP, fresh pyrethrums residues plusTSP and the decomposed pyrethrums residues plus TSP. Treatments were appliedaccording on the increasing dose of phosphorus. The soil used was low in Bray 1 Pwith 4.27 mg kg-1 of soil while the total phosphorus was very high with 2328 mgkg-1 of soil. The P Bray 1 increased with the increasing dose of TSP. A combinationof Pyrethrum residues composted with TSP improved P responses and dry matteryield appreciably compared to other treatments. The highest value of P efficiencywas 23.13 % in the treatment with pyrethrums residues decomposed plus TSP (75kg P ha-1), while the lowervalue was observed in the treatment with TSP alone(25kg Pha-1). The correlation between studied parameters and applied treatmentswere positive and highly significant. 129
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa106. Development of ELISA for the detection of Xanthomonas campestris pv. musacearum Nakato V.1, Akinbade S.A.2, Kumar L.3, Bandyopadhyay R.4 and Beed, F.1 1 International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 2Interna- tional Institute of Tropical Agriculture (IITA), Ibadan, Nigeria; 3International Crops Research Institute for the Semi-Arid Tropics, Patancheru, India; 4Department of As- tronomy, University of Florida, Gainesville, USAAbstractXanthomonas campestris pv. musacearum (Xcm) is the causal organism of BananaXanthomonas Wilt (BXW) of banana (Musa spp.) in the Great Lakes region of Africawhich incorporates Burundi, Kenya, Rwanda, Tanzania, Uganda and DRC. Rabbitpolyclonal antibodies (PCAs) were produced against pure isolates of Xcm fromUganda and used to develop a direct antigen coating enzyme-linked immunosorbentassay (DAC-ELISA) for the detection of Xcm in infected banana tissues. In DAC-ELISA, the PCAs were specific to Xcm and did not react with Xanthomonas vasicolapv. vasculorum of maize and sugarcane, Xanthomonas vasicola pv. holcicola ofsorghum or Escherichia coli. The working dilution was used to determine up towhich PCA dilution ELISA was able to detect Xcm and was observed to be 2.5 x10-2 and 5 x 10-2 for 1:10000 and 1:5000 PCA dilutions respectively. Sensitivitywas carried out to compare how sensitive the PCA dilutions were to Xcm and otherXanthomonads and in the different plant plants. Sensitivity is important especiallywhen the need to detect infection in asymptomatic plants is necessary. Antibodysensitivity was 6.25 x 10-6 for pure Xcm cultures. The PCAs detected Xcm fromall infected banana tissues e.g. pseudostem, leaves and flowers. The use of PCAwas found to reliably detect Xcm when compared to PCR diagnostic and culturingmethods using semi-selective media. The development of PCAs for Xcm could befurther developed into lateral flow devices for use in the field or at border points forthe detection of Xcm. 130
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa107. Integrated Pest Management in Banana Plantations in Cameroon: Role Model for Smallholder Farmers Nambangia Justin African Research Center on Bananas and Plantains (CARBAP), CameroonAbstractCameroon is a Central African Nation with agriculture as its main economic activity.Agriculture accounts for about 45% of the Gross Domestic Product and employsabout 70% of the people. In order to boost income generation and food security,the government has been putting every effort to improve/increase production ofstaple food crops like banana/plantains. This move by the government has beenresulting to emergence of medium-to-large banana/plantain farms by individualsor groups. To really maintain yield of these emerging farms, there is real need forintensification. Generally, intensive agriculture will involve application of manytechniques that will ensure plant health and yields. Most of the smallholder farmersdo not have adequate knowledge on the these techniques. Most of these farmersare therefore copying the techniques used in the large commercial plantationslocated in the Littoral and SouthWest Regions of the country. In these plantations,Integrated Pest Management (IPM) is a common strategy used and includes cropsanitation, wise use of pesticides, monitoring of pests/diseases, pruning, and use offertilizers. Although these emerging farms are nearer the Regions where these largeplantations are found, and most of the farmers work or had work in the plantations,they still face certain problems not evidence in the large commercial plantations.Some of the problems include agrochemicals not usually available or very expensive(no government subsidies), injudicious use of pesticides, lack of basic bio-ecologicalinformation on pests/diseases. The urge to intensify coupled with some of theseproblems is resulting to environmental problems such as deforestation, pressureson biodiversity and loss of ecological services. Ways of minimizing some of theseproblems are discussed; typically, regular organization of workshops/trainings forfarmers and re-launching of government subsidies to resource-poor farmers areparamount. 131
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa108. Variations in on-farm plant densities and their impact on yield in low input East African Highland banana (Musa spp.) cropping systems: A case study of Rwanda Ndabamenye Telesphore1,4, Van Asten P.2, Vanhoudt N.3, Blomme G.4, Annandale J.5, 8 Swennen R.6, Bagabe M.C.X, Sallah P.Y.K and Barnard R.9 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 2International In- stitute of Tropical Agriculture (IITA), Kampala, Uganda; 3Belgian Nuclear Research Centre (SCK•CEN), Biosphere Impact Studies, Boeretang, Belgium/Hasselt Univer- sity, Environmental Biology, Diepenbeek, Belgium; 4Bioversity International, Kampala, Uganda; 5Department of Plant Production and Soil Science, University of Pretoria, Pretoria, South Africa; 6Katholieke Universiteit Leuven, Leuven, Belgium; 7 Crop Pro- tection Unit, Rwanda Agricultural Research Institute, Kigali, Rwanda 8Crops Research Institute, Kumasi, Ghana;9 Institute of Plant Sciences, Zurich, SwitzerlandAbstractBananas are a primary food and cash crop for smallholders in Rwanda and much ofthe East African Highlands. Their production declines due to poor farm managementand decline of soil fertility. Farmers still believe that among the yield improvingfactors, plant density management offers some prospect. Farmers use bunch sizeas their indicator of yield. They often decrease banana mat (i.e. a single motherplant with interconnected suckers) densities in an effort to increase bunch size, butthe effectiveness and profitability of this practice has never been studied. Further,not much research has been executed to report on the variability in plant density.An on-farm survey was conducted in contrasting agro-ecological sites of Rwanda(Ruhengeri, Rusizi, Bugesera, Ruhango, Butare, Karongi and Kibungo) to determineexisting densities and their impact on yield. A plant density assessment method wasused that measures the average distance of five mats to their respective nearest fourmats to calculate the average mat spacing. Plant densities (mats ha-1) and yields(t ha-1) respectively ranged from 2326 and 35.8 in Ruhengeri, to 2130 and 35.1 inRusizi, to 1513 and 18.0 in Bugesera, to 1509 and 20.3 in Ruhango, to 1491 and 17.8in Butare, to 1416 and 30.2 in Karongi, and to 1006 and 20.4 in Kibungo. The densitywas strongly positively correlated with rainfall (R2 = 0.80), whereby high plantdensities (>1500 mats ha-1) were found in high rainfall areas (>1300 mm year-1) andlowest plant densities (1000-1500 mats ha-1) were found in lower rainfall areas (900-1200 mm year-1). Lower soil and leaf banana nutrient contents (especially N, K, Caand Mg) were observed on weathered soils (Acrisols) and were accompanied by lowyields in comparison to fertile soils (Andosols, Nitisols). Farmers tended to reducemat densities if (i) they wanted to intercrop, and (ii) to increase bunch mass to adaptto market preferences. The plant densities recommended by extension bodies (3 × 3or 2 × 3 m; i.e. 1111 and 1666 mats ha-1, respectively) are not practiced by farmers,nor do they seem to be very appropriate, as higher densities seem more productivein areas with high rainfall and relatively good soil fertility. 132
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa109. Effects of plant density on growth and yield of East African highland bananas (Musa spp.) in low input cropping systems in Rwanda Ndabamenye TelesphoreX, Van Asten P.2, Blomme G.3, Ragama P.X, Swennen R.5, Annandale J. X, Vanlauwe B. 7 and Barnard R.X 2 International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 3Bioversity International, Kampala, Uganda; 5Katholieke Universiteit Leuven, Leuven, Belgium; 7 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya;AbstractNumerous studies reported on the effects of plant density on the growth and yieldof dessert bananas in the humid tropics but plant densities for smallholder farmersin low input East African highland banana (Musa spp., AAA-EA genome) croppingsystems are virtually not studied. On-station field experiments were conducted inthree low input contrasting agro-ecological sites of Rwanda (Kibungo, Rubona andRuhengeri) to determine the effect of plant density on vegetative growth and yieldof AAA-EA cultivars over two cropping cycles. The plant densities (plants ha-1) of1428, 2500, 3333, 4444 and 5000 were tested. Two cooking (Ingaju, Injagi) and one beer(Intuntu) cultivars were used. Effect of density on plant growth (height and girths)varied by site and was influenced by cultivar type. Due to intra-mat competition,increasing plant density resulted in taller plants with thin pseudostems in Kibungo.In Rubona and Ruhengeri, both plant height and girths increased at 4444 and 5000plants ha-1 with a positive effect on pseudostem volume. Changes in leaf area index(LAI) showed that it decreases from Kibungo to Ruhengeri and it was 3.6, 3.6 and2.8 at 95%, 93% and 96% as the maximum intercepted solar radiation in Kibungo,Rubona and Ruhengeri respectively. The crop cycle was extended with increasingplant density and site effect was significant. The effects of site and density on yieldtraits were also significant. Ruhengeri as more fertile and rainfed site favouredhigh significant increase (64.7) in bunch mass compared to Kibungo (-25.3) andRubona (-35.1). Agronomic and economic yields were function of cultivars and sites.Compared to low, high densities resulted in higher yields per ha (i.e. about 56%, 52%and 69% increase in t ha-1 for Kibungo, Rubona and Ruhengeri respectively). Yieldsof beer cultivars were significantly increased under high densities but the reverseoccurred for cooking cultivars. Agronomic annual yields were at the maximum(plateau) at 3333 and 4444-5000 plants ha-1 in Kibungo and Rubona respectively buta linear increase in yield was found at 5000 plants ha-1 in Ruhengeri. High densitiesresulted in lower economic yields in both Kibungo and Rubona but relatively positivenet monetory returns per ha were accounted for in Ruhengeri. Despite, we suggestthat both agronomic and economic optimal plant densities are lower (< 3333 plantsha-1) in dry and less fertile area but seem to be higher (> 4444 plants ha-1) in rainfedand relatively fertile area. Therefore, plant densities higher than 3333 and 4444 plantsha-1 are unsuitable and would result in an unsustainable system. 133
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa110. Maize and soybean intercrops under different planting patterns in Nyakigando (Eastern Province of Rwanda): Land equivalent ratio LER. Ndayisaba Celestin1, Vanlauwe Bernard2, Pypers Pieter2, Gahigi Aimable3 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Land and Natural Resource Management Unit, / Kenyatta University, Nairobi, Kenya; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 3ISAR/CIALCA project, Umutara, RwandaAbstractA study was conducted in Nyakigando, Nyagatare District, in the Eastern Provinceof Rwanda during 2009 A season (September 2008 to February 2009). The studywas established in 9 different farms of small holder farmers to investigate benefitsassociated to intercropping compared to mono cropping. Mono cropping treatmentsof maize (53333 plants/ha) and soybean (266666 plants/ha) were compared to 2:2and 2:1 (soybean: maize) which had 53333 plants of maize and 266666 plants ofsoybean, and 40000 plants of maize and 266666 plants of soybean/ha respectively.Soybean and maize in mono cropping were planted at 75 cm X 5 cm and 75 cm X50 cm respectively. In 2:2 rows arrangement, a pair of soybean rows (33 cm X 5cm) was planted on 1 m separating two pairs of maize rows (50 cm X 50 cm was aspacing in paired rows of maize). In 1:2 rows arrangement, a pair of soybean rows(33 cm X 5 cm) was planted on 1 m separating two single rows of maize (1m X 50cm). Intercropped soybean was affected by the associated maize. Yields were higherin mono crops, followed by 2:1 and lastly by 2:2. Yields were significantly differentbetween mono cropping and intercropping, and between intercropping treatmentsthemselves. Maize yields were significantly different only in mono crop. They weresimilar for 2:1 and 2:2. The LER means were 1.279 and 1.178 respectively for 2:1 and2:2, indicating the superiority of intercrops to mono crops equivalent to 27.9% and17.8% respectively for 2:1 and 2:2. 134
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa111. Yam Bean (Pachyrhizus spp.) a Potential New Crop for Rwanda Ndirigwe J.1, Tumwegamire S.2, Musabyemungu A.1, Kankundiye L.1 and P. Ndayemeye1 Institut des Sciences Agronomiques du Rwanda, Sweetpotato Programme, Huye, 1 RWANDA; 2 International Potato Center (CIP), P. O Box 22274, Kampala, Uganda.AbstractThe root and tuber crops produced by legumes have long been recognized asimportant, and the FAO has recommended them as a source of human nutrition(FAO, 1989). Yam bean (Pachyrhizus spp.) is one of few tuber forming legumeswith excellent multipurpose dualities and uses. Originated from Central and SouthAmerica, this plant shows by far the widest adaptation to environmental stressconditions, no requirements of nitrogen fertilizer, high storage root starch yieldslinked with high protein and micro-nutrient concentrations, and the potential use ofroots and seeds makes the yam bean a potential source to develop a new nutrient-rich staple for Rwanda. It has additional advantage in contrast to common growntropical root and tuber crops (cassava, potato, sweetpotato and yam) that yam beanplants have an efficient symbiotic relationship with rhizobia and that they are easilypropagated by seeds and have fewer problems with pathogens transmitted bypropagation than clonally propagated crops. Recent introduction of different yambean accessions in low and mid altitude zones of Rwanda produces heavy storageroots that weigh between 300 and 4000 g and have relatively high protein, zinc andion content. Tubers have a protein content of 8-18% (dry weight) based on recentanalysis of more than 8 accessions. Tuber is always eaten and may be processed inmany products. 135
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa112. Evaluation of performance and acceptability of new selected yellow and orange-fleshed sweetpotato at Rubona Ndirigwe J.1, Nyampinga I.2, D. Shumbusha1, and C. Ndatimana3 Institut des Sciences Agronomiques du Rwanda, Sweetpotato Programme, Huye, 1 RWANDA ; 2Univeristé Nationale du Rwanda, Faculty of Agriculture, Huye, RWANDA ; 3Kabutare Secondary School, Huye, RwandaAbstractOrange fleshed sweetpotato play an important role in combating vitamin A deficiency.Efforts are underway to develop high beta-carotene sweetpotato varieties. Ninepre-released and introduced orange-fleshed sweetpotato (Ipomea batatas) cultivarswere evaluated at Rubona to assess their acceptability and their yield performance.Kwezikumwe were used as standard local check. Those genotypes were combinedand evaluated for agronomic and post-harvest acceptability for specific traits suchtuber skin colour, flesh appearance, foliage coverage, resistance to diseases andpests, root yields, taste, flavour, starchiness, fibreness and general acceptability tomeet preferred traits of farmers to ease acceptability. Variety 97-062 was ranked bestfor roots yield (18.08 t ha-1) across seasons and other different attributes. GenotypesCacearpedo, 19902/1, and 97-062 had high amount of beta-carotene content of1355U RHS 9/2 each followed by SPK-004 with 1205U RHS 3/3. A comparison intrend of different attributes on post-harvest evaluation showed that there is a strongpositive relationship in sweetness, dry matter and general acceptability. For allattributes, genotypes SPK-004, Cacearpedo and Kwezikumwe also ranked higherfor consumer acceptability attributes by farmers. Findings showed that farmers arelikely to select their preferred varieties according to their own criteria, skills andexperiences. 136
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa113. Micropropagation and in vitro radio sensitivity test in Congolese Cassava (Manihot esculenta Crantz) accession Ndofunsu A.1, Luyindula N.1, Kembola k.1, Bulubulu O.1, Kikakedimau N.1, Chikelu M2 and Jankowicz J.2 1 Commissariat Général à l’Energie Atomique, Kinshasa, DRC; 2Plant Breeding Unit, FAO/IAEA, Biotechnology and Agricultural Laboratory, Vienna, AustriaAbstractCassava is the main source of dietary starch and householdd income for over70 percent of the population in DRC. Considering the limitations for the use ofconventional methods in the improvement of this important crop, induced mutationoffer unique opportunities to enhance genetic variability exploitable for someagronomic traits improvement such as pests resistance, high yield. In vitro cultureof Cassava (Manihot esculenta) var. Boma Genotype obtained by meristems culturein MS medium supplemented by 20 g/l of sucrose in continued light and wereexposed to Cobalt-60 gamma irradiation to determine the optimal doses for eventualuse as orientation for selection of effective mutagenic treatments that can induceusefull genetic changes. Nodal segments were irradiated with different doses (5,10, 15, 20, 25 and 30 Gys) while a control badge was not irradiated, the dose leadingto an average 50 percentage damage was determined as the optimal dose (6 Gy).The promissing Cassava mutant obtained by irradiation mutation combined withtissue culture technics can be selected and may have high potential for agriculturalintensification in humid highland systems of subsaharian Africa region. 137
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa114. Soil phosphorus fractionations and phosphorus-use efficiency of faba beans (Viciafaba L.) in the highlands of southwest Ethiopia Nebiyu Amsalu1, Diels Jan2 and Boeckx Pascal3 1 Jimma University, Jimma, Ethiopia; 2Division of Soil and Water Management, Faculty of Biosci- ence Engineering, Katholieke Universiteit, Leuven Kasteelpark, Heverlee, Belgium; 3Ghent University, BelgiumAbstract:Low phosphorus availability limits crop production in acid soils of the tropics.Understanding the forms and dynamics of P in soils and improving P uptake andutilization efficiency of crops may reduce this problem. This study was conducted toinvestigate the status of soil P fractions and pools and P utilization efficiency of fababeans in the humid tropics of Southwestern Ethiopia. Phosphorus fractions in soilsof varying depth were examined with sequential extractions. The response of fababean varieties to P application on grain yield formation, P uptake and utilizationefficiency of selected faba bean genotypes grown at farmer’s fields without (0 kg)and with (30 kg ha-1) P fertilizer as triple super phosphate was also assessed. Pfractionation results indicated that the sum of all the P fractions ranged from 648to 1024 mg P kg-1. The slowly available P pool accounted for the largest P fraction(57-67%), the readily available P for the smallest proportion (5 - 6%) and the resinP (the most labile P form that is available to plants) for the lowest (1%) indicatingthat P is a limiting factor for crop production and calls for replenishment andincreasing the bioavailability of soil P stocks to ensure sustainable crop productionin southwestern Ethiopian agro-ecosystems. Results from a field experiment showedthat grain yield was significantly (P<0.05) affected by variety and P application.Without P fertilization, grain yield ranged from 2.3 to 5.7 t ha-1. With P fertilizationhowever, this range was from 4.1 to 5.9 t ha-1. Yields were generally higher with Papplication for varieties Obse (5.9 ±0.77) and Degaga (5.8 ±0.16) with a P responseof 68.6 and 48.7%, respectively. Grain yield response to P application generallyranged from -7.0 (Moti) to 78.3% (Gebelcho), while the range of apparent P recoverywas 19.7 to 42.6 % as measured by the difference method and 73.4 to 97.5% by thebalance method for varieties CS-20DK and Obse, respectively. Variety Moti wasnon-responsive to P application but was efficient in utilizing P however Gebelchowas highly responsive but not efficient. Correlation analyses between grain yieldand P parameters revealed that P concentration in plant parts and total shoot Pcontent were not necessarily associated positively with grain yield and total grain Pcontent. However grain yield was positively correlated with P utilization efficiencyat 0 kg P application (r= 0.915**). Total P yield and utilization efficiency contributedmore to grain yield formation in faba beans at both P levels. This study may helpin selecting P efficient varieties in low-P soils. Therefore, variety Moti would besuitable in farming systems where little or no fertilizer is used and where cropyields are associated with subsistence farming. On the other hand, variety Obseand/or Degaga could fit well in cropping systems where access to P fertilizer oraffording to buy it is possible. 138
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa115. Performance of elite Faba Bean (Vicia faba L.) varieties at two different altitudes on Nitisols of southwestern Ethiopia Nebiyu Amsalu1, Diels Jan2 and Boeckx Pascal3 1 Jimma University, Jimma, Ethiopia; 2Division of Soil and Water Management, Faculty of Biosci- ence Engineering, Katholieke Universiteit, Leuven Kasteelpark, Heverlee, Belgium; 3Ghent University, BelgiumAbstractA field experiment has been carried out involving fifteen elite faba bean varietiesand a local variety in RCBD with three replicates at Jimma and Dedo, southwesternEthiopia, in 2007/2008 cropping season. The aim was to evaluate varieties foradaptation and grain yield performance allowing selection and promote adaptablevarieties for further integrated soil fertility management practices. Combinedanalysis of variance showed that the effect of location was highly significant (P<0.01)on plant height, pods per plant, seeds per pod and grain yield per hectare. Themain effect of variety was highly significant on plant height, 1000 seeds weight andgrain yield per hectare. The interaction effect of location and variety was also highlysignificant (P<0.01) on 1000 seeds weight and grain yield. The highest grain yieldat Dedo and Jimma was obtained with the local variety (3.1 t ha-1) and Walki (1.9 tha-1), respectively. Average grain yield for Dedo and Jimma was 2.3 and 1.2 t ha-1,respectively. Out of the total variation observed for grain yield, a relatively largevariation (40.1%) was accounted for by the location. The remaining was due to theinteraction effect (25.6%), varieties (15.7%) and the block and error term together(18.6%). No variation was observed in nodule number for variety, location or theirinteraction. Correlation analysis among yield and yield components indicated thatgrain yield was highly significantly and positively (P<0.01) correlated with plantheight and seeds per pod at Dedo and with plant height and pods per plant atJimma. The present study highlighted that most varieties showed good adaptationand grain yield performance predominantly at Dedo and pointed out to the presenceof potential faba bean varieties for production in the region and similar areas.However, quantifying the magnitude of nitrogen fixation and balance is requiredto evaluate the potential of faba bean to contribute to long-term crop productionstability and effects in legume-cereal rotation. 139
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa116. Maize response to macro and micro nutrient fertilizer combinations across nutrient deficient smallholder fields in western Kenya Njeru, C1 ., Ashiono, G1., Esilaba, A1 ., Huising, J2., Kihara, J 2 and Okoth, P 2 Kenya Agricultural Research Institute (KARI), Kakamega, Kenya; 2 Tropical Soil and 1 Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; AbstractCurrent fertilizer blends mainly combine nitrogen, phosphorus and potassiumminerals, with only a few blends incorporating sulfur, calcium and magnesium intheir formulations. However, variable crop responses by different fertilizer blendsdue to variability in macro and micro nutrient deficiencies in smallholder farmsrequire improved and targeted blending for increased agronomic and economicefficiency. A study was conducted to determine factors that limit cereal cropgrowth, including nutrient deficiencies, soil chemical imbalance and physicalconstraints and, their relative importance to overall crop productivity. Thirty-twofield experiments were established during 2010 short rains season in Gem andUgenya districts of western Kenya, with each field established 8 partially replicatedtreatments. Crop growth, grain yield and dry matter accumulation were assessed inresponse to application of two (N, P), three (N, P, K) and multi-nutrient (macro andmicronutrients) fertilizer combinations under different altitudes, moisture regimes,striga density and farm management conditions. Treatment effects were subjectedto a generalized linear model analysis using SAS statistical software. Treatmentslocated in higher altitudes (above 1350 m.a.s.l) resulted to higher (62-72 %) grainyields compared to treatments established in lower altitudes (below 1349 m.a.s.l)with the 3-mineral fertilizer blend giving higher yields relative to 2-mineral blendsacross both altitudes ranges. Similar treatment’s trend were observed in fieldslocated in areas with higher mean monthly rainfall (41.7 mm) compared to thoselocated in lower mean monthly rainfall (< 20 mm). Multi-purpose (N, P, K andmicro nutrients) treatment produced 37-86 % better grain and DM yields comparedto two and three fertilizer combination across fields situated in high, medium tolow soil striga seed density areas. All treatments produced the highest grain yieldsin outfields compared to midfields and infields, which recorded the high yieldvariability. This study underscores the challenge in identifying suitable fertilizerblends for heterogeneous farming systems in western Kenya. 140
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa117. Identification of high yielding and stable maize varieties for Rwandan mid-altitudes environments Ngaboyisonga Claver1, Nizeyimana Fidele1, Nyombayire Alphonse1, Gafishi Martin K.1, Gahakwa Daphrose2 and Jane Ininda3 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 5Rwanda Agricul- ture Board (RAB), Kigali , Rwanda; 3AGRA, Nairobi, KenyaAbstract:Environmental and biotic stresses such as drought, low fertility, diseases andweeds are causing losses of million tons of maize grain annually in Sub-SaharanAfrica. The utilization of drought tolerant, Nitrogen Use Efficiency (NUE), extra-early maturing, disease and insect resistant maize varieties has boosted maizeproduction in areas where drought and disease infections are severe. Trials,with the objective of identifying suitable varieties for Rwandan mid-altitudeenvironments characterized by frequent drought and infestations of Maize StreakVirus Disease (MSVD) and Turcicum Leaf Blight Disease (TLBD) were conductedin four sites (Rubona, Bugarama, Nyagatare, Karama) in 2009 B and 2010 A. Theyhad 21 entries that included nine new hybrids varities, seven new Open PollinatedVanities (OPVs), one hybrid check and five OPVs checks. Grain yield (t/ha at15 % grain moisture content) and nine agronomic traits were recorded. Multipleregression of the nine traits on grain yield and the AMMI (additive Main EffectsandMultiplicative Interactions) model for grain yield were used to analyze data.The accumulated analysis of variance of the multiple regression showed that sixtraits contributed significantly to sums squares of regression. The AMMI analysisshowed that grain yield variation due to environments, varieties and Varieties ×Environments Interaction (VEI) were highly significant (p<0.01), however varietieseffects accounted for 53.2 % of sums squares of treatments while environments andVEI effects accounted for 30.6 % and 16.2 % respectively. The AM1 biplot showedthat three hybrids varieties (CML442/CML440//CML445, CML312/CML202//CML445 and CML144/CML159//CML182), and two OPVs ( NYA1 and RUB2) hadhigh yields (≥ 8.00 t/ha) and small IPCA1 scores (≤ 0.2) and hence they were stableacross environments. By using AMMI1 and AMM2 biplots and the six selected traitssix maize varieties that were either stable and high yield or possessing useful traitswere identified for mid-altitudes of Rwanda. 141
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa118. Assessing incidence, severity and spread of the Banana Bunchy Top Disease (BBTD) in Oriental Province, North Eastern Democratic Republic of Congo Faustin Ngama Boloy 1, Bonaventure Ibanda Nkosi 2, Benoît Dhed’a Djailo3*, Pascale Lepoint4 and Guy Blomme5 1 IFA-Yangambi, DR Congo; 2Faculté des Sciences agronomiques, University of Kisan- gani (UNIKIS), DR Congo; 3Science Faculty, UNIKIS, DR Congo; 4Bioversity Inter- national, CIALCA Bujumbura office, Bujumbura, Burundi; 5Bioversity-Uganda office, Kampala, UgandaAbstractBananas and plantains (Musa spp) are an important food crop in DR Congo. Bananabunchy top disease (BBTD) is one of the most important biotic constraints forbanana cultivation. BBTD was first identified in DR Congo in 1958 at the INEACYangambi research station. Since then, it has been reported in Bas Congo and theKivus. Disease spread throughout the Congo basin has not been studied. An initialstudy, to determine the incidence and severity of BBTD in banana and plantainproducing regions of OrientalProvince, North Eastern Democratic Republic ofCongo, was carried out during 2009-2010. BBTD surveys were conducted on1,890 farms across 4 districts and 21 territories. 30 mats were assessed per farm.Visible disease symptoms were recorded and immuno enzymological tests usingTAS-ELISA were carried out.An average of 81% disease incidence was observedacross Oriental Province. Disease severity levels were low and ranged from score1 (42%) to 3 (17%). These disease development stages correspond to dark greenstreaks on the leaf veins, dark green streaks on leaf midribs and petioles, andmarginal leaf chlorosis. Only 3-6% of mats had advanced disease symptoms (i.e.,dwarfing of leaves, bunched leaves which stand upright and are brittle).All plantainand banana cultivars grown in farmers’ fields were susceptible to the disease.ThevectorPentalonia nigronervosa was found on 74% of all assessed mats and severalsimple colonies without winged insects were most frequently observed (on 40% ofmats with aphids). All samples collected on plants showing dark green streaks onleaf midribs and petioles and marginal chlorosis of the leaves, and on plants with atypical bunchy top appearance (i.e. severity scores 2 to 5) had positive TAS-ELISAresults. 24% of plants with dark green streaks on the leaf veins (i.e. severity score1) gave negative ELISA results, while 32% of symptomless plants tested positive.Although BBTD is widespread in Oriental Province, disease severity is relative lowwith a corresponding limited impact on production. There is however an urgentneed to carry out immuno enzymological (TAS-ELISA) testing in order to identifyBBTD-free plants for further multiplication of disease free planting materials. 142
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa119. Isolation and characterization of endophytic bacteria of bananas in Kenya Ngamau C.1, Matiru V. N.1, Tani A.2 and Muthuri C.W.1 Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya; 2Institute 1 of Plant Science and Resources, Okayama University, Kurashiki, JapanAbstractThis study was conducted with the aim of isolating and characterizing bananaendophytic bacteria on the basis of their potential as biological fertilizers. Bananamaterial was collected from five different geographical regions in Kenya to enhancediversity. Isolation of bacteria was done using five (5) different isolation mediaand the isolates were characterized on the basis of their morphology, biochemicaland molecular characteristics. A total of 214 bacterial isolates were obtained andcharacterized. Microorganism profiling was done using MALDI-TOF/MS and theisolates were clustered into 53 genotypes. Based on their functional characteristics, 43isolates were selected for 16S rRNA gene sequencing. The 43 strains showed variedlevels of positive nitrogenase activity as measured by the acetylene reduction assayand 37 strains were observed to solubilize phosphates by the formation of visibledissolution halos on agar plates (NBRIP medium). Siderophore production of theisolates was determined using Chrome Azurol S (CAS) agar plates and all the isolateswere observed to be positive for siderophore production with 3 strains showingdistinctively high level of production. Using the 16S rRNA gene sequencing, the43 strains were identified as Serratia spp. (17 strains), Pseudomonasspp. (12 strains),Enterobacter spp. (4 strains), Rahnella spp. (4 strains), Raoultella spp. (2 strains), Bacillusspp. (1 strain), Klebsiella spp. (1 strain), Yersinia spp. (1 strain) and Ewingella spp. (1strain). In conclusion, isolates 48-2 (K32) (Ewingella spp.), 37-2 (ME19) (Rahnella spp.),40-2 (ME18) (Rahnella spp.), 37-3 (ME19) (Rahnella spp.), 2-1 (J1) (Enterobacter spp.),54-2 (K50) (Pseudomonas spp.) and 54-1 (K50) (Pseudomonas spp.) were identified aspotential biofertilizers and greenhouse and field investigations are recommendedfor confirmation of this potentiality. 143
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa120. Planting dates effect on maize yield performance under rainfed conditions in the Central Highlands of Kenya Ngetich F.1, Mugwe J.N.1, Mucheru-Muna M.1, Shisanya C.A.1, Diels, J.2and Mugendi, D.N.1 1 Kenyatta University, Nairobi, Kenya; 2Division of Soil and Water Management, Faculty of Bioscience Engineering, Katholieke Universiteit, Leuven Kasteelpark, Heverlee, BelgiumAbstractRainfed farming systems in the Central Highlands of Kenya have been experiencinglow and declining agricultural productivity. High spatial and temporal variability ofrainfall, reflected by dry spells and recurrent droughts is among the most importantfactors affecting agricultural productivity in the region. With this backgrounda study was set up with the objective of evaluating the effects of planting datesand rainfall variability on observed and simulated maize yield performanceand to assess AquaCrop model performance and efficiency. The study area wascarried out in Mbeere District in Kenya, representing a low potential area in termsof agricultural productivity due to low and erratic rainfall. The trial followed a 3x 2 randomised complete block design replicated thrice. The main factors werethree staggered planting dates (dry planting, wet planting and late planting) whilethe sub factors were two maize varieties. Phenological stages’ durations, dailyrainfall, maximum & minimum temperature, grain and biomass yields were keyparameters. AquaCrop model simulation exercise was carried out after modelparameterization and calibration using crop, soil and climatic data collected fromthe trial site. Analysis of variance was used for analysis of the experimental dataand the differences between treatment means were examined using least squaredifference at 5% level of significance. The performance and efficiency of the modelwas evaluated using root mean square error and correlation coefficients. The trialresults showed 28% significant (p=0.05) increase in dry planted maize stover yieldsduring the long rains season of 2009 followed by wet planting while the simulatedresults followed the same trend. Despite erratic rainfall conditions in the study area,after calibration, AquaCrop model simulations of maize production under differentplanting dates produced reliable predictions. 144
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa121. Impact des résultats de la diversité génétique de la collection régionale bananière sur les communautés rurales Ferdinand Ngezahayo Institute de Recherche Agronomique et Zootechnique (IRAZ), MashitsiAbstractL’Afrique au Sud du Sahara se trouve confronté à de multiples défis notammentl’insuffisance de la production agricole, et l’ explosion démographique sans cessecroissante. Avec une continuelle réduction des superficies cultivables par habitant,la seule solution possible s’avère être impérativement L’intensification agricole. Lasolution à ce problème crucial de l’intensification agricole suppose une maitrise desfacteurs et outils de production. ; parmi ceux-ci - l’utilisation des variétés performantes(productives et résistantes au maladies) - l’ amélioration de la fertilité des sols - la mécanisation agricole etc.Depuis 1983 l’ IRAZ a entrepris la recherche bananière au niveau de la CEPGL et undes volets de recherche est justement l’amélioration variétale . Malgré les crises politico–économiques qui ont secoué la région  ; l’IRAZ possède actuellement une collectionde 299 accessions de bananiers à Mashitsi, et constitue l’une des plus importantescollections du monde au niveau de la diversité génétiques des bananiers d’altitude. Cepatrimoine communautaire constitue un réservoir de matériel végétal très varié avec despotentialités énormes pour l’accroissement de la production alimentaire (rendement,résistance aux maladies et autres stress biotiques et abiotiques). Déjà dès 1988 soit quatreannées après la mise en place de cette collection régionale, les travaux de caractérisationnous ont permis de déceler les 16 meilleurs cultivars au point de vue de – Cycle végétatifcourt - Rendement élevé - Résistance aux maladies - Qualités organoleptiquesA partir de ce matériel végétal performant , différentes expérimentations on étéeffectuées dans la communauté ( essais de comportement variétal à différentes zonesagro-écologiques,essais sur les systèmes de cultures etc. ) L’ IRAZ possède donc certainsrésultats de recherche qui , une fois exploités efficacement pourraient transformer levisage de nos collines et mieux garnir nos plats . Le présent travail cherche à mettre lalumiére sur l’impact des résultats de recherche en milieu réel avec exemple à l’ appui( cas du Burundi, Commune Giheta) mais surtout chercher des voies de sortie pourl’intensification agricole. La question se pose alors en termes de transfert de technologieset à trois niveaux - Recherche – Vulgarisation- Agriculteurs - Ce transfert de technologies implique des méthodologies et approches qu’on pourrait - résumer comme suit  : Au niveau de la recherche ( R.A.P  : recherche –action- participative ) - - Au niveau des agents d’ encadrement et fermiers (S.T.S :Science –technique- Société) 145
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa122. Plant and soil interactions between adjunct coffee and banana plots in Burundi: preliminary assessment in farmer field conditions. Nibasumba Anaclet1, Baret Philippe V.2, Jassogne Laurence3 and Van Asten Piet4 1 Institut des Sciences Agronomiques du Burundi (ISABU), Burundi; 2Université catholique de Louvain, Belgium; 3Université Catholique de Louvain-la-Neuve/ International Institute of Tropical Agriculture (UCL-IITA), Belgium; 4International Institute of Tropical Agriculture (IITA), Kampala, UgandaAbstractCoffee and banana are often occurring together in smallholder farms in Burundi.Some farmers even intercrop coffee and banana although it is strongly un-recommended by extension services. As studied in other countries like Uganda, theobjective of this study is to analyse whether the banana-coffee association could bea possible alternative to coffee monocropping in the agro-ecological conditions ofBurundi. Because currently farmers do not intercrop coffee and banana in Burundi,we decided to do a preliminary assessment based on observation of farmer systemswhere banana and coffee were planted side by side.Sixty plots in the regions ofKirimiro and Buyenzi were studied for yield and yield components (e.o. density,bunch weight, weight of 100 cherries) of both banana and coffee. Soil and foliarnutrients were measured and a agricultural practises were described. In each plot,four subplots were considered: coffee far from banana, coffee close to banana, bananaclose to coffee and banana far from coffee.The first analyses points out to significantdifferences for banana yield close and far from coffee and coffee quality close and farfrom banana. Mulch application and water conservation and availability seem to beimportant explanatory factors for these differences.Those preliminary observationsraise very interesting insights for the organisation of fully controlled trials and forthe discussion of the extension of intercropping recommendations at larger scales. 146
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa123. Impacts of banana xanthomonas wilt disease on banana productivity and livelihoods of farm households in Burundi Niko Nicolas1, Ndayihazamaso, P.2, Jogo, W.3, Karamura, E.3, Lepoint, P.4, and Tinzaara, W.3 1 Institut des Sciences Agronomiques du Burundi, Burundi; 2Institut des Sciences Agro- nomiques du Burundi, BP 795 Bujumbura, Burundi; 3Bioversity International, Kam- pala, Uganda 4Bioversity International, Bujumbura, Burundi;AbstractBanana is a major staple food for the majority of households in Burundi with anestimated annual per capita consumption of 300 kg. The crop occupies more than25% of agricultural land. Banana production is estimated at 1,549,164 tones per yearmaking banana the first crop in terms of production volumes. This counts for 40%of total food production and 15% of GDP. Besides its nutritional and economic roleat national and household levels, banana plays an important environmental role asit protects against soil erosion. However, the crop is threatened by several diseasesincluding Black sigatoka, Bunchy top, Cigar end rot, Fusarium wilt, Cercospora andBanana Xanthomonas Wilt (recently confirmedin 7 of the 17 provinces, 5 of whichborder Tanzania). A study was carried out in the affected provinces to assess theimpact of the disease on banana productivity and livelihoods of farm households.In each of the 7 affected provinces, two communes were selected and 6 households(3 affected and 3 unaffected) were, in turn, randomly selected from each commune,making a total of 84 households surveyed. The results indicated that on average,33% of the total banana mats per farm were infected with BXW (since its arrival).Compared to pre-infection levels, the total banana yield loss due to BXW infectionwas estimated at 30–52%, hence a reduction in the amount of bananas harvested byfarm households. This in turn had negative livelihood impacts on?. Switching frombanana to other crops such as ; reduction of banana-based meals and reduction insales of own-produced bananas were the main strategies used by affected householdsto cope with the disease. The study concludes that public awareness in general andempowering farmers in particular will be crucial in the fight against the epidemic. 147
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa124. Farmers’ knowledge and its application to control of banana diseases in Burundi Niko N. 1, Ndayihazamaso, P.1, Niyongere C.1, Karamura, E. 2, Lepoint, P. 2, Tinzaara, W. 2 and Jogo, W. 2 1 Institut des Sciences Agronomiques du Burundi, Bujumbura, Burundi; 2Bioversity International, Kampala, UgandaAbstractIn Burundi, banana has an important role in the socioeconomic life of the country,being grown as a food security crop in all agro-ecological zones. Unfortunately,this crop faces a number of biotic stresses including diseases and pests that limit itsproduction. ,. In previous studies, the main constraints reported in the production ofbananas in Burundi were Fusarium wilt, Banana Bunch Top Disease (BBTD), blacksigatoka, weevils and nematodes. Since, Banana Xanthomonas Wilt (BXW) has beenreported in neighbouring DR Congo, Rwanda and Tanzania and is considered asan additional threat to banana production in Burundi. Hence a baseline survey wascarried out to establish distribution and incidence of banana diseases and pests inBurundi and determine farmers’ knowledge and its application to control bananadiseases. The survey was preceded by training of enumerators on disease recognition,spread mechanisms and control measures. The survey was carried out in December2009 in four key provinces of Burundi including Cibitoke (bordering DR Congo)Kirundo (bordering Rwanda), Muyinga and Makamba (bordering Tanzania). Inthe provinces surveyed, the main banana diseases and pests were Fusarium wilt onKayinja cultivar (site Provinces); BBTD on Yangambi Km 5; Armillaria corm rot, blacksigatoka, weevils and nematodes on highland bananas. Farmers ranked BBTD andFusarium wilt as the most critical diseases threatening household food security andincome. Black sigatoka, weevils and nematodes were most widely distributed acrossthe country, but locally and for specific cultivars, BBTD and Fusarium had the highestincidences in western and rift valley regions of the country. The survey underlined thatfarmers were unaware of BXW symptoms, spread mechanisms or control measures.Moreover, farmers regularly used cutting tools to de-bud, de-sucker, de-trash, harvestleaves and bunches, weed and remove corms. This lack of knowledge poses a potentialhurdle to effective management of banana diseases in Burundi. 148
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa125. Occurrence, distribution and farmers’ awareness of banana bunchy top disease in affected regions of Burundi, Eastern DR Congo and South-Western Rwanda Célestin Niyongere1&2, Turoop Losenge2, Elijah Miinda Ateka2, Désiré Nkezabahizi3, Pascale Lepoint4 and Guy Blomme5 1 Institut des Sciences Agronomiques du Burundi (ISABU), Bujumbura, Burundi; 2 Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya; 3University of Lake Tanganyika, P.O Box 5403, Mutanga, Bujumbura, Burundi; 4Bioversity International, CIALCA Bujumbura office, Bujumbura, Burundi; 5Bioversity International Uganda office, Kampala, UgandaAbstractBanana bunchy top disease (BBTD) was first reported in 1958 in sub Saharan Africaat the INEAC Yangambi research station in the Democratic Republic of Congo (DRCongo). Diseased plants were reported in 1987 in the Rusizi valley encompassingthe border regions of Burundi, Eastern DR Congo and Rwanda. Since then, no studyabout BBTD had been carried out in this region. A diagnostic survey was conductedfrom September to October, 2008 in three provinces (Bujumbura rural, Cibitoke andBururi “Rumonge”) of Burundi, two districts (Kamanyola and Nyangezi) in SouthKivu, DR Congo and the Rusizi district in the Western province of Rwanda. A totalof 7,830 banana mats, 30 per plot, were assessed on 261 farms (196 in Burundi, 34in Eastern DR Congo and 31 in Rwanda). A structured questionnaire was used toassess, cultivar diversity, BBTD incidence and severity, presence and occurrence ofthe aphid vector (Pentalonia nigronervosa Coquerel) and farmers’ awareness aboutBBTDmanagement. Leaf samples were randomly collected on symptomatic plantsfor further PCR analysis to confirm the disease. PCR analysis of samples collectedin the three countries confirmed the presence of BBTV. Similar banana varieties aregrown across the three countries, indicating the cross-border movement of plantingmaterials which may have influenced disease spread over the past decennia. Theregional average of BBTD incidence and aphid occurrence was 25% and 46%,respectively. However, no significant relationship between aphid occurrence andBBTD incidence (R=0.3, P= 0.623) was observed. Among the interviewed farmers,90% were able to recognize advanced BBTD symptoms (bunchy top appearance);while 95% of farmers were unaware of disease management options and statedthat no locally grown cultivar is resistant to the disease. This pinpoints the needfor awareness raising at the level of policy makers, extension services, NGOs andfarmers. In addition, tolerant cultivars need to be part and parcel of control optionpackages. 149
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa126. Is the diffusive gradient in thin films (DGT) technique an effective tool in predicting the phosphate availability to maize (zea mays) in p-deficient soils in Western Kenya? Njoroge R.1, Six, L.2, Okalebo, J.R.1, Otinga, A.N.1, Pypers, P.3, Merckx R.2 Department of Soil Science, School of Agriculture and Biotechnology, Chepkoilel 1 University College, Eldoret, Kenya; 2Departement Aard- en mgevingswetenschappen Afdeling Bodem- en waterbeheer, Katholieke Universiteit Leuven, Belgium; 3Pypers P: Tropical Soil Biology and Fertility Institute of the International Centre for Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya.AbstractMost soils in western Kenya are marked by low phosphorus (P) concentrationsdue to their high affinity to sorb P. Consequently maize production is limited withyields as low as 1 t ha-1 against the estimated potential of 6 t ha-1. Application oflarge amounts of inorganic fertilizers to alleviate the P deficiency is constrainedby cost and availability. Combining organic and inorganic P sources have beenadvocated. Given the high cost of P fertilizer, sound fertilizer recommendations arerequired for P use efficiency. Therefore, an accurate and reliable soil test to assessthe P availability to higher plants in tropical soils is required. The potential of DGT(a novel method) to predict P availability in P deficient soils was assessed againsttraditional methods (Olsen and AEM) using Sega and Kuinet soils. P sources includedvarious combinations of inorganic (TSP) and organic (Tithonia diversifolia and FYM)fertilizers and maize was the test crop. Incubation study tested P availability usingthree different P availability methods. Dry matter (DM) yields and P uptake wasused to assess maize response to P fertilizers. Incubation study showed an overall Pavailability higher in Sega soils than Kuinet indicating stronger P fixation by Kuinetsoil. Response of maize to P fertilizer was observed, with significant increases inbiomass yield (34.45 g and 27.61 g in Kuinet and Sega respectively compared tocontrol (1 g). Non linear regression analysis between the P availability (Olsen, AEMand DGT) and plant response (RY and P uptake) showed good correlation. The R²values ranged from 0.87 to 0.93 for RY and from 0.91 to 0.97 for P uptake. The DGTmethod showed equal potential to measure P availability in P deficient soils as thetraditional methods hence can be used interchangeably. However, more researchto evaluate its potential to test P availability on a wider range of tropical soils isneeded. 150
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa127. Challenges and opportunities for macropropagation technology for Musa among small-holder farmers and small and medium scale enterprises Njukwe Emmanuel1, Ouma Emily1 and Van Asten Piet1 International Institute of Tropical Agriculture (IITA), Uganda office, Kampala, 1 UgandaAbstractLack or shortage of healthy and improved planting material is a major constraintto the expansion of banana and plantain production. The situation is furtheraggravated by the lack of formal systems of producing and distributing qualityplanting materials thereby forcing farmers to depend on natural regeneration ofplants for the supply of planting materials. This is usually a very slow process,producing small numbers of planting materials that are likely contaminated. Toovercome this constraint, several techniques have been developed to rapidlymultiply banana and plantain planting materialsincluding micropropagation underaseptic conditions in the laboratory by culturing plant cells, tissues or organs. Whilethese aseptic production methods can provide large numbers of planting materials,they are not adapted to the conditions of small-scale farmers nor are they routinelyapplicable to agricultural realities of the developing world, particularly in Africa.Therefore, user-friendly techniques that require little technical skills or equipmentwould prove more attractive to adoption by small-scale farmers. Since it is unlikelythat the small-scale farmer will develop the capacity to do micropropagation,IITA has been looking at alternative means of producing planting materials in thecontext to the wide scale distribution of improved banana and plantain varieties.The alternative methods can be classified into two categories: field techniquesbased on complete or partial decapitation and macropropagation, practiced awayfrom the field. Treatment of the suckers to reduce the risks of transmitting soil-borne contaminants is strongly recommended and forms an integral component ofthe dissemination package for small-scale farmers. Macropropagation technique,although genotype-dependent, can produce 8-15 new plants per corm within 15days while scarification of buds has the potential to further increase the numberof plantlets by a factor of 2-3 within the same time. Plantlets obtained through thismethod have the uniformity of micropropagation seedlings while being less proneto post-establishment stress in the field. This method is simple and cheap, althoughit requires minimum investment to set up germination chambers and weaningfacilities, which makes it suitable for small and medium scale enterprising farmers.However, its utilization is undermined by several factors, the most critical of whichis lack of improved varieties resistant to endemic and emerging pests and diseases. 151
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa128. Effectiveness of Banana Xanthomonas Wilt Management Technologies in Kagera region, Tanzania Nkuba J.1, Mukandala L.1, Ndyetabura I.1, Bulili S.1, Mkulila S.1, Tinzaara W.2, Karamura2 E., Jogo W.2 and Rietveld A.2 1 Agricultural Research Institute-Maruku, Tanzania; 2Bioversity International, Kam- pala, UgandaAbstractBanana Xanthomonas wilt (BXW) caused by Xanthomonas campestrispv. musacearumwas first confirmed present in Tanzania in 2006 in Muleba district and since thenit has been spreading and up to 2011 confirmed in all the countries of east andcentral Africa. In Tanzania, after the outbreak of the disease, several measures wererecommended to contain the disease. The ministry of agriculture in collaborationwith local and regional partners tested and disseminated cultural technologies forBXW control. Awareness creation to farmers and other stakeholders were extensivelyconducted. Amongst of technologies disseminated to farmers, included uprootingand destruction of infected plants/mats, de-budding, use of clean planting materials,the decontamination of field tools and quarantine. The approach adopted on BXWdisease control involved sensitization activities, training of trainers, formationand implementation of task forces. This study was conducted to assess adoptionof the disseminated management technologies and to determine their effects onBXW distribution and incidence in the two districts of Bukoba and Muleba districtsof Kagera region, Tanzania. A total of 120 households were interviewed using astructured questionnaire from each of the two districts. The farmers who used therecommended technologies had lower (4%) disease incidences in their farms ascompared to those who did not use them (30%). Among the farmers who wereusing recommended technologies, those who were using them in a package hadreduced disease incidence than those who used them independently. Adoptions ofthe technologies were observed to be influenced by socioeconomic factors, such asawareness of the disease dynamics at the farm level, labour costs and availability.The results generally indicated that all interventions needed to be applied as apackage in order to achieve effective and sustainable management of the disease. 152
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa129. Impact of Banana Xanthomonas wilt on farmers’ livelihoods in Kagera-region, Tanzania Nkuba J.1, L. Mukandala1, S. Bulili1., A. Rietveld2, W. Jogo2, W.Tinzaara4 and E. Kara- mura2 Agricultural Research Institute-Maruku, Tanzania; 1 2 Bioversity International, Kampala, Uganda;AbstractBanana is the main food and cash crop for a large majority of farmers in Kagera regionof Tanzania. Since 2006 however the devastating disease Banana Xanthomonas Wilt(BXW) has been spreading through the region, affecting farmers’ plantations in allof the seven districts grow bananas. The impact assessment study of the disease onfarmers’ livelihoods was conducted in three districts; Muleba, Bukoba and Missenyiof Kagera region. Selection of the sites was based on severity of the disease and agro-ecological zone. Three wards per district were purposively selected and 30 farmers(20 affected by BXW, 10 not affected by BXW) were selected per ward adding to atotal of 120 households. BXW was mentioned as the main constraint to productionby 70% of respondents. Yields of affected farmers have been declining considerably;resulting in sales of banana bunches dropping by 73% and bunch prices doubling.About 63% of respondents mention paying school fees as one of the main uses forbanana sales-income, it is likely that school-enrolment could negatively be affected.Farmers’ coping strategies include reduction of consumption of banana-basedmeals and switching to other crops particularly root and tuber crops. Neverthelessfood security is overall negatively affected. Enhancing the capacity of farmers inappropriate application of recommended control measures is essential in containingthe disease and consequently retaining household welfare levels. 153
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa130. Effect of banana leaf pruning on banana and bean yield in an intercropping system in Eastern Democratic republic of Congo Ntamwira Jules1, Pypers P.,2 Van Asten P.3, Vanlauwe B.2, Vigheri N.4, Badesire A.5and Blomme G.6 1 Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA), DRC ; 2Tropical Soil and Biology Institute of the International Center for Tropical Agri- culture (CIAT-TSBF), Nairobi, Kenya; 3International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 4Université Catholique du Graben, Butembo, NorthKivu, DR Congo; 5Université Catholique de Bukavu(UCB), DRC; 6Bioversity International, Kampala, Uganda AbstractBanana-bean intercropping systems are used by many eastern DR Congolese small-scale farmers to maximize land use and intensify crop production. The shade effectof the banana leaf canopy on bean yield has not been studied in detail. A studywas conducted at the Institut National pour l’Etude et la Recherche Agronomiques(INERA) Mulungu research station to determine the effect of banana leaf pruningon banana and bean yield.The East African highland cooking banana ‘Barhabesha’(Musa AAA-EA group) was established in April 2007 at a spacing of 2 by 3 meter.The treatments consisted of different levels of banana leaf canopy coverage (5 leaves[5L] and all leaves [AL]) and leguminous crop varieties (the bush bean ‘NgwakuNgwaku’ and the climbing bean ‘AND10’) which were planted in the bananaplot. Bean yields were assessed during 4 cropping seasons (2008B, 2009A, 2009Band 2010A).Banana leaf pruning did not have a significant effect on time fromplanting to flowering and time from flowering to bunch harvest for both legumeintercropping treatments. Leaf pruning did not have a significant effect on bananayield for respectively climbing and bush bean intercropping (32.3 and 28.6 t/ha forAL; 32.2 and 26.3 t/ha for 5L). The average banana bunch weight was higher in theclimbing bean (AL: 19.4 / 5L: 19.4 kg) compared to the bush bean intercropped plots(AL: 17.2 / 5L: 16.1 kg).A reduction in the number of banana leaves (i.e., from allleaves to 5 leaves) enhanced bean yield for both legume types. Although this effectwas more pronounced for the climbing bean. Under the all banana leaves treatment,climbing bean yield (358 kg/ha) was slightly but not significantly higher than bushbean yield (335 kg/ha). However, climbing bean yield (512 kg/ha) was significantlyhigher than bush bean yield (362 kg/ha) for the 5L treatment. A cost-benefit analysisof banana-bean intercropping revealed that bean cultivation is more profitablewhen banana leaves are pruned (457 $/ha for bush and 467 $/ha for climbing bean)compared to the all leaves treatment (396 $/ha for bush and 272 $/ha for climbingbean). In addition, the highest legume profits are obtained during season B whichhas lower rainfall levels and hence a lower incidence of fungal diseases comparedto season A. 154
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa131. Effect of banana leaf pruning on legume yield in banana-legume intercropping systems in Eastern Democratic Republic of Congo Ntamwira Jules1, Pypers P.2, Van Asten P.3, Vanlauwe B.2, Ruhigwa B.4, Lepoint, P.5 and Blomme G.6 1 Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA), DRC; 2Tropical Soil and Biology Institute of the International Center for Tropical Agri- culture (CIAT-TSBF), Nairobi, Kenya; 3International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 4IFA, Institut Facultaire des Sciences Agronomiques de Yan- gambi, DRC; 5Bioversity International, Burundi; 6Bioversity International, Kampala, UgandaAbstractIntercropping is practiced by the majority of small-scale farmers in eastern DR Congoas a result of declining farm/plot size and food security needs. A banana-legumeintercropping experiment was conducted in Mulungu at the research station of the‘Institut National pour l’Etude et la Recherche Agronomiques’ (INERA) to evaluatewhether banana leaf pruning improves legume biomass and grain yield withoutreduction in banana production. The treatment factors consisted of combinations ofthree different levels of banana leaf pruning (i.e. maintain 4 leaves, 7 leaves and allleaves) with three leguminous crops (i.e. bush bean, climbing bean and soybean).Plots with sole banana or leguminous crops were also included. This resulted ina full factorial design with fifteen treatments. The banana genotype was an EastAfrican highland cooking banana ‘Barhabesha’ (Musa spp., AAA-EAH). The bananaplants were field established in December 2009. The legume crops were planted inthe established banana fields and observations were taken during two consecutivecropping seasons (2010B and 2011A). Legume yield was highest under mono-cropping conditions during both legume cropping seasons. Banana leaf pruningdid not affect legume yield during the first legume cropping season as the bananaplants where only 3 months old with a pseudostem height of around 1 meter anda limited leaf canopy cover (LAI <1). The banana LAI during the second legumecropping season (at 9 months after banana planting) was significantly higher (4leaves - LAI 0,698; 7 leaves – LAI 1,181; 9 leaves – LAI 1,613) and this resulted in asignificant negative effect on legume yield, especially for the ≥7 leaves treatmentsand for soybean. Soybean yield during the second legume cropping was 1,347 kg/haunder mono-cropping, 938, 462 and 232 kg/ha for the 4, 7 and all leaves treatment,respectively. The effect of banana leaf pruning was less pronounced on bush andclimbing bean yields where yield increased from 199 to 326 kg/ha and from 280 to814 kg/ha for bush and climbing beans, respectively, with increasing leaf pruninglevels. Banana leaf pruning had a significant negative effect on banana plant heightat 12 months (241, 282 and 319 cm for 4, 7 and all leaves treatments, respectively). 155
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa132. Effects of commercial biochemical formulations on the growth of maize and soybean in savanna soils of Nigeria Nwoke C.1, Jemo M.2, Yusuf A.A.3 and Abaidoo R.C.2 Osun State University, Osogbo, Nigeria; 2International Institute of Tropical 1 Agriculture, Ibadan, Nigeria; 3Ahmadu Bello University, Zaria, NigeriaAbstractImproving the fertility of tropical soils is crucial to success in the fight againsthunger and food insecurity, both rampant in sub-Saharan Africa. Consequently,many commercially produced biochemical formulations are being offered tofarmers in the region to improve the soil and boost crop productivity. Some ofthese formulations have not been subjected to rigorous scientific scrutiny to checktheir effectiveness and also to ascertain the conditions under which they enhancethe yield of crops. This study evaluated the effects of biochemical products on thegrowth and yield of maize (Zeamays) and soybean (Glycinemax) under greenhouseconditions. The crops were grown for 8 weeks in soils from two agro-ecologicalzones in Nigeria. The biochemical products were applied as recommended by theproducers and the treatments included a control (without addition of any product)and a reference (i.e., with all nutrient elements applied at optimum rates). Threepromising biochemical formulations were further evaluated on maize under fieldconditions in three agro-ecological zones in Nigeria. The results of the greenhousestudy showed that the shoot dry matter yield (DMY) of maize was improvedby many of the products. The most significant were Turbotop, Agroleaf high N,Agroleaf high P, and Agroleaf general. For soybean, three of the products (Agroleafhigh N, Agroleaf high P, and Agroleaf general) enhanced shoot DMY significantlywhen compared with the control. Considering the effects of the products on plantheight and shoot DMY, the three versions of Agroleaf (high N, high P, and general),Turbotop, and Vitazyme seemed to influence maize growth positively. The threeversions of Agroleaf products may potentially enhance the growth of soybean.Under field conditions, Turbotop increased the grain yield of maize by 60% in Kaya(northern Guinea savanna), 53% in Mokwa (southern Guinea savanna), and 36% inShanono (Sudan savanna); Agroleaf high P increased maize grain yield by 80% inKaya but had no appreciable effect in Mokwa and Shanono. In the three locations,the improvement in maize grain yield due to the application of Agroleaf generalwas below 20%. 156
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa133. Patterns of water infiltration and soil degradation over a 120-year chronosequence from forest to agriculture in western Kenya Nyberg Gert1, Bergués Tobella Aida1, Kinyangi James2 and Ilstedt Ulrik1 1 Swedish University of Agricultural Sciences (SLU), Sweden; 2CGIAR-ESSP Program on Climate Change, Agriculture & Food Security, International Livestock Research In- stitute, Nairobi, KenyaAbstractSoil degradation is commonly reported in the tropics where forest is convertedto agriculture. Much of the native forest in the highlands of western Kenya hasbeen converted to agricultural land in order to feed the growing population, andmore land is more being cleared. In tropical Africa, this land sure change results inprogressive soil degradation, as the period of cultivation increases. Sites that wereconverted to agriculture at different times can be evaluated as a chronosequence;this can aid in our understanding of the processes at work, particularly those in thesoil. Both levels and variation of infiltration, soil carbon and other parameters areinfluenced by management within agricultural systems, but they have rarely beenwell documented in East Africa. We constructed a chronosequence for an area ofwestern Kenya, using two native forest sites and six fields that had been convertedto agriculture for varying lengths of time. We assessed changes in infiltrability (thesteady-state inflilration rate), soil C and N, bulk density, 13C, and the proportion ofmacro and microaggregates in soil along a 119 year chronosequence of conversionfrom natural forest to agriculture. Infiltration, soil C and N, decreased rapidly afterconversion, while bulk density increased. Median infiltration rates fell to about 15%of the initial values in the forest and C and N values dropped to around 60%, whilstthe bulk density increased by 50%. Despite high spatial variability in infiltrability,these parameters correlated well with time since conversion and with each other.Our results indicate that landscape planners should include wooded elements inthe landscape in sufficient quantity to ensure water infiltration at rates that preventrunoff and erosion. This should be the case for restoring degraded landscapes, aswell as for the design of new agricultural landscapes. 157
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa134. Partial nitrogen and phosphorus budgets in maize farming systems supplied with fertilizers in the context of the African Green revolution Generose Nziguheba1, Cheryl Palm1, Fred Frimpong2, Elicana Manumbu3, Joseph Mensah-Homiah2, Patrick Mutuo4, Phelire Nkhoma5, Gerson Nyadzi3, Lekan Tobe6, Pedro Sanchez1 1 The Earth Institute at Columbia University, New York, USA; 2Bonsaaso Millennium Villages Cluster, Ashanti, Ghana, 3Mbola Millennium Villages Cluster, Tabora, Tan- zania;, 4Millennium Development Center of East and Southern Africa, Nairobi, Kenya, 5 Mwandama Millennium Villages Cluster, Zomba, Malawi, 6Pampaida Millennium Villages Cluster, Zaria, Nigeria AbstractIn order to achieve the Millennium Development Goal of halving the number ofpeople suffering from hunger in Africa, the Hunger Task Force of the UN MillenniumProject and African Green Revolution initiatives target a substantial increase in cropproduction from the current cereal yields of below 1t ha-1 to 3t ha-1. Meeting sucha target requires drastic changes in the current agriculture practices including thesupply of nutrients to currently depleted soils that prevail in most rural agriculturalareas. Applying the recommendations from the Hunger Task Force, the agriculturesector in the Millennium Villages Project (MVP) has enabled smallscale farmers toaccess fertilizers, improved seeds, and intensive training on appropriate agronomicpractices. The result has been an overall doubling of staple crop yields, with averagemaize grain yields of more than 3 t ha-1 in all sites where maize is a major crop.Although it is generally recognized that fertilizers will play an essential role in theAfrican Green Revolution, there are also growing concerns about negative impactsthat the increased use of nutrients inputs in Africa may have on environment asexperienced in other parts of the world. A quantitative estimate of nitrogen andphosphorus inputs from fertilizers and outputs in maize was conducted in 4 maizegrowing sites (Bonsaaso, Ghana; Mbola, Tanzania; Mwandama, Malawi; andPampaida, Nigeria) in the MVP. A partial nutrients budget indicates that N exportedin maize exceeded the N added in fertilizers, indicating nitrogen mining of up to 60kg N ha-1. However it is also evident that only a portion of the applied nutrientsis taken by the maize, and therefore a need to quantify other major pathways ofnutrients applied with inputs in order to assess their environment impact. 158
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa135. Synthèse des résultats des tests participatifs sur l’amélioration des formules d’engrais Nzohabonayo Zacharie1, Breman Henk1, Simbashizubwoba Cyriaque1, Hatangimana Thomas1 and Kamale Kambale Jean Marie1 1 International Fertilizer Development Centre (IFDC), CATALIST project, BurundiAbstract :Une série de tests participatifs et de démonstrations ont été réalisés depuis Octobre2007 dans la zone d’action du projet CATALIST à savoir le Burundi, le Rwanda et l’Estde la RDC (Kivu Nord et Kivu Sud). La plupart des parcelles des tests ont enregistréjusqu’à 6 saisons de cultures successives. L’objectif des ces tests et démonstrationsétaient d’appuyer le développement des systèmes de production plus productifs,rémunérateurs et durables, entre autre à travers la validation participative desrecommandations d’engrais actuelles, qui soient agronomiquement efficaceset financièrement rentables selon différentes cultures et différentes zones agro-écologiques. Dans le cadre de la gestion intégrée de la fertilité des sols promue parIFDC, les engrais chimiques étaient utilisés comme source d’éléments nutritifs pourles plantes en combinaison avec les amendements organiques et minéraux pouraméliorer et maintenir les qualités du sol afin d’assurer une meilleure efficacité deséléments nutritifs apportés sous forme d’engrais chimiques. Les résultats obtenusmontrent une augmentation du niveau de production grâce à la GIFS. Les valeursdu RVC, calculées avec des prix de 2011, indiquent une rentabilité financière pourla plupart des cultures testées, ce qui favorise une adoption rapide des innovations.L’analyse de l’évolution de l’efficacité agronomique montre que l’agriculturedurable est bien possible si elle est faite dans un cadre de GIFS. Ainsi pour le blé,l’efficacité agronomique de N diminue avec le pH, le blé est très sensible à la toxicitéaluminique et sensible à l’acidité. Avec l’analyse des tests dits spéciaux (tests additifs,tests soustractifs et tests de lutte contre l’acidité), les données de pluviométrie et depH du sol ainsi que les formules d’engrais utilisés dans tous les tests, il est possibled’améliorer les recommandations de formules et de doses d’engrais en tenantcompte des différentes situations (pluviométrie, potentialités des cultures/variétés,acidité du sol, réponse des cultures aux formules de fertilisation et expérience desproducteurs). Il a été remarqué que le NPK bon marché, ayant vraisemblablement leKCl comme composant, influence négativement sur la productivité de la pomme deterre. L’utilisation d’un NPK plus cher doit être considérée. Pour les céréales, aussilongtemps que K n’est pas limitant, l’utilisation du DAP + l’urée + 5 t/ha de matièreorganique peut être recommandée. Pour le riz irrigué, une bonne gestion de l’eauest un préalable à l’efficacité des engrais chimiques. 159
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa136. Bean Utilization in Great Lakes Region of Central Africa: The Case of Smallholder Farmers in Burundi Ochieng, J.1, Birachi, E.2, Ruraduma, C.3, Katengwa, S..4 1 CIALCA project, Kenya; 2International Center for Tropical Agriculture-Africa (CIAT), Kigali, Rwanda; 3Institut des Sciences Agronomiques du Burundi (ISABU), Burundi; 4 CIAT, Butare, RwandaAbstractBeans is a very important staple food crop in Great Lakes region of Central Africanbeing a major source of food and revenue for smallholder farmers who comprisethe bulk of the poor population. Dry beans are source of protein and micronutrients,particularly iron and zinc and the country’s average consumption per capita of 60kg/year is among the highest in the World. An interview schedule was used tocollect data from a sample of 380 farmers, obtained through a multistage samplingtechnique. Since the bean production system is characterized with low input lowoutput, a larger output is utilized for household consumption followed by marketsales and stored for food. Other important uses of beans include as stored for seedsand gifts. Besides, informal seed systems dominated the seed sector in Burundi withhome saved (38.8%) and local market (43.5%) being the major sources of seeds. Morethan half of the farmers use local seeds, a trend observed in most of the provinces.However, farmers showed absolute dissatisfaction with their current sources (25%)and quality of seeds (45%) they buy from the market. Transport losses, market price,quantity produced and retained for food significantly influences amount of beanssold by smallholder farmers. Therefore, in order to promote commercialization ofbeans in this region, it is important to emphasize on interventions that increasefarm productivity and foster commercial linkages between input supply and ruralcommunities. The study recommends that farmers be continuously encouragedto improve production through adoption of improved seeds and other outputenhancing technologies so as to increase amount of beans supplied in the market.Policies that would improve the market-led approaches to production and utilizationof beans are fundamental for increased food access and rural incomes. 160
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa137. Musa germplasm diversity status across a wide range of agro- ecological zones in Rwanda W. Ocimati1, G. Blomme1, A. Rutikanga2, D. Karamura1, P. Ragama3, S. Gaidashova4, A. Nsabimana5 and C. Murekezi6 1 Bioversity International, Kampala, Uganda; 2Bioversity International/CIALCA Project, Kigali, Rwanda; 3Kabarak University, Private Bag 20157, Kabarak, Kenya; 4Institut des Sciences Agronomiques du Rwanda (ISAR); 5Kigali Institute of Science and Technology, P.O. Box 3900, Kigali Rwanda; 6Rwandan Agricultural Development Authority (RADA), Kigali, RwandaAbstractBanana and plantain (Musa sp.) are major staple and income-generating cropscovering 23% of the total cultivated land in Rwanda. Their cultivar diversity hasdeclined over the past decades, a trend likely to continue with the government’spolicy of market-driven production and regionalization of crop cultivation. A Musagermplasm diagnostic survey was carried out in 2007 in five Rwandan districtsusing a random systematic method on a transect from Lake Kivu (WesternProvince)to Kirehe district (EasternProvince) bordering Tanzania. Across all sites, 118 farmseach having at least 50 mats were visited. The study focused on Musa germplasmdiversity, socio-economic utilization options/practices that maintain Musa diversityon-farm and Musa genetic erosion. Musa cultivar names obtained from farmerswere compared with the National Banana Germplasm Collection database of theRwandan Agricultural Research Institute, Rubona. Forty-four Musa cultivars wererecorded across the five districts. Higher cultivar diversity was observed in the eastdeclining westwards to the Lake Kivu region as reflected by the number of cultivarsand cultivar evenness. Karongi and Rusizi districts in the west with low cultivarevenness had seven predominant varieties, while Bugesera and Kirehe in the easthad 14 widely grown varieties. Sixty eight percent of Musa cultivars had a lowdiversity index (Simpson 1-D < 0.2) necessitating their conservation ex-situ. The beercultivars ‘Intuntu’ (AAA-EA group, 33%), ‘Indaya’ (AAA-EA, 10%), ‘Umuzibwe’(AAA-EA, 7.3%), ‘Kayinja’ (ABB, 6.9%) and ‘Intokatoke’ (AAA-EA, 5.6%) dominatethe banana production landscape in Rwanda. Next in importance are the AAA-EAcooking bananas ‘Barabeshya’ (5.2%), ‘Ingaju’ (3.7%) and ‘Mujuba’ (2.9%), and thedessert varieties ‘Poyo’ (AAA, 4.5%) and ‘Kamaramasenge’ (AAB, 1.7%). Cookingbanana cultivation predominates in the district of Kirehe, while beer bananapredominate the Musa landscape in the other four districts of Rwanda. Taste/flavor,bunch size and market demand are the most important criteria for banana cultivarselection and thus greatly influence cultivar conservation and distribution on-farm.Diseases greatly contributed to genetic erosion. Fusarium wilt is mainly responsiblefor the loss of dessert banana varieties (‘Kamaramasenge’, ‘Gisukari’ and ‘GrosMichel’) and the ABB beer banana ‘Kayinja’, while Xanthomonas Wilt has devastatednumerous plantations with predominantly beer types in the Western province. 161
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa138. Does Xanthomonas campestris pv musacearum colonise banana cord root tissue? W. Ocimati1, F. Ssekiwoko2, E. Karamura1, W. Tinzaara1 and G. Blomme1 1 Bioversity International, Kampala, Uganda; 2 National Agricultural Research Organization (NARO), National Banana Research Program, Kampala, UgandaAbstract:Banana Xanthomonas wilt (BXW) caused by Xanthomonas campestris pvmusacearum(Xcm)is a devastating bacterial disease. Infection of vegetative plants through contaminatedgarden tools results in leaf yellowing/wilting and eventual plant death. Floral infectionsresult in wilting of male bud bracts (stage 1), followed by wilting of the rachis (stage2), premature fruit ripening (stage 3) and bunch rotting/eventual death of the wholeplant (stage 4). The movement of bacteria in infected plants is systemic. Corm tissueand lateral shoots have already been colonised when the rachis starts to decay after aninflorescence infection. Vegetative plants showing yellowing/wilting of leaves alreadyhave the bacteria in their corm tissue. The presence of Xcm in cord roots of banana plantsat different development stages has not yet been investigated. Cord root samples werecollected from symptomatic plants (East African Highland banana [Musa AAA-EA]and ‘Pisang awak’ [Musa ABB]) in farmer’s fields in Luwero, Central Uganda, for bothinflorescence (all 4 disease development stages; 36 plants) and tool-infected vegetativeplants (14). In addition, cord root samples were collected from artificially inoculatedAAA-EA and ‘Pisang awak’ plants in both the vegetative (13) and reproductive stage(42) in Kifu forest, Mukono district, Central Uganda. Plants in the vegetative stage (9months old) were inoculated by cutting the pseudostem with a contaminated knife, whilebacterial ooze was smeared on male flower/bract scars of mature plants. An additionaltwenty vegetative plants (9 months old) were inoculated by cutting the cord roots with acontaminated knife and drenching the surrounding soil with aXcm suspension (108 cellsper mL) and subsequently monitored during 12 months for symptom development.Overall, the presence of bacteria in the cord roots was significantly lower comparedto corms. Although all corms of the assessed vegetative stage plants in farmer’s fieldscontained the bacteria, only 11.1% of ‘Pisang awak’ plants had bacteria in their cord roots.In addition, though the bacteria were found in corms of farmer field-grown plants withdecaying rachis and more severe inflorescence disease development symptoms, only14.3% of AAA-EA plants at the premature fruit ripening stage had the bacteria in theircord roots. A higher percentage of cord root infections (57.1% for AAA-EA and 33.3%for ‘Pisang awak’) was observed in the artificially inoculated vegetative stage plants.Similarly, a higher percentage of cord root infections were observed on the artificiallyinflorescence inoculated plants. The percentage of cord root infections increased withprogressing disease development for both cultivars. For example, incidence in AAA-EAincreased from 20% at the decaying rachis stage to 83.3% at the bunch rotting stage. Theresults suggest that cord roots could contribute to garden tool transmission during e.g.weeding. Therefore, hand weeding and herbicide use is advised when diseased mats arepresent in a field. When uprooting diseased mats/fields all corm and cord root tissueneed to be removed to prevent a prolonged presence of bacteria. 162
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa139. On-farm Musa germplasm diversity status across different agro-ecologies in the north and south kivu provinces of Eastern Democratic Republic of Congo W. Ocimati1, D. Karamura1, C. Sivirihauma2, V. Ndungo2, E. Delanghe3, J. Adheka4, B. Dheda4, J. Ntamwira5, H. Muhindo2, P. Ragama6 and G. Blomme1 1 Bioversity International, Kampala, Uganda; 2Catholic University of Graben (UCG), North Kivu, Democratic Republic of Congo; 3Catholic University of Leuven (KUL), Belgium; 4University of Kisangani (UNIKIS), Kisangani, DR Congo;5INERA, Mulungu Research Station, Bukavu, South Kivu, Kinshasa-Gombe, DR-Congo; 6 Kabarak University, Kabarak, KenyaAbstractBanana and plantain constitute the second most important source of calories after cassavaand rank first as far as acreage and production are concerned in Eastern DemocraticRepublic of Congo (DR Congo). Musa plantations contribute to the conservation of theenvironment due to its perennial nature and canopy cover. However, like in all otherbanana and plantain growing areas of East and Central Africa, yield and diversity in DRCongo is declining. A Musa germplasm diagnostic survey carried out in four differentagro-ecologies in both North (NK) and South Kivu (SK) assessed the on-farm Musadiversity and farmer Musa selection criteria that create/maintain diversity. Diversitywas defined using two diversityindices (i.e. richness and dominance/evenness). A totalof 32 and 35 cultivars were recorded in NK and SK, respectively. NK had more cultivarswidely grown compared to SK. For example, only 5 cultivars were grown in one localityin NK compared to 16 cultivars in south Kivu. All the NK sites had a high cultivarevenness (i.e. most cultivars are widely grown), while all SK sites except Burhale had alow cultivar evenness. The low evenness in SK is due to the dominance of one AAA-EAbeer cultivar ‘Nshikazi’. Long-term on-farm Musa diversity conservation will hence beeasier in NK. 40% and >60% of NK and SK cultivars, respectively, where not widelygrown. Hence, conservation of these cultivars is urgently needed. Cooking AAA-EAcultivars (35%) dominate in NK followed by beer (27%), plantain (21%) and dessert (17%)cultivars. Cooking cultivars are grown across all altitudes, while beer types dominate atthe high altitudes of Munoli (1,733 masl) and the plantains dominate at the low altitudesites in Mutwanga (1,049 masl) and Mangodomu (969 masl). In SK, beer types dominate(72% of the banana landscape) followed by dessert (21%), cooking (6%) and plantains(1%). Dominance of beer types can be attributed to the high mean altitudes (1,553 to 1,992masl). ‘Vulambya’ (AAA-EA cooking, 22%), ‘Nguma’ (AAB plantain, 13%), ‘Tundu’(AAA-EA beer, 10%), ‘Pisang awak’ (ABB beer, 8%), and ‘Mukingiro’ (AAA-EA beer, 7%)predominate in NK, while ‘Nshikazi’ (AAA–EA beer, 66%) predominates in SK. In NK,soil fertility tolerance and resistance to pests and diseases were critical to farmers, whilein South Kivu, availability of planting materials was the major selection factor. Cultivarselection criteria thus reflected the major constraints experienced by each province andinfluenced the diversity trends of cultivars. Causes of cultivar erosion included weeds,non-adaptability to competition and the environment, pests and diseases, destructionby stray domestic animals, soil infertility, poor suckering ability, reversion from cookingto beer type and toppling. Among the causes of genetic erosion, Xanthomonas Wilt hasdevastated numerous plantations in this region. 163
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa140. Systemicity and speed of movement of Xanthomonas campestris pv. musacearum after garden tool mediated infection W. Ocimati1, F. Ssekiwoko2, M. Buttibwa3, E. Karamura1, W. Tinzaara1, S. Eden-Green4 and G. Blomme1 1 Bioversity International, Kampala, Uganda; 2National Agricultural Research Organization (NARO), National Banana Research Program, Kampala, Uganda; 3 National Agricultural Research Organization (NARO), National Crops Resources Research Institute (NACRRI), Namulonge, Uganda 4EG Consulting, Larkfield, Kent, UKAbstract:Xanthomonas wilt (XW) caused by Xanthomonas campestris pv.musacearum (Xcm) indiscriminatelyattacks all banana cultivars. Insect vectors, infected planting material and contaminated gardentools are the main modes of spread. Cultural practices (e.g. early male bud removal, disinfectionof garden tools and rouging) are so far the most effective ways of XW control. However, thesemeasures are laborious, expensive and frequently abandoned by farmers. Insight in spread/systemicity and speed of Xcm movement after a garden tool infection will help in fine-tuningexisting control methods. An on-station trial using AAA-EA and ‘Pisang awak’ (Musa ABB)was established at KifuForest, Mukono district, Central Uganda. 9.6 month old and one-yearold vegetative stage banana plants of both cultivars were inoculated with Xcm (1.0 x108cfu/mL)using a contaminated knife/machete. The treatments consisted of de-leafing (i.e. 3 leaf petioleswere cut) and de-suckering (i.e. one sucker pseudostem was cut at soil level). Mats of eighty 9.6months old plants per treatment and genotype were sampled (4 plants at 3-day intervals fora 60-day period) and plant parts (i.e. mother plant corm and pseudostem, mat cord roots andlateral shoots) analysed in the laboratory to assess the speed of Xcm movement. Suspensionsof cross-sections of these plant parts were cultured onCellubiose Cephalexin Agar (CCA) at24oC for 72 hours. In addition, twenty one-year old inoculated plants per cultivar and treatmentwere monitored for incubation period and incidence during 13 months after inoculation (AI).Incidence for both treatments was based on yellowing/wilting of mother plant leaves. In anadditional trial, 3 leaves for each of 20 AAA-EA and 20 ‘Pisang awak’ plants were inoculatedthrough either the leaf tip (10 plants per genotype) or leaf base (10 plants per genotype) andsymptom development observed for a period of 5 months. The bacterial movement wassystemic, while speed of Xcm movement did significantly vary between the de-leafing and de-suckering treatment but not between genotypes. In de-leafed plants, the bacteria were found inthe mother plant corm between 13-15 days AI, while in the attached suckers at 24 days AI. Inde-suckered plants, bacteria were found in the mother plant corms at 19.5–22.5 days AI, while inother attached suckers between 53 and 61 days AI. At 13 months AI, 100% and 90.5% incidencewas observed in de-leafed compared to 35% and 45% in de-suckered AAA-EA and ‘Pisangawak’ plants, respectively. The incubation period in de-leafed plants varied between 38–162 and27-163 days, while in de-suckered plants it varied between 46–383 and 70–217 days for AAA-EA and ‘Pisang awak’, respectively. Symptom expression in the de-suckered mother plantswas delayed and could be linked to the fact that the bacteria had to move through the rathercompact corm tissue. The incubation period for de-leafed plants increased with plant height,especially for the AAA-EA plants where disease incubation period increased by 0.4 days foreach centimeter increase in plant height. The disease incubation period did not differ betweengenotypes and was 43.4 days for the leaf tip and 37.7 for the leaf base treatment. Time fromdisease expression to complete leaf yellowing/wilting significantly varied between treatmentswith 5.7 and 22 days recorded for leaf base and leaf tip inoculations, respectively. This suggeststhat the disease spreads faster in the direction of the Xylem flow. 164
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa141. On-farm Musa germplasm diversity in different agro-ecologies of Burundi W. Ocimati1, G. Blomme1, D. Karamura1, P. Ragama2, P. Lepoint3, J.-P. Kanyaruguru3, F. Ngezahayo4, V. Ndungo5 and S. Hakizimana4 Bioversity International, Kampala, Uganda; 2Kabarak University, Kabarak, Kenya; 1 Bioversity International/CIALCA Project, Bujumbura, Burundi; 4IRAZ, Machitsi, 3 Burundi 5 Université Catholique de Graben, Butembo, North Kivu, DR CongoAbstract:The Great Lakes Region of East Africa, of which Burundi is part, constitutes asecondary centre of Musa diversity, especially for the east African highland bananas.However, Burundi has suffered a decline in Musa production and germplasmdiversity. For example, BBTD has decimated banana in the Rusizi valley, North-Western Burundi. A Musa germplasm diagnostic survey carried out across 132farms, each having at least 50 mats, in three provinces of Burundi (Gitega in Central[1,601 masl], Kirundo in Northern [1,490 masl] and Cibitoke [1,130 masl] in North-Western Burundi) assessed the on-farm Musa diversity, farmer Musa selectioncriteria that influence Musa diversity and Musa genetic erosion. Cultivar diversitywas defined using two diversityindices (i.e. richness and dominance/evenness).Musa cultivar names obtained from farmers were compared with the NationalBanana Germplasm Collection database of the Institut de Recherche Agronomiqueet Zootechnique (IRAZ). Thirty-five Musa cultivars were recorded across the threeprovinces. Gitega and Kirundo, relative to Cibitoke, had high cultivar richness andevenness and thus a higher Musa diversity. Gitega had 31 cultivars followed by29 in Kirundo and only 13 in Cibitoke. The measure of cultivar evenness/relativeabundance (i.e. Simpson 1-D index) was 0.79 in Kirundo, 0.77 in Gitega and 0.65 inCibitoke. Low cultivar diversity in Cibitoke can be attributed to the BBTV epidemicthat has affected Musa production in this low altitude province. Though 11 cultivarswere widely grown across all three provinces, four cultivars, ‘Igitsiri’ (AAA-EAbeer, 31%), ‘Igisahira gisanzwe’ (AAA–EA cooking, 31%), ‘Igipaca’ (AAA-EAbeer, 9.4%) and ‘Yangambi- Km5’ (AAA beer, 5.8%) cover 88% of the Burundianbanana landscape, while the other 31 share the remaining 22%. The four dominantcultivars have a high market potential. 57% of cultivars had either zero or a negativeSimpson 1-D index value suggesting a low relative abundance (i.e. only presenton a few farms). It is hence recommended that these cultivars be conserved. Themost important selection criteria influencing cultivars maintained on farm include:flavour, pulp taste and juice quality, followed by market demand/prices. 30% of therespondents experienced cultivar erosion, with 69%, 29% and 19% reporting lossin Cibitoke, Kirundo and Gitega, respectively. This confirms the negative impactof BBTV on Musa diversity in Cibitoke. The most affected cultivars in order ofimportance, across Burundi, included ‘Kamaramasenge’ (AAB), ‘Igisubi’ (ABB) and‘Pisang awak’ (ABB). Diseases (88.6%) were the major causes of this disappearance.BBTV indiscriminately affects Musa cultivars in the low altitude regions, while theAAB dessert types and the ABB beer types are affected by Fusarium wilt. Othercauses of cultivar erosion were drought, soil infertility and weeds. 165
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa142. Yield responses of cowpea (Vigna Unguiculata) varieties to phosphorus fertilizer application across a soil fertility gradient in Western Kenya highlands Odundo Sylvester1, Okalebo J.R.2, Othieno, C.O.2, Ojiem J.O.3, Lauren J.G.4 And Medvecky B.4 1 Christian Agricultural And Related Professionals Association (CARPA), Nairobi , Kenya; 2Moi University, Chepkoilel campus, Eldoret, Kenya; 3Kenya agricultural Research Institute, Kakamega, Kenya; 4Cornell University College of Agriculture and Life Sciences Ithaca, NYAbstractDeclining soil fertility confounded with inadequate fertilizer use and growingof poor non-improved local cowpea (Vigna unguiculata) seed varieties, has led todecreased cowpea yield in smallholder farms in the highlands of western Kenya.However, P application in these farms and growing of improved cowpea varietiesmay result to increased yield. Against this background, three local non-improved(Enzegu, Khaki and Ilanda) and five improved (ICV1, 1CV12, CB46, IT92K-282-2 and1T83D-442) cowpea varieties were screened at 0, 15, and 30 kg P/ha fertilizer rates toinvestigate their dry matter (DM) and grain yield production within four soil fertilityclusters (high: Koibem, medium-high: Bonjoge, medium-low: Kiptaruswo andlow: Kapkerer) in Nandi South district, western Kenya. The experiment conductedduring long rain (LR) and short rain (SR) seasons 2009 was arranged factorially andlaid out in a RCBD design with three replications at each site. Data was collected onDM and grain yield. Data collected were subjected to analysis of variance using SASstatistical software, release 8.2. Least significant difference test separated means ofparameters whenever significant difference was detected at ≥ 95% confidence level.During LR and SR, P application resulted to a significant (p≤0.05) increase in meancowpea DM within sites. In Koibem (LR), significant (p≤0.05) DM increase wasshown by Enzegu from 286 kg/ha to 499 kg/ha at 0 and 30 kg P/ha fertilizer ratesrespectively. In Kapkerer (SR), 30 kg P/ha fertilizer rate resulted to a significant(p≤0.05) 75% DM increase relative to the control. During SR, P application resultedto a significant (p≤0.05) increase in cowpea grain yields within sites. In Bonjoge, 15kg P/ha rate resulted to a significant (p≤0.05) 85% grain yield increase relative to thecontrol. The results of this study show that the cowpea varieties screened performeddifferently at the different test sites suggesting effects of environmental conditions.While cowpea productivity is influenced by soil fertility status, application of P isessential for enhancing DM accumulation and grain yield production. 166
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa143. Upscaling the use of fertilizer / manure to raise maize production in western kenya: the World Phosphate Institute (IMPHOS) approach R. Okalebo1, B. Amar2, C.O. Othieno1, K.W.N. Magiroi1, A.K. Kipkoech1 and M.A. Osundwa1 Moi University, Department of Soil Science, Eldoret, Kenya; 2World Phosphate 1 Institute (IMPHOS), MoroccoAbstractThe constraints of food insecurity and poverty in sub-Saharan Africa (SSA) are wellarticulated in the literature. Thus diagnostic surveys across small-scale farms inwestern Kenya region have pinpointed widespread N and P deficiencies, widespreadon low organic matter and acid soils, mainly the Acrisols and Ferralsols. Cropresponses to these two nutrients have been extensively found. Nonetheless, thereis none to very minimal adoption of demonstrated soil fertility management in theregion and most of SSA, with the well known reasons of fertilizer unaffordabilityand its poor distribution and erratic credit facilitation, among others. In partnershipbetween Moi University and IMPHOS, an activity was initiated in 2009 aimedat intensified fertilizer use through demonstrations of affordable but effectivefertilizer treatments across 160 farms selected in a participatory manure in UasinGishu, TransNzoia and Siaya maize growing districts in western Kenya. Treatmentsconsisted of the popular DAP; DAP with agricultural lime (21% CaO) from Koru,Kisumu, Kenya; Minjingu phosphate rock (MPR) from Tanzania (13% P + 38% CaO) and RUTUBA organic market refuse manure with ½ DAP. Each treatment wasapplied at the recommended rates of 75 kg N + 26KG P/ha, receiving a blanket kgK / ha as nuriate of potash. The design used was a randomized complete designwith farms constitutory replications. The large plot size of 25m x 10m enhanced theevaluation of treatments in each farm, with a side-by-side control treatment for eachplot. The farmers managed the trials from planting to harvest. Soil test data at theinception of the trials showed widespread acidity (pH<5.5), low available P (<5mg/ kg). Treatments gave striking maize yield increases (<0.5 t / ha on controls to 5– 6 t / ha from treatments). Performance of treatments varied with the district (oragroecological zone). But overall, DAP + lime and MPR out yielded the rest. Thesewere associated with soil pH rise to about 6.8 level. Both economic and laboratoryanalyses of data and maize samples are underway to determine the profitabilityand nutrient use efficiency from each of the 4 treatments. Meanwhile we targetdissemination of results. Some farmer groups are beginning to buy stock and selltheir own lime and MPR, especially in Sega (Siaya) area; maize storage structuresare also being constructed, to store the harvest not witnessed over several decades 167
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa144. Rapid assessment of potato productivity in Kigezi and Elgon highlands in Uganda Okoboi Geofrey1, Kashaija Imelda2 and Lemaga Berga3 Makerere University, Kampala, Uganda; 2International Potato Center (CIP), Nairobi, 1 Kenya; 3Regional Network for Improvement of Potato and Sweet Potato (PRAPACE), Kampala, UgandaAbstractThe potato is an important crop for food and income in Uganda, most especially inthe highland areas. For the past five years, potato output and yield has remainedthe same or even declined yet the population is growing rapidly. Understanding theperformance as well as the constraints to increased yield of the crop at farm levelis an important step to promoting interventions that increase productivity as wellas improve rural livelihoods. As part of the larger project work by CIP to improvepotato productivity in the countries of Uganda, Kenya and Ethiopia, a rapiddiagnostic survey among key stakeholders in potato production areas of Kigeziand Elgon highlands was conducted to assess the current status of, opportunitiesand constraints in the sub-sector. Simple statistical methods including ranking,correlation analysis, and gross margin analysis were used to analyse the data.Farmers in Kigezi highlands were found generally to use more improved inputs(seed, fertiliser and fungicides) in potato cultivation than their counterparts inElgon highlands. Farm level differences in the intensity of improved inputs (seed,fertiliser and fungicides) use were found to have been responsible for differencesin yield, resulting in significant differences in gross income. Farmer use of owninputs including seed and labour greatly influenced gross profit, giving an illusionof high returns. Otherwise when the opportunity cost of the farmer’s own inputs isimputed into production costs, low input-low output peasant farmers would earnpeanuts. A range of constraints affecting farmer production were ranked includinghigh price improved inputs, adulterated fertilisers and fungicides, emergency ofrare pests, unpredictable weather, low soil fertility, and land scarcity. This paperconcludes that there is need for government through for example NAADS and/ornon-governmental organisations to support farmers to intensify the use of improvedinputs to increase productivity and income. 168
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa145. Effectiveness of liming and phosphorus fertilizer materials on maize production in Western Kenya acid soils Omenyo V.1, J. R. Okalebo1, C. Othieno1, J. K. Kiplagat1, D. S. Mbakaya2, B. Jama3 Moi University, Eldoret, Kenya ; 2Kenya Agricultural Research Institute Kakamega, 1 P. O Box 159, Kakamega, Kenya; 3Alliance for a Green Revolution in Africa (AGRA), Nairobi, KenyaAbstractSoil acidity is a major contributor to soil infertility in western Kenya. Smallholderfarmers in this region have persistent low yields (<1 and <0.5 t ha-1 season-1 maizeand legumes respectively) in comparison to the potential estimates of 6 - 8 t ha-1season-1. Liming, an intervention recommended to ameliorate soil acidity, ishardly practiced in the region where acid soils occupy about 0.9 million hectares ofland. An on farm research was conducted during the 2010 long and short rains inselected sites (Kakamega North & Ugenya districts) to evaluate direct and residualeffects of various lime sources on Phosphorous availability and maize yields. Thiscomprised of agricultural lime from Koru, (20.8 % CaO) and AthiRiver, (45 % CaO),Minjingu phosphate rock (MPR) (38% CaO, 29% P2O5) and Mavuno fertilizer (26%P2O5, 10% N, 10% CaO, 4% MgO, 4% S2O). Triple superphosphate (46% P2O5),supplied P to the two agricultural limes. To achieve the research objectives, twoseparate experiments were carried out. First, the two agricultural limes were used todetermine the effective lime rate affordable to the smallholder farmers. The secondexperiment tested the effectiveness of the four liming materials on P availability andmaize yields. Results indicated significant (p<0.05) responses of maize yield to thesoil amendments material applied. Lime applied at 1.5 t ha-1 gave the highest yieldof 4.65 t ha-1 (Ugenya) and 3.76t ha-1(Kakamega North). Maize grain yield increasedfrom 2.06 (control) to 6.21, 5.19, 4.59 and 3.92 t ha-1 (Ugenya), and 2.08(control) to4.47, 3.78, 4.27, and 3.29 t ha-1 (Kakamega North) where Mavuno, Koru, Athi limeand MPR were applied respectively. The high yield given by Mavuno fertilizer couldbe due to the additional nutrients it contains. An economic analysis is underway, toenable us come up with effective and economical package for smallholder farmersin the region. 169
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa146. Effect of Liming on some Soil Chemical Properties and Yield of Soybean in an Acid Ultisol of Mbato, South Eastern Nigeria Onyegbule Ugochukwu1, Jiwuba F., Nwanguma E I 1 National Horticultural Research Institute, NigeriaAbstractField experiments were conducted at National Hortcultural Research Institute,Mbato Okigwe in 2006 and 2007 to determine the effect of liming on yield of sixSoybean varieties (TGX 1440-IE, TGX 144-IE, TGX 1448-2E,TGX 1740-1F, TGX 1844-18E, TGX 923-2E). The trials were laid out as a split plot in a randomized completeblock design with three replicates. Six lime rates of 0, 0.45, 0.90, 1.35, 1.80 and 2.25t/ha were the main plot while the six soybean varieties were the sub-plots. The resultobtained showed that liming significantly increase soil Ph from 5.01 to 5.8 andreduced liming exchangeable acidity from 1.02 to 0.08. lime application increasedplant height, number of nodules, number of pods and seed yield relative to control.TGX 1844-18E gave the best performance in terms of mean seed yield of 19614kg/ha, 3190kg/ha in 2006 and 2007 respectively and mean pod number of 49.5/plantin 2007. TGX 923-2E gave the highest number of nodules of 27.6/plant while TGX1444-E performed best in terms of mean plant height with a value of 37.1cm2 in 2007.Effect of lime application rates and their interaction were not significant (P>0.05).Also, the interaction effects of lime application and soybean varieties on the yieldparameters measured were not significant (P>0.05) 170
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa147. Optimal rates and mode of combined farmyard manure (FYM) and triple superphosphate (TSP) application for maize production in Western Kenya Otinga Abigael1, Okalebo J.R.2, Njoroge R.2, Emong’ole M.2, Six L.1, Gohole L.2, Muasya R.3, Vanlauwe B.4, Pypers P.4, Smolders E.1 and Merckx R.1 1 Katholieke Universiteit, Leuven Division Soil and Water Management, Department Earth and Environmental Sciences, Leuven, Belgium; 2 Chepkoilel University College- a constituent college of Moi University, School of Agriculture and Biotechnology, Department of Soil Science, Eldoret, Kenya; 3 Kenyatta University, Department of Agricultural Science and Technology, Nairobi, Kenya; 4 Tropical Soil Biology and Fertility Institute of the International Centre for Tropical Agriculture (TSBF-CIAT), P. O. Box 30677, Nairobi, Kenya.AbstractIn western Kenya, production of maize, the staple crop, is constrained by lowsoil P, limited P fertilizer application and high P fixation by the soils. Inorganicor organic P fertilizers are the most common options for increasing available P,but use of both inputs is constrained by physical availability and/or availabilityof financial resources. We hypothesize that the combined application of mineralfertilizer (TSP) and farmyard manure (FYM) increases P uptake efficiency of themaize crop. Field experiments were conducted during four subsequent seasonsin three sites (Sega, Bokoli and Teso) in western Kenya with varying soil fertilitystatus. The interactions between organic and inorganic P application on maize yieldwere evaluated by substituting FYM by TSP at 0, 25, 50, 75 and 100 % of the Prate. Response to fertilizer was also assessed, and the effect of concentrating organicmaterials in the planting rows evaluated. Thus, FYM at a rate of 13 kg P ha-1 wasbroadcast or applied only to 50 % and 25 % of the area around the planting rows.Response to P fertilizer rates in the first season was variable for all sites, with clearand slight responses in Sega and Bokoli, respectively, while in Teso no response wasobserved. Similarly for the substitution treatments, no clear trend was observed inthe first season. In the subsequent three seasons, however, maize grain yields clearlyresponded to increasing P rates. Further, yield increased with increasing proportionof FYM in the P application, and in Sega, the site with lowest P availability and pH,maize yield obtained with sole FYM application were 9 - 17 % higher than withsole TSP addition. Substitution of FYM by TSP at rates of 25 - 75% only yieldedsmall differences, and hence the relative availability and cost of both inputs willdetermine the profitability of their use. The effects of concentrating the FYM in theplanting rows varied between sites and seasons. Cumulative yields for the fourseasons indicated FYM concentrated at 50 % of the planting area to be better thoughnot significantly different than concentration at either 25 % or broadcast at Sega andBokoli sites. Conversely, for Teso, concentrating the FYM at 25 % of the plantingarea gave higher cumulative grain yields across the four seasons. This indicatesimportant interactions with soil properties and probably rainfall conditions, whichrequire further study. 171
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa148. Analyse de la fluctuation des prix du soja et de haricot dans la zone d’intervention du projet CIALCA au Sud-Kivu Polepole Sylvie1 Tropical Soil and Biology Institute of the International Center for Tropical 1 Agriculture (CIAT-TSBF), DRCAbstractLa production et la commercialisation des légumineuses (Soja et haricot) jouentun rôle important dans l’alimentation et le revenu des ménages dans la région duSud Kivu. L’inaccessibilité des intrants (semences des variétés améliorées, engraisminéraux, inoculum, chaux, pesticides…) due entre autres aux prix élevés et leurrareté poussent les paysans à produire à des coûts très élevés soit à diminuer laproduction. Les petits agriculteurs se trouvent face à un petit nombre d’acheteurs etsont souvent obligés d’accepter le prix que les acheteurs proposent car ne pouvantpas influencer le prix. En période de semis une mesure de  1.5 kg de (soja et deharicot) coute trois fois plus cher qu’en période de récolte. Pour ce faire, nous avonsprélevé les données bihebdomadaires de prix de soja et de haricot sur 8 marchésdont 6 locaux et 2 urbains. Les résultats ont montré que dans les zones où le sol estpauvre (axe walungu) le prix s’avère être élevé pour les deux périodes (soudure etrécolte) par rapport à l’axe Nord (Luhihi et Kabamba) où le sol semble être fertile.Malheureusement, dans ces milieux le niveau d’accès aux crédits reste faible carles offres sont rigides ou inexistantes avec des conditions d’accès très sélectives.La capacité des petits producteurs à stocker leurs produits à la récolte moyennantun crédit qui les permettra de faire face aux besoins sociaux (santé, éducation,nourriture) peut aider à minimiser les fluctuations saisonnières, à tirer bénéfice dudifférentiel de prix entre la période de récolte et de soudure ainsi qu’à augmenter lebudget du ménage. 172
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa149. Optimised DNA capture protocols in the field, extraction and PCR diagnostics for Banana Xanthomonas Wilt and Banana Bunchytop virus using simple DNA capture kits Ramathani Idd1, Valentine Nakato Gloria1, Beed F1 1 International Institute ofTropical Agriculture (IITA), UgandaAbstractFarmers in Sub-Saharan Africa (SSA) routinely experience significant agriculturaland financial losses due to plant diseases. This is due to lack of technical capacityto diagnose plant pathogens responsible for disease. The desperate need is formethods that rapidly and precisely diagnose plant pathogens as a fundamentalstep toward disease management. Furthermore some diseases produce symptomsthat are easily confused e.g. leaf chlorosis of banana due to Panama disease andBXW or due to limited potassium thus leading to wrong diagnosis. The essence ofthis study was to establish optimal field sampling protocols and PCR conditions aswell as evaluate the viability, efficiency and reliability of FTA cards, PhytoPASS &2 minute DNA dipstick.Optimal field sampling and DNA extraction protocols forthe different kits were established. The optimal conventional PCR conditions for thedetection of Xanthomonas campestris pv musacearum (Xcm) and banana bunchytop virus (BBTV) were established at an annealing temperature of 60 0C and 530C respectively. 1-3 µl of FTA card extract, 1-3 µl of 100X PhytoPASS extract and asingle 2 mm disc for 2 minute DNA dipstick provided adequate DNA template foramplification of respective Xcm (650 bp) and BBTV (239 bp) DNA fragments. AllDNA capture kits were effective at capturing pathogen DNA directly from the fieldwith percentage of symptomatic samples that gave amplification for DNA fragmentsat 86 % (FTA cards), 60 % (PhytoPASS kits) and 74 % (2 minute DNA dipsticks) forXcm samples collected in Uganda and 94 % (FTA cards), 87 % (PhytoPASS kits) and95 % (2 minute DNA dipsticks) for BBTV samples collected in Zambia Howeverstatistical analysis revealed significant variation among the three DNA capturekits (P<0.001). Variation in number of detectable bands mainly occurred amongreplicates of a single sample as compared to different samples. Viral DNA (BBTV)(92 %) was more detectable across all kits as compared to bacterial DNA (Xcm) (73%) on all symptomatic samples for Xcm and BBTV tested. Ring testing across threelaboratories in Uganda, United Kingdom and Zambia for BBTV samples revealedconsistent results in Uganda and UK though a slight variation in Zambia due toonly testing a single replicate per sample. Recommendation is that all replicates persample are tested as a means of increasing confidence of the final diagnosis. PCRamplification performed on BBTV samples stored for 6 months revealed that bothFTA cards and PhytoPASS are effective at maintaining pathogen DNA integrity(100 %) over a long duration under storage. However for 2 minute DNA dipstickthere was a noticeable reduction (from 100% to 90%) in detectable band for BBTVDNA fragment. Considering the economics, ease of use, user perception, and timerequired for sampling, DNA extraction and PCR diagnostics the 2 minute DNAdipsticks and FTA cards proved to be the most suitable kits for use across the ECAregion. 173
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa150. Opportunities and threats in the banana beer value chain in Central Uganda Rietveld A.1, Mpiira S.2, Jogo W.1, Karamura E.K.1 and Staver C.1 1 Bioversity International, Kampala, Uganda; 2National Agricultural Research Organi- zation (NARO), National Banana Research Programme, Kampala, UgandaAbstractThe main banana production systems in Uganda are East African Highland banana(EAHB) and beer-banana (mostly Kayinja) systems. This paper examines the futureof banana-beer in the context of existing and potential threats (e.g. diseases includingBanana Xanthomonas Wilt (BXW), declining soil fertility, diminishing demand,competition from other products, quality issues) and opportunities (affordability,increased education of young people and increased urbanization). The paper seeksto answer three fundamental questions: How are current banana-beer value chainsorganised? What role does banana beer play in urban areas and is there potentialto increase demand? What are the future prospects of banana-beer production andmarketing (will future generations of producers, traders and consumers continuebanana beer brewing trading and drinking?) Key informant interviews wereconducted with banana-beer producers, local and urban traders and retailers incentral Uganda. The study showed that the area under beer-banana has decreasedconsiderably during the last decade due to the devastating effects of BXW. Althoughin some areas farmers have replanted beer-bananas, others erroneously believe thatBXW stays in the soil and have therefore abandoned the crop after being attackedby the disease. Accordingly, production of beer has decreased. The banana-beervalue chain is usually short and has little formal organisation. Relations betweenchain actors are based on trust. Most banana-beer traders either process bananassourced from their own farm or buy from other farmers in the locality. No realprofessional processors exist and most banana-beer is brewed in the same villageswhere the bananas are produced. Quality standards are less defined than with othercompeting products. While banana-beer remains of cultural importance for socialevents in rural areas and is still an important source of cash income for many ruralhouseholds, it is considered an inferior good, largely consumed by the poor, in urbancentres. In order to increase demand for beer-bananas, urban market opportunitiesfor other beer-banana based products, like fresh juice, should be evaluated. Qualityissues should be addressed. Producers should receive information and training onhow to control BXW. 174
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa151. Preliminary assessment of biochar application to soil in maize- based cropping systems in Kenya - soil fertility and crop responses Roing de Nowina Kristina1,2, Andrén O1, Chibole L2, Nyambega L2 and El Khosht F1 Swedish University of Agricultural Sciences, Sweden; 2Tropical Soil and 1 Biology Institute of the International Center for Tropical Agriculture (CIAT- TSBF), Nairobi, KenyaAbstractLand degradation is a major cause of food insecurity and environmental degradationwhich affects the majority of the people in Sub-Saharan Africa. The IntegratedSoil Fertility Management approach is used to increase land productivity andalleviate poverty by providing technology options that increase farmers’ income.Biochar has recently gained interest as a soil amendment for yield improvementwhile concurrently contributing to C sequestration. To study the effects of biocharapplication, researcher-managed on-farm trials were established in 2006 at fourlocations, two in Western Kenya and two in Central Kenya, and are still on-going.Trial design consists of three main treatments, black fallow (control), crop and crop+ fertilizer (50-60 kg urea-N ha-1), and sub-treatments with and without biocharapplication (5 kg m-2). The crop rotation includes maize followed by beans. Soilproperties and crop yields are monitored on a seasonal basis. Soil physical (soilaggregate stability, moisture content) and biological properties (mineralization,decomposition, micro and macro fauna) as affected by bio-char application hasalso been studied. Initial analysis indicates that application of black C results inconsistent yield increases of 500-1000 kg ha-1. These results and other aspects of bio-char application as soil amendments will be presented and discussed. 175
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa152. Farmers’ knowledge and perception on climbing bean-based cropping systems in Rwanda Ruganzu, V. 1, J. Mutware1, B. Uwumukiza2, N.L.Nabahungu1 and I. Nkurunziza1 Rwanda Agriculture Boad (RAB), Kigali, Rwanda; 2National University of 1 Rwanda (NUR), Butare, RwandaAbstractConsidering the variability of agro ecological and social-economic conditions in thecountry, there is a need to understand climbing bean-based cropping systems. Thisstudy aimed at assessing farmers’ knowledge and perceptions on the productivityand profitability of existing climbing bean-based systems in Rwanda. A formal andinformal survey were carried out in four sites representing major agroecologicalzones producing climbing bean namely, Musasu, located in central plateau,Nyamasheke in Impala, Musanze in volcanic land, Rwerere in Buberuka high landand Nyagatare in Eastern savana. This study showed that existing climbing beanbased systems are monocropping, climbing beans intercropped with maize, cassavaand banana. Climbing beans monocropped is the dominant system as it is practicedby more than 55 % in all targeted area. Staking materials used by farmers onmonocropped climbing beans are Calliandra, Pennisetum, Leucaena, Eucalyptus andcassava trees. Lack of staking materials, lack of inputs including improved seeds,fertilizers, pesticides and pest/diseases were major constraints in climbing beancropping systems. This study revealed further that climbing bean monocropped isthe more productive system. Agricultural policy should improve the supply systemof all inputs in order to enable farmers to take full advantages of using improvedclimbing bean-based cropping systems. 176
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa153. Gender involvement in bean crop production in Burundi Ruraduma Capitoline Institut des Sciences Agronomiques du Burundi (ISABU), BurundiAbstractIn Burundi, common bean (Phaseolus vulgaris L) is an important source of foodat the household level for resource constrained farm households vulnerable tomalnutrition. It is a cheap source of protein when consumed cooked together withmost cereals and vegetables among most rural households in Africa.Burundi’saverage consumption per capita of 60 kg/year is the highest in the world. Drybeans are also the most marketed food commodity in the country, and an importantsource of income for most households. A survey done in six provinces of Burundifor assessing the gender participation in bean crop production has been conducted.Stratified and Simple random sampling techniques were used to select the surveyunits. Provinces and communes have been taken as strata while. In each communeselected 5 farmers association were chosen randomly from a list of farmersassociations within the commune. A sample of 60 farmers associations was usedfor the study. Data collected were analyzed with Gen Stat 12th Edition. One samplet-test model was fitted to test whether women participation in bean crop productionis equal to men participation. The test was statistically significant with a p-value <0.05. In bean crop production, women participate more than men. Indeed, resultsfrom survey data analysis showed that for a farmers association of 50 people, 35 arewomen while 15 are men. In Burundi, women are mainly involved in agriculturalactivities while men are most interested in activities that generate income. 177
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa154. Incidence, distribution and farmer knowledge of banana Xanthomonas wilt in Rwanda Rurangwa E.1, Night G1,2, Gaidashova S2, Gahakwa D2, Nyirigira A, Rutikanga A3, Mu- rekezi C4, Nduwayezu A, Mugiraneza T.5, Mugiraneza T., Mukase F1, Ndayitegeye O, Tinzaara W3, Karamura E3and Jogo W.6 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 2Rwanda Agricul- ture Board (RAB), Kigali , Rwanda; 3Bioversity International/CIALCA Project, Kigali, Rwanda; 4Rwandan Agricultural Development Authority (RADA), Kigali, Rwanda; 5 National University of Rwanda, Rwanda; 6Bioversity Internationa UgandaAbstractBanana Xanthomonas wilt (BXW) caused by Xathomonas campestris pv musacearumwas officially reported in Rwanda in 2005. Interventions so far have included raisingawareness (through meetings, radio and TV, posters and pamphlets), eradicationof infected plants and training using a top-down approach. The objective of thecurrent study was to determine current BXW distribution and incidence, andfarmers’ knowledge of disease symptoms and diagnosis, mechanisms of spreadand management. The survey was conducted in 2010 in 12 districts, including thoseaffected and those free from BXW. A total of 108 respondents were interviewedusing a structured questionnaire. Awareness of BXW symptoms varied from 53 to84% while awareness of modes of spread ranged between 24 and 73%. Awarenessof control methods varied from 8 to 72% and use of control methods from 7 to42%. Proportion of farms affected varied from district to district, with the lowestincidence in Gakenke, Ruhango and Kayonza (11%) and the highest in Rutsiro(89%). It is recommended that campaigns be conducted to enhance awareness ofdisease management. Also, participatory methods of BXW management shouldbe employed to facilitate adoption of technologies. Finally, research should beconducted to develop user friendly methods of tool disinfection and destruction ofinfected plants. 178
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa155. Indigenous arbuscular mycorhizal fungi and growth of tissue cultured banana plantlets under nursery conditions in Rwanda Rurangwa, E.1, J.M. Jefwa2, B. Vanlauwe2 and L. Turoop3 1 Institut des Sciences Agronomiques du Rwanda(ISAR), Kigali, Rwanda; 2Tropical Soil Biology and Fertility-Institute of CIAT, Nairobi, Kenya; 3Jomo Kenyatta University of Agriculture and Technology, Nairobi, KenyaAbstractArbuscular mycorrhizal fungi (AMF) occur naturally in soil although they mayvary in distribution and abundance. Degraded soils are common in the tropics andare low in nutrients and soil biota, rendering them unsuitable in crop production.Tissue cultured bananas benefit from Arbuscular mycorrhizal fungi with magnitudeof response variable between cultivars and soil types. Effective exotic commercialinoculants are available but indigenous AMF may be more adapted to local soilconditions. A green house experiment was carried out at the Institut des SciencesAgronomiques du Rwanda (ISAR), Rubona (Rwanda) in collaboration with CIAT-TSBF to assess the effect of indigenous AMF on growth of two banana cultivars intwo soil types. Three AMF inoculants (single Glomus mosseae and two mixed derivedfrom banana growing regions at Kibungo and Rubona) were evaluated against thetwo soil types from Kibungo and Rubona. Two tissue cultured banana cultivars;Kamaramasenge (AAB) and Mpologoma (Cooking-AAA-EA highland) inoculatedwith AMF species were evaluated for their performance in the two soil substrates.Treatments were replicated three times. Mycorrhization was done at the hardeningstage and eight weeks after, the plants were potted into 1 litre containers. Growthparameters (height, length and width of the youngest leaf, girth of the stem, andnumber of functional leaves) were evaluated every two weeks. The results showedperformance of inoculated TC banana to be dependent on the banana cultivar, withMpologoma more responsive than Kamaramasenge . Kamaramasenge was notresponsive to inoculation, it attained higher growth without inoculation. The studyhas shown that mixed cultures of indigenous AMF species from banana rhizosphereto be more effective than single species inoculants from the same environments. 179
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa156. A methodological framework of linking the soil map of Rwanda with the Farmer soil knowledge for more effectiveness of the Integrated and Participatory research paradigm. Rushemuka Pascal1, Mbonigaba M. Jean Jacques2and Bizimana Jean Pierre2 Institut des Sciences Agronomiques du Rwanda (ISAR), Kigali, Rwanda; 2National 1 University of Rwanda (NUR), RwandaAbstractRwanda has a digital land resource database including a soil map at 1:50,000 scale.The usefulness of this map in the Integrated and Participatory research paradigmis limited by the medium scale and the Soil Taxonomy language. This classificationis inaccessible by none soil specialists whom the map is supposed to serve in thisnew research paradigm. Meanwhile, each soil series in the field has a simple farmername, easily identified -by farmers- at the same title as tree and animal species.In addition, farmers have exact idea on the soils distribution in the landscape. Amethodological approach of establishing communication bridges between the twosystems was developed. Twenty-two soil series were identified and located fromRwanda soil map countrywide. Field visits were organised and the consideredsoil series were described according to Soil Taxonomy by means of soil profiledescription and soil laboratory analysis. Farmer soil types were identified by freelisting during the farmer participatory research. More insights were gained bycapturing the grammar (theories). The communication bridges between the twosystems were established by identifying the diagnostic horizons of the farmer soiltypes. Further links were achieved by relating the soil profiles to the soil mappingunits by means of geographic coordinates. The results show that the relationshipcould only be possible at high Soil Order level. This is normal since the farmerclassification is qualitative -based on the observation- while the Soil Taxonomy isquantitative –until microscopic level. But still, the possible linkage was useful. Thefarmer soil types were found to be more suitability classes than soil types as knownin technical soil knowledge. The use of the farmer soil types supplemented thescale – the where/location/scale- and communication –what/name/classification-barrier consequently allowing the technical soil knowledge to tackle the –how/management/- issue. 180
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa157. Banana Xanthomonos wilt management: Effectiveness of selective mat uprooting coupled with control options which prevent disease transmission. A case study in Rwanda and Eastern DR Congo A. Rutikanga1*, C. Sivirihauma2, A. Uwera3, G. Blomme4, N.Vigheri5, W. Ocimati4, P. Lepoint6 and C. Murekezi7 1 Bioversity International/CIALCA Project, Kigali, Rwanda; 2 Bioversity International/CIALCA Project, Butembo, North Kivu, DRCongo; 3 Institut des Sciences Agronomiques du Rwanda (ISAR), Kigali, Rwanda; 4 Bioversity International, Uganda office, Kampala, Uganda; 5 Catholic University of Graben, Butembo, North Kivu, DRCongo; 6 Bioversity International/CIALCA Project, Bujumbura, Burundi; 7 Rwanda Agricultural Development Authority, Kigali, RwandaAbstract:Xanthomonas campestris pv. musacearum (Xcm) is mainly spread through insectvendors from a diseased to a healthy inflorescence, contaminated garden tools andinfected planting material. Following insect or garden tool mediated infection, thebacterium spreads in a systematic manner throughout the plant, including physicallyattached lateral shoots. Cultural practices are the only recommended managementoption for controlling the disease. Research-led and farmer implemented trials wereestablished in Rwanda and Eastern DR Congo to assess the effectiveness of selectiveuprooting of diseased mats in combination with early male bud removal and theprohibition of garden tools use for de-leafing, de-trashing, de-suckering and weeding.Four farmers’ fields were selected for each of the following initial BXW field incidencelevels: 1:14-29%, 2:30-35% and 3:42-45%. These were replicated in three sectors of Rubavudistrict in Western Rwanda. In parallel, in North Kivu, eastern DRC, two fields wereselected for disease level 1 and 3. Banana plants were monitored on a monthly basis fordiseases symptoms in both trial and adjacent control plots (with no BXW management)during a ten-month period. In Rwanda, six out of 12 farmers rigorously applied therecommended control options and on average 35.8% of visibly healthy mats remainedin the plots versus 4.8% in adjacent control plots. In contrast, the other six farmers whodid not fully adhere to the recommended control options package remained with only9.3% of visibly healthy mats in the trial plot versus 3.0% in the adjacent plots. In DRCongo higher percentages (56.8 and 31.8%) of visibly healthy plants remained in the trialplots compared to the adjacent control plots (15.2% and 8.8%) for the tow ranges of theinitial disease incidence 22-29 and 40-44%, respectively. A significantly higher number(56.8%) of visibly healthy plants was recorded under conditions of low initial diseaseincidence (22-29%) in DR Congo, while in Rwanda a higher number of asymptomaticplants occurred in plots where farmers adhered to the recommended BXW managementoptions. Although selective uprooting under conditions of low initial infection and incombination with the rigorous application of management options that reduce diseasetransmission resulted in a higher number of visibly healthy plants (36% in Rwandaand 57% in Eastern DR Congo), new infections were still observed 10 months after trialestablishment. We are hence inclined to recommend the complete uprooting of diseasedfields and subsequent fallowing/establishment of break crops when disease incidence isabove 14%. A trial to evaluate selective uprooting at below 14% initial disease incidencelevels is recommended. 181
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa158. AUGMENTATION DU RENDEMENT DE MAIS PAR L’UTILISATION STRATEGIQUE DES ENGRAIS CHIMIQUES ET LA ROTATION AVEC DES VARIETES AMELIOREES DE SOJA ET HARICOT VOLUBILE AU SUD-KIVU MONTAGNEUX Sanginga Jeanmarie1, Rehani Juma1, Pypers Pieter2 and Vanlauwe Bernard2 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), DRC; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, KenyaAbstractLa fertilité du sol, sous des formes diverses, est une préoccupation de tous les temps,à cause de la mise en valeur du milieu naturel par l’homme et à son exploitation poursatisfaire certains de ses besoins. La répétition des cultures sans une applicationsuffisante des intrants agricoles en un même endroit entraîne un appauvrissementdes sols en constituants nécessaires à la nutrition des plantes. Une étude a étéconduite avec l’objectif d’évaluer l’augmentation en rendement de maïs (i) par larotation avec l’haricot volubile et le soja, en utilisant des variétés améliorées avecune production élevée de biomasse, en un indexe de récolte basse par rapport auxvariétés traditionnelles, et (ii) par l’utilisation stratégique des engrais chimiques. Desessais ont été menés pendant 2 cycles de rotation (4 saisons) suivant un dispositiffactoriel en champs collectifs paysans gérés par les membres des associations danstrois villages du groupement de Luhihi, dans le territoire de Kabare, Province du SudKivu, en République Démocratique du Congo Bukavu. Généralement, le rendementde soja (1.0 - 1.5 t ha-1) était plus élevé que le rendement d’haricot (0.7 - 1.3 t ha_1),et l’application des engrais augmentait les rendements des légumineuses par 15 - 40%. Les rendements des variétés améliorées des légumineuses étaient comparablesavec ceux des variétés traditionnelles. Le rendement de maïs qui suivait leslégumineuses était 27 - 57 % plus élevé par rapport à la monoculture de maïs, et 20 -34 % plus élevé après des variétés améliorées de soja et haricot volubiles par rapportaux variétés traditionnelles, surtout en deuxième cycle de rotation. L’applicationdes engrais augmentait les rendements par 22 - 39 %, indépendamment du systèmede culture. Ces résultats démontrent que la rotation avec des variétés amélioréesd’haricot volubile et soja avec indexe de récolte basse, et l’utilisation stratégique desengrais chimiques sont à recommander pour les agriculteurs de la région de Sud-Kivu. 182
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa159. Production performance of three Cassava varieties in the forest- savanna margins of Eastern Cameroon Sarr Papa Saliou1, Araki Shigeru2 And Njukwe Emmanuel3 1 Center for African Area Studies, Kyoto University, Japan; 2Graduate School of Asian and African AreaStudies, Kyoto University, Japan; 3International Institute of Tropical Agriculture (IITA), Kampala, UgandaAbstractCassava (Manihot esculenta Crantz) is grown throughout the tropics on a great varietyof soils, but is mainly founds on Ultisols, Oxisols and Entisols which are generallycharacterized by low soil fertility. Continuous production under these conditionscan lead to soil nutrient depletion. Moreover, several diseases are responsible forreducing Cassava yield. This study was established at Andom village (Bertoua,Cameroon) in three different sites (1, 2, 3). Treatments consisted of three varieties;one local (Ntolo) and two improved (92/0326, 96/1414) varieties. In each site,treatments were replicated 6 times in a completed randomized block design. Aftersowing the stem cuttings, weed was controlled throughout the cultivation period(12 months). At harvest, above ground and tuber fresh weights were recorded. Insite 1, the results showed the two improved varieties giving higher above groundand tuber fresh weights. For instance, tuber production of 92.0326, 96/1414, and thelocal variety Ntolo were 16.98 t/ha, 16.57 t/ha and 10.10 t/ha, respectively. In sites2 and 3, 96/1414 performed better, followed by 92/0326, and the local variety Ntolowas less performing. Tuber production in site 2 of 96/1414, 92/0326, and Ntolowere 12.26 t/ha, 8.08 t/ha and 3.31 t/ha, respectively; and in site 3, it was 15.69 t/ha, 10.44 t/ha, and 4.10 t/ha, respectively. In a site, data on soil analysis showed notmuch difference in term of nutrient content and physical properties. This indicatedthat rather depending on soil physico-chemical properties, the well performance ofimproved varieties rely on other factors such as plant genetic, disease resistance,physiological properties such as high photosynthetic rate. Indeed, the local varietyshowed many adventive roots without accumulation of carbohydrates. Thisexperiment also showed high productivity variation among the different sites; sites1 and 3 showing the better growth than site 2. 183
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa160. Positive Seed Potato Selection - a low cost knowledge based intervention to improve potato yields in Eastern Africa Schulte-Geldermann Elmar1, Borus Dinah1 , Lemaga Berga2 and Gildemacher Peter R.1,3 1 International Potato Center (CIP), Nairobi, Kenya; 2Regional Network for Improve- ment of Potato and Sweet Potato (PRAPACE), Kampala, Uganda; 3Royal Tropical In- stitute (KIT), Amsterdam, The NetherlandsAbstractThe innovative extension system known as “Positive Selection” (PS) was developedby CIP and partners. Through the training, potato producers learn how to maintainor even improve the quality of their potato seed for a longer period through positiveselection. The process involves training farmers to recognize healthy plants whichare not showing symptoms of seed borne diseases such as virus or bacterial wiltinfection. Healthy plants, representing about 10% of the crop, are marked and laterharvested to provide next year’s seed. The intervention is relatively low cost andrequires less contact time than a conventional farmer’s field school. Essential in thetraining curriculum is that the farmers plant a demonstration experiment in whichthey compare the yields of plots with their seed selection method with yields of plotswith seed from positive selection. We carried out on-farm research to assess whetherfarmer-managed positive seed selection could improve yield. Positive selectiongave an average yield increase in farmer managed trials of 34%, corresponding to aUS$ 360 increase in profit per hectare at an additional production cost of only US$8 per ha. Moreover, virus levels in PS seed were reduced by about 50% comparedto farmer-saved seed. PS can be an important alternative and complementarytechnology to regular seed replacement, especially in the context of imperfect ruraleconomies characterized by high risks of production and insecure markets. It doesnot require cash investments and is thus accessible for all potato producers. It canalso be applied where access to high quality seed is not guaranteed. Finally thetechnology fits seamlessly within the seed systems of sub-Sahara Africa, which aredominated by self-supply and neighbor-supply of seed potatoes. 184
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa161. Strategies to overcome the shortage of quality potato seed in Eastern Africa Schulte-Geldermann Elmar1, Borus Dinah1, Lemaga Berga2and Barker 1 International Potato Center (CIP), Nairobi, Kenya; 2Regional Network for Improvement of Potato and Sweet Potato (PRAPACE), Kampala, UgandaAbstractPotato yields in Eastern Africa are between 6-10 t*ha-1. One of the main reasonsfor this low yield is the use of poor quality seed by farmers. Currently the formalseed system is only able to supply about 1% of the country’s demand and on-farmmanagement of seed borne diseases is hardly practised. Viruses and other seedborne diseases can cause severe seed degeneration leading to decrease in yield,quality and economic losses. Viral infections like PVY, PLRV and bacterial wilt,caused by Ralstonia solanacearum are the main diseases affecting seed quality in theregion.To increase the availability of high grade potato seed, CIP, together withits national partners, has developed components of an innovative seed strategywhich both dramatically lowers the cost of production of pre-basic or “starter” seedcoupled with extension based interventions to train smallholders in better on-farmmanagement of their own seed. Engagement with the private sector as a means towiden the supply base and satisfy demand for clean seed is also a key componentof the strategy. Because the strategy involves delivering low cost, quality seed togrowers in 3-5 field generations, rather than the conventional 6 to 7 generations, thenew CIP strategy has been named the “3G” system. CIP believes that wide-scaleadoption of these technologies, as well as increasing farmers capacity in diseasemanagement and storage, would be an appropriate response to current concernsover rising food prices, help to secure seed supplies for the next few seasons andto put the whole seed supply chain onto a more sustainable path for the future.The introduction of new technologies, lowering seed production costs, improvingfarmer knowledge and widening and strengthening the seed supply base (includingprivate sector suppliers) will also put the whole seed production chain onto a moresustainable basis for the future. 185
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa162. The effect of altitude on growth and yield of plantain in north Kivu, eastern Democratic Republic of Congo Sikyolo, I.1, Vigheri, N.1, Sivirihauma, C.2, E. De Langhe3, Ocimati, W.4 and Blomme, G.43 1 Université Catholique du Graben, Butembo, NorthKivu, DR Congo; 2Bioversity Inter- national, CIALCA Project, Butembo, North Kivu, DR Congo; 3Katholieke Universiteit Leuven, Belgium; 4Bioversity International, Kampala, UgandaAbstract:The Congo Basin is an important center of diversity for plantain. Plantain is mainly grown below1,200 masl. However, some plantain cultivars can be found up to 2,200 masl in the highlandsalong the Albertine rift valley in North Kivu. This study assessed the effect of altitude onplantain growth and yield at 4 sites in North Kivu (Mavivi at 1,100 masl, Maboya at 1,450 masl,Butembo at 1,850 masl and Ndihira at 2,122 masl). Five plantain cultivars (‘Nguma’, ‘Kotina’,‘Musilongo’, ‘Vuhindi’ and ‘Vuhembe’) commonly grown in North Kivu were assessed at eachsite. Fifteen vigorous sword suckers of each plantain cultivar obtained from farmer’s fields wereplanted, in 3 replications of 5 plants, at each trial site. Plantain growth and yield parameterswere then assessed over a period of 2.5 years. Growth and yield parameters of the plantaincultivars ‘Musilongo’ and ‘Kotina’ were also assessed in 20 farmer’s fields in Butembo, Maboyaand Mavivi, while the plantain ‘Vuhembe’ was only assessed at one farm in Ndihira. Generallyat the trial sites, plant height, pseudostem circumference and bunch weight decreased with anincrease in altitude, while first crop cycle duration, time from flowering to harvest and meannumber of suckers increased with altitude. At flowering stage, the average mother plant heightacross the 5 plantain cultivars varied significantly by site and was 331, 354, 391, 407 cm atNdihira, Maboya, Butembo and Mavivi, respectively. Mean first crop cycle duration across allplantain cultivars was 15.6 months at Mavivi, 16.2 at Maboya, 17.4 at Butembo and 28.6 monthsat Ndihira, while time from flowering to harvest was 4.4 months at Mavivi, 4.7 at Maboya, 5.2 atButembo and 7.6 months at Ndihira. The mean number of suckers per mother plant across the5 plantain cultivars was 2 at Mavivi, 3 at Maboya, 5 at Butembo and 8 at Ndihira. The averageplantain bunch weight was significantly higher at the lowest trial location (‘Nguma’ 31.5 kg;‘Vuhindi’ 27.8 kg; ‘Musilongo’ 25 kg; ‘Kotina’ 23 kg and ‘Vuhembe’ 20.5 kg) compared toNdihira at 2,122 masl (‘Kotina’ 12.5 kg; ‘Vuhembe’ 11, 2 kg; ‘Musilongo’ 9,9 kg; ‘Nguma’ 6,8 kgand ‘Vuhindi’ 3,9 kg). These results show that there is no plantain cultivar which is performingwell at all trial altitudes. A large number of partially developed and hence non-harvestablebunches were observed at Ndihira (47% for Vuhembe, 53% for Musilongo, 47% for Kotina, 60%Nguma and 67% for Vuhindi). In addition, a significant increase in rachis length was observedat Ndihira. Although there is a 400 meter altitude difference between Maboya and Butembo,few significant differences were observed in growth and yield traits. The altitude effect is mostlikely overshadowed by the poor soil fertility characteristics that reduced growth and yield atMaboya. Similar growth and yield trends were observed in farmer’s fields for mean plant heightat flowering, time from flowering to harvest and bunch weight. Mean mother plant height atflowering in farmer’s fields for the assessed plantain cultivars was 292, 286, 286 and 330 cmat Ndihira, Butembo, Maboya and Mavivi, respectively. Time from flowering till harvest, infarmer’s fields for the assessed plantain cultivars was 8 months at Ndihira, 6.1 at Butembo, 5at Maboya and 4.5 at Mavivi. Mean bunch weight across all plantain cultivars was 11.2 kg atNdihira, 14.9 kg at Butembo, 16.2 kg at Maboya and 25.6 kg at Mavivi. These findings indicatethat an increase in altitude and resulting lower temperatures negatively influence plant growth,first crop cycle duration and yield, while it positively influences suckering in plantains. 186
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa163. Banana bunchy top in Burundi: A disease with the potential to spread to higher altitudes? Simbare Alice1, Lepoint Pascale1, Blomme Guy2, Niyongere Celestin3 and Nintije Pierre4 1 Bioversity International, Burundi; 2Bioversity International, Kampla, Uganda; 3Insti- tut des Sciences Agronomiques du Burundi (ISABU), Burundi; University of Burundi, Bujumbura, BurundiAbstractBanana Bunchy Top Disease (BBTD) was reported for the first time in Burundi in1987. Ever since, the disease has continued its spread throughout the Rusizi valleywith the help of traditional sucker exchange, civil unrest and massive populationmovement. It was thought, due to an unfavourable temperature effect, that thedisease was confined to the valley given that no cases were reported in neighbouringhighlands. Transmission of BBTD is dual, via infected plant material enablingspread over long distances in addition to short distance dispersal facilitated bythe BBTD vector, Pentalonia nigronervosa Coquerel (Hemiptera, Aphididae).The viruliferous potential of the vector and the effect of altitude/temperature onsymptom expression were evaluated in on-station (screen house) research-led trialsat two contrasting agro ecological zones in Burundi (Bujumbura, 818 masl, meantemperature 25°C and Gisozi, Mwaro province, 2,000 masl, mean temperature 17°C).In addition, alternative host range (Alpinia sanderiana, Canna musafolia, Colocasiaesculenta, Ensete ventricosum, Musa laterita, Musa ornata, Strelizia reginae andXanthosoma sagittifolia) was assessed in a screen house trial in Bujumbura. Resultsindicate that aphids collected in Gitega province, (BBTD-free, 1,650 masl, meantemperature 19°C) do not harbour the Banana bunchy top virus (BBTV) in naturalconditions in contrast to individuals sampled in Cibitoke province (BBTD hotspot,800 masl,mean temperature 25°C). Both populations are capable of virus acquisitionand transmission when reared on BBTV infected banana plants in Bujumbura as wellas in Gisozi. Moreover, transmission rate is directly correlated with the number ofviruliferous aphids used for inoculation (5, 10 and 20 aphids), with a higher efficiencyat warmer temperatures (89%, 82%, 91% for Bujumbura versus 33%, 67%, 83% forGisozi). On the other hand, the time between inoculation and initial observation ofsymptoms (incubation period) is inversely correlated with temperature (21 days inBujumbura versus 84 days in Gisozi). With regards to the host-vector relationship,BBTV transmission was successful - and confirmed by TAS-ELISA - to Enseteventricosum, and Musa ornata. Findings highlight the potential spread of BBTD tohigher altitudes given that the banana aphid is naturally associated to Musa spp.(and omnipresent at all elevations) and quarantine measures lacking. 187
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa164. How does the length of a fallow period, after uprooting of a Xanthomonos wilf infected banana field, influence infection of newly established clean planting materials? Case studies of Rwanda and North Kivu DRCongo C. Sivirihauma1, A. Rutikanga2, U. Anuarite3, C. Murekezi4, G. Blomme5, W. Ocimati5, P. Lepoint6 and N.Vigheri7 1 Bioversity International, Butembo, North Kivu, DR Congo; 2Bioversity International, Kigali, Rwanda; 3 Institut des Sciences Agronomiques du Rwanda (ISAR), Kigali, Rwanda ; 4Rwanda Agricultural Development Authority, Kigali, Rwanda ; 5Bioversity International, Kampala, Uganda ; 6Bioversity International, Bujumbura, Burundi; 7 Université Catholique Graben, Butembo, North Kivu, DR CongoAbstractBanana Xanthomonas Wilt is a devastating bacterial disease that could cause up to 100%yield loss when strategic control measures are not implemented. Currently, cultural practicesare the only recommended means for managing BXW. No cultivar is reported as resistantnor can the disease be controlled usin gchemcials. On-farm trials were established at threesites, namely, Eastern and Western Rwanda and Northern Kivu (Kisungu territory) in theDR Cnogo. The main objective was to determine the most effective fallow period duration forBXW elimination from a highly infected banana field. At each site, three banana fields withan initial disease incidence of at least 70% were selected. All banana mats and most debriswere removed prior to the trial establishment. Thereafter, clean suckers of ‘Kamaramasenge’(Musa AAB group) and ‘Injagi’ (AAA-EAH) in Rwanda and ‘Kamaramasenge’, theplantain ‘Musilongo’ (AAB) and ‘Vulambya’ (AAA-EAH) in DR Congo were planted inthe experimental plots at monthly intervals for a period of ten months. In Rwanda, tenplants per variety were platned each month in parallel rows in each field. In DR Congo,ten plants of each variety were randomly planted across the three trial plots (in single rowsof 10 plants per plot). In both countries, disease incidence in suckers was monitored for aperiod of 15 months (i.e. up to 5 months after the last planting). In Rwanda, BXW symptomswere observed during the first three months of re-planting for both varieties. For ‘Injagi’, thedisease incidence was 22, 27 and 9% for month one, two and three, respectively, whereasthe variety ‘Kamaramasenge’ had an incidence of below 2% for the first three months ofreplanting. However ‘Injagi’, the BXW incidence sharply declined during month four (2.4%)and five (1.7%). Healthy suckers of the two varieties planted from month six onwards didnot get infected. In DR Congo, the highest incidence was observed during the first six monthsof re-planting for all varieties. In addition, a steady decrease in BXW incidence from monthone (70%) till month ten (10%) was observed in the trial fields. The prolonged appearance ofdisease symptoms (i.e. beyond replanting month 5) could be linked to the extremely high(>80%) disease incidence of/and close proximity to neighboring diseased fields. A possibletransmission of the disease by foraging goats, larger flying birds and runoff water into thetrial plots could have occurred. In contrast, diseased mats were continuously uprooted inneighboring farmer’s fields in Rwanda. In both Rwanda and Eastern DR Congo, diseaseeradication efforts should be carried out in a concerted way by farmers. The bacterium islikely to survive for up to 6 months in soil and/or remaining plant debris, under Rwandanconditions. Therefore, replanting of previously BXW infected fields should be done 6 monthsafter thorough uprooting of diseased bananas. 188
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa165. Potential use of banana juice as an alternative energy source in banana tissue culture media Ssamula A.1, Mukasa S.B.1, Arinaitwe G.2 1 Makerere University, Kampala, Uganda; 2University of Leeds, Faculty of Biological Sciences, Leeds, UKAbstractThis study was aimed at evaluating the potential of banana juice as an energysources in the culture medium for in-vitro micropropagation of banana. Banana juicewas extracted from Mbidde, Kayinja and Km 5 banana varieties. The quality andamount of banana juice necessary to support TC growth of Nakabululu, Nakitembeand Nakinyika banana cultivars as an alternative to table sugar was then evaluated.0.423, 0.433 and 0.386 liters of banana juice/kg pulp obtained respectively from thethree banana cultivars had varied compositions of salts, sugars and organic acids.The mean shoot height and proliferation rate of in-vitro bananas cultured on mediasupplemented with 50 ml/l Mbidde juice; 20, 30, 40 and 50 ml/l Kayinja juice; 40and 50 ml/l Km 5 juice was as good as when cultured on media supplementedwith 30g/l table sugar. However, media supplemented with 50 ml/l of each of thebanana juices showed varied cost increments to TC medium. On the other hand,media supplemented with each of the other amounts of banana juice showed variedcost reductions to TC medium. Locally extracted banana juice can potentiallysubstitute commercial sugar. Being an organic extract, the contribution of bananajuice to bananas growing in-vittro remains to be evaluated. 189
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa166. Forests, Biodiversity and Food Security Sunderland Terry1 1 Centre for International Forestry Research (CIFOR), Bogor, IndonesiaAbstractAn increasing amount of evidence has been accumulated linking human health andfood security to biodiversity and the maintenance of diverse forest-based systems.Clear links on the positive side include the provisioning services of forests such asfoods, medicines and shelter, and cultural services such as indigenous knowledgeand traditional health care systems. Recent research by the Centre for InternationalCentre for Forestry Research highlights the importance of forests for health andparticularly the food security of local populations. Such research on the linkagesbetween forests and food security is timely as increasing international attention toclimate change fuels increasing interest in climate change mitigation, and adaptation.While many forest and biodiversity researchers focus on the role of “mitigation,” therole of forests in “adaptation”: the maintenance of human well-being and livelihoodsecurity in the face of climate and other environmental and socioeconomic changes,is equally important. This presentation will expand on the links between humanhealth, food security, biodiversity, and forest maintenance increasing awarenessamong scientists, strengthening inter-disciplinary communication and therebyhelping to bridge epistemological gaps. 190
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa167. Drought stress, nitrogen and potassium deficiency effects on dry matter partitioning in East african highland bananas Taulya Godfrey1, van AstenPiet1, Leffelaar Peter2 and Giller Ken2 International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 2Plant 1 Production Systems, Wageningen University, Wageningen, The Netherlands..AbstractDrought stress, nitrogen (N) and potassium (K) deficiencies are key limitations inUganda’s banana cropping systems. Crop modelling is useful in complementingfield experimentation in developing site-specific integrated soil fertility managementoptions against the limitations. It requires understanding of crop dry matter (DM)production and allocation responses to growth limitations. This study tested thehypothesis that drought stress, N and/or K deficiency increase DM allocation tobelow-ground (BG) compared to above-ground (AG) biomass fractions. A nutrientomission trial was conducted on a Haplic Ferralsol at Kawanda and a Lixic Ferralsolat Ntungamo in central and southwest Uganda, respectively planted with bananacultivar Kisansa at 1,111 mats ha―1. Up to 400 and 600 kg K and N, respectively ha―1yr―1 were applied either as sole or combined inputs in RCBD with 4 replications.From daily rainfall records at weather stations close to each trial, cumulative rainfall(CRF) was computed over 52 weeks after emergence (WAE) per plant harvested incrop cycles 1 (C1), 2 (C2) and 3 (C3). Plants that received less than the first quartileCRF (1107 mm) were considered drought-stressed; otherwise they were `moisture-sufficient’. DM allocation was evaluated as the ratio of the sum of pseudostem andleaf (AG) DM to corm (BG) DM plant― at harvest. ANOVA was run cycle-wise persite in GenStat using unbalanced treatment structure. Without K input AG: BG ratioswere significantly (P<0.05) lower by 15, 10 and 8%, in C1, C2 and C3, respectivelyat Kawanda and by 30 and 32% in C1 and C2, respectively at Ntungamo. N inputsignificantly (P<0.05) decreased pseudostem and leaf DM and increased corm DMfor all cycles at Kawanda but significantly (P<0.05) reduced (14%) the AG: BG ratioin only C1. N input had no effect on the AG: BG ratios for all cycles at Ntungamo.Drought stress had no effect on the ratio for all cycles at both sites. It is concludedthat K deficiency increases allocation of DM to BG in East African Highland bananas. 191
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa168. Can reduced tillage in maize-based systems in the savanna reduce soil erosion and meet farmers’ needs? Tossah Boglo K.1, K. Zoupoya, K. A. Ablede, K. Sourou, K. Afawoubo, J. Diels2 1 Institut National des Sols (ITRA), Lome, Togo; 2Division of Soil and Water Management, Faculty of Bioscience Engineering, Katholieke Universiteit, Leuven Kasteelpark, Heverlee, BelgiumAbstractThe ‘Region Centrale’ of Togo is densely populated and intensively cropped with maize (Zea maysL). This region is located in the Derived Savanna, an agroecological zone with a length of growingperiod between 211 and 270 days and soils that are prone to water erosion (soil associations withLixisols as dominant soil). The Derived Savanna covers 24% of Togo, and similar soils and maize-based cropping systems occur in a band stretching from Cameroon to Guinea covering about 66millions of hectares. In the ‘Region Centrale’, the use of inappropriate agricultural practices bysmallholder farmers such as manual ridging along the slope, frequent hoeing for weed control,and removal of crop residues cause excessive runoff, leading to severe erosion of the topsoil,soil nutrient depletion and decrease of cereal yields. We compared reduced tillage options to thecurrent farmer practice in a 3-year on-farm experiment. The aim was to identify practices that atthe same time increase farmers’ revenues and limit soil erosion. The on-farm experiment started in2008 and was carried out in two pilot sites (Affem and Sessaro/Laoudè) in the ‘Region Centrale’of Togo. Four treatments were compared: (1) “Farmer practice” (FP-) consisting of the commonmanual ridging at planting and 2-3 hoeing operations for weed control during maize growth.The fertilizer mean rate used on (FP-) was closed to the recommended one (45 kg N, 22,5 kg Pand 22,5 kg K per ha) which was decided by the farmer(2) “Farmer practice with fertilizer” (FP+)being the same as the FP- treatment except that fertilizer was applied each year at a rate of 76 kgN, 30 kg P, and 30 kg K per ha, (3) “Full ridging with fertilizer” (FullRidge+) consisting in thecommon manual ridging for land clearing and selective herbicide (Atrazine) spraying for weedcontrol during maize growth and (4) “Partial ridging with fertilizer” (PartialRidge+) consistingof a total herbicide (Glyphosate) application to kill fallow/weed vegetation before planting, andAtrazine application to control weeds during maize cropping. In the farmer practices (FP-/+)and in the FullRidge+ treatments, the old ridges are manually rebuilt every year by cutting halfof these old ridges to incorporate weeds into the old furrow where new ridges are rebuilt. In thePartialRidge+ treatment, the old ridges were manually rebuilt with a hoe at one side only, thusreducing soil disturbance considerably. The type and amount of fertilizer applied in the FullRidge+and PartialRidge+ treatments was the same as in the FP+ treatment. The 4 treatments werereplicated in 23 farmers’ fields, and maize yield data were analysed with a mixed model analysisof variance. The treatment effect on grain yield was statistically significant (p<0.0001) and showedno interaction with year or with site (i.e. pilot site). Average maize yields (kgDM/ha) amountedto 2080 for the FP- treatment, 2370 for the FP+ treatment, 2660 for the FullRidge+ treatment and2720 for the PartialRidge+ treatment. The profitability of the reduced tillage systems was assessedthrough partial budget analysis. Relative to the farmer practice FP- involving conventional tillage,the reduced tillage system “PartialRidge+” gave an excellent marginal rate of return of 221%,while the other reduced-tillage variant “FullRidge+” gave a marginal rate of return of 225%. Inorder to assess effects on water erosion, runoff plots were installed in two fields with contrastingsoil; one on a Plinthosol in Sessaro, one on a Gleyic Cambisol in Laoudè. Comparing the measuredrunoff under natural rainfall in the “FP-” and the “PartialRidge+” systems revealed that theintroduction of reduced tillage reduced runoff from 57 to 34 mm on the Plinthosol site, and from76 to 27 mm on the Gleyic Cambisol. Total sediment loss was likewise reduced from 1.5 to 0.8 t.ha-1on the Plinthosol, and from 5.8 to 0.9 t.ha-1 on the Gleyic Cambisol. 192
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa169. Effect of land use change and slope position on soil organic carbon in Kitabi watershed, Rwanda Tumwesigye Wycliffe Pilot International, UgandaAbstractSoil organic carbon (SOC) is widely used as a proxy for soil health and soil fertility.Land use change (LUC) has been implicated as one of the factors leading to theloss of SOC and increased release of greenhouse gases (GHGs) to the atmospherehence contributing to global climate change (GCC). Rwanda is a mountainouscountry and has faced a challenge of land use inter-conversions between forests,perennial crops and annual crops over the years. The impact of LUC on SOC stocksis poorly documented. The aim of this study is to investigate the effect of LUC andslope positions on SOC stocks in Kitabi watershed. Landsat TM-5 images of 2008and 1986 were used to make a land use change map using Maximum LikelihoodClassification (MLC) algorithm in Erdas. Slope positions were derived from the DEMusing Topographic Position Index (TPI) tool and the output raster was overlaid withthe LUC map to identify sample strata. Soil samples were obtained using stratifiedtopo-sequential random sampling from annual crops, community tea and factorytea. A total of 134 soil samples were taken from the three LU categories along eachof the three slope positions: upslope, middle slope and down slope. Soil sampleswere taken from 10 m x 10 m plots in each of the three land use categories at twodepths 0-20 cm and 20-50 cm using a soil auger. A total of 62 farmers from the threeLU types were interviewed about the farm management practices in the study area.SOC laboratory analysis was done using Loss on ignition (LOI). One-Way ANOVAand Games Howell tests were used to analyse the data. Results indicate that 17.1%of land was converted from annual crops to tea plantations. Significant differencesin SOC stocks exist across the three LU types (p <.001). Converting land from annualcrops to factory tea significantly affects SOC stocks (<.001) while LU conversionfrom annual crops to community tea has no significant effect on SOC stocks (p >.05).Slope position has a significant effect on SOC stocks in annual (p <.05) but it has nosignificant effect on SOC stocks in tea plantations (p >.05). The interaction of LUand slope positions has no significant effect on SOC stocks across the three land usetypes (p = .061). Soil erosion control measures in annual crops to reduce loss of SOCand soil nutrients are recommended. 193
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa170. Efficiency of phosphorus fertilizer use by soybean varieties and its effect on a subsequent maize crop Vandamme Elke1,2, Pypers Pieter2, Vanlauwe Bernard2, Baijukya Fredrick2 and Merckx Roel1 1 Katholieke Universiteit Leuven, Leuven, Belgium; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, KenyaAbstractThe process of nitrogen (N) fixation needs substantial amounts of phosphorus (P).The incorporation of soybean into rotations aiming at soil fertility improvementthrough N fixation can thus be hampered by low P conditions often met in stronglyweathered, P-fixing soils. It is known that large amounts of N can be fixed bysoybean when P fertilizer is applied. The use of large quantities of P fertilizer ishowever not within reach of many resource-poor farmers. For the development ofsustainable Integrated Soil Fertility Management (ISFM) practices, it would thereforebe desirable to explore the genetic variability that exists between different varietiesin their capacity to take up P and use it in efficient ways for increased levels of Nfixation. Increased P uptake can include both efficient uptake of poorly availablesoil P or small quantities of P applied as fertilizer. Field trials were established on 4locations across Western and Nyanza province in Kenya, with different prevailingsoil P conditions. During the short rainy season, 5 soybean varieties were planted incombination with 4 different rates of TSP fertilizer (no P application, 1/4th of `high’P rate, 1/2nd of `high’ P rate, and `high’ P rate), with the `high’ P rate differing forthe different fields, based on their soil P characteristics, and considered to be beyondthe minimum rate to which a soybean crop does not respond anymore. During thesubsequent season (long rains), plots were split: 120kg N/ha was applied to 1 subplot, while the `high’ P rate was applied to the other part, and maize was planted inall plots.The results of these trials demonstrate differences in rotational `N’ and `P’effects of various soybean varieties on a subsequent maize crop, in relation to theirP efficiency. They also highlight the potential of the use of improved germplasm insustainable agronomic practices for low-input farming systems in the tropics. 194
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa171. The study of juvenile growth of suckers of banana plantain by macropropagation in the East of the Democratic Republic of Congo. Vigheri, N.1, K. Muliata1, K. Muhiwa1, C. Sivirihauma2 1 Université Catholique du Graben, Butembo, NorthKivu, DR Congo; 2Bioversity International, CIALCA Project, Butembo, North Kivu, DR CongoAbstractBanana, one economic crop for many farmers of the tropic world, is a nonnegligible source of the better quality glucides. The culture in vitro is a means ofquick production of healthly suckers, this one is expensive for farmers, needing alaboratory, electricity and technical competences. The macropropagation is anothermeans which could multiply and produce quickly and healthly suckers. The testshave been in Butembo (1774 masl, N 00° 07’ 29.5’’, E 029°16’1’’) and Mavivi (1064masl, E 00°34’ 23.4’’, N 029° 28’41.8’’). The used vegetal material was of baionettesuckers from 6 cultivars : Nguma, Musilongo, Vuhindi, Obubit, Kotina and T6. Thecultivars Nguma, Musilongo and Vuhindi have got a growth rate of respectively196%, 106% and 103% at Mavivi comparatively to Butembo. In the two sites, a netdifference is observed among Nguma, Musilongo and Vuhindi respectively witha growth of 422%,224% and 220% for Mavivi site comparatively to Butembo site.The diameter of the cultivar T6 presents suckers bigger than the others cultivars inButembo whereas Vuhindi presents big suckers in Mavivi site. The cultivar Obubitpresents a high number of primary suckers in Butembo whereas T6 presents manyprimary suckers in Mavivi site. The comparison of cultivars in the two sites showsthat the suckers grow quickly in Mavivi with growth rate 205% for T6 and 210% forKotina. The cultivar Kotina has produced more suckers per square meters in Maviviwhereas it is Obubit which is more performent in Butembo. In all sites, Vuhindi hasproduced less suckers than the others cultivars. 195
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa172. Socio economic impact of Banana Xanthomonas Wilt in Eastern of DRCongo Vigheri N.1 and O. Fina 1 Université Catholique du Graben, Butembo, NorthKivu, DR Congo; AbstractSince the apparition of the bacterial wilt of the banana in 2001 in the locality ofBwere in North Kivu, the disease was spread on a surface of almost 1000 km length200 km large in the provinces of the South and North Kivu and oriental since theterritory of Kabare and the territory of Aru. The results of survey on the banana andbanana plantain represent 41.5% cultivated area. In the territories of Rutshuru andBeni, 90% of the banana fields are infected involving 72% of the fields which areabandoned. The severity of Banana Xanthomonas Wilt is 61% in the endemic zone1(post endemic) and 39% in the endemic zone. The disease is increase accordingto 91% of farmers. The investigation showed that 86% farmers know the varioussymptoms of the disease and 70 % are unaware of the mechanisms of propagation.72% of the farmers do not know the control methods and prevention. At the socio-economic level, with the apparution of BXW, 91% of farmers sell per week lessthan 5 bunches. Moreover, before the disease, 47% of the farmers sold the bunchesagainst 19% which are bought.This situation involved the drastic reduction in theincomes explained in particular by non frequentation of the children at school,the insufficiency of the products of first need in the households and the juveniledelinquency increased by 80%.The surveyed people (71 %) took 3 meals per daybefore the disease. With the presence of BXW, the investigation showed that 53%,43% and 12% of the families take respectively one, two and three meals per day.Moreover, 96% farmers do not have anymore the hope sufficiently to find food inthe future. The farmers are disarmed to these complex problems of the BXW andespecially the urgent request of the population is to find a holistic and sustainablestrategies. 196
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa173. Implementation of mycorrhiza and biofertilizers technology in plant production Vosatka Miroslav1, Latr Ales2 and Albrechtova Jana3 1 Research Centre of Bioindication and Revitalisation, Institute of Botany, Academy of Sciences of the Czech Republic, Pruhonice, Czech Republic; 2Symbiom Ltd., Lan- skroun, Czech Republic; 3Department of Experimental Plant Biology, Faculty of Sci- ence, Charles University in Prague Prague, Czech RepublicAbstractThe applied research and commercial exploitation of mycorrhizal fungi in agricultureand forestry has entered its booming phase and science is helping industry toproduce higher quality mycorrhizal inocula, develop suitable formulations ofinocula and more efficient modes of its application. The economic feasibility of themanufacturing and application of the mycorrhizal fungi in extensive agricultureand forestry though remains to be fully addressed. For extensive use relativelyhigh inoculum cost and high dosages per hectare can hamper full exploitation asopposed to application of mycorrhiza in horticulture and intensive agriculturewhere individual plants can be inoculated prior transplantation at reasonablecost. One of the main challenges for scientific community is to support mycorrhizaapplication in the case studies which reflect more closely real conditions of plantcommercial cultivation and thus facilitate faster technology transfer into practice.The local manufacturing of high quality mycorrhizal inocula in developing countriesshould help full implementation of the mycorrhizal biotechnology. Examples ofsuccessful applied research, possibilities of local manufacturing, results of practicaluse of mycorrhiza and also problems associated with field testing and applicationare given. Potential and procedures of local manufacturing of mycorrhizal fungiin developing countries are discussed with focus on improvement of efficacy andsustainability in cultivation of food and non-food crops in subtropical and tropicalregions of Africa. 197
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa174. Evaluation Of Kenyan Endophytic Fusarium Oxysporum Isolates For Bio-Control Of Banana Nematodes (Pratylenchus goodeyi) Waweru Bancy1, Losenge Turoop1, Kahangi Esther M.1, Coyne Danny2 and Dubois Thomas3 1 Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya; 2Interna- tional Institute of Tropical Agriculture, Kampala, Uganda ; 3University of Bonn, Insti- tute of Crop Science and Resource Conservation (INRES), GermanyAbstractGreenhouse studies were conducted to evaluate the efficacy of two non-pathogenicFusarium oxysporumisolates (4MOC321 and 11SR23) from banana (Musa spp.) plantsin Kenya, against Pratylenchus goodeyi. Isolate V5W2 originating from Uganda wasused as a positive standard. Two month old tissue culture-derived plantlets (cv.Giant Cavendish and cv. Grand Nain) were inoculated with endophytes at pottingand one month later inoculated with 500 P.goodeyi/plant. The experiments werelaid out in a completely randomized design with control plants inoculated withnematodes but no endophytes. Plant growth response to endophyte treatment wasevaluated over a period of four months. Nematode population, percentage damageand colonization were determined at termination of the experiments. Percentagereduction of the population of Pratylenchus goodeyi ranged between 47-60% inendophyte-inoculated plants compared to non-inoculated plants, while percentageroot necrosis was reduced by>30 %. The number of dead roots was significantly(<0.0001) lower in endophyte inoculated plants when compared to the control plants.Relatively enhanced growth was observed for plants inoculated with endophyteswhen compared to the control plants. Kenyan isolates performed equally as goodas the Ugandan isolate (V5W2). Results from this study demonstrated that Kenyanendophytic isolates have the potential to enhance growth of tissue cultured bananaplants as well as control P. goodeyi. 198
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa175. Evaluation of different amaranthus spp. Lines for horticultural characteristics and yields in Rwanda Waweru Bancy1, Kagiraneza Boniface2, Kahia Jane3, Ndereyimana Assinapol4 and Buso- bozi Martin5 1 Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya; 2Institut des Sciences Agronomiques du Rwanda (ISAR), Kigali, Rwanda; 3National University of Rwanda (NUR), Rwanda; 4Higher Institute of Agriculture and Animal Husbandry (ISAE), Rwanda; 5Rwanda Agriculture Board (RAB), RwandaAbstractAmaranthus spp.are an important vegetable crop in Rwanda but little research hasbeen carried out to determine its yield potential. Evaluation trials were carried outat ISAR-Rubona and Karama stations, Rwanda to determine the horticultural andyield characteristics of selected lines collected from different countries in South andEastern Africa. Fifty eight lines of Amaranthus spp. were evaluated. The experimentswere laid out in a randomized complete block design (RCBD) with three replications.Management and other agronomic practices were done as recommended. Datacollected included; days to 1st flowering, days to 50% flowering, total leaf andseed yield. All parameters significantly (P< 0.05) differed between lines. Results forRubona stationshowed mean leaf yields ranging from 2.29 t/ha to 39.53 t/ha withline RW-AM-12, ML-AM-3, RW-AM-3 and UG-AM-40 giving mean leaf yields ofover 25 t/ha. The mean seed yields ranged from 51.28 kg/ha to 2318.82 kg/ha withline HTT showing the highest seed yields. Line TZSMN-82-B was the first regardingdays to 1st flowering (35 days) and to 50 % flowering (37.66 Days). At Karamastation, the highest leaf yield was observed with line UG-AM-61(36.95 t/ha) whileLine UG-AM-65 was the first regarding the days to 50 % flowering (57.33 days). LineHTT produced the highest seed yield (6391.00 kg/ha) and line RW-AM-10 producedthe lowest seed yield (241.33 kg/ha).Significant differences in leaf and seed yield,days to 1st flowering and 50% flowering among the lines of amaranths may helpin identifying superior cultivars that can either be used to develop new varieties ordirectly disseminated to farmers and consumers for utilization. 199
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa176. Effects of rhizobium inoculation and phosphorus sources on the productivity of groundnut in Samaru, northern Guinea savanna of Nigeria Yusuf Ado1, Jemo M2, Ncho C.2 and Abaidoo R.C.2 1Ahmadu Bello University, Zaria, Nigeria; 2International Institute of Tropical Agri- culture, Ibadan, NigeriaAbstractThe form and composition of fertilizer phosphorus (P) as well as the effectivenessof rhizobium inoculants will affect legume nutrition and yield. A field trial wasconducted in 2010 to evaluate the effect of three P sources and three rhizobiuminoculants on the yield and yield components of groundnut in the northernGuinea savanna of Nigeria. The P sources were Agroleaf liquid fertilizer, singlesuperphosphate (SSP) and triple superphosphate (TSP). The rhizobium inoculantswere biofix, vault and mixture of the two. Two controls, no inoculants and no P wereincluded in the treatment combinations. The difference between nodulation andshoot dry matter yield of inoculated and uninoculated plants was not significant.Similarly, there were no significant differences in pod and haulm yields betweenthe rhizobium inoculants. However, uninoculated plants produced significantlyhigher pod (20%) and haulm (28%) yields than the average yield of the inoculatedplants. Nodulation, biomass, haulm or pod yield were not influenced by any of theP sources and the results were similar to where no P was added. The results showthat the soil P might be adequate to support groundnut production without furtheraddition or the cultivar was adapted to the low soil P conditions in the Nigeriansavanna. The rhizobium strains in the inoculants seems not to be only ineffectivebut were inferior to the indigenous soil population. 200
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa177. Evaluation of commercial and laboratory rhizobium inoculants on nodulation and yield of promiscuous soybean in the Nigerian savanna Yusuf Ado1, Ncho C.2, Jemo M2, Nwoke O.C.3 and Abaidoo R.C.2 1 Ahmadu Bello University, Zaria, Nigeria; 3International Institute of Tropical Agricul- ture, Ibadan, Nigeria; 4Osun State University, Osogbo, NigeriaAbstractInoculation of soybean with effective rhizobium will improve its productivityespecially where indigenous soil populations are not adequate in strain number,quality or effectiveness to fix atmospheric nitrogen. In 2010, field screening of 14commercial and laboratory rhizobium inoculants was conducted in Kadawa (Sudansavanna) and Samaru (northern Guinea savanna) to identify effective and promisingproducts on two soybean genotypes. In Kadawa, three commercial products andseven strains resulted in increased nodulation but none of the inoculants resultedin significant increases in biomass and/or grain yield compared to the control. InSamaru, two commercial products and six strains increased nodulation. Of these,only three strains resulted in significant increases in biomass and/or grain yield.Although strains TSBF 531 and TSBF 560 did not increase nodulation at P < 0.05, theyalso made significant increase to grain yield relative to the control, on the averageof 35%. Therefore, effective inoculants to consider in Samaru are 1496 MAR, USDA4675, USDA 110, TSBF 531 and TSBF 560. Interaction between soybean genotypeand inoculants was observed only on nodule fresh weight in Samaru. The lack ofsignificant interaction between rhizobium inoculants and soybean genotypes in mostof the yield parameters shows similarity in genetic determinants of compatibilitybetween the genotypes with the symbiotic partners. 201
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa178. Gender and spatial analysis of the relative profitability and costs of production of beans at the household level in East and Central Africa Zozo Rachel1, Eliud Birachi2, Bernard Vanlauwe3 and Jonas Chianu4, W.Chiuri1 Consortium for Improvement of Agricultural-based Livelihoods in 1 Central Africa (CIALCA) CIAT-TSBF, Bukavu, DRC; 2International Center for Tropical Agriculture-Africa (CIAT),Kigali, Rwanda;3International Center for Tropical Agriculture-Tropical Soil Biology and Fertility Institute (CIAT-TSBF), Nairobi, Kenya; 4African Development Bank, Tunis, TunisiaAbstractLegumes and especially beans provide some of the most grown crops in East andCentral Africa region. The question of whether certain crops, specifically beans, aremore beneficial to women, when compared with the men, relative to cash crops andother cereals has been raised from time to time. In the central Africa region and inparticular in the Democratic Republic of Congo (DRC), beans production have beenpromoted in the recent years. Beans are widely cultivated in central Africa region,and they contribute to better nutrition in soil fertility improvement. The economicbenefits and costs associated with beans production has not received adequateattention at the household level and between male and female farm actors. Basedon beans, this paper examines the profitabilities and costs of production for beans atthe household level, among male and female farmers in the South Kivu Province ofthe DRC. The paper uses results obtained from a survey of 160 farmers in 10 villagesin South Kivu Province of DRC. Data was collected on household characteristics,costs, prices and quantities associated with bean production. An ordinary leastsquares (OLS) regression was used to assess factors that influence the observedbeans production costs for beans among the households and consequently access toinput markets. The results indicate the average age of bean farmers is relatively lowand that there is no significant difference between the profits received by men andwomen farmers. This is despite the result that men face relatively higher costs thanwomen farmers, and this likely reduces the margins to similar levels as women.The results also show that larger surfaces put under beans are inversely associatedwith margins from the beans, an observation that may be explained by low use ofproduction enhancing inputs. In order to increase outputs farmers were more likelyto increase area under cultivation rather than use more inputs. The results also showthat farmers located in remote areas suffer higher production costs in acquiringinputs, usually at higher costs than those located in optimal locations. Such farmerswere found to face lower costs because they are using almost no additional inputsbesides seeds. Interventions that would enable such farmers to affordably accessproductive inputs are likely to impact positively on the farmers’ economic welfare. 202
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa179. Introgression of Pythium root rot resistance gene into Rwandan susceptible common bean cultivars J. Nzungize1, P. Gepts2, R.Buruchara3, A.Male3, P.Ragama4, J. P. Busogoro5 and J. P. Baudoin1. University of Liege, Gembloux Agro-Bio Tech, Belgium ; 2University of California, 1 Davis; 3CIAT, Pan Africa Bean Research Alliance, Kampala, Uganda ; 4National Agriculture Research Organization, Kampala, Uganda  ; 5Belgium Technical Cooperation, IPM project, Kigali, Rwanda.AbstractA breeding scheme was carried out to introgress resistance genes to bean Pythiumroot rot in various commercial varieties grown in Rwanda. The achieved crosseswere performed between three selected susceptible varieties (R617-97A, RWR 1668and Urugezi) which are adapted to the various ecological production zones ofRwanda and two known sources of resistance to Pythium root rot (RWR719 andAND1062). Following each inter varietal hybridization generation, a series of 4successive back-crosses was achieved by using the susceptible parents as the initialparent lines to be improved for their respective behavior to Pythium root rot disease.At each back-cross generation, the PYAA 19800 SCAR marker linked to Pythiumroot rot resistance in the two sources of resistance (varieties RWR 719 and AND1062) was used to identify and to proceed to early selection of progenies possessingthe gene of interest. The target materials serving for the molecular analyses wereprepared from young trifoliate leaves of 2-weeks bean plantlets. It was observed thatat each back-cross generation, there were variable proportions of plants exhibitingpresence of the resistance gene according to the SCAR marker profiles. In additionto that observation mainly based to molecular profile, it was also revealed that theproportion of bean seeds having the same color as the susceptible parent line wasincreasing progressively. Finally, to assess if the individual plants exhibiting theSCAR marker are effectively resistant to the Pythium root rot disease, inoculationtests were carried out with a Pythium ultimum strain on each of them. This ultimatebiological evaluation revealed that all the plants showing the SCAR marker wereresistant to development of Pythium root rot symptoms after inoculation, confirmingthus real introgression of the resistance characteristics through the breeding schemeadopted in our work. 203
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 204
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEME 2: SYSTEM INTEGRATION 205
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 206
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa180. From intensification to agro-ecology: pathways for transition Baret Philipe Université catholique de Louvain, BelgiumAbstractThe concept of intensification is at the heart of the Green revolution. The rationaleis that the most efficient method to increase food production is to increase yield byha. In this approach, the food production is disjunct from the food demand andconsumption. An alternative and integrated approach is based on the food systemconcept. In this option, food security is discussed in a systemic framework wherefood production and food consumption are interconnected under the pressure ofdifferent drivers. Food system approach is the key for an agro-ecological visionfor African agriculture. Agro-ecology put forward principles of managementthat as inspired by an ecosystemic vision of the agricultural system. The purposeis not the maximisation of yield but the optimisation of resources by not relyingon unrenewable resources and by maximising recycling. Applications in Africademonstrate the power of this paradigm to boost rural development in the respectof environmental and social criteria of welfare. 207
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa181. A comparative and multi-scale approach to evaluate banana cropping systems Philippe Baret1 and Julie Van Damme1 1 Université catholique de Louvain, BelgiumAbstractA major constraint of agricultural systems of Central Africa is the return of soilfertility. On the long term, successive crises due to fertility renewal issue inducedmajor reconfigurations of the systems. The last one lead to the shift from acattle-based system to a banana-based system. Our approach is based on both acomparative framework and a systemic analysis. Five settings in three countries(Rwanda, Burundi and RDC) are studied in parallel to take into account variationsin agro-ecological and institutional conditions. In a system-based perspective, weuse a combination of quantitative (field measurements, economical valuation) andqualitative methods (semi-directed interviews) to acknowledge the integratednature of the intensive cropping systems of the Great Lakes region. It allowssmallholders to assess long term risk in terms of monetary benefits but also in termsof labour intensity and system stability. The originality of the approach is to providea comprehensive and reproducible tool for a diagnosis at the farm level taking intoaccount qualitative dimensions. Alternative indicators of productivity are used andwill facilitate analysis of innovation processes in a comparative framework. 208
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa182. Statistical and spatial comparison of livelihood capitals assessed by three independent surveys in South Kivu in the Democratic Republic of Congo Bouwmeester Hein1, Van AstenP.2, Heuvelink G.B.M.3 and Ouma E.2 1 International Institute of Tropical Agriculture (IITA), Tanzania; 2International In- stitute of Tropical Agriculture, Bujumbura, Burundi; 3Wageningen University, Land Dynamics Group, Wageningen, the NetherlandsAbstractMany development projects in Africa aim to improve the livelihoods of the people.These projects often assess livelihood indicators through baseline surveys that areexecuted at the household level. The point-based observations are extrapolatedto the surrounding region for which the livelihood indicators are then deemedto be accurately enough described to allow the formulation of a strategy and toassess the impact of a project. However, there is no consensus of how thesesurveys should spatially be designed and how many observations are necessaryto accurately estimate the properties of the region. In this study the statisticalinterference and the spatial correlation of three independent baseline surveys inSouth Kivu in the Democratic Republic of Congo are compared. The surveys varyin spatial distribution and in sampling size but are similar in content and have beenrealized at about the same time. From each survey ten indicators are selected thatdescribe the human, financial, social, physical and natural livelihood capitals ofthe regions’ population. There are significant statistical differences and similaritiesbetween some of the livelihood capitals that can be largely contributed to the spatialconfiguration of each of the three surveys. However, in many cases the variabilitywithin specific villages is as high as the variability within the entire region. Therefore,we recommend that common livelihood indicators (e.g. descriptions of populationmeans and distribution) can be obtained by surveys that focus on a limited (e.g. <10)number of villages only. Such a sampling design would cost significantly less thana survey that is more spatially balanced and covers the entire region. Alternativesampling designs remain justified to capture project specific properties (e.g. spreadof diseases) because these may exhibit a different spatial distribution pattern thenthe livelihood indicators described in this paper. 209
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa183. Promoting the use of an ‘Integrated Crop Management (ICM)’ to ensure increased and sustainable banana production systems in Rwanda Busogoro Jean-Pierre1, Dennis Ndamugoba, Francis Nkurunziza3, Jean-Marie Vianney Nkunduwimye and Julianus Thomas MINAGRI-BTC IPM project Technical Advisor; 3Rwanda Agriculture Boad (RAB), 1 Kigali, Rwanda;Abstract:Banana constitutes one of the main components of the food security in Rwanda which isproduced in almost all the districts of the country. Practically, farmers involved in bananaproduction in Rwanda grow a lot of different varieties which are utilized in variousways as an end product.In many cases, production levels reached so far for the differentbanana varieties are very low in the present traditional banana production systems. Inthe frame of the present work, further investigations have been carried out to determinethe various constraints leading to that low productivity prior to developing appropriatesolutions. The main constraints identified through these efforts were the following (1)low knowledge of farmers in relation with the function of different parts of banana,(2) high pressures of pests and diseases affecting the crop, (3) use of inappropriatecropping practices, (4) accelerated decrease in soil fertility and lack of proper integratedsoil fertility management (ISFM) to ensure its restoration, (5) unsuitable exploitation ofthe existing genetic diversity of banana. Based on these observations, an Integrated CropManagement program by using the Farmer Field School (FFS) approach was designedand implemented to educate farmers and disseminate knowledge and technology in aparticipatory manner. The technical components of the strategy implemented throughthe present work were relative to the following topics:(i) Skilling farmers in relation with various components of the banana production system,(ii) Suitable exploitation of genetic resources through maintaining and increasing the genetic diversity,(iii) Improving the cropping practices (hole making, planting density, suckers selection and preparation, fertilisation etc) in old and in new banana fields,(iv) Promoting simple ICM methods and techniques to ensure sustainable management of pests and diseases in banana farms,(v) Improving the access of farmers to quality planting materials.The proposed scheme for a global ICM use has been tested in different banana productionareas and generated interesting results in terms of farmers’ knowledge. Moreover, thecropping practices have been improved by the different farmers who participated in theimplementation of the ICM scheme. Finally, a progressive and significant increase of theproductivity level has been recorded for different banana varieties following applicationof the ICM scheme. In conclusion, promoting the implementation of ICM scheme is anappropriate way to make the banana production systems economically beneficial entechnically sustainable. 210
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa184. Adapting to climate change in potato and sweet potato systems in East Africa. Claessens Lieven1, Stoorvogel Jetse2, Antle John3, Thornton Philip4 and Herrero Mario4 1 International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Nairobi, Kenya/Wageningen University, the Netherlands; 2WageningenUniversity, the Netherlands; 3Oregon StateUniversity, USA; 4InternationalLivestock Research Institute (ILRI), Nairobi, KenyaAbstractSub-Saharan Africa (SSA) is predicted to experience considerable negative impactsof climate change. The IPCC Fourth Assessment Report emphasizes that adaptationstrategies are essential. Addressing adaptation in the context of small-scale, semi-subsistence agriculture raises special challenges. An important constraint is thatdata demands are high, because site-specific bio-physical and economic data arerequired. The development of relatively simple methods for ex ante evaluation ofadaptation at the household and system levels is therefore needed. In an ongoingresearch project coordinated by the International Potato Center (CIP), we test a newapproach to ex ante impact assessment that produces site-specific results that can alsobe aggregated for regional analysis. The methodology uses the kinds of data that aremore often available in resource-poor countries. The stochastic approach integratessocio-economic and bio-physical data on farmers’ land allocation, production, inputand output use. Characteristics of the agricultural system regarding resources andproductivity are analyzed and compared for both current and projected climate.Possible adaptation strategies are then assessed for their capability to reduce oroffset the adverse effects of climate change. We apply the methodology to severalstudy areas in East Africa where potatoes or sweet potatoes are an important part ofthe agricultural system. After characterizing the current systems with actual climatedata, the effects of a perturbed climate are analyzed and a variety of adaptationstrategies tested. Despite the limitations, the new approach offers a flexibleframework for evaluating adaptation strategies using scarce data of resource-poorcountries in SSA and other parts of the world. It allows a rapid integrative analysisfor timely advice to policymakers and for exploration of technology and policyoptions. 211
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa185. Ex ante assessment of dual-purpose sweet potato in the crop- livestock system of western Kenya: a minimum-data approach. Claessens Lieven1, Stoorvogel Jetse2 and Antle John3 1 InternationalCrops Research Institute for the Semi-Arid Tropics (ICRISAT), Nairobi, Kenya/Wageningen University, the Netherlands; 2WageningenUniversity, the Netherlands; 3Oregon StateUniversity, USA;AbstractMixed crop-livestock systems have a crucial role to play in meeting the agriculturalproduction challenges of smallholder farmers in sub-Saharan Africa. Sweet potatois seen as a potential remedial crop for these farmers because of its high productivityand low input requirements, while its usefulness for both food and feed (`dual-purpose’) make it attractive in areas where land availability is declining. In thispaper we develop and apply a `minimum-data’ methodology to assess ex ante theeconomic viability of adopting dual-purpose sweet potato in Vihiga district, westernKenya. The methodology uses and integrates available socio-economic and bio-physical data on farmers’ land use allocation, production and input and output use.Spatially heterogenic characteristics of the current system regarding resources andproductivity are analyzed to assess the profitability of substituting dual-purposesweet potato for other crops currently grown for food and feed. Results indicatethat a substantial number of farmers in the study area could benefit economicallyfrom adopting dual-purpose sweet potato. Depending on assumptions made,the adoption rate, expressed as the percentage of the total land under adoptingfarms, is between 55 and 80%. The analysis shows that the adoption rate is likelyto vary positively with the average total yield of dual-purpose sweet potato, theharvest index (the ratio between tuber and fodder yields), the price of milk, and thenutritional value of available fodder. This study demonstrates the usefulness of theminimum-data methodology and provides evidence to support the hypothesis thatdissemination of the dual-purpose sweet potato could help improve the livelihoodsof smallholder farmers operating in mixed crop-livestock systems in East Africa. 212
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa186. The role of land management and rural public works interventions for agricultural intensification: an integrated environmental modelling approach Luuk Fleskens University of Leeds, School of Earth & Environment, Leeds, United KingdomAbstractAgricultural productivity in Africa has stagnated compared to other regionsof the world. The humid highlands of Central Africa are no exception and percapita production has fallen rather than increased over the last 50 years. Furtherexpansion of agricultural land is undesirable or has even reached physical limits andintensification is universally proclaimed as the way forward. However, the scope oftechnologies such as fertilizer application and use of improved plant varieties maybe limited if not addressed in a holistic way. Deforestation, soil nutrient mining,soil erosion and soil acidification are environmental degradation processes thatjeopardise agricultural productivity, and need to be mitigated in order for newtechnologies to be successful. The rugged topography, (extremely) small fieldsize and limited accessibility of many humid highlands are important obstaclesto intensification. Upstream-downstream interactions need to be duly taken intoaccount as well, with forests, wetlands and lakes providing many crucial ecosystemservices that need to be maintained to protect livelihoods. In this paper, I will showthat investments in sustainable land management and rural public works are pivotalfor the success of agricultural intensification strategies. However, when comparinginvestment options, one should take into account financial viability. The paperdraws from an extensive study using linked spreadsheet models to evaluate ruralpublic works in Rwanda, Burundi and Congo DRC and spatially-explicit integratedenvironmental modelling developed for dryland areas. Considering degradationprocesses and investment costs as influenced by environmental conditions anddistance to markets, the modelling approach is shown to be a useful instrument tosupport decision-making. In particular, combinations of different interventions canbe evaluated. 213
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa187. Enhanced peace building and farmers/grazers alliances for inclusive agropastoral production in North West Cameroon Fon Julius1 and Yobo A Koue Fidèle1 1 Netherlands development organization, SNV, CameroonAbstractPastoralism in the NW region faces some challenges that result in conflicts amongresource users. Often, grazers encroach in to farming areas, or cattle tracksand drinking points for animals are blocked by farmers for other uses. All thesedegenerate into violence that leads to burning of homes, maiming and killing ofanimals and persons. In a bid to improve the productivity of the agro-pastoralismsystem, SNV designed a strategy for advisory support that had three componentsnamely participatory conflict management by stakeholders, promoting farmingalliances among farmers and grazers leading to emergence of paddock farmingin agro pastoral communities and increasing general stakeholder awareness onthe causes and consequences of farmer-grazer conflicts.The participatory conflictmanagement entails stimulating community level dialogue platforms wherefarmers and grazers are able to report incidences of conflicts and seek solutions. Thisprocess has led to over 20 % reduction in farmer-grazer conflicts in the concernedcommunities. Increased stakeholder awareness on the causes and consequencesof farmer/grazer conflicts through public debates has equally coerced the localadministration to provide moral support to these dialogue platforms leading to theirincreased effectiveness.With peace building among farmers and grazers, there is theopportunity of farming alliances to promote the night paddock manuring farmingsystem. This entails farmers fencing their fields and negotiating for cattle to spendnights on farmers field and leading to in situ manuring of the field. The farmersrealize increased yields with highly valued organic crops. This increased yields arecommercialized to increase the revenues of the farmers who equally share the yieldswith the grazers. The farmers are also involved in planting forage near their fieldsfor grazing of the cattle in the paddocks. Therefore, we end up with an integratedsystem of crops and livestock that is mutually beneficial to both the farmers andgrazers and agricultural intensification is achieved as the manured fields can becultivated for over five years before the farmers will need to shift to another field. 214
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa188. Coffee-banana intercropping systems as an opportunity for smallholder coffee farmers Laurence Jassogne1, Nibasumba Anaclet2, Lydia Wairegi3, Philippe Baret4, Jonasz Deraeck4, David Mukasa5, Ibrahim Wanyama5, Gatarayiha Celestin5, Ghislaine Bongers5 and van Asten Piet5 1 Université Catholique de Louvain-la-Neuve/International Institute of Tropical Agriculture (UCL-IITA), Belgium; 2ISABU-UCL-IITA, 3CABI-IITA, Nairobi, Kenya; 4 Université Catholique de Louvain (UCL), Belgium; 5International Institute of Tropical Agriculture (IITA), UgandaAbstractCoffee and banana are respectively primary cash and food crops in the East Africanhighlands region; i.e. Rwanda, Burundi, northwest Tanzania, west and central Kenya,and east Democratic Republic of Congo. These two crops often occur on the samesmallholder farms either planted on separate plots or intercropped. In certain countriesintercropping coffee and banana is tolerated while in others, governments recommendto grow these cultures on separate plots. Even if intercropping coffee and bananawould lead to a decrease in coffee yields under certain conditions, it gives advantagesto smallholders farmers. Intercropping offers higher returns per unit land compared tomonocropped coffee. Farmers increasingly revert to intercropping due to declining farmsizes in an effort to reduce risks related to income and food security. Researchers haveidentified the potential opportunity of intercropping coffee and banana for smallholderfarmers, but many public and private development partners have not yet fully embracedthis technology. We discuss benefits and constraints of intercropping coffee and bananabased on results from Burundi, Rwanda and Uganda. We aim to understand driversof this system in Uganda where intercropping is a common practice so a frameworkcould be developed and suggested to develop research and recommendations forintercropping coffee and banana in Burundi and Rwanda where intercropping is underexperimentation and has high potential of development. 215
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa189. Integrated Soil fertility management for optimizing crop productivity in the highlands of Rwanda Kagabo Desire1, Nabahungu N. Leon1, Mugabo Josaphat2, Mugabe Jonas3, Moses Te- nywa4, Claver Ngaboyisonga1, Majaliwa M. Jackson4, Fungo Bernard5, Murorunkwere Françoise1 and Musana S. Bernard1 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 2Rwanda Ag- ricultural Board (RAB), Rwanda; 3Forum for Agricultural Research in Africa (FARA), Ghana; 4Makerere University, Faculty of Agriculture, Kampala, Uganda; 5 Kachwekano Zonal Agricultural Research and Development Institute (KAZARDI), Kabale, UgandaAbstractAgricultural production in the densely populated tropical highlands of Rwanda issubject to serious soil fertility constraints. Previous studies showed that on-farm yieldincrements from the use of multi-purpose legume trees and herbaceous species failed tocompensate the cost of labour investments during green manuring and soil phosphorusdeficiency. Integrated Soil Fertility Management (ISFM) involving farmyard manure(FYM) and limited amounts of inorganic fertilizer could be an alternative in increasingagronomic nutrients use efficiency and improving crop productivity. In this regard, atrial was laid out in two consecutive seasons in Rwerere, Northern Rwanda on threelandscape positions (summit, hillside and foothill) with 9 replicates per landscapeposition. On each landscape position, trial contained 2 factors (fertilizer applicationand soil conservation technology) laid out as a randomized complete block design.Fertilizer application contained four levels: no fertilizer, diamonium phosphate (DAP),FYM and FYM + DAP. The soil conservation technology factor contained three levels:bench terraces, grass strips and without soil conservation technology. FYM applicationincreased crop yield, but did not improve the soil organic matter levels. The use of DAPas a supplement significantly increased crop yields irrespective the landscape positionand soil conservation practices. On bench terraces FYM permitted the restoration of soilproductivity, but reached a high level of crop production only when DAP was appliedas supplement. FYM was only sufficient when supplemented by N and P fertilizers in allinvestigated plots. The relation between nutrient management strategies and crop yieldperformances was established. Local quality of FYM could not improve the crop yieldalthough supplemented with limited mineral fertilizer. 216
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa190. Nutrients flows analysis in soils of smallholder farmers in Cyabayaga watershed Kabiligi M.1, Nabwami J.2, Musana B.1 and Nabahungu N. L.1 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 2Department of Soil Science, Makerere University, Kampala, UgandaAbstractThe aim of this study was to assess nutrient flows in soils of Cyabayaga watershed.Cyabayaga watershed is divided in 7 sectors namely Nayagatare, Gatunda, Rukomo,Mimuli, Katabagyemu, Mukama and Ngarama sectors. Partial nutrient (N, P and K) flowswas collected using the MonQi was collected through a survey using MonQi structuredquestionnaire, administrated to a random sample of 5 farmers per sector. Highestamount of nutrients were significantly allocated in wetland fields while allocation ofnutrients in homestead fields and remote hillside fields was almost the same. The mostimportant of N and P was DAP while important source of K was paddy rice straw. TheN balance in Gatunda was -40.2 kg ha-1 season-1 and -28.6 kg ha-1season-1 in Rukomo.Furthermore, the highest P and K negative balance was in Rukomo and Mimuli sectorsrespectively. The highest N, P and K positive balances were in Katabagemu, Mimuli andMukama sectors respectively. Groundnut and maize plots were experiencing highestnegative nutrients balance (e.g N balance in groundut plot was-40.6 N ha-1 season-1). Nand K balance were positive in rice and banana plots; whilst P balance was positive inbanana, bean, maize, rice and tomato plots. The average of N, P and K balance at farmlevel in Cyabayaga watershed were -10.6 N ha_1 season_1, 19.44 P ha_1 season_1 and-12.3 K ha_1 season_1 respectively and most of nutrients were lost to market. 217
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa191. Effects of agricultural land uses on soil properties and crop response in wetlands of East Africa Kamiri Hellen1 and Becker Mathias2 1 Karatina University, Nyeri, Kenya; 2University of Bonn, Bonn, GermanyAbstractLand use changes and intensification of agricultural production are envisaged to altersoil attributes of the wetlands in East Africa and have in some instances affected theircapacity to support crop growth. These changes were investigated in four representativewetlands in order to determine (1) key soil parameters (C, N and P) and their responseto different land use changes and (2) the effect of these land use changes on the biomassaccumulation and nutrient uptake of rice (Oryza glaberrima) grown in potted soilunder both flooded and aerobic conditions. The wetlands comprised floodplains andinland valleys located in different climatic zones and at different altitudes, comprisingfloodplains in the lowlands (<500 masl), inland valley in the mid-hills (700-1700 masl),and floodplain and inland valley in the highlands (>1700 masl). Land use types in allthese wetlands included: - undisturbed land under natural vegetation, land cultivatedwith lowland crops (rice: Oryza sativa or taro: Colocassia esculenta) under anaerobic soilconditions, land cultivated with upland crops (maize or vegetables) in drained andaerobic soil conditions, and degraded / abandoned areas with fallow vegetation. Theprogressive change in land use from undisturbed sites to intense cultivation differentiallyaffected soil parameters in the different wetland types. Thus, the sandy clay soils inthe mid-hill and the floodplain wetland reacted most sensitively to land use changeswith significant decline in soil organic C and total N while P contents responded lessto land use changes. Rice biomass accumulation and nutrient uptake responded to soilconditions (wetland types as well as land use) and soil aeration status. The highlandsoil from both the floodplain and inland valley supported a larger biomass and nutrientuptake, irrespective of the land use. Crop response was mainly determined by differencesin soil N contents between land uses in the inland valley and by differences in soil P andN between land uses in the floodplains. 218
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa192. Assessing Challenges and Opportunities of the Animal- Agriculture System in the Alpine Region of Uvira territory in Sud-Kivu Province of the D.R. Congo Katunga Musale1, Ouma Emily2, MAASS Brigitte L.3 and Chiuri Wanjiku L.4 1 International centre for Tropical Agriculture (CIAT)/Institut National d’Etude et de Recherche Agronomique (INERA), DRC; 2International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 3Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 4CIAT (Centro Internacional de Agricultura Tropical)/CIALCA, Kigali, RwandaAbstractThe Alpine region of Uvira territory in the Southern part of Sud-KivuProvince faceslow agricultural productivity challenges largely due to human population pressureon the natural resource base. During the dry season, conflicts between crop farmersand livestock holders (Bafuliru and Banyamulenge) are common as the latter searchfor pasture thereby creating temporary settlements. This agricultural region is located2500 meters above sea level and is almost inaccessible due to poor road infrastructure.To understand the interactions between natural resources (forests, pastures, soils)and sedentary agriculture and to propose solutions for sustainable natural resourcemanagement, participatory rural appraisal (PRA) sessions covering three farmer groupinterviews were conducted in July 2010 in Marungu, Kitembe and Kahololo localities.The livelihoods of the Banyamulenge were transformed from pastoralism to a sedentarysystem with the introduction of crop cultivation after 1980. Maize, bush beans andpotatoes are cultivated with limited success because of late crop maturity under theprevalent climatic conditions. Livestock, mainly cattle, sheep and goats is managedunder extensive system, relying on natural pasture far from the human settlements. Inthe region, livestock play an important role to define people’s wealth and is mainlymanaged by men. Interviewees expressed a real need of forages during the dry season;however, cultivation of forages is unknown. On the other hand, pastures appear to bedegenerating due to overgrazing.In order to address the problems of natural resourcemanagement and agricultural production identified in this region there should be effortsto improve security. Access by farmers to efficient and effective agricultural extensionservices is fundamental in order to promote locally adapted and profitable crop andlivestock production while at the same time, sustaining the productive resource base. 219
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa193. Availability of animal feed resources at farm and village scale in Umurera, Rwanda Klapwijk, C.J.1 and Van Wijk, M.1 1 Wageningen University, Wageningen, The NetherlandsAbstractRwanda is the most densely populated country in Africa, resulting in agriculturalintensification and overexploitation of natural resources, the latter leading to foodinsecurity. To improve the situation the government initiated the ‘One farm, one cow’-program, to distribute cows to the poorest families. The viability of the program wasstudied, using the research-hypothesis: ‘Can each farmer in Umurera produce sufficientfodder to keep cattle?’ Umurera-village is representative for Rwanda’s Central Plateauarea. Land-availability per farmer ranged between 0.10-2.86 ha. Most important fodderfor cattle were: grasses (56%), banana plant-parts (21%) and crop-residues (15%). Onequarter (25%) of the feed consisted of uncultivated grass. The feed composition for cattleof wealth-category II and III is almost equal, while farmers from WC-I fed less grassesand larger quantities of marshland-herbs and crop-residues. The amount of fodderon offer for cattle ranged between 42-179 kg fresh weight per animal per day; someanimals were underfed. Fodder-amounts for local cattle of WC-II were substantiallylower than amounts on offer for improved cattle, agreeing with literature. Milk-yieldranged between 1.33-4.58 l/d. The amount of refusals and the chemical analysis of plantsamples indicated a low quality of some fodder.Calculations on current possibilities for farmers to produce fodder resulted in negativeconclusions for the poorest farmers (WC-I). The effects of five scenarios were alsoexplored; the quantity of three cultivated fodder-species was increased, decreased orkept equal. The calculated fodder-production (kg DM/year) per farmer indicates thatin several scenarios two poorest farmers are likely able to keep local cattle. However,it might be impossible for farmers to realize the necessary investments and the annualfodder-production in Umurera likely differs from the calculated numbers. The programuses only improved cattle and is therefore not viable in its current setup. The viabilitywould increase if cattle-breed would be changed from B. taurus to B. indicus. Anothermore realistic option would be the distribution of milking goats. 220
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa194. Promoting Conservation Agriculture to Improve Land Productivity and Profitability among Smallholder Farmers in Western Kenya Koala S.1, Okeyo, J.1, Adolwa, S.I.1 and Savini1 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, KenyaAbstractSmallholder farmers in Africa are trapped in a vicious cycle of poverty and land degradationcoupled with increasing population and demand for food. In addition to this demand for food,there is an increasing demand for the production of renewable resources, including bio-energy,based on the same natural resources as food production. So far food production in Africa hasonly grown at half the rate as the demand. This has also a direct impact on rural livelihoods,since still some 65% of Africa’s population lives in rural areas depending on agriculture.However, farming as now widely practiced in Africa, is not sustainable in the long run, fromeither environmental or economic viewpoints. The challenge of agricultural sustainability hasbecome more intense in recent years with the sharp rise in the cost of food and energy, climatechange, water scarcity, degradation of ecosystem services and biodiversity, and the financialcrisis. There is, therefore, need to harness appropriate and affordable agricultural technologiesthat are highly productive and at the same time positively contribute to environmental servicesas an element of sustainability. Conservation Agriculture (CA) is being increasingly promotedas constituting a set of principles and practices that can make a contribution to sustainableproduction intensification because it addresses missing components in the intensive tillage-based standardized approach to agriculture intensification. As an effect of CA, the productivepotential of soil rises because of improved interactions between the four factors of productivity:(a) physical: better characteristics of porosity for root growth, movement of water and root-respiration gases; (b) chemical: raised CEC gives better capture, release of inherent and appliednutrients: greater control/ release of nutrients; (c) biological: more organisms, organic matterand its transformation products; (d) hydrological: more water available. Wherever CA hasbeen adopted it appears to have had both agricultural and environmental benefits.The, aim ofthe project was to promote widespread adoption of conservation agriculture by smallholderfarmers while protecting and improving soil conditions to achieve higher yields and enhancedenvironmental services in East Africa. The project has created widespread awareness ofconservation agriculture to 4500 households in the target districts using the mother-babyapproach, field days and demonstrations. Over 1200 farmers have been trained on the principlesof CA technology. Farmers identified two CA technologies as most promising in the region: i)80% preferred the Cereal-legume rotation (specifically the soybean-maize rotation) and ii) 20 %preferred cereal-legume intercrop, with desmodium as cover crop. Under the rotation system,the cereal component was grown during the long rains (March-June), while soybean duringthe short rains (September-November). The selection of the maize-desmodium intercrop wasbased on i) striga weed infestation, ii) need for alternative animal feed, and iii) productionof desmodium seed for sale. For the intercrop plots, desmodium provided more than 70%ground cover, minimizing weed competition and surface run off. Average maize grain yieldwas significantly higher than the control (1.2 t/ha) in both CA (2.8 t/ha rotation and 3.0 t/haintercrop system) and conventional agriculture plots (2.8 t/ha). To promote development ofmanufacturing enterprises the project facilitated the training of 8 artisans in fabrication of CAtools, soybean processing and strengthening of two farmer groups for collective action.UnderCA increase in crop yields was the benefit ranked highest by farmers. However, under thecurrent fertility status in most farms, CA cannot be practiced effectively without addition ofnutrients especially nitrogen and phosphorus to the system. 221
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa195. Integrating grain legumes in maize based systems for improved soil healthy, food security and incomes by smallholder farmers in Zambia Milambo Laston Zambia Agriculture Research Institute (ZARI), ZambiaAbstractThe integration of grain legume crops into the continuous maize cropping systemsin Zambia has the potential to contribute significantly to national food securitythrough improved soil health and higher crop yields to smallholder farmers. Grainlegume crops (soybean, groundnuts and cowpea) were grown in rotation withmaize in `Mother Demo’ trials in 5 districts of Zambia. Fertilizer treatments were0, 20 and 40 kg P /ha; 0, 6, and 12 kg N/ha and 0, 33 and 66 kg K/ha applied asSoymix B (5 %N2O:20%P2O5:20%K2O) basal for legumes and 0, 20 and 40 kg P/ha; 0,64 and 70 kg N/ha and 0,8 and 17 kg K/ha applied as Compound D (10%N2O:20%P2O5:10%K2O) basal and Urea (46%N2O) top dressing for maize.Soybean was inoculated in all the plots. Agriculture lime was applied as a broadcastin all the plots at 200 kg/ha. Conservation Agriculture methods of basins or rippingwere used in all the plots. The `mother demos’ were planted in 15 agriculture camps; 3camps in each of the 5 districts. In each camp, cowpea and maize rotation demo, andgroundnuts and maize rotation demo were replicated three times while the soybeanand maize demo was replicated four times in a randomized complete block design.Each `Mother Demo’ measured 49m x 32m (1568m2) and each of the six plots fromone `Mother Demo’ measured 15mx15m (225m2). The objective was to demonstrateto farmers the benefits of maize and legume crop rotation farming system, andalso of applying chemical fertilizers to legume crops. Data collected included soilsamples at 0 - 20 cm depth before the demos were planted in order to determinethe baseline fertility status of the demo sites, date of planting, plant population andheight. Soil samples will also be taken after harvest to see the treatment effect. Otherparameters to be measured during the harvesting of the crops in June 2011 includebiomass production and grain yield. The results and conclusion will be reportedonly after harvesting of the crop. 222
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa196. Spatial multi-scale analysis of coffee farming systems in quality variation of Bourbon coffees of Rwanda Mukashema Adrie1 and Veldkamp A. Tom2 National University of Rwanda, Rwanda; 2Faculty of Geo-information Science and 1 Earth Observation, University of Twente, The NetherlandsAbstractSpatial variability of speciality bourbon Coffee in Rwanda reveals the need of in-depth study of coffee farming systems at various scales. Lack of information oncoffee-based farming system, structure and resource flow in coffee farm is achallenge to yield and quality forecast. Little is known in coffee research what scalebetter illustrate the difference in yield and quality of coffee within and betweenspatial ranges of physical and human factors of coffee production. Three differentscales were identified and analysed for speciality coffees and ordinary coffees ofRwanda. Quality of coffee revealed a spatial trend across regional, watershed to farmscale. The results indicated also that the current performing coffee farming systemsare highly linked with the level in which each system adheres to the three scales.However, the temporal variation of speciality coffee of Rwanda using Golden Cup2007, Cup of excellence 2008, 2009 and 2010 show an adherence to the farm scalewithin the catchment scale regardless the regional scale. The study determined howall these scales are relevant not only in monitoring yield and quality of coffee butalso in distribution of inputs in order to sustain speciality coffee market in Rwanda. 223
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa197. Agricultural intensification for food security in the most popular provinces of North Burundi. Ndimubandi Jean1 and Orshoven Jos Van2 National University of Burundi, Burundi; 3Katholieke Universiteit Leuven (KUL), 1 BelgiumAbstractThe agricultural sector in Burundi has been and still considered as guarantor offood security, engine of national economy and family and a driving force of growthin other sectors of national life. However, it is largely characterized by a farmingsubsiste nce developed by 1.2 million households with low incomes and use 0.5 haeach on average. Food crops whose products are mainly for family consumptionare estimated to 90% of cultivated area and they contribute up to 46% of GDP.Obviously, we believe that only a proportion of 5% of the population has no foodinsecurity issue in this country where people are over 8 million.Governmentpriorities are indicated in strategic documents such as CSLP, SAN, etc... The overallobjective of the National Agricultural Policy (Stratégie Agricole Nationale, SAN inFrench) is, first, to rehabilitate the production tool and revitalize farming activityin order to boost production and eventually to transform subsistence agricultureinto marketable agriculture. An annual growth rate of 6% is maintained. In terms ofdevelopment, the project’s overall objective is “to reverse the trends of household foodinsecurity through promotion of production systems intensification and sustainablemanagement of natural resources.” More specifically, this study has the ambition to:1. Enhance and share with actors involved in agricultural the knowledge in order tocontribute to sustainable intensification of agricultural ecosystems and agriculturaldiversification. 2. Involving and mobilizing structures for sharing knowledge onproduction systems. 3. Contribute to value chains promotion and agribusiness. 224
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa198. Plant and soil interactions between adjunct coffee and banana plots in Burundi: preliminary assessment in farmer field conditions. Nibasumba Anaclet1, Baret Phillipe V.2, Jassogne Laurence3 and Van Asten Piet4 1 Institut des Sciences Agronomiques du Burundi (ISABU), Burundi 2Université Catho- lique de Louvain (UCL), Belgium; 3Université Catholique de Louvain-la-Neuve/Inter- national Institute of Tropical Agriculture (UCL-IITA), Belgium; 4International Insti- tute of Tropical Agriculture (IITA), Kampala, UgandaAbstractCoffee and banana are often occurring together in smallholder farms in Burundi.Some farmers even intercrop coffee and banana although it is strongly un-recommended by extension services. As studied in other countries like Uganda, theobjective of this study is to analyse whether the banana-coffee association could bea possible alternative to coffee monocropping in the agro-ecological conditions ofBurundi. Because currently farmers do not intercrop coffee and banana in Burundi,we decided to do a preliminary assessment based on observation of farmer systemswhere banana and coffee were planted side by side.Sixty plots in the regions ofKirimiro and Buyenzi were studied for yield and yield components (e.o. density,bunch weight, weight of 100 cherries) of both banana and coffee. Soil and foliarnutrients were measured and a agricultural practises were described. In each plot,four subplots were considered: coffee far from banana, coffee close to banana, bananaclose to coffee and banana far from coffee.The first analyses points out to significantdifferences for banana yield close and far from coffee and coffee quality close and farfrom banana. Mulch application and water conservation and availability seem to beimportant explanatory factors for these differences.Those preliminary observationsraise very interesting insights for the organisation of fully controlled trials and forthe discussion of the extension of intercropping recommendations at larger scales. 225
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa199. A Resource-based Characterization of Farmers in the Rural Central African Highlands Ouma Emily1, Van Asten Piet2 and Dubois Thomas2 1 International Institute of Tropical Agriculture, Bujumbura, Burundi; 2International Institute of Tropical Agriculture (IITA), Kampala, UgandaAbstractIdentification of farmer typologies has become central to agricultural researchand development efforts in recent years for purposes of improved targeting oftechnological and policy interventions. Nonetheless, the precise identification offarmer typologies in quantitative data has largely remained methodologically elusive.This paper uses principal component analysis and cluster analysis in order to identifyexisting typologies among smallholder farmers in Central Africa by assessing theirresource endowments and how these assets influence their agricultural practices andlivelihood outcomes. Using a random sample of 2800 households from CIALCA’smandate areas in Rwanda, Burundi and the DRC three distinct farmer typologiesare identified. The first cluster “resource-rich entrepreneurs” comprise farmers whohave access to financial and natural capital though their social capital is not welldeveloped. They are closely located to basic amenities including urban markets andare engaged in commercialization of agricultural produce and off farm activities aspart of their livelihood strategy. Few farmers belong to this category. Farmers in theRwandan mandate areas particularly Gitarama had a relatively higher proportionof its households in this grouping. The second cluster “the resource-constrained”comprise the highest proportion of farmers from the DRC and Burundi mandateareas and are rated lowest in terms of physical, natural, social and financial capital.They are largely agricultural subsistence oriented and suffer from household foodinsufficiency. The last cluster “the natural-resource rich” farmers have relativelylarge land holdings and livestock units but are remotely located from basic amenitiesand markets. They are mainly involved in subsistence agriculture and petty tradeas their livelihood strategy. Interventions aimed at enhancing livelihoods for eachfarmer typology are then drawn based on these farmer characterizations. 226
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa200. Increasing Benefits of Smallholder Farmers from Improved Soil Fertility Through Integration of Pigeon Peas, Groundnuts and Conservation Agriculture in Maize Production Systems in Malawi Phiri Samu National Smallholder Farmers Association of Malawi, MalawiAbstractAgriculture remains the main economic activity for 80% of population of Malawi, contributing36% of the GDP. Since 2005, the Government of Malawi has continued to invest heavily inagricultural production especially to meet food security by providing input support of fertilizerand seed for the staple food crop, maize, and in selected cash crops, e.g., cotton. However therehas been increasing realization that the solution to maintenance and improvement of soil fertilitycannot be solely met through usage of inorganic fertilizers. There is need to address the healthof the soil. The government of Malawi in 2008 Agricultural Input Program therefore deliberatelyincluded 3 major legumes (groundnuts, beans and pigeon peas) to help to fix nitrogen biologically.The National Smallholder Farmers’ Association of Malawi (NASFAM) supported by the Alliancefor a Green Revolution in Africa (AGRA) implements a Project entitled “Increasing benefits ofsmallholder farmers from improved soil fertility through integration of pigeon peas, groundnutsand conservation agriculture in maize production systems in Malawi to compliment thegovernment of Malawi efforts on same. The overall goal of the Project is to improve food securityand incomes of over 30,000 smallholder farmers through integrated soil fertility managementusing grain legumes (groundnuts and pigeon peas) and fertilizer trees (Tephrosiacandida) in 3central region districts of Malawi (Lilongwe, Kasungu and Salima). The target legumes can fixbetween 150 - 200 kg N ha-1, of which one third is available for the succeeding crop in a rotation.At the fertilizer prices of US$ 82 per 50 kg bag as it was in 2008/09 growing season, this wouldhave cost the farmer approximately US$492 per ha to apply the recommended rate of 92 kg N ha-1sourced from combination of Di - Ammonium Compound fertilizer (23 kg N). Additionally, ifone third of the nitrogen fixed by legumes could have been available from the previous season, itwould have met approximately half of the requirement thus giving the farmer substantial savingsfrom the purchase of fertilizer. This would translate into a saving of approximately US$ 164 per haif Urea is the N source, or even greater saving of US$ 328 per ha with D Compound. The fertilizerrequirement from any one source would have been completely substituted by either ground nutsor pigeon pea. That is, the fertilizer substitution and saving potential is immense and will behigher if legumes particularly pigeon peas are low - dosed with P-based fertilizers to enhancetheir biological nitrogen fixation.In addition to improve soil fertility benefits, smallholder farmers’incomes would increase from sale of surplus production. The improved agronomic practices areexpected to result in yields of the legumes that currently are under 1.0 ha-1 to increase to between1.5 and 2.0 MT ha-1 over 3 years. Some of the produce will result into improving householdnutrition given the high protein content of the legumes. Pigeon peas and groundnuts commandbetter market prices from both local and global markets. Currently pigeon peas price at the localmarket is about US$ 0.78 per kg which is almost double that of maize that averages US$ 0.30 per kgand therefore farmers could get some additional incomes from legumes, driving re - investment infarm inputs and achieve agricultural income and crop diversification.The project intends to reachat least 30,000 smallholder farmers in 3 central region districts of Malawi (Lilongwe, Kasunguand Salima) with an improved maize-legume system. This system improves access to improvedlegume seeds, demonstrates and trains well farmers on how best to integrate the legumes intothe maize-based system. In addition, the project is promoting integration of legumes with otherlegumes (a system known as doubled -up). In the doubled-up case, pigeon pea is integrated intogroundnuts that farmers in this region put more land into. The project is also training farmerson the principles and practice of conservation agriculture with trees (CAWTs) which has severalbenefits in Malawi where soils are inherently poor. It improves soil structure and increasesorganic matter content in the soil that lead to better water holding capacity. A recent approach,conservation agriculture with trees (CAWT) that fix nitrogen is receiving widespread adoption.Tree species such as Faidherbia albida have been recognized and accepted by farmers in the drierareas of Malawi as a source of fertilizer and are managed within the field in such a way that theeffects of shade are minimized and the benefits of nitrogen from the fallen leaves are maximized. 227
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa201. Farmer adaptive testing confirms increased crop productivity through Integrated Soil Fertility Management (ISFM) in cassava- legume intercropping systems in the highlands of Sud-Kivu, DR Congo Pypers Pieter1, Sanginga JM2, Walangululu MJ3 and Vanlauwe B1 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 2Tropical Soil and Biology Institute of the International Cen- ter for Tropical Agriculture (CIAT-TSBF), DRC; 3UCB, Bukavu, DR CongoAbstractResults from previous demonstration trials showed that the productivity of cassava-legumeintercropping systems can be significantly increased through the use of improved germ-plasm, judicious fertilizer use and crop arrangement. Farmer-managed adaptive trials werecarried out with 585 households in four sites located on two axes with contrasting agricul-tural potential during two consecutive cropping cycles with the objectives to evaluate theeffect of judicious fertilizer use and adapted agronomic practices on legume and cassavastorage root yields across a wide range of field types and fertility levels. Farmers received“packages” with planting material and were trained to install and manage the trials by sitefacilitators. Two packages were formulated to evaluate different aspects of the technologiesthrough a simple design with three plots. In both packages, the first plot was a farmer’scommon practice, where the legume seed was broadcast and cassava cuttings were plantedwithout a specific arrangement, while in the second plot, cassava was planted at the recom-mended spacing of 1m by 1m, and two bean lines were planted in between the cassava rows.In the third plot of the first package, fertilizer was applied and crops were arranged in thesame way as in the second plot. In the third plot of the second package, cassava was plantedat a modified spacing of 2 m between lines by 50 cm within the line, with four lines of beansbetween the cassava rows. In the second package, all three plots received fertilizer. Afterharvest of the beans, the bimodal rainfall pattern allowed a second intercrop, and soybeanwas planted with additional fertilizer application in the respective treatments. Householdand field characteristics as well as trialmanagement were recorded, and crop yield assess-ment was supervised by technical teams. About one quarter of the farmers did not correctlyimplement the trial or did not collect all essential information, and were excluded from theanalysis. In the traditional practice, average bean grain yields were 1000 kg ha-1 on the north-ern axis, and 600 kg ha-1 on the southern axis. The subsequent soybean crop yielded about700 kg ha-1 on both axes. Fertilizer addition increased bean grain yields by 11 and 24 % onthe northern and southern axis, respectively, and modifying the cassava crop arrangementfrom 1 m by 1 m to 2 m by 50 cm increased yields by 6 and 17 %, respectively. Effects weremore pronounced on the subsequent soybean crop: fertilizer application and improved croparrangement increased grain yields by 23 % and 21 % respectively. Relative to the traditionalpractice, these measures represented an increase in legume productivity by 44-60 %. Cassavastorage root yields were much larger on the northern axis (on average 23 t ha-1) than on thesouthern axis (on average 7 t ha-1). Fertilizer application increased cassava yields by almost20 % on both axes. The cassava crop arrangement of 2 m by 50 cm did not negatively affectcassava yields, relative to the recommended 1 m by 1 m arrangement. Variability betweenparticipants was very high, with legume and cassava yields in the farmers’ practice rangingbetween 0 and 3.0 t ha-1, and 0 and 58 t ha-1, respectively. Negative treatment effects wererarely observed.In conclusion, farmer adaptive testing confirms that a simple agronomicmeasure modifying the crop arrangement can largely increase legume productivity in cas-sava-legume intercropping systems, without negatively affecting cassava production. Ad-ditional judicious fertilizer application can further increase both legume and cassava yields.Variability in crop response to fertilizer and modified crop arrangement will be explored,and related to differences in soil fertility, soil type and management. 228
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa202. Intensification options for the extensive farming systems of central Mozambique: application of the NUANCES framework Rusinamhodzi L.1, Dahlin S.2, Corbeels M.3, Wjik Van M.4 and Giller K.E.4 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF),, Zimbabwe; 2Department of Soil Science, Swedish University of Agri- cultural Sciences, Uppsala, Sweden; 3Agricultural Research for Development (CIRAD), Embrapa-Cerrados, Brazil; 4Plant Production Systems, Wageningen University, Wa- geningen, The NetherlandsAbstractCentral Mozambique is characterized by relatively extensive agricultural systemswhich is a reflection of the generally low population density, limited capital resourceendowments, and market access constraints. Slash and burn, limited fertilizer use,and low crop-livestock integration are common practices. On the other hand, therising population pressure and a dwindling resource base means that productionsystems have to be intensified to produce more food from small pieces of land.Intensification entail the use of external inputs, improved varieties and breeds, moreefficient use of labor, and better farm management of which a greater proportionof farmers cannot afford. The complexity of the interaction between multipleprocesses underlying agricultural production and farmers’ decision making hasto be understood. Approaches are required to capture all the interactions, trade-offs in resource and labour allocation on different fields and different farms. Wetherefore use the NUANCES framework which combines detailed farming systemcharacterization, on-farm experiments and simulation modeling to improvetargeting of suitable production systems for a particular locale. The objective ofthis study is to apply the NUANCES framework for analyzing and exploring thesustainability of intensification options in the low-input farming systems of centralMozambique. Current options to improve soil productivity include fallowing andmaize-legume intercropping. Analysis of crop residue managements suggests thatconservation agriculture is currently not an option in these systems. Surprisingly inthis site, farmers with livestock do not use manure for crop production due to labourlimitation and lack of general knowledge on manure management and its effect oncrop productivity. Soil analysis results show that fallowing on the sandy soils doesnot result in improvement of soil organic carbon but significant increases in soil bulkdensity. In the short term, improved fallows are an option for improving the qualityof grazing land as well as adding good quality organic matter to the soil. Resultsfrom maize-legume intercropping showed higher productivity, improvements inincome generation, returns to labour and rainfall infiltration. We conclude that thecurrent practices of slash and burn, and fallowing are unsustainable and there isneed to intensify maize-legume intercropping and to integrate more livestock andcrops by recognizing the value of manure in improving soil fertility and crop yields. 229
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa203. Land-use intensification and efficiency of food crop production in Southwestern Nigeria Saka J.O.1, Okoruwa V.O.2, Oyekale A. S.2 and Onio. A. 1 Federal College of Animal Health & Production, I.A. R&T, Ibadan, Oyo State Nigeria; 2 Faculty of Agriculture and Forestry, University of Ibadan, NigeriaAbstractIncreasing use-intensity of arable land through shortened fallow period is becomingparamount in Nigerian agriculture. However, the implication of continuouscultivation, cropping intensities, and agro-ecological diversities on the potential forincreased food production is has not been adequately explored in Nigeria. The effectof land-use intensity on the efficiency of food crop farmers in South-western Nigeria(SWN) is investigated. Data were generated through of survey of 341 farmers selectedby multi-stage sampling techniques from two states in Southwestern Nigeria. Datawere analyzed employing descriptive statistics, Continuous Cultivation IntensityIndex (CCII), Cropping Intensity Index (CII) and regression. All tests were carriedout at p=0.05. The CCII was 0.74±0.19 while CII was 1.2±0.6. The CCII was notsignificantly different across agroecologies while CII was significantly higher in thederived savannah (1.4±0.7) than in the forest (1.0±0.4) and southern guinea savannah(1.3±0.5year/ha) agro-ecologies. About 22% and 58.7% of farmers engaged farmlandunder high and very land-use intensity respectively with about 40.9% engaging inproduction system that encourages soil mining. Average technical efficiency (TE)of the farmers was 76.3% while TE was significantly higher in forest (77%) andderived savannah (78%) than southern guinea savannah agro-ecology (72%). TEwas significantly enhanced by access to credit, mixed cropping, closeness to marketand significantly hindered by increase frequency of cultivating land. 230
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa204. Intensive rice system (SRI) around forest protected areas (Madagascar Highlands) Serpantie Georges1 and Rakotondramanana Modeste1 1 Institut de Recherche pour le Développement (IRD), Antananarivo, MadagascarAbstractOn the Betsileo Highlands of Madagascar, the potentialities of SRI (Intensive RiceSystem) were not concretized by a massive adoption. Lowest adoption occurredaround forest protected areas in landlocked zones, where SRI extension was yetimplemented. In assumption, SRI model met specific ecological and socio-economicconstraints. An in situ investigation at plot level (practiced technical sequences,labour requirements, crop components analysis) was implemented on randomsamples of plots, fifteen plots per system. Three systems were compared: practicedSRI (SRIp), practiced SRA -improved rice system-(SRAp), betsileo system (BS),during three years, on two sites (near the forest, near the regional road). This workwas supplemented by qualitative investigations at farm and region levels. TheBS was more intensive and more yielding than SRI promoters told. It yielded 2,9to 4 t.ha-1 depending on fertilizers, year and varieties, against 2 t.ha-1 in officialdiscourses. SRIp and SRAp did not fit rigorously to the prescribed models andtestified to a local adaptation by adopters. The SRIp generally benefited more organicmanure than BS. SRIp cumulated many operations, care and paid labour. The yieldof SRIp exceeded Betsileo one only in case of organic manure (+30%). Accordingto yield components, it was ascribable to the effects of initial aerobic conditions ofSRI seedlings-bed on the organic matter mineralization and on the root growth,leading to more vegetation per square meter and more grains per panicle than inanaerobic BS. In case of manure, the labour productivities of the three systems werequite similar. This low attractiveness, the low availability of manure, the cost ofspecialized hired labour, and the lack of mineral soils, reduced SRI adoption bythe poor farmers of the forest edge. SRI did not meet there the good conditions ofextension seen elsewhere, near the roads and markets. 231
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa205. Adoption of organic farming techniques as an alternative approach to addressing livelihood concerns in Gasabo District Taremwa Nathan1, Samvura Nepomscene, Mutandwa Edward3 and Uwimana Placide4 National University of Rwanda, Rwanda; 3Higher Institute of Agriculture and Animal 1 Husbandry (ISAE); 4Ministry of Education, RwandaAbstractOrganic farming is a system of agriculture that encourages healthy soils and cropsthrough such practices as nutrient recycling of organic matter, crop rotation, propertillage and avoidance of synthetic fertilizers and pesticides. Due to escalating costsof artificial fertilizers and their negative effects on the environment, adoption oforganic farming systems is being considered as the appropriate alternative tolivelihood improvement through improved agricultural production. Thus a studyon;<<ADOPTION OF ORGANIC FARMING TECHNIQUES AS AN ALTERNATIVEAPPROACH TO ADDRESSING LIVELIHOOD CONCERNS IN GASABODISTRICT>>.The main objective was to assess the adoption of organic farming andits impact on livelihood improvement.The survey was conducted with 75 farmersworking with Vi-LIFE Program in Gasabo district and three organic promoters fromGako Organic Farming Training Centre, Urwibutso Sina Gerard Enterprise andABAKUNDAKAWA Cooperative respectively.Both qualitative and quantitativedata have been collected, thereafter statistical analysis has been done usingregression equation, T-test for comparison of means and net farm income analysisto estimate the profitability organic and inorganic farming systems. The T-testfor comparison of means showed that there is no significant difference betweenproduction getting under organic and under inorganic farming system in cropsand vegetables in Gasabo district. Organic and artificial mean yields respectivelywere 53, 125kgs and 60.75 kgs for maize, with 0.397 as p-value; 34.3684 kgs and41.6667kgs for beans, with 0.266 as p-value; 530kgs and 533.33kgs for cabbage, with0.973 as p-value; 590kgs and 613.05kgs for tomatoes with 0.760 as p-value. In termsof income; organic coffee gross margin (8,103,750Rwf/ha) is higher than inorganiccoffee gross margin (4,634,500Rwf). Organic practices namely kitchen gardens,agriculture-livestock integration, use of natural plants to control pests, agro-forestrypractices, and efficient exploitation of small farms with high productivity amongothers are aspects that would contribute to livelihood improvement. 232
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa206. Intensification of crop-livestock farming systems in East Africa: A comparison of 3 sites in the highlands of Ethiopia and Kenya Tegegne Mekonnen Kindu1, Valbuena Diego1, Duncan Alan1 and Gérard Bruno1 1 International Livestock Research Institute (ILRI), Addis Ababa, EthiopiaAbstractSmall scale crop-livestock farms represent a large fraction of the rural populationin the East African highlands. Yet, the level and pace of intensification vary amongregions, villages and farms. The objective of this study was to (i) compare the extentof crop-livestock intensification and how this is changing, (ii) assess driving forcesand possible consequences of crop-livestock intensification, and (iii) explore optionsto overcome constraints to existing crop-livestock intensification in three sites inthe highlands of Ethiopia and Kenya. A total of 8 villages per site were surveyedin two sites in Ethiopia (Kobo and Nekemte) and one site (Kakamega) in westernKenya. A survey was carried out with representative groups of 10-20 farmers usinga structured interview in each village to gather quantitative data at village level. Thethree sites generally depend on rain-fed agriculture. Crop residues are a strategicproduction component that are dominantly used for animal feed in all the sites.Population densities range from 250 persons per km-2 in Kobo to 1000 persons perkm-2 in Kakamega. Application of manure, use of inorganic fertilizers and improvedseed are more pronounced in Kakamega and Nekemte than Kobo. Ninety-one and46 % of the households in Nekemte and 57 and 32 % of the households in Koboapply herbicides and pesticides in their farms. Irrigation agriculture has becomean emerging practice in Kobo as compared to the other two sites. Unlike the twoEthiopian sites, 12% of the households in the Kakamega site own crossbreed cattle.The level of intensification varies among the three sites mainly due to variations inmarket options, population dynamics, land use policies and availability of waterand system oriented technological options. Because of the complexity and variation,different solutions are called for in different contexts. Dealing some of the issues,for example, the water, land-use and technological options in Kobo, the market andland-use in Nekemte and the population related issues and technological options inKakamega could lead to a more sustainable intensification of crop-livestock farmingin the East African highlands. 233
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa207. Integrated water management for agricultural intensification and resilience in East African Highlands Tilahun Amede International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia/ International Water Management Institute (IWMI), Colombo, Sri LankaABSTRACTIntegrated water management is a multi-disciplinary, knowledge-intensiveengagement embracing the whole range of wider practices from in-situ moistureconservation through water harvesting to large scale irrigation. It is an importantstrategy to intensify agricultural systems and adapt to climate and market shocks.Water management is a landscape phenomenon, governed by interaction of systemcomponents at farm, landscape, basin scales. This paper presents highlights ofresearch finding on agricultural water management in East African highlands, thechallenges and the interventions required to improve water management across thecontinuum; enriched by case studies from the region. The paper emphasises theneed for incentives and participatory approaches in sustainably managing smallscale irrigation schemes, enhancing adaptation capacity of communities to recurrentdrought and improving productivity and income. Moreover, water managementinterventions were adopted only when they were satisfying short term benefitsand responded to farmers’ priorities in terms of food security, income and riskmanagement. Improving the performance of irrigation projects could be achievedthrough developing scheme-specific intensification strategies, appropriate targetingand facilitation of collective action. Improving crop and livestock water productivity,estimated as economic returns per unit of water depleted, was found to be a keyintensification strategy. For instance, growing crops in trenches (e.g. ‘zai’ pits) couldincrease crop water productivity by about 300%, while improving access to wateringpoints could increase livestock water productivity and milk yield by about 35%. Thepaper also displays how benefits from water investments, in terms of food securityand income in the face of climate change, could be substantially increased; throughovercoming design constraints, improving ownership of schemes and watershedby local community, upstream-downstream linkages, protecting schemes fromboulders and siltation and employing rainwater management strategies. It alsorecognizes the need for stronger institutional linkages and integrated approaches. 234
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa208. The integrated soil fertility management (ISFM): an approach to optimize agricultural production in Rwanda Ukozehasi, C. 1, B. Vanlauwe2, H. Breman3, P. Pypers2, & C. Murekezi4 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 3International Fertilizer Development Centre (IFDC), CATALIST project, Burundi; 4Rwandan Agricultural Development Authority (RADA), Kigali, RwandaAbstractThe study was conducted in the 7 districts representing the agro- ecological zones ofRwanda, with the purpose of evaluating the responsiveness of crops to the integratedsoil fertility management (ISFM) practices. The research involved soil sampling andanalysis before and after application of ISFM. The treatments were attributed to theplots basing to the prior results of soil analysis. The leaf was sampled and analyzedfor nutrients content to diagnose crop production constraints. The laboratoryanalysis revealed that ISFM practices improved considerably the soil properties inall the sites compared to the control. The treatments with ISFM practices yielded twoto three times of the production from the control. The study confirmed the potentialof ISFM practices to optimize crop production and sustain soil health. 235
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa209. Adaptation to climate change through the choice of cropping system in sub-Saharan Africa Waha Katharina Potsdam Institute for Climate Impact Research, GermanyAbstractMultiple cropping systems are common farming systems in many countries of sub-Saharan Africa (Francis, 1986) and therefore need to be considered in the evaluationof climate change impacts on Sub-Sahara African agriculture. Growing two crops inthe same field in sequence (sequential cropping) increases farm level productivityand provides more security because crop yields are obtained two or more times in ayear (Andrews & Kassam, 1976). Under climate change many areas in sub-SaharanAfrica are likely to experience a decrease of the length of growing period whilein some highland areas rainfall changes may lead to an elongation of the growingperiod (Thornton et al., 2006). Therefore farmer’s choice of an adequate croppingsystem and crop cultivar might be an important adaptation strategy to weatherand climate change (O´Brien et al., 2000; Thomas et al., 2007). As the traditionalsequential cropping systems are advantageous management strategies which allowfor risk spreading and increased crop productivity we test the susceptibility ofthis system to future climatic conditions. By comparing crop yields which can beobtained in the traditional sequential and three alternative cropping systems wetest the ability of each system to contain negative impacts of climate change ofcrop yields. From a household survey (Dinar et al., 2008) on farming and croppingactivities of over 8000 households in eight sub-Saharan Africa countries (BurkinaFaso, Cameroon, Ethiopia, Ghana, Kenya, South Africa, Zambia, Zimbabwe) themost frequent sequential cropping system cultivated in each country and districtcan be identified. The crop productivity under current and projected future climaticconditions until 2050 is analyzed using the global dynamic vegetation model formanaged land LPJmL (Bondeau et al., 2007) and climate projections of three GeneralCirculation Models (GCMs): ECHAM5(Jungclaus et al., 2006), HadCM3(Cox et al.,1999), and CCSM3 (Collins et al., 2006) for SRES A2. Results show that although inmost countries crop yields decrease, the extent and even the direction of crop yieldchange can be influenced by choosing another cropping system and/or adapting thesowing date. In Cameroon and Ghana it will be advantageous to apply a differentthan the traditional sequential cropping system. In Zambia and South Africa cropyields will be less affected or even increase if only the first crop of the traditionalsequential cropping system is grown. In Benin, Burkina Faso, Zimbabwe and Kenyacrop yields decrease in all cropping systems. 236
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa210. Lessons Pour la Soustenabilité de la Macro-Propagation au Sud- Kivu Zagabe Roger Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA), D.R. CONGOAbstractL`absence de système semencier permanent pour la culture de bananiers prévaut à larareté de semences de qualité au Sud-Kivu, une province traditionnelement dominéepar la culture de bananiers. Ceci rend difficile le renouvellement de plantations déjàtrès vieilles et dont la productivité à baisser et, le rétablissement de celles detruitespar le BXW qui occasionne des pertes économiques estimées à 16000$/ha/annéedans le kivu où 80% de la population rurale vit de la banana et de ses produits. Lamacro propagation de bananiers introduite par IITA/Cialca-Project dans la régionavait pour but d`inciter les organizations paysannes à s`engager dans la mise enplace des sources adaptées de semences de bananiers, locales, plus accessibles paragriculteurs. Ces activités avaient consistées en la formation de ces organizationsdirectement ou à travers des ONGs (TOT) organisées en faveur leurs membressur la technique de multiplication rapide de semences de bananiers. Il était espéréqu`en poursuite, ces organizations adopteraient une stratégie de continuité pareux même de l`activité et en faire bénéficier aux communautés locales en assurantl`existence d`une source d`approvisionnement en semences de bananiers de bonnequalité dans leurs milieux. Les observations montrent que dans les zones dominéespar le wilt l`intensification de l`activité est plus forte; avec des interventions plusfinancées des ONGs humanitaires. Les ONGs nationales execute ce programme àl`echelle reduit. Les organizations paysannes, bien qu`elles manifestent le besoin del`activité, leurs niveau d`engagement dans l`exécution des activités au quotidientdemeure faible. La barrière coutimière prime à l`inexistance de marché pour lesplantules de bananiers et reduit les possibilités d`expension de leurs production.L`implication du pouvoir public dans la coordination d`ensemble des interventionssoutiendraient plus la macro-propagation de bananiers au Sud-Kivu. 237
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 238
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEME 3: DRIVERS FOR ADOPTION 239
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 240
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa211. Farmers’ perceptions on constraints and opportunities of Inland valley- based cropping system and commodity value chains in Benin and Mali Adetonah Sounkoura1, Coulibaly Ousmane2 and Sessou Eric2 University of Lome, Benin; 2International Institute of Tropical Agriculture (IITA), 1 Cotonou, BeninAbstractVegetable production requires the use of chemical pesticides. Unfortunatelypesticides have negative effects on health and the environment, especially in urbanand peri-urban areas. The introduction of alternative methods of pest control toproduce healthy vegetables. This study uses a theoretical framework to analyzeconsumer behavior to its conventional and organic product. In total, 303 consumerswere selected in Benin and Ghana on the basis of their perceptions, preferences andprevious experiences on healthy vegetables. The results show that half of consumersare unaware of the dangers associated with the consumption of conventionalvegetables in Benin and Ghana. Less than half of consumers in both countries areaware of healthy vegetables. An analysis of the Probit regression model shows thatthe factors that influence the willingness to pay healthy vegetables by consumers inBenin are the risks associated with consumption of vegetables treated with chemicalpesticides, the price of the vegetable, the size of vegetable, appearance, experiencein the consumption of healthy vegetable, household size, and level of knowledgeabout healthy vegetables. In Ghana, the variables with a high probability of influenceon willingness to pay for healthy vegetables are: the price of vegetable, freshnessthe availability of vegetable, consumer age and agro-ecological zone. In additionto the states and institutions of research and development have an obligation toprotect the health of consumers, ensure fair application of practices in food tradeand promote organic farming specifically biopesticides. A subsidy policy by thestate on organic inputs contribute to the decrease in prices of vegetables and healthywill also increase the secure food and nutrition and reducing poverty. 241
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa212. Communication and dissemination channels influencing integrated soil fertility management adoption in Western Kenya Adolwa, I. S.1, 2, Okoth, P. 1, Esilaba, A. O.3, Mulwa, M. R. 2, Mairura F.S. 1and Nambiro, E.1 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 2The university of Nairobi, Department of Agricultural Economics, Nairobi, Kenya; 3Kenya AgriculturalResearch Institute, KARI H/Q, Nairobi, KenyaAbstractLack of access to timely and accurate information has been identified as a majorhindrance to the development of rural agriculture in Africa. As a result, the socio-economic wellbeing of agricultural producers has been impacted on negativelyresulting in high poverty levels. Nyanza and Western provinces in western Kenyaare among the poorest with poverty levels of 65% and 61%, respectively. A studywas carried out to evaluate the existing information/knowledge communicationand dissemination channels, and assess the influence of these channels on uptakeof Integrated Soil Fertility Management (ISFM) knowledge among smallholderfarmers in western Kenya.Structured questionnaires were administered to 120farmers from Vihiga and Siaya districts. In Vihiga, farmers were sampled in asystematic random manner from available lists of participant and non-participantfarmers, whereas in Siaya, farmers were selected based on randomly selecteddiagnostic trial sites of the Africa Soil Information Service project. Community-based channels were found to be significantly advantageous. Farmers’ preferredinformation source, channel and knowledge source were own experience, farmerfield days and farmer groups respectively. A probit regression model showed thatoff-farm income, education level, distance from nearest information centre, livestockvalue, and district of residence were the socio-economic variables that significantlyinfluenced farmer access to ISFM information and knowledge, and subsequentuptake. In conclusion, community-based channels should continue to be promotedas vehicles of information communication and dissemination. Investing in educationand information centers as well as using Information Communication Technologies(ICTs) to complement community-based channels will enhance farmer access toISFM information and knowledge. 242
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa213. The role of rural producer organizations in enhancing market participation of smallholder farmers in Uganda: enabling and disabling factors Ampaire Edidah L.1 and Charles Machethe2 1 Internation Centre for Tropical Agriculture (CIAT), Kampala, Uganda; 2Department of Agricultural Economics, Extension and Rural Development, University of Pretoria, South AfricaAbstractDevelopment stakeholders have rediscovered the important role that rural producerorganizations (RPOs) can play in rural development, especially in strengtheningsmallholder market access. Changes in the global agricultural economy stemmingfrom trade liberalization and globalization mean that that adopting an agriculture-for-growth agenda in sub-Saharan Africa requires improving smallholdercompetitiveness. But because many constraints limit the ability of smallholderfarmers to individually compete in agricultural markets, collective action in theform of RPOs is seen as important in enabling farmers to achieve competitivenessin the market.Reinitiating of marketing RPOs in Uganda was intended to fill up the‘marketing gap’ that resulted from the collapse of the earlier cooperative system andthe implementation of structural adjustment programs. The government, throughits rural development strategy, has invested efforts in forming a hierarchy of farmerassociations as a framework for commercialization of smallholder production.However, there is limited information on whether marketing RPOs are effectivelylinking their members to the market and how their effectiveness can be improved.This paper discusses factors that influence the effectiveness of second-tier marketingRPOs in linking their members to output markets. Data was collected from 62second-tier marketing RPOs and 1,377 individual members sampled from the fourregions of Uganda. Effectiveness of an RPO (the dependent variable) was definedas the percentage of farmer members who used the RPO for marketing some oftheir production in 2009. To analyze the factors that influence RPO effectiveness,a censored least absolute deviations estimator regression was run against selectedRPO characteristics as explanatory variables. Our findings show that a large RPOsize, democratic leadership and higher proportions of women in RPOs are likely tosignificantly increase effectiveness. On the other hand, a high proportion of RPOleaders trained in leadership and involved in related business activities is likely tohave a significant negative effect on the effectiveness of such organizations. 243
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa214. Impact of Access to Subsidized Certified Improved Rice Seed on Poverty Reduction in Nigeria Awotide Bola Amoke1, Awoyemi Timothy1, Taiwo Diagne Aliou2and Ojehomon V.E.Titilayo3 University of Ibadan, Nigeria; 2Africa Rice Center, Cotonou, Benin; 3National Cereals 1 Research Institute (NCRI), Badeggi, Niger State, NigeriaAbstractThis study adopted the Randomized Control Trial (RCT) method to access theimpact of the use of subsidized certified rice seed poverty. The respondents wererandomly divided into two distinct groups: the treated and the control. The farmersin the treated group were given voucher to procure certified seed from designatedagro-dealers at subsidized rate, while the farmers in the control group were notgiven. Two separate data set were utilized for this study: A baseline data collected in2008 prior to the distribution of the seed and a post intervention data collected afterthe 2010 production season. The data was collected with the aid of a well structuredquestionnaire. The study reveals that the area cultivated increased from 2.0habefore the intervention to 3.5ha after the intervention. Also yield increased from200kg/ha in 2008 to 4200kg/ha in 2010. In addition, there was a significant decreasein the proportion of the population below the poverty line after the intervention.The percentage of poor below the poverty line which was 52%(male), 28%(female),50% (total) in 2008 reduced to 40%(male), 22%(female) and 36%(total) in 2010 afterthe intervention. To access the impact of the intervention on the beneficiaries, thestudy adopted the Local Average Treatment Effect (LATE) estimation technique.The study reveals that the intervention has a positive impact of 114kg/ha on riceyield and also a significant positive impact of N32158.00 on the farmers’ revenue.The findings of this study shows that the use of subsidized improved certified seedcan lead to a sustainable increase in rice production, therefore we recommend thatprovision of subsidized certified rice seed should be included as a component ofagricultural development strategies in Nigeria. 244
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa215. Institutions and the Adoption of Technologies: Bench Terraces in Rwanda Bizoza Alfred National University of Rwanda (NUR), RwandaAbstractLocal institutions shape the adoption of technologies. The paper specifies `soft’ and`hard’ social capitals, among other factors, to estimate their impacts on adoptionof bench and progressive terraces in rural Rwanda. The results substantiate thatsome forms of social capital, i.c. trust and co-operation in collective labour, matterin the adoption process of bench terraces in Rwanda. These results help to guideboth research into and policy on how local institutions can play better roles and theextent to which the institutions can substitute direct interventions by NGOs andpolicy-makers in soil and water conservation in Rwanda. 245
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa216. Analyse des systèmes semenciers et stratégies de dissémination zonale des technologies Cialca dans la zone d’intervention du projet Cialca, au Sud-Kivu montagneux. Chifizi Adrien DIOBASS, DRCAbstractIl est connu par les acteurs impliqués dans la problématique du développement agricoleet sécurité alimentaire au Sud-Kivu et en RDC en général, que la problématique de labaisse de la production agricole dans notre région est tributaire du manque de techniqueset des technologies agricoles adéquates, adaptées et innovantes.Plusieurs structures derecherches et de vulgarisation ont justement intégré dans leurs stratégies de lutte contrel’insécurité alimentaire, l’utilisation des nouvelles technologies agricoles mise au pointpar CIALCA, et voudraient donc donner un caractère de business à l’activité agricoledans les sites satellites et les sites d’actions. Cependant, dans beaucoup de pays africainsle goulot d’étranglement le plus sérieux en ce qui concerne l’accès et la diffusion desnouvelles technologies agricole, est l’absence des systèmes de dissémination adéquateet efficace. Lorsqu’une nouvelle technologie agricole est diffusée, il n’existe pas unmoyen évident pour la distribution et la diffusion compatibles avec les territoriaux desbénéficiaires. .Le CIALCA a introduit et diffusé depuis bientôt 5 ans dans les sites ditssites d’actions au Sud-Kivu montagneux (Kabamba, Luhihi, Burhale et Lurhala), desnouvelles technologies agricole et ce, en partenariat avec des structures d’encadrementdes organisations paysannes et les paysans eux-mêmes. Ce faisant, ces technologiesagricoles sont en train d’être disséminé tant bien que mal par les paysans au traversles partenaires locaux et nationaux organisés sur un espace géographique difficilementcontrôlable et extensible, dans des sites dits sites satellites. De plus, dans les sites d’actionset satellites de Cialca, il ya ainsi des localités éloignées des périmètres de diffusions quiaccèdent aux technologies agricole par des canaux particulièrement variés notamment,les canaux sociaux, des canaux d’échanges commerciaux, etc.… . L’adoption se fait enchangeant ce qui peut être changé dans cette technologie et par échange de matérielet de savoirs à 3 niveaux ( entre associations voisines, par la recherche et par des lienssociaux entre localités). Le résultat obtenu, a permis de relever plus de 25 nouvellesOrganisations paysannes  dans les localités des sites d’actions aux cotés de 24 engagéesdans des questions d’expérimentations scientifiques et des essais agronomiques avec leschercheurs de Cialca. Dans les sites satellites, plus de 10 partenaires de développementqui diffusent ces technologies auprès de leurs membres. Diobass, un des partenairesactifs travaille avec 42  organisations paysannes par dissémination horizontale destechnologies. Le travail effectué a permis également de mettre en surface des tellesinteractions sur le plan de la structuration des Organisations paysannes acteurs locauxavec 4 synergies de producteurs constituées autour des approches de warrantage etde stockage des produits agricoles dans les sites d’action et 12 comités locaux dedéveloppement , avec au moins 1500 ménages utilisateurs  des technologies et 3481ménages dans les sites satellites autour des questions de recherche actions. Ceci a permisen plus de comprendre quels sont les nouveaux sites qui adoptent les technologiesCialca, quelle est la nature des produits CIALCA en diffusion dans les ménages , et enrelevant les changement éventuels observées dans la technologie lors de son adoptiondans des zones de plus en plus éloignées des centres de diffusion ainsi que des défisauxquels ils sont confrontés. 246
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa217. Targeting farmer’s priorities for effective agricultural intensification in the humid highlands of eastern Africa Divine Foundjem-Tita1, Tchoundjeu Zac2, Speelman Stijn1, D’haese Marijke1 and De- grande Ann2 Ghent University, Belgium / World agroforestry Centre, Cameroon; 1 2 World Agroforestry Centre, ICRAF-West and Central Africa, Yaoundé, CameroonAbstractAgroforestry and trees on farmers’ fields have been reported as important assets tomeet virtually all millennium development goals amongst which poverty reductionand climate change mitigation are the most prominent. However, their uptakeseems to be impeded by internal factors at household level as well as externalfactors determined by the policy and legislative environment. This paper reviewsand contextualizes these internal and external factors to the household that mayinfluence farmers’ decision to plant trees on their farms. Taking Cameroon as a casestudy we use qualitative content analysis to analyse whether existing policies andlegislations governing trees in Cameroon provide incentives or are a disincentive forfarmers to plant trees. The findings reveal that, although most national government,regional and international bodies address tree planting/agroforesty in their strategicpapers and mission statements, the legislations in Cameroon designed to follow upupon the policies are opposed to poverty reduction goals, as the latter legislationsand regulations are more conservation-oriented and provide no clear procedure asto distinguish between the same species found in the wild and on farmers’ fields.We propose better dialogue and an inter-sectorial approach amongst the forestryand environment sectors, land tenure departments, and the agriculture ministryto revise current legislation and regulations governing trees and land tenure inCameroon. This revision should make provisions for incentive-driven policiesand appropriate implementation strategies that would encourage farmers to planttrees and take advantage of the opportunities agroforestry offers in meeting themillennium development goals and other climate change mitigation efforts likepayment for environmental services. 247
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa218. Factors affecting the adoption of banana tissue culture technology by smallholder banana growers in Western and Central Uganda. Jagwe J.1, Dusabe J.1, Abele S.1, Coyne D.1 and Dubois T.3 1 International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 3University of Bonn, Institute of Crop Science and Resource Conservation (INRES), GermanyAbstractThis article investigates the factors affecting the adoption of banana tissue culturetechnology by smallholder banana growers in Western and Central Uganda. Aflexible moment-based approach is used as a basis with the assumption that farmersare risk averse, and that they use a vector of conventional and other inputs such aspests/disease control measures. The linkage of tissue culture technology and bananayield is established using OLS regression. The Heckman procedure is used to analysethe determinants of adoption while taking into account the selection biases that mayoccur as a result of prior exposure of farmers to the tissue culture technology. A costand benefit analysis of using conventional suckers versus tissue culture plantlets wasperformed using partial budgets. Results indicate that the level of education of thehousehold head, the level of exposure to tissue culture technology, extension serviceprovision and household banana prioritisation positively influence banana yields.Exposure to tissue culture technology is positively influenced by level of educationof the household head, the number of extension visits paid to the household andthe household’s membership to a farmer group or an association. A positive andstatistically significant relation is observed between banana tissue culture adoptionand the age of the household head, the size of the household, the banana acreage,distance to the nearest major town, and knowledge about other pests/diseasetreatment methods. Using tissue culture planting material is significantly lessprofitable than conventional planting material in the Southwestern region, beyond300 km from the major banana market, Kampala, but with more fertile soils and lesspest and disease pressure, whereas it is significantly more profitable in the centralregion within 100 km from the Kampala market. 248
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa219. Socio-economic determinants of farmers’ adoption of BXW control options in Uganda Jogo Wellington1, Karamura Eldad1, Tinzaara William1, Kubiriba Jerome2 and Rietveld Anne1 1 Bioversity International-Uganda, Kampala, Uganda; 2National Agricultural Research Organization, Kawanda, Kampala UgandaAbstractBanana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestrispv. musacearum ,is one of the recent threats to bananas in ECA. Strategies formanaging the disease using cultural control methods were developed basedon avoiding introduction of BXW into banana fields through infected plantingmaterials; breaking off male buds using a forked stick and not using cutting tools;cutting and burying or heaping infected plants and cleaning cutting tools usedto destroy infected plants with detergent or flaming. Since 2002, there has beenongoing campaign efforts aimed at raising farmers’ awareness of the disease andcontrol options. However, little is known about the extent to which farmers areapplying these control measures and how their application is influenced by farmers’socio-economic context. Moreover the disease is resurging in many places whereit had been controlled. The study, therefore, was aimed at identifying which andin what way do farmer socio-economic characteristics influence decisions to adoptcultural control measures for BXW. Data on disease distribution and incidence,farmers’ awareness of disease symptoms and control measures, banana productionand socio-economic characteristics of farmers were collected using structuredhousehold surveys on 350 households selected from ten districts representing themain banana producing districts and the two main banana cropping systems. AMultinomial Logit model was applied for empirical analysis. The results indicatedthat household income (related to cost of control), lack of labour and inputs arekey constraints to application of BXW control measures. The study concludes thatdeveloping cultivars with resistance to BXW using transgenic technologies may bethe long-term solution to the BXW pandemic given the evidence of resurgence andthe fact that the informal sector is and will remain as the main source of plantingmaterial for smallholder farmers in the foreseeable future. 249
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa220. Information Asymmetries and Technology Adoption: The Case of Tissue Culture Bananas in Kenya Kabunga Nassul Ssentamu1, Dubois Thomas2 and QaimMatin1 1 Georg-August University of Göttingen, Germany; 2International Institute of Tropical Agriculture, Kampala, UgandaAbstractClassical adoption models implicitly assume homogenous information flow acrossfarmers, which may not be true for new technologies. In such cases, selection bias inadoption parameters occurs. Here, we focus on tissue culture (TC) banana technologythat was introduced in Kenya about 10 years ago. Up till now, adoption rateshave remained relatively low. We employ the average treatment effects approachto account for selection bias and extend it by explicitly differentiating betweenawareness exposure (having heard of a technology) and knowledge exposure(understanding the attributes of a technology). Using a sample of 385 Kenyanbanana farmers, we find that estimated adoption parameters differ little whencomparing the classical adoption model with one that corrects for heterogeneousawareness exposure. Parameters however differ considerably when accountingfor heterogeneous knowledge exposure. This is plausible: since TC bananas havebeen in the market for several years, many farmers have at least heard aboutthis technology. However, since successful use of TC requires notable changes intraditional cultivation practices, a proper understanding is not yet very widespread.These results are also important for other technologies that are knowledge-intensiveand/or require considerable adjustments in traditional practices, as is the case formany other agronomic innovations. 250
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa221. Farmer’s roles in testing and up-scaling promising technologies: the Case of inoculants and P application on soybean in DR Congo and Rwanda S Kantengwa1, F. Baijukya1, D. Mongane2, F. Nzeyimana3, J. Sanginga2 and B. Van- lauwe1 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), DRC; 3Institut des Sciences Agronomiques du Rwanda (ISAR), RwandaAbstractParticipatory approaches are widely accepted as the best way to develop andupscale appropriate agricultural technologies to smallholder farmers in the tropics.This philosophy was used to quantify the effectiveness of application of inoculant(strain USD 110), Phosphorus fertiliser (Triple Super Phosphate, TSP) and theircombination on soybean (Glycine max), along the existing gradients in soil fertilitystatus with 60 farmers in South Kivu region of DR Congo and 50 farmers in the Eastand Southern districts of Rwanda. Inoculant applied alone increased soybean grainyield by 18% (range of 0-35%) in DRC Congo and 10% (range 0-20%) in Rwanda.Application of P alone increased soybean grain yield to the range of 0-40% in DRCongo and 0-28% in Rwanda while application of a combination of P and inoculantincreased soybean grain yield by 50% and 45% (range 0-100%) in DR Congo andRwanda respectively. Soy bean yields were in the range of 200-3,200 kg /ha and 90-1,600 kg /ha for DR Congo and Rwanda respectively. Although the results indicatea divide between enthusiasm and desire to make impact in farms and landscapes inwhich technologies work positively, -and a sense of despair where failed, ownersof both responsive and none-responsive farms provided not only useful adjunct tomore detailed experiments to understand the mechanisms and processes underlyingpotential improvement but also suggestions on the speed and required packages toincrease the adoption of technologies. Key famer’s roles in the whole process arediscussed. 251
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa222. Determinants of smallholder farmers’ participation in staple food market in Sud-Kivu, DRCongo Kasereka Bishikwabo1, Maertens Miet2, Birachi Eliud3, Pypers Pieter4 and Ouma Emily5 1 Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA); 2 Katholieke Universiteit Leuven, Belgium; 3Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Kigali, Rwanda; 4Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT- TSBF), Nairobi, Kenya; 5International Institute of Tropical Agriculture, Bujumbura, BurundiAbstractWe explored smallholder farmers’ participation as sellers of fresh banana, legume(soybean, bean and groundnut) and cassava products in five locations in South Kivu- DR Congo. As more than 70% of rural population is smallholder farmers whoderive their livelihood from agriculture, it is interesting to investigate the factors thatdetermine their market participation, for they earn money for investing in inputsand increase their production while raising their contribution to economy which inturn allows government to get income to use for improving market infrastructure.We performed a probit analysis using data collected in 2006 from a baseline studywith 383 households. The binary dependent variable “Market” has value 1 if thefarmer sold produces and 0 if not. In total 54 % of households of small scale farmerssold 42,131 kg of bananas, 3,673 kg of legumes and 1,062 kg of cassava. The 16variables used in the model belong to farmer characteristics, market, environmentaland institutional factors. Five variables in the model bear coefficients with positivesignificant effects on market participation. These variables with significant effects aretotal area cultivated (in ha), education of household head (1 if household head has atleast one year of secondary school), access to urban or regional market (1 if farmersells his product in an urban or regional market), altitude (1 if farmer grows cropsin an action site with altitude <1800 m a.s.l. and the number of children of five yearsand below is higher. The variables are jointly significant. These results indicate thatsmallholder farmers well endowed with land and who cultivate banana, legumes orcassava in an agroecological zone below 1,800 m a.s.l. and are integrated to an urbanor regional market (here: Bukavu, Kabamba, Katana, Mugogo or Munya) are morelikely to sell their produces. 252
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa223. Evaluation of existing inputs delivery systems for banana and legumes based systems in Burundi. Kimana Chrystal1, Ouma Emily1, Van Asten Piet1, Anyango Apollo and Nyandwi Jean Baptiste 1 International Institute of Tropical Agriculture (IITA), Kampala, UgandaAbstractBananas and legumes are the most predominant crops in Burundi. These crops serveas food and income generation for the producers. Productivity of these crops hasbeen affected by several factors. Producers are faced with challenges in attemptingto access quality seeds, fertilizers and pesticides needed to enhance production.This is largely due to the high prices of the inputs (Price of 1Kg of DAP USD 1.5),long supply chains and their unavailability closer to the producers. A study wasconducted in Kirundo, Gitega, Bujumbura Urban and Cibitoke provinces of Burundito evaluate the gaps in the input delivery systems for bananas and legumes. Thestudy elicited information from 130 traders using questionnaire interviews. Thetraders included agro-inputs dealers, extension workers from the Ministry ofagriculture, NGOs, private tissue culture laboratories and organic manure traders.The results showed the main types of inputs stocked to be seeds, inorganic fertilizersparticularly Urea, Detane, KCL and DAP. Trade in planting materials particularlyconventional banana suckers was low due to the culture of free exchange of plantingmaterials among neighbours. Major constraints faced by the agro-input dealers werehigh transportation costs as most of them sourced from neighbouring countries,price fluctuation, supply delays, lack of market information, high taxes and poorinfrastructural facilities particularly for storing the inputs. Private tissue culturelaboratories faced higher tax regimes and high capital outlays. Efforts that targetreduction of taxes by the government and widening of distribution networks for theinputs to enhance access by farmers may prove useful towards improving the inputdelivery chain. 253
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa224. Improving Farmers livelihoods through the scaling of legume based soil fertility restoration technologies in Kenya, Uganda and Tanzania Koala Saidou 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya;AbstractLand degradation and soil fertility deterioration in particular is one of the mostserious threats to food production in the African continent. The population is trappedin a vicious cycle between land degradation and poverty and the lack of resourcesand knowledge to generate adequate income and opportunities to overcome thesechallenges. This necessitates the development of sustainable cropping systemsbased on the integration of well-adapted legume plants and appropriate agronomicmanagement practices.Grain legumes have a unique role to play in reversing thesetrends in productivity, poverty and food and nutritional insecurity. In part, this isbecause legumes have the capacity to fix nitrogen from the atmosphere. Moreover,it is cheaper to provide protein by growing grain legumes than it is to producemeat and milk products. Despite the importance of grain legumes in restoration ofsoil fertility and to human nutrition, the use and consumption of legumes in manycountries in sub-Saharan Africa (SSA) is very low due to inadequate availability.The project’s main objective was to identify legume technologies that can enhancesoil fertility restoration in the smallholder farming landscapes of East Africa whichpre-dominantly practice cereal-based cropping systems. The farmers in all the threecountries using mainly visual indicators such as colour of the leaves, size of thestems, pods or ears identified the most promising legume crops for adoption andadaptation. In Kenya, assessment of the crop yields showed that soybean is the mostpromising legume crop for rotation under cereal-legume conservation agriculturesystem, especially for the short rains season. The average grain yield of soybeanwas 1.1 t ha-1, which is still lower than the global average of 2.25 t ha-1 though inSub-Saharan Africa yields are commonly below 0.5 t ha-1. Average maize yieldunder reduced tillage was 1.1, 1.1 &1.7 t ha-1 for continuous, intercrop and rotationalsystems respectively, while for conventional tillage the average yields were 2.3, 1.6& 2.6 t ha-1 for continuous, intercrop and rotational systems respectively. However,these yields were affected by a drought in the latter stages of growth. In Tanzania,mean maize yields for the farmers ranged from 2.9 to 3.7 t ha-1 in SIDO sub-location,3.0-3.5 t ha-1 in Chekereni sub-location and 2.6-3.7 t ha-1 in Chanzuru sub-location.This is lower than the potential yield of 4.5 t ha-1 observed in researcher managedplots for maize var. SITUKA. Cowpea yields on the other hand varied from 781-1240kg ha-1, 916-1000 kg ha-1 and 927-1130 kg ha-1 for SIDO, Chekereni and Chanzurusub-locations, respectively. In Uganda farm Yard manure treatment had the bestscore (1) for growth performance and grain yield (2750kg ha-1) followed by NPK (2)and (2053 kgha-1), while the control treatment had lowest yields. The legume cropsestablished failed due to droughty conditions. Nevertheless farmers were convincedof the need to fertilize their soils in order to increase yields. 254
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa225. Production Risk and Smallholder Adoption of Maize in Kenya Lutta Mohammed Kenya Agricultural Research Institute (KARI), Nairobi, KenyaAbstractIn this study, smallholder perceptions on changing farming risk and their influenceon uptake and deployment of improved maize varieties, and crop managementoptions that are recommended were investigated. The study goals were to gainunderstanding to assess the potential demand for improved maize varieties and itsdeterminants. Data obtained from a survey of a random sample of 78 smallholdingsin the hilly masses of Machakosdistricts in Kenya were analyzed using the Heckmanprocedure. Results showed that the main concerns of households in the area (meansize = 6 persons) was to obtain production of at least 170 kg of maize, 43 kg ofpigeonpeas, 38 kg of beans and 18 kg of cowpeas for subsistence per season. Farmerperceptions on changing patterns of rainfall and farming risk have significance foruptake of improved maize varieties. Perceptions on production risk may be impactingnegatively on fertilizers adoption and access to credit. It is proposed that in additionto investment into development of improved crop varieties, some effort be directedat developing and implementing schemes to preserve bio-diversity within the localcrop populations. A strategy to help smallholders overcome constraints to creditaccess due to their perception of production risk needs to be developed. 255
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa226. The Role of Collective Action in Enhancing Smallholders’ Agroforestry Products Market Access in Cameroon Mbosso Charlie1, Nimino Godwill, Degrande Ann1, Van Damme Patrick2 and Tchound- jeu Zacharie1 1 World Agroforestry Centre, ICRAF-West and Central Africa, Yaoundé, Cameroon; 2 Ghent University, BelgiumAbstractMany small scale farmers could derive appropriate incomes from their productsif they had easy access to markets and were empowered with adequate tools tocompete with other segments of the market. Some constraints such as limited andconflicting market knowledge, lack of networks and associations and inadequateprocessing and storage methods have been identified as obstacles for marketexpansion of Agroforestry Tree Products (AFTPs). Among the different solutions toimprove the situation, collective action was seen as action which can significantlyenhance the production and the marketing of AFTPs. The present paper reviews thegroup sales undertaken in Cameroon to improve the marketing of two importanthigh-value indigenous fruit trees namely Irvingia gabonensis and Ricinodendronheudelotii. These two indigenous fruit trees are mainly exploited from the wild. Butthanks to Participatory Tree Domestication Techniques developed by ICRAF andpartners since a decade, the species are being gradually planted on-farm by farmersin Cameroon, Nigeria and Gabon. Understanding how collective action can helpaddress the inefficiencies, coordination problems and barriers related to marketingby smallholders is particularly crucial. We therefore draw on findings fromresearch in Cameroon looking at the role of collective action in enhancing producergroups’ production capacity and bargaining power vis-a-vis other market players(collectors and other intermediaries). The main findings of this research suggest thatmore attention should be given to the management of production on farm and to themobilization of the product from group members before group sales. It also calls forenhanced communication between producer groups and traders in order to buildtrust relationships with and without assistance from a third party as facilitatingagent. 256
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa227. Analyzing Legume Market Chains to Enhance Adoption, Livelihoods and Environmental Systems within Maize-Based Farming Systems in Malawi Mkondambiri Amon Kabuli1, Kabambe Vernon1 and Mapfumo Paul2 1 Bunda College, Malawi; 2International Centre of Maize and Wheat Research (CIMMYT), Harare, Zimbabwe1Bunda College, MalawiAbstractAccelerated agricultural growth is a fundamental pre-requisite for rapid reductionof poverty. However, reducing poverty and increasing food security will requireintensification and diversification of the region’s cereal-based farming systems toinclude strategic high-value crops such as legumes that contribute to improvedsoil fertility, sustained productivity, income growth, and environmental servicefunctions. This study was undertaken in Mid February to Early March 2009 andinvolved farmers, agro-dealers, rural assemblers and trading points in SouthernMalawi. The study aimed at assessing the marketing chains for grain legumes inMalawi with a special focus on the seed supply systems, the actors, transactioncosts and the business environment that the commodity goes through as it movesfrom producers to target buyers and consumers. A combination of rapid marketappraisal and value chain analysis was employed for interviews with producers(farmers), traders and processors. The study found that vendors/private traderswere the major buyers of most legumes in the district and usually came frommajor cities to buy produce in small lots using hanging scales. Prices were foundto be variable within season and between buyers. During the period of the study,the buying prices ranged from K98.89 per kilogram for pigeon peas, K159.50 perkilogram for soybeans, K145.50 per kilogram for beans for most vendors. Therewere certain dynamics related to price fluctuations within the market chain whichwere mostly due to the seasonal nature of the crops, being low at harvest (April/May) and high at planting time (November/December). Traders identified certainfactors that influenced the prices paid to farmers for their legumes. Analysis of theseed supply systems indicated that there were mostly informal seed system wherefarmers either used own-saved seed or seed exchanges, and at other times grainbought at the local markets for their legume production. The study recommendedincreased farmer understanding of the market dynamics and adherence to goodcultural practices to increase legume production, incomes and livelihoods. 257
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa228. Factors influencing the adoption of intensification strategies by plantation crops farmers: the case of Zimbabwe Mudyazvivi Elton SNV, ZimbabweAbstractIn the last Thirty years of an independent Zimbabwe, government, donors and civicorganisations have pumped hundreds of thousands of dollars in projects to intensifythe production of plantation crops mainly tea, coffee and banana, with little success.A number of white elephants are testimony to the claim of wasted resources madein this study. A study of Zimbabwe’s Eastern highlands and literature reviewedreveal that there were some fundamental factors that were not addressed, reducingthe adoption of productivity and quality improving technologies promoted. Yet theregion has abundant opportunities which could transform the lives of smallholdersif underlying factors and strategies had been understood and addressed. Themain hypothesis of this study was that: smallholders would adopt agricultureintensification technologies if it led to more profit, had limited risk, when therewere available support services and when they had enough available householdresources. Data for the study was collected from three areas - Chimanimani, Mutasaand Chipinge districts - through focus group discussions and review of project andbaseline reports. Some follow-up interviews of promoting organisations were doneto inform information from other sources. The study used descriptive, correlationsand qualitative methods to analyse research data and findings. One of the mainfindings of the study was that adoption of productivity enhancing technology suchas use of fertilisers and improved planting material increased with better performingmarket system and subsequently profitability. Where the market system workedbetter, smallholder actually sought out yield and quality enhancing technologies tocapture more value in the market. Also, other factors that correlated positively withadoption of agricultural intensification technologies were household wealth rankand effective household labour. There are however some enablers that need to beembedded in intensification strategies such as direct positive effect on householdfood security, extension support and agro-inputs delivery system. Smallholdersendeavored to strike a balance of income and household food security. Theresearch concludes that past efforts to intensify the production of tea, coffee andbananas (cash crops) did not comprehensively address the factors that this researchunearthed. In addition, the fundamental factor for the success of such efforts is themarket performance. Household socio-economic factors and support services arealso useful in determining effectiveness of adoption of agricultural intensificationstrategies. 258
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa229. Analysis of the promotional policy of the fruit and vegetable value chain in Rwanda C. Mukantwali 1, G .Nyirahanganyamunsi 1, D. Mukaminega 2, H. Vasaanthlakam 2, D. Gahakwa1 Rwanda Agriculture Board (RAB), Kigali , Rwanda; 2Kigali Institute of Science and 1 Technology, RwandaAbstract:The objective of this study was to review the Rwanda policy options related tofruit and vegetable sub-sector in Rwanda. Desk research to gather informationrelated to fruit and vegetable sub-sector in Rwanda as well as to Small and MediumScale Enterprises was conducted. The policy documents were collected from theMinistry of Agriculture and Ministry of Commerce on Enabling environment fordevelopment of fruit and vegetable sub-sector; Development of financial and nonfinancial services and Putting in place supportive institutional infrastructures. Thestudy was conducted in participatory manner by a multidisciplinary team fromacademic, research institutions, fruit and vegetable processors and Directorateof Horticulture in Ministry of Agriculture. The study find that in the fruit andvegetable sub-sector, a number of challenges that up to now hinder the progressof the sub-sector and its contribution to the economy of the country were foundnotably: Insufficient production of fruits and vegetables both quantitatively andqualitatively; Unavailability of the necessary information related to Production,processing and marketing of fruit and vegetables to all stakeholders; Lack ofconducive Environment for better trade of fruits and vegetables. It was recommendedthat relevant institutions should facilitate acquisition and adaptation of post harvesttechnologies as well as enhance networking between research, extension services,developmental institutions, farmers, processors and exporters while payingattention to the necessary infrastructures to link producers and processors to themarket with high quality products. 259
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa230. The impact of adoption of improved rice varieties on farm households’ income in Rwanda: a Propensity Score Matching Approach Mutware Joseph1, Kees Burger2, Innocent Ndikumana3, Chantal Ingabire1 and Elie Réné Gasore3 1 Rwanda Agriculture Boad (RAB), Kigali, Rwanda; 2Development Economics, Wa- geningen University and Research Center, The Netherlands; 3Institut des Sciences Agronomiques du Rwanda (ISAR), RwandaAbstractThis study examines the impact of adoption of improved rice varieties on farmhouseholds’ income in Rwanda. It employs a propensity score-matching approachusing cross-sectional data of 180 rice farmers randomly selected from six ricegrowing areas of Rwanda purposively selected. Findings show a robust positiveand significant impact of adopting improved rice varieties. With an annual averagerice income estimated at $ 539.3469 in 2008 at constant prices, results reveal thatadoption of improved rice varieties exhibits a rice income difference of $ 386.45translating an annual rice income increase of 13.59 % among farmers. Findings showfurther that the actual average yield of improve rice varieties is four tonnes ha-1which is still low compared to the potential yield of seven tonnes ha-1 and above.The findings suggest that future policies should strengthen farmers’ capacity incrop management and improve rice infrastructures in order to increase the yieldof improved rice varieties and thereby increase rice income. In addition, policiesshould focus on empowering farmers’ institutions (cooperatives) given their crucialrole in facilitating farmers’ access to credit, extension services, cost-effective inputsand output markets. 260
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa231. Integrated Soil Fertility Management adoption lies in the socio- economic domain of the farmer Nambiro E.1, Okoth P.1, Murage A.W2, Kimani P1, Macharia R 1and Huising J.1 1 Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 2Kenya Agricultural Research Institute (KARI), Agricultural Economics, Naivasha, KenyaAbstractDespite the development of improved maize germplasms in Kenya, the realizationof the full production potential by farmers in Western Kenya has not beenattained. Several factors nuance together and contribute to this obscurity such thatpinpointing to the actual major factors and their degree of contribution cannot beeasily discerned. The factors include soil fertility, high cost of agricultural inputs,access to adequate agronomic knowledge, cost and availability of labour and inputs,and the contribution of pests and diseases. The Integrated Soil Fertility ManagementPractices (ISFM) has been accepted as a framework that can be used to address thissituation through judicious combination of several soil management and farmerpractices. Unlike the previous studies, this study estimates the percentage ofadoption of ISFM practices and evaluates the factors that determine their adoption.Agronomic and household social-economic data was collected from 317 framinghouseholds in the Siaya area of Western Kenya during the long rains season of2011. The study used an ordered probit model in the analysis. Results show thatinformation access, particularly from farmer groups played a significant role indetermining the intensity of ISFM (p <0.1). Age of the household head, rented tenureand farmers’ perception on soil erosion had a negative influence on the adoptionintensity. Farmers access to information and farming knowledge through farmergroups and keeping the youth (19-25 yrs) interested in farming are likely factors thatcould be used enhance adoption of technologies. 261
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa232. Agricultural innovations that increase productivity and generate income: Identification and testing process in Rwandan Innovation Platforms C Ngaboyisonga1, J Mugabo2, B S Musana3, M M Tenywa4, C Wanjiku5, F Murorunkwere3, S Ntizo3, N Birasa6, J Gafaranga7, J Tuyisenge3, J Mugabe8, S Nyamwaro9 and R Buruchara10 1 University of Nairobi, Faculty of Agriculture, Department of Plant Science and Crop Protection, Nairobi, Kenya; 2Rwanda Agricultural Board (RAB), Rwanda; 3Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 4Makerere University, Faculty of Agriculture, Kampala, Uganda; 5 CIAT (Centro Internacional de Agricultura Tropical)/ CIALCA, Kigali, Rwanda; 6National University of Rwanda; 7Imbaraga; 8Forum for Agricultural Research in Africa (FARA), Ghana; 9Trypanosomiasis Research Centre, Kenya Agricultural Research Institute, Kikuyu, Keny; 10CIAT (Centro Internacional de Agricultura Tropical), Kampala, UgandaAbstractThe central question in increasing productivity and generating income in Africanagriculture is how to move from technology generation to innovations that respondthe constraints of agriculture production along the value chain. This is considered inthe context of subsistence agriculture, smallholder production systems, inefficientmarketing and investments by private sector, preponderance of public interventionand inadequate policies. The Integrated Agricultural Research for Development(IAR4D) presents an opportunity to address the question as it involves innovativeprinciples and a demand driven research while recognizing and utilizingorganizational capacities of stakeholders and relevant agricultural policies. The keyelement in identification and testing of agricultural innovations in the concept ofIAR4D was the establishment of Innovation Platforms (IPs). IPs are multi-level, multi-stakeholder positioned as central units for diagnosis, planning, implementation,monitoring, evaluation, feedback and re-planning while providing the nicheand opportunities for stakeholders to expand the spaces of engagement throughpartnerships, networks and linkages within and across scales. IP stakeholderswere used to identify and to rank constraints to agriculture production along thevalue chain in their respective sites. Two to three main constraints were identifiedand translated into research questions that were supposed to generate practicalsolutions for productivity and better marketing strategies while conserving naturalresources. The research proposed a package of innovations and each stakeholderwas assigned a role in testing, disseminating and adopting each of them. Researchagenda based on beneficiaries demand, targeting value addition and incomegeneration was elaborated and implemented. Achievements so far indicate highefficiency of agricultural innovations collectively identified and participatory testedby IP stakeholders and hence validate the efficiency of IAR4D over traditionalparticipatory methods of agricultural research and dissemination. 262
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa233. Analysis of drivers for adoption of Conservation Agriculture practices in Malawi Ngwira Robert Chitedze Research Station, Lilongwe, MalawiAbstractConservation Agriculture is being adapted in Malawi as crop productionintensification system through various development initiatives. This paperanalyses the success achieved in one initiative done by a local Non GovernmentalOrganization (NGO), Total Land Care (TLC). Conservation Agriculture initiativesstarted in 2005 through collaborative project between TLC and International Maizeand Wheat Improvement Centre (CIMMYT). It is estimated that the number offarmers practicing CA has since reached 7500. The major driver for this change hasbeen the use of improved seed and herbicides provided as loans by TLC to farmerscomplemented with good policy support from government - providing subsidizedfertilizers to farmers. At farm level the provision of herbicides provided anopportunity for improved weed control and hence labor savings from CA. The shiftfrom the labor demanding manual preparation of ridges and furrow to planting onprevious years’ ridges or flat was quite attractive to farmers. This allowed farmersto allocate their time to other cash crops such as cotton, rice among others as well ashorticultural crops. Herbicide use has also relieved women farmers from the burdenof weeding as most labor to control weeds is done by women. However, factorshindering CA adoption were found to be at national and farm scale. National scalefactors included lack of policy incentives for CA equipment and lack of markets tooffer attractive prices for maize. The paper concludes that future approaches for upscaling of CA in the country will require innovative approaches towards improvedaccess to inputs, markets, information and equipment. 263
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa234. Adoption and Dissemination of Improved Bean Varieties in Burundi Niyuhire M C1, Ouma E2, Ndimurirwo L. and Ruraduma C.1 1 Institut des Sciences Agronomiques du Burundi (ISABU), Burundi; 2International Institute of Tropical Agriculture, Bujumbura, BurundiAbstractBeans are among the most important subsistence and staple food crops in Burundi.Due to biotic stresses in the 1990s, particularly the bean mosaic virus, severalinitiatives were undertaken by different players to breed for high yielding anddisease resistant varieties. Despite these initiatives, the level of adoption of theimproved bean varieties and producer preferences still remain unclear. Using datafrom farmer focus group discussions and farm level surveys, this study investigatesdeterminants of adoption and dissemination pathways of improved bean varietiesin Gitega, Kirundo and Muyinga in Burundi. The results indicate the importance ofspecific traits such as taste, color, yield, market price and maturity period to adoptionof the improved varieties by households. The sources of improved bean seeds areformal, informal and seed fairs. Bean production systems comprise climbing beanswhich are more productive, common bean which is useful for consumption andmarket and mixed common and semi-climbing bean system sowed in associationwith banana and maize. Preferred high yielding bean varieties with good marketprices include G13607 and the yellow variety, KIRIJANA. Others include the whitevariety URWERA which has a good taste and INABUSHIRASONI which is an earlymaturing variety. Organic manure is used at a limited rate and mineral fertilizersrarely applied because of high price. Beans are conserved in bags and pots mixedwith INGINANGINA powder soaked in water. Bean production is mainly for homeconsumption, seeds and market. The common bean varieties are more expensivethan the climbing type because of their good taste. The price increases steeply at thetime of sowing (March - October) and at the start of the academic year. The pricealso varies according to the variety. 264
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa235. Drivers to adoption of soil fertility amendment technologies: An empirical Analysis in western Kenya Odendo M1, Muyekho F.M.2, Jama, B2 Kenya Agricultural Research Institute (KARI), Kakamega, Kenya; 2Alliance for a 1 Green Revolution in Africa (AGRA), Nairobi, KenyaAbstractAlleviation of low soil fertility is an important step to improving smallholderagricultural productivity in western Kenya. Past research has yielded severalproven technologies for soil fertility management, including use of organic andinorganic inputs that can increase maize yield, the staple food crop, from 0.5t ha-1to 4.5t ha-1. In 2010, KARI, with financial support from AGRA, initiated a project topromote adoption of these technologies. An understanding of the factors that affectthe adoption is essential both for economists studying the determinants of growthand for the generators and disseminators of such technologies. At the initiation ofthe project a baseline survey was conducted to provide benchmarks for ex postimpact assessment and insights on factors that are likely to influence adoption ofselected soil management technologies in four districts in western Kenya. Data werecollected from a random sample of 327 households using a structured questionnaireand analyzed by descriptive statistics and binary logit model. Results showed thatfactors which influenced adoption varied by soil amendment technologies. Thefactors which had positive and significant effects (p≤0.05) on adoption of inorganicfertilizers were education level of household head, membership in groups, access tooff-farm income and location of the district in a high agriculturally potential area,whilst distance to major markets and gender of the household head had significantmixed effects on the adoption of manure and inorganic fertilizers. Householdswhich owned cattle were most likely to adopt manure. Understanding thesefactors is important in targeting different soil amendments to farmers during thenext project cycle, which focuses on moving beyond the demonstration plots byfacilitating farmers’ access to inputs and output markets. Furthermore, this paperdiscusses lessons learnt in scaling-up technologies beyond demonstration plots andsuggests a way forward to enhance the adoption. 265
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa236. Adoption and impact of tissue culture bananas in Burundi Ouma Emily1, Van Asten Piet1 and Dubois Thomas2 1 International Institute of Tropical Agriculture, Bujumbura, Burundi; 2International Institute of Tropical Agriculture (IITA), Kampala, UgandaAbstractPests and diseases are one of the key factors influencing low banana productivity insmallholder farming systems in the Central African Highlands where the crop is animportant staple. In parts of Rwanda, Burundi and North and South Kivu provincesof eastern DRC, diseases such as banana bunchy top virus (BBTV) and bananaxanthomonas wilt (BXW) are prevalent thereby creating a large demand for newplanting material and improved varieties that may have higher yield potential withdisease or nematode resistance. In order to improve banana productivity, accessby farmers to improved pest and disease-free planting material is fundamental.Traditional methods of propagating bananas using suckers serve to perpetuate theproblem of pests and diseases thereby reducing production even further. Bananaplantlets obtained from tissue culture technology are potentially disease freealternatives but remain largely inaccessible to most smallholder farmers due to thehigh cost of plantlets. This study employs an average treatment effects framework toexamine adoption and impact of tissue culture bananas in Burundi using a sampleof 306 banana farming households. In Burundi, tissue culture banana are producedby 2 private laboratories which sell plantlets to FAO and NGOs. FAO and the NGOsthen provide the plantlets for free to farmers through the Direction Provincialede l’Agriculture et de l’Elevage (DPAE) or through local bodies. Results from thestudy show that land size and locational factors influence adoption of tissue culturebananas by farmers. However adoption does not necessarily result in increment inbanana productivity compared to conventional suckers. Institutional factors relatedto farmer access, technology delivery and follow-up are identified as key factors forinterventions if any gains from tissue culture technology are to be realized. 266
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa237. Floresta-Burundi Rukundwa Sebitereko Lazare University of Pretoria, South AfricaAbstractFloresta-Burundi a officiellement lancé ses activités de développement dansla province de Rutana en Commune Giharo, zone Muzye en octobre 2008. Cescérémonies étaient rehaussées par la présence des autorités provinciales, communaleset les représentants des ONGs et les groupements de bases. La célébration a étéprécédée par la plantation de manioc sur 18,8 hectares de manioc et 6500 plants agroforestiers. Floresta-Burundi veut renforcer les interventions et des initiatives localespar une approche intégrée: protection de l’environnement, agriculture, activitésgénératrices de revenues et le développement spirituel pour un développementcommunautaire durable. Dans cinq ans (2011-2016) Floresta-Burundi va travailleravec 2500 ménages dans les provinces de Rutana, Bururi, Bubanza, Makamba, etBujumbura Rural. STRATEGIES ET ACTIVITES - Faire une étude participativesur l’état et les besoins dans l’agriculture de banane et manioc, pomme de terre etlégumes et maïs; - Augmenter la production et installer des unités de conservationet de transformation de manioc dans la province de Rutana pour les membres desassociations de base; - Renforcer la culture maraîchère pour la consommation dansles ménages et pour la production économique; - Octroyer de petits crédits auxagriculteurs membres des associations de base afin d’augmenter leurs productionspar le système d’épargne communautaire (Village Community Bank – VICOBA)ou un système coopératif;- Encourager les membres des associations de base pourune vie fraternelle et le développement dans leurs communautés respectives.   -Disponibiliser les plants (pépinières) et encourager les membres des groupementsde base de planter les arbres au tour de leurs domiciles et leurs champs et introduiredes foyers améliorés dans le but de la protection de l’environnement.- Renforcerles capacités des groupements de base dans différents domaines de l’agriculture,environnement et micro-crédits. Floresta-Burundi est affilié et soutenue par Plantwith Purpose, USA basé en San Diego, Californie. Elle travaille en partenariat avec :FAO Burundi, Ambassade de Royaume de Belgique, World Relief, Help Channel,DPAEs, AVRDC, CIALCA, Eirene International, Association Umuryango, CEPBU,etc. 267
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa238. The role of community structures in BXW management in the Kagera region, Tanzania Sayi B.1, Nkuba J.1, Mukandala L.1, Mushongi C.1, Mukulila S.1, Ndyetabula, I.1, and Jogo W.1, 1 Agricultural Research Institute-Maruku, TanzaniaAbstractIt is widely accepted that collective action is effective in managing epidemics of cropdiseases. Examples can be drawn from experiences with cassava mosaic disease andcoffee wilt disease in Eastern and Central Africa (ECA). However, with regards toBanana Xanthomonas Wilt (BXW), which is a major threat to bananas in ECA, theapproach has not been widely applied, let alone documented. This study, therefore,was aimed at examining the role of community structures in management of BXW inthe Kagera region in Tanzania. In 2006 the BXW disease was confirmed for the firsttime and it then spread in all districts of Kagera region severely reducing bananayields and negatively affecting farmers’ income and food security. This is societalissue that necessity the establishment of community structures for managing thedisease at different levels (sub-village, village, ward and district). Interviews withkey-informants from established BXW management committees at all levels wereconducted in 3 districts (Bukoba, Muleba and Tarime). In addition to committeemembers, farmers were also interviewed to solicit data on perceptions on functioningof community structures. Results of the study indicated that members of communityBXW committees were more knowledgeable and motivated than those farmersnot involved. Where they work BXW is declining in general. Results indicate thatsocial capital and community heterogeneity is key determinants for collective actionin managing the disease. The study concludes that local structures for BXW areeffective in managing the disease but require support from other stakeholders. 268
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa239. Assessing risk and management options for multiplication and movement of cassava in the face of CBSD: the experience of the Great Lakes Cassava Initiative Smith J.1, Macarthur, R.1, Weekes, R.1, Tomlinson, T.1, Adams, I.1 and Boonham, N.1 1 Food and Environment Research Agency, York, United KingdomAbstractThe Great Lakes Cassava Initiative (GLCI) has a goal of providing healthy cassavamaterial of varieties that are appropriate to 1.15 million farmers of 6 countries withinthe Great Lakes region. An underlying tenant of the project is to reduce current pestlevels within farmers’ fields and to prevent further introduction and spread of newpests, most notably Cassava Brown Streak Disease. Through partnering with boththe research and phytosanitary communities of the 6 GLCI countries, a complexappraisal on the risks associated with the movement of cassava planting has beenundertaken. With the aim of developing a national Pest Risk Analysis for CBSD,what is known and unknown about CBSD, the causal virus and association withplanting material has been captured and attributed to measures of uncertainty andrisk, management options and researchable gaps of knowledge. The outcomes ofthe analysis are discussed in the context of the GLCI and the wider effort to progressbreeding initiatives that effectively and durably control cassava virus diseases. Thecase is made for greater emphasis to be placed on risk-profiling current and potentialpests, either newly introduced or of evolved virulence, and to be better prepared tomitigate outbreaks before they ‘pass the point of control’. 269
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa240. Enhancing farmers’ access to quality planting materials through community-based seed and seedling systems: Experiences from the Western Highlands of Cameroon Takoutsing Bertin1, Degrande Ann1, Asaah Ebenezar1, Tsobeng Alain1 and Tchoundjeu Zacharie1 1 World Agroforestry Centre, ICRAF-West and Central Africa, Yaoundé, Cameroon AbstractIncreasing production and productivity in crop and agroforestry sub-sectors iscrucial to assure food security and livelihood enhancement. Yet, lack of qualityplanting material has been repeatedly identified as a major constraint to adoption ofimproved agricultural practices. Insufficient capacity of national seed and seedlingsystems and the sluggish growth of the private sector have failed to meet the demandof smallholders, calling for alternative ways of providing quality planting materialto farmers. This paper draws lessons from a community -based seed and seedlingproduction and dissemination system in the Western Highlands of AsaahCameroon.The system builds on the concept of Rural Resource Centres and strengthens farmers’capacities to multiply improved planting material of food crop and fruit tree species.Rural Resource Centres in the Western Highland of Cameroon are now sources ofseeds and seedlings for farmers and institutional clients. Due to proximity of thesecentres to production zones, the approach has effectively improved accessibilitythrough reduced production, transport and distribution costs and also affordability.Meanwhile, selling planting materials provides income for Rural Resources Centresand ensures sustainability of the system. Availability of quality seeds has increasedon-farm crop yields by 20 to 40 %, while demand for improved seedlings hassurpassed supplies in participating communities. Scaling-up this approach will firstof all require transfer of knowledge on how to produce seeds and seedlings to RuralResource Centres and making foundation germplasms available. However, it willalso necessitate that production capacities of Rural Resource Centres be enhanced,and partnerships with a range of stakeholders be built, especially with governmentservices in charge of seed certification and quality control. Moreover, the approachshould entail improving storage, packaging and marketing strategies. Finally, inaddition to the challenge of projecting and meeting future demands of farmers andother stakeholders, issues of seed quality and genetic diversity need to be addressedwhen designing and implementing effective seed supply strategies and policies. 270
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa241. Adoption of Organic Farming Techniques as Alternative Approaches to Address Livelihood Concerns in Rwanda. Taremwa Kanuma Nathan1, Samvura NepomsceneX, Mutandwa Edward2, Uwimana Placide3 National University of Rwanda, Rwanda3Higher Institute of Agriculture and Animal 1 Husbandry (ISAE); 3Ministry of Education, RwandaAbstractThe impacts of climate change in Rwanda are cross-cutting and have been felt byvarious sectors including agriculture, health, energy and a significant effect onthe existing eco-systems. Following the MDGs and Rwanda’s Vision 2020 there isgrowing demand for food production and this has consequently encouraged farmersto rely on application of artificial fertilizers despite its harmful effects on climate.Thus a study on; << ADOPTION OF ORGANIC FARMING TECHNIQUES ASAN ALTERNATIVE APPROACH TO ADDRESSING LIVELIHOOD CONCERNSIN GASABO DISTRICT>> was undertaken. The main objective was to assessthe adoption of organic farming and its impact on livelihood improvement andenvironmental sustainability. The survey was conducted with 75 farmers workingwith Vi-LIFE Program in Gasabo district and three organic promoters fromGako Organic Farming Training Centre, Urwibutso Sina Gerard Enterprise andABAKUNDAKAWA Cooperative respectively. Both qualitative and quantitativedata have been collected, thereafter statistical analysis has been done using regressionanalysis, A paired T-test for comparison of means and net farm income analysis toestimate the profitability of organic and non-organic farming systems. Productionobtained under organic and non-organic farming systems is the same for both cropsand vegetables in Gasabo District. Organic and artificial (non-organic) mean yieldsrespectively were 53, 125 kg and 60.75 kg for maize, with (p = 0.397); 34.3684 kgand 41.6667 kg for beans, with (p = 0.266); 530 kg and 533.33 kg for cabbage, with(p = 0.973); 590 kg and 613.05 kg for tomatoes with (p = 0.760). In terms of income;organic coffee gross margin is (8,103,750 Rwf/ha) which is higher than non-organiccoffee gross margin (4,634,500 Rwf). Organic farming can serve as a mitigatingfactor for climate change and also contribute to livelihood improvement. 271
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa242. Cattle and livelihoods of poor households in Rwanda: Impact assessment Uwimana Gaspard1, Niyuhire M.C2 , Ndimurirwo L.2 and Ruraduma C.2 Rwanda Agriculture Board, Rwanda; 2Institut des Sciences Agronomiques du 1 Burundi (ISABU), BurundiAbstractSince 2003, the government of Rwanda and different NGO’s distributed cattle topoor households through different livestock development programmes. However,the contribution of these cattle to livelihoods improvement of households in thewhole country was questionable. This study aimed at assessing cattle performancesand socio-economic benefits in highland and lowland zones. Thirty farmers fromeach zone were surveyed using questionnaire technique. Economic benefits weremeasured by calculating the gross margins from milk on monthly basis andlivelihood categories were used to analyse household livelihoods. In both zones,less than 2 inseminations were needed per pregnancy for most of the farmers. Thecalving intervals ranged from 11 to 13 months in highlands and from 12 to 16 monthsin lowlands. Most of the farmers in both zones were satisfied with the cow they gotand with the production level of their cows. Average milk yield per household perday was 15 litres in highlands and 8 litres in lowlands. A household in highlandsproduced on average 1.5 heifers, and 1.4 bulls while in lowlands, 0.8 heifers and 1bull were produced. The gross margins from milk production per month were 508frws in highlands and -3816 frws in lowlands. Farmers that achieved new assetsthrough keeping cattle represented 93% in the highlands and 70% in the lowlands.Home tools were the most achieved assets representing 64% of the farmers in thehighlands and 38% in the lowlands. Medical insurance was the most achievedservice representing 67% of farmers in highlands and 73% in the lowlands. Farmersthat passed on a heifer represented 50% in the highlands and 33% in the lowlands. Itwas found that expensive inputs contributed to low benefits with a negative impacton household livelihoods. 272
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa243. Agricultural modernisation from above and from below: Confrontation and integration in rural Rwanda Van Damme Julie1and Ansoms An2 1 Université catholique de Louvain, Belgium; 2University of Antwerp, BelgiumAbstractIn its 2008 World Development report, the World Bank pleads for a ‘Green Revolution’for sub-Saharan Africa, pointing to the importance of including smallholder farmersin such productivity-enhancing process. In this article, we focus in particular on thebanana cropping system. First of all, we show how innovations ‘from above’ designedat the macro level - in line with the principles of the proposed green revolution- are received on the ground. Furthermore, we identify the intermediary role ofactors operating at the meso level (cooperatives, local authorities) in the top-downimplementation of such innovations. We then illustrate how smallholder farmersdevelop their own alternative innovative techniques to adapt to the constraintsimposed by increasing land scarcity and land degradation. We show how suchinnovation ‘from below’ offers alternative ways to improved productivity, whileacknowledging the risk-coping behaviour of small-scale farmers. We argue how abalanced combination of these two pathways of innovation could inspire nationaland international policy makers’ agricultural strategies. 273
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa244. Adoption Determinants in Humid Highland Systems: A highly- disaggregated productivity and transport cost evaluation tool for assessing the spatio-temporal variability of fertilizer profitability in maize-based systems Zhe Guo1, Koo Jawoo1, Wood Stanley1 1 International Food Policy and Research Institute (IFPRI), Washington DC, USAAbstractPoor physical access to markets is often cited as a primary constraint to increasedmarket participation, adoption of improved inputs, production specialization andother sectoral goals for smallholder agriculture in Africa. Higher transport costsand limited policy incentives pose a particularly significant barrier to adoption andsmallholder commercialization in highland zones which are typically more remoteand poorly served with infrastructure investments. This paper describes a strategicevaluation methodology developed at IFPRI to first identify and inventory physicalfactors strongly influencing transport costs; such as road density/connectedness,road conditions, land cover types, slopes and transaction costs. With these elementscharacterized and mapped for any given region (in this case Kenya, Tanzania,Uganda, Rwanda and Burundi), a spatial-explicit price model is developed tosupport simulation of transport costs between regional market locations and farmlocations. The model is further calibrated using price information from householdsurvey in order to provide more reliable estimates of farm-gate input and outputprices, and then extended to assess the potential profitability of imported inputs(e.g., chemical fertilizers) at farm locations across the region by also including cropsimulation-based estimates of output productivity responses to increased input use.The changing patterns of farm-gate prices and input profitability under differentpolicy scenarios are then derived and the implications of those results discussed.The policy scenarios to be reported include: a) a baseline based on 2005 conditions, b)increased transport efficiency (reduction in unit transport costs), c) reduction in thelanded cost of fertilizer in regional ports (e.g. through multi-country procurement),and d) harmonization/simplification of border crossing procedures (reductionin border crossing costs). The research suggests these policies - individually andjointly – can have very significant impacts on the potential scale and spatial patternsof profitability (as estimated using value-cost ratios) and, we hypothesize, potentialadoption of improved inputs. 274
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa245. Sustainable improvement of the Banana Cropping System in North Western Tanzania Mgenzi S.R. Byabachwezi1, Nkuba Jackson Madulu1 and Rony Swennen2 1 ARI Maruku, Bukoba, Tanzania; 2Katholieke Universiteit Leuven, Kasteelpark Aren- berg 13 bus 2455, 3001 Leuven, BelgiumAbsractThe project ‘Improvement of the Banana Cropping System in Kagera Region andKibondo District in Kigoma Region’, is a joint undertaking between the Governmentsof Belgium and Tanzania aiming to contribute towards increased incomes and foodsecurity in North Western Tanzania. Banana is the most important staple food inmany communities of the Great Lakes Region of East Africa; in the Kagera Region,banana is food for about 70 to 95 percent of the total population and it plays a verysignificant role to the regional economic development. The combination of increasinginfestations of banana pests and diseases, tenure pressure, declining soil fertility,and inadequate access to markets, are threatening banana farmer’s livelihoods.Growing local banana varieties susceptible to one or more of these threats has led toa decline of banana production and high vulnerability to food and income insecurityfor poorer farmers. In 1997, the Belgian-Tanzanian funded Kagera CommunityDevelopment Programme (KCDP) was established with the goal of improvingthe standard of living for the rural communities, with a component focused onnew banana varieties that are resistant to several pests and diseases, alone or incombination. Banana plants rosed in nurseries and multiplied in multiplicationfields were distributed to farmers in 5 districts. By 2003, at the end of the project anestimated 2.5 million banana suckers had diffused among farmers either directlyfrom the multiplication fields or indirectly from farmer to farmer. This secondphase that started in February 2009 plans to distribute another 2.2 million bananasuckers. The principal axes to achieve this include are (1) Consolidate institutionalcapacities and networking; (2) Improve the efficiency of the dissemination of thebanana varieties; (3) Disseminate best management practices for improved bananaproduction & protection; (4) Improve post harvest, value adding and marketingskills. In this presentation we will focus on the strengthening of the institutionalcapacities and the farmer empowerment as the necessary step to have a maximumimpact. 275
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 276
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa THEME 4: COMMUNICATING COMPLEX KNOWLEDGE 277
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 278
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa246. Processes and partnerships for effective regional surveillance of banana diseases Beed F1, Kubiriba J2, Mugalula A3, Kolowa H4, Bulili S5, Nduwayezu A6, Murekezi C7, Sakayoya E8 Ndayihanzamaso P9, Mulenga R10, Abass M11, Mathe L12, Masheka Bahige13, Onyango M14, Omoto E15 , Nakato V16 , I.Ramathani1, Bouwmeester H1 1 IITA,Uganda 2NARO,Uganda 3MAAIF, Uganda 4MAFS, Tanzania 5ARI, Tanzania 6 ISAR, Rwanda 7ISAR, Rwanda, 8DPV, Burundi 9ISABU,Burundi 10ZARI,Zambia 11 Ministry of Agriculture, Zambia 12UCG, DRC 13INERA DRC 14KARI, Kenya 15 KEPHIS,KenyaAbstract:The first and critical step to manage a disease is to diagnose the causal agent(s). Once thisis done appropriate control methods can then be deployed. This study reports results froman initiative that targeted Banana Xanthomonas Wilt (BXW) and Banana Bunchy top Virus(BBTV) across the Great Lakes Region and its surrounds. Countries involved were Burundi,DRC, Kenya, Rwanda, Tanzania, Uganda and Zambia. Representatives from both nationalresearch (NARs) and regulatory organisations (National Plant Protection Organisation)formed a network with the aim of forging stronger relationships and knowledge sharingwithin and between countries. The network prioritised where national surveys shouldbe targeted based on regional needs. The zones to survey were selected close to countryborders, where the presence of disease(s) was unknown but where infestation risk was highdue to the proximity of diseased areas, and where disease outbreaks had been reported butnot confirmed. Each disease survey was designed to be spatially representative. This allowedfor data generated from each country’s national survey to be collated to provide a regionaloverview. Field based diagnoses of disease; based on plant symptoms, were supported bylaboratory based, molecular, diagnostic methods. This required the use of novel methods tocapture pathogen DNA in the field for cross border transfer to the laboratory for analyses.These methods were optimised based on technical experiences and perception of users andalso farmers. The farmers managing fields from which samples were obtained completedquestionnaires that were analysed to demonstrate their knowledge of how to recognise andmanage disease. The regional abundance of disease for the targeted areas surveyed werevisualised into clear GIS maps. GIS mapping also allows for the interpolation of diseasedata when overlaid with other existing data sets e.g. climate or trade routes combined withdisease incidence can be used to define reasons for disease spread.Therefore, GIS maps can beused to prioritise investments, in terms of time, staff or money, for future surveys or diseaseintervention campaigns. Recommendations were made on how to ensure quality control ofresults in a regional surveillance network e.g. ensuring GPS coordinates are accurate andhow best to communicate risk due to disease from grassroots extension to policy makers.Processes and partnerships were identified that are critical to manage banana diseases at theregional level in an informed manner. These can be expanded into a plant health care servicethat has the capacity to support a farming systems approach. This is essential as pathogensdo not respect country borders and the threat they currently pose will increase as agriculturebecomes intensified, the environment becomes degraded and as a result of increasedpathogen introductions through trade and travel. As resources are limited and technicalcapacities varied, a pivotal factor to the successful management of diseases across regions, isefficient partnerships and knowledge sharing. A coordinated network of collaborating labsneeds to be established with tiered capacities, and thus responsibilities, to perform regionaldiagnostics and training in a routine and sustained manner. 279
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa247. PARTENARIAT DE CIALCA POUR UNE DISSEMINATION EFFICACE ET DURABLE DES TECHNOLOGIES Bisimwa Charles1, Antoine Lubobo2, Sanginga Jean Marie3, Vanlauwe Bernard4 and Njukwe Emmanuel5 1 Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA), DRC; 2HARVEST PLUS, DRC; 3Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), DRC; 4Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 5International Institute of Tropical Agriculture (IITA), Kampala, UgandaAbstractLes approches de partenariat adoptees par CIALCA pour une disséminationdurable de ses technologies passent par un processus avec des stratégies qui ontpermis aux intervenants en recherche-développement de la région de les utiliserefficacement. Le partenariat est une relation dans laquelle au moins deux partiesayant des objectifs compatibles s’entendent pour travailler ensemble, partager lesresponsabilités, risques et résultats des actions par l’association des ressources pourla réalisation d’ un projet. Le CIALCA par sa philosophie et approche géographique,développe trois types de partenariat stratégique liés par des protocoles et MoU signésprécisant responsabilités et obligations ; activités et résultats escomptés : partenariatcommunautaire avec les associations à la base et ONG ; partenariat avec les servicesétatiques et partenariat régional ou international. Cette plate forme travaillantavec des instituts nationaux de recherche, des universités et ONG nationales dansles zones agro écologiques identiques des pays de la région de Grands Lacs (RDCongo, Rwanda et Burundi) a développé des technologies à disséminer auprès deses bénéficiaires. La dissémination passe par le développement, la mise en œuvred’un processus de partenariat partant des sites d’action vers les sites satellites entenant compte des politiques nationales mais aussi des aspects socio culturels despopulations. Pour éviter que les actions menées ne restent localisées sous forme des« îlots de succès » et réduites à plus petite échelle, il faut envisager leur renforcement àtravers un partenariat efficace et durable. Face à cette approche utilisée par CIALCA: quelles leçons utiles à capitaliser et à pérenniser pour les autres intervenantsen Recherche-Développement dans la région des hautes altitudes humides del’Afrique subsaharienne? Etant parvenu à standardiser sa stratégie opérationnelle,son approche de partenariat constitue un succès que les autres organisationsdans la région devraient adopter. Et alors le CIALCA contribuera efficacement àl’amélioration de la sécurité alimentaire et a l’épanouissement socio-économiquedes populations des Hautes altitudes humides de l’Afrique subsaharienne. 280
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa248. Bringing CAADP to the Farmer Through IAR4D Approach Chiuri W1, Bizoza A2, Adewale A3 and Buruchara R4 CIAT (Centro Internacional de Agricultura Tropical)/CIALCA, Kigali, Rwanda; 1 National University of Rwanda (NUR), Rwanda; 3Merck Research Laboratories, North 2 Wales, Pennsylvania, United States; 4CIAT (Centro Internacional de Agricultura Tropical), Kampala, UgandaAbstractRegional and integrated collective actions for agriculture development in Africahave a long history to address poverty and food insecurity in the region. Thoughsome successes can be identified, the continent seems to be degenerating into abjectpoverty and food insecurity every year. These successes are meant to be replicatedon a wider scale. Thus, a new collective attempt to improve agriculture by Africancountries The Comprehensive Africa Agriculture Development Program (CAADP)under the auspices of the New Partnership for Africa’s Development (NEPAD) hasbeen proposed to accelerate economic growth through agriculture developmentand to eliminate hunger and reduce poverty. However, some of these collectiveactions remain as institutional properties rather than farmer owned. There arelimited individual country case studies to show how CAADP would affect people’slivelihoods. In this study we use experiences from Rwanda to show how CAADP canbe brought down to the farmer level through the Integrated Agricultural Researchfor Development (IAR4D) which is on its 2nd year trial in Sub-Saharan Africa underthe challenge program. 281
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa249. Impact of the Integrated Agricultural Research for Development for improved farmers’ livelihood in Rwanda: Lessons from Sub- Saharan Challenge program Kagabo Desire M.1, Nabahungu Leon2, Mugabo Josaphat1, Mugabe Jonas3, Moses Tenywa4, Claver Ngaboyisonga5, Majaliwa Jackson6, Fungo Bernard7, Murorunkwere Françoise1, Musana Bernard1 1 Institut des Sciences Agronomiques du Rwanda (ISAR), Rwanda; 2Rwanda Agricultural Board (RAB), Rwanda; 3Forum for Agricultural Research in Africa (FARA), Ghana; 4Makerere University, Faculty of Agriculture, Kampala, Uganda; 5 University of Nairobi, Faculty of Agriculture, Department of Plant Science and Crop Protection, Nairobi, Kenya; 6Makerere University, Faculty of Agriculture, Kampala, Uganda; 7Makerere University, Faculty of Forestry and Nature Conservation, Kampala, Uganda;AbstractThe objective of this paper is to assess the impact of the Integrated AgriculturalResearch for Development (IAR4D) approach on Natural Resource Managementand the role of integration of crops, livestock and market interface issues foraddressing the profitability of farm and farmers’ livelihood.Baseline and end-lineof household data concerning soil conservation, production increase, householdincome, and indicators of integration of soil conservation with market shareincrease, productivity based innovation such as good seeds and fertilizer use andtheir possible mutual benefit and/or conflict were analyzed. Explicative modelswere constructed based with and without IAR4D approach.The results show apositive correlation between increase of crop production and soil conservationmeasures adoption. Crop production of farms protected with soil conservationmeasures and farmers’ awareness on natural resource management were higherin action site compared to the counterfactual sites. The increase of the market shareand technology adoption level including soil conservation explained the differencesof crop and livestock productivity observed between action sites. 70% of changesof yield and farmers income were explained by commodity prices and biophysicalconditions. In general a farm of 0.46 ha per household with soil conservation measuresgenerated on average a Net Farm Income (NFI) of 0.6 USD a day compared to 0.4USD for farms without soil conservation measures. The milk production with atleast 2 Tropical Livestock Units (TLU) per household induced more profit on farmwith 0.8 USD of daily agriculture income increment compared to 0.3 USD for farmswithout livestock. 282
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa250. Beyond the pilot sites: can knowledge-intensive technologies diffuse spontenously? Kiptot Evelyne Kenya Forestry Research Institute (KEFRI), Nairobi, KenyaAbstractRapid and cost effective transfer of knowledge-intensive agricultural technologies isof paramount concern to research and development organisations. However, verylittle information exists on whether such technologies can diffuse spontaneouslyfrom pilot sites. This study sought to examine the diffusion and adoption ofimproved tree fallows and biomass transfer technologies in villages neighbouringpilot sites in western Kenya. Pilot sites refer to villages where an agroforestryprogramme worked with farmers to test and disseminate knowledge-intensiveagroforestry-based soil fertility management technologies using a community basedparticipatory approach known as the village committee approach. Data in non pilotsites was collected through household interviews and observations. Findings of thestudy show that although there was spontaneous diffusion of the technologies, asubstantial number of farmers who heard about the technologies never adopted.The low adoption was attributed to insufficient knowledge to implement thepractices, lack of immediate tangible benefits and insufficient resources such as landand labour. Spontaneous diffusion was mostly through informal social networkswhich unfortunately were not sufficient on their own to enhance the adoption of theknowledge intensive technologies. A conducive context and technical support areimportant determinants for adoption to take place. 283
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa251. Assessment of ISFM knowledge and training needs of smallholder farmers in the central highlands of Kenya Macharia Joseph1, Mucheru-Muna M.1, Mugwe J.N1., Mairura F.S.2 and Mugendi D.N.1 1 Kenyatta University, Nairobi, Kenya; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, KenyaAbstractSoil nutrient depletion has been recognized as one of the major biophysical constraintsaffecting agricultural production in Sub Saharan Africa. Despite past research thathas developed various soil fertility management options, few technologies from pastsoil research have been adopted and utilized by target farmers. Poor technologyadoption is associated with low levels of knowledge and awareness by farmers.This study was carried out to assess the knowledge levels and consequently thetraining needs of smallholder farmers on soil fertility technologies in Central Kenyawhere 300 farm households were randomly selected. Questionnaires and fieldobservations were used to gather data. The data was analyzed using SPSS. Resultsindicate that majority of the respondents (69%) had moderate levels of knowledgeon Integrated Soil Fertility Management (ISFM) technologies. Age, active femalesin farming, farming experience, and number of groups significantly influenced theISFM knowledge levels held by farmers. The priority training needs of farmersincluded knowledge and skills in soil fertility testing, organic fertiliser utilizationand liming, while their most preferred training methods were field days and on-farmdemonstrations. There is need to improve farmers’ levels of knowledge throughtraining, taking into account socio-demographic characteristics, especially gender,age, household size and labour availability, farming experience, group membershipand farm size. Farmer training needs and preferred training methods should also betaken into account. Policies are needed so as to support practical and participatoryapproaches to ISFM technology dissemination. This will lead to enhanced ISFMadoption, increased crop production and poverty reduction. 284
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa252. Research partnership management: lessons drawn from the lake kivu pilot learning site of Sub-saharan challenge program Mugabe Jonas Musabwa1, Tenywa Moses2, Chiuri Wanjiku3, Buruchara Robin4 And Adekunle Adewale5 1 Forum for Agricultural Research in Africa (FARA), Ghana; 2Makerere University, Faculty of Agriculture, Kampala, Uganda; 3CIAT (Centro Internacional de Agricultura Tropical)/CIALCA, Kigali, Rwanda; 4CIAT (Centro Internacional de Agricultura Tropical), Kampala, Uganda; 5Forum for Agricultural Research in Africa (FARA), GhanaAbstract:Successful partnerships have been used in the business world for a while. The samemodel is now penetrating agricultural research in many regions of the developingworld. In Sub-Saharan Africa, year 2008 saw the implementation of a research-based project known as Lake Kivu Pilot Learning Site (LKPLS) involving threecountries, namely; Rwanda, DR Congo and Uganda at their common boarders.The project used Innovation Platforms (IPs) as tools for implementation of theIntegrated Agricultural Research for Development (IAR4D) concept. The take-offand implementation of activities of this new concept because of the complexity ofthe institutional arrangements took longer time than anticipated. The inceptionperiod defining methodology and institutional mechanisms took more than threeyears (2005-2007) while the implementation period lasted for the same number ofyears (2008-2010). The project partnership involved among others CGIAR centers,research institutes, universities, extension, farmer organizations, NGOs, privatesector, and local authorities from the three countries. Building up such a consortium/partnership is a new experience for the actors customized to work separately. Thelong inception period registered a high turner-over of actors and institutions whichaggravated the complexity.This paper highlights how the consortium was built andactivities were implemented by the partnerships within the LKPLS, the challengesfaced and how partners have managed them in order to draw some lessons for thefuture. 285
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa253. Linking farmer field school and potato markets to natural resource management in the highlands of southwestern Uganda Muzira Robert1, Vanlauwe Bernard2, Basamba Twaha3, Rwakaikara Mary-Silver1 and Wanjuki Chiuri5 1 CIAT (Centro Internacional de Agricultura Tropical), Kampala, Uganda; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT- TSBF), Nairobi, Kenya; 3Makerere Univerisity, Kampala, Uganda; 5CIAT (Centro In- ternacional de Agricultura Tropical)/CIALCA, Kigali, Rwanda;AbstractExploring the synergy of Farmer Field Schools (FFSs) and profitable market linkson agricultural production is important in enhancing adoption of improvedSoil Fertility Management (SFM) innovations in smallholder farming system. Acomparison study on SFM innovations was conducted in the highlands of southwestern Uganda in communities with and without FFSs having urban and localpotato market links respectively. Improved farmer-markets links in communitieswith FFSs was an incentive to agricultural production. Farmers used more inorganicfertilizers in potato fields located on different slope positions and placed moreland (4.94 ha per household) under cultivation compared to their counterparts incommunities without FFSs (1.66 ha per household). While training farmers in SFMin potato production and linking them to good market opportunities improvedinvestments in SFM innovations, there was still net negative nutrient flow balancesfor most nutrients more especially with households with limited resources. 286
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa254. Willingness to pay for extension services in Uganda among farmers involved in crop and animal husbandry Mwaura Francis1, Okoboi Geofrey2 and Muwanika Fred Roland3 Economic Policy Research Centre, Uganda; 2Foodnet, International Institute of 1 Tropical Agriculture, Bandali Rise , Bugolobi, Kampala, Uganda; 3Economic Policy Research Center Kampala, UgandaAbstractAlthough the Ugandan government is determined to aid farmers increase agriculturalproductivity as an intervention on increasing food security and reducing povertythrough extension services, resources constraints are dampening its efforts. Privateextension services providers are being invited to take up information disseminationroles with queries on the availability and demand of the services among farmersto attract private sector and factors influencing the demand for extension services.Database collected by the Uganda Bureau of Statistics (UBOS) on national servicedelivery throughout the country in 2008 among 5363 and 3318 farmers involvedin crops’ and animals’ husbandry was used to predict willingness to pay, amountfarmers were willing to pay for extension services and factors that were to influencewillingness to pay. It was established that about 35% and 40% of the farmerswere willing to pay on average Ugandan shillings 3,400 (US$ 1.8) and 3,700 (US$2) per trip for extension services in crop and animal husbandry respectively. Keyfarmer’s attributes that influenced willingness to pay included sex, age, educationlevel, regions of residence and preferred means to receive the services. The demandfor extension and preferred price are low for private sectors engagement and thegovernment should first educate the public on the importance of the services toboast the demand before thinking on privatization of the services. 287
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa255. Assessing the Existing Institutional Capacity for the Implementation of the National Biotechnology and Biosafety Policy Measures in Kenya Nyanga Rose Ministry of Higher Education Science and Technology Kenya, Nairobi, KenyaAbstractBiotechnology refers to any technique that uses living organisms (Parsley, 1992). Inplant biotechnology, three applications of broad fields of study such as plant tissueculture, genetic engineering and plant molecular markers are commonly used.Kenya like many other developing countries is burdened with a rapidly growingpopulation and a deteriorating climate and the environment over the years yet itmainly depends on agriculture as one of its major sources of income and food. Thecountry is one of the African counties that have realized how biotechnology canbe used to reduce the challenges and has developed the interest and the capacityto undertake research in biotechnology and apply the results to provide someof the solutions through supportive policies and infrastructure. The NationalBiotechnology and Biosafety policy have been developed and is in the process ofbeing implemented. Reports from KARI indicate that biotechnology activities havebeen taking place in the country for more than twenty years. The assessment of theexisting institutional capacity for the implementation of the national biotechnologyand biosafety policy measures in comparison with other successful countries givesinformation on how far Kenya has gone in the area of biotechnology research forpurposes of bench marking. This study employed structured questionnaire surveyand semi-structured interviews research designs as a guide in data collection frominstitutions that deal with biotechnology and biosafety at various levels both socialand academic in Kenya. The data was be analyzed using appropriate computerbased programmes based on the cause effect theory whereby, presumption is madethat chronologically, the cause precedes the effect. In such a situation the cause arethe policy measures which when implemented, precede the effect of the policy.Comparative weakness was observed on the implementation process and the plansavailable for implementation. 288
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa256. Evaluating Multi Stakeholder Innovation Platforms in Lake Kivu. P.Pali1, J. Njuki2 , W. Chiuri3, M.M. Tenywa4 , J. Mugabe5, R. Buruchara6, A. Adekunle7 1 International Livestock Research Institute (ILRI), Nairobi, Kenya; 2International Centre for Tropical Agriculture-Harare, Zimbabwe; 3CIAT (Centro Internacional de Agricultura Tropical)/CIALCA, Kigali, Rwanda; 4Makerere University, Faculty of Agriculture, Kampala, Uganda; 5Forum for Agricultural Research in Africa (FARA), Ghana; 6CIAT (Centro Internacional de Agricultura Tropical), Kampala, Uganda; 7 Forum for Agricultural Research in Africa (FARA), GhanaAbstractMonitoring and evaluation has increasingly been used in the context of accountabilityin large projects, and less for its learning function. This paper is based on theintegration of a learning approach applied to innovation systems. A monitoringand evaluation system was implemented into the functioning of multi stakeholderinnovation platforms (IP’s) located in the Lake Kivu. Innovation platforms (IP’s)are the implementation models for integrated agricultural research for development(IAR4D) - an innovation systems approach. Diverse interactions that occur betweenmulti stakeholders in response to a pre determined issue trigger varied actions,activities, processes, knowledge, information and technology transfer within the IP,hence necessitating a learning function from the internal workings of these IP’s.We present the results of the stakeholders’ perceptions of the IP interactions andselected monitoring and evaluation tools that track the functioning of these multistakeholder platforms. Overall, the perceptions of the ninety three stakeholdersare that the issues that were discussed during the IP activities were relevant andunderstood by the participants. Reported outcomes were the increased knowledgeof approaches, markets and interactions. Performance monitoring and evaluationhas enabled tracking of activities and processes, with the expected impacts beingimproved productivity, natural resource management and access to markets. 289
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa257. CIALCA participatory on-farm trials: Can we both collect high quality data and increase farmers’ learning? Katharina Paul Birthe1, Vanlauwe Bernard2, Sanginga Jean-Marie3, Gahigi Aimable4 and Pypers Pieter2 1 Wageningen University, Netherlands; 2Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT-TSBF), Nairobi, Kenya; 3Tropical Soil and Biology Institute of the International Center for Tropical Agriculture (CIAT- TSBF), DRC; 4Institut des Sciences Agronomiques du Rwanda (ISAR), RwandaAbstractKnowledge-intensive technologies such as Integrated Soil Fertility Management(ISFM) often face challenges in farmers’ acceptance and adoption, especially inSub-Saharan Africa. Reasons may include insufficient on-farm evaluation and alack of understanding of farmers’ priorities. Participatory on-farm research is anapproach to bridge the gap between research and reality. Since 2008, thousandsof farmers have participated in CIALCA participatory on-farm assessments ofISFM technologies in DR Congo, Rwanda and Burundi. They are provided with atrial package, which includes the required inputs, a trial protocol, and a field databook. Facilitators and agronomists from farmer associations, NGO partners andCIALCA assist in trial installation, management and data collection. These TypeII trials (researcher-designed, farmer-managed) aim at collecting crop performancedata across a wide range of agro-ecological and socio-economic conditions whileincreasing farmers’ understanding of the ISFM technologies.Despite of increasedpopularity of participatory on-farm research in recent years, comprehensivedocumentation and evaluation of such approaches is hardly available. Therefore,this study aims to (i) document innovation in participatory on-farm research design;(ii) assess the success of the approach in terms of data collection and farmers’learning and identify influencing factors; (iii) formulate recommendations forfuture improvement. The evaluation study was conducted from June-August 2011in two mandate areas in DR Congo and Rwanda. A combination of quantitativeand qualitative methods was used to allow for identification of general patterns aswell as deeper understanding of central issues: (i) Statistical analysis of field booksand technical evaluations; (ii) Questionnaire survey among 200 farmers and 50facilitators linked to field books; (iii) in-depth, semi-structured interviews with 25key informants (farmers, facilitators, CIALCA and NGO staff). Preliminary resultsfrom data analysis and informal surveys show that the success of the approachvaries between and within mandate areas. Both data quality and farmers’ learningseem to rely on quantity and quality of facilitation, and motivation and capabilitiesof farmers and facilitators, and other site-specific characteristics. 290
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa258. Integrated communication approaches for effective management of Banana Xanthomonas wilt in East and Central Africa Tinzaara W.1, Karamura, E.1, Blomme, G1, Ocimati, W.1, Kubiriba, J.2 and Jogo, W.1 Bioversity International, Kampala, Uganda; 1 2 National Agricultural Research Organization, Kawanda, Kampala UgandaAbstractThe East and Central African (ECA) region has suffered from a devastating BananaXanthomonas wilt (BXW) epidemic caused by Xanthomonas campestris pv.musacearum. BXW is widespread in Uganda, DR Congo, Rwanda, Kenya, Tanzaniaand has recently been confirmed present in Burundi. The disease causes yield lossesup to 80-100%, especially in ABB banana-based production systems in CentralUganda and eastern DR Congo. Current available information indicates that allcultivars in the region succumb to the disease and this, combined with the speedat which the epidemic spreads to new areas, threatens at least 30 million peoplewho depend on the crop for their livelihoods. Recommended control options inthe region include destruction and disposal of infected plants/mats, disinfectingtools used in the plantation, using clean planting materials, early removal of malebuds and quarantine measures. Raising awareness of all stakeholders along theproduction-to-consumption chain by empowering them with knowledge and skillsfor diagnosis and management of the disease is seen as an integral component ofthe intervention strategy to control the epidemic and restore banana productivity.Several communication tools have been used to disseminate information for themanagement of BXW. These approaches include radio campaigns, videos, trainingby institutions, posters, brochures, newspapers and television. Participatorydevelopment communication (PDC) approach has also been used for themanagement of the disease. While these communication approaches, if adhered towill contribute to awareness creation among stakeholders, and hence slow downdisease spread, no single approach can provide a long-term effect. Integration ofdifferent communication approaches may provide a feasible and sustainable tool forthe management of the disease. This paper discusses the different communicationapproaches currently being used in the region to control the disease; and howintegrated communication approaches may provide effective and sustainablesolutions for the management of BXW in ECA. 291
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa259. Dynamic evolution of innovation networks and the roles of innovation intermediaries in agricultural netchains: Potato net chains in Rwanda, Uganda and Democratic Republic of the Congo Silvia Andrea Pérez Perdomo1,2, Andrew Farrow1, Robin Buruchara1,Wanjiku Chiuri1, Eliud Birachi1 1 International Center for Tropical Agriculture (CIAT), Kampala, Uganda; 2Communi- cation and Innovation Studies, Wageningen University, The NetherlandsAbstractThis research tests new combinations of analytical approaches to track the evolution ofinnovation networks, providing evidence from case studies of the potato netchain in theLake Kivu Pilot Learning Site of the Sub-Saharan Africa Challenge Programme in thehighlands of Rwanda, Uganda and the Democratic Republic of the Congo. A combina-tion of netchain analysis and mapping the ‘challenges of innovation’ allows for innova-tion to be tracked as a non-linear and cyclical process, from a longitudinal and networkstructural perspective. These analytical tools enable the visualisation of changes in thestructure of the innovation networks through time, such as the configuration of actorsin the potato netchain, and the type of interdependencies between them that arise whenfacing, among others, production and marketing challenges.The analysis of the potatonetchains from three cases shows different interdependencies - reciprocal, sequentialand pooled - between actors. These interdependencies are facilitated by innovation in-termediaries at certain challenges or stages in the cycle of innovation. Examples of facili-tation include finding new actors who can bring new knowledge and/or benefit fromthe development of new products during the explorative phase of the innovation cycle,or the formalisation of contracts in an exploitative stage of the cycle of innovation. Thisfacilitation of interdependencies is subsequently recognized as a source of value addi-tion in the innovation process.Our findings also demonstrate how innovation networksevolve dynamically through time, and based on the presented evidence we concludethat an important role for innovation intermediaries is to keep the cycle of innovation influx maintaining stability and change along the innovation trajectory. 292
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa Author IndexAuthor Abstract No.AAbubakar et al 31Adetonah et al 211Adheka et al 32Adolwa et al 212Ampaire and Machethe 213Araki et al 33Awotide et al 214Ayedun et al 34BBagula et al 35Baret and Van Damme 181Baret 180Baryeke et al 36Bashagaluke et al 37Beed et al 246Betemariam et al 38Bisimwa et al 247Bizimana et al 39Bizoza 215Bolonge et al 40Boukary et al 41Bouwmeester et al 182Breman 19Bulili et al 42Buruchara et al 26Busogoro et al 183CChifizi 216Chiuri et al 248Claessens et al 184Claessens et al 185DDegrande 23Dhed’a et al 43Divine et al 217Dunjana et al 44 293
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan AfricaEEkesa et al 45Emera et al 46FFon and Yobo 187GGaidashova et al 48Gaidashova et al 49Gaidashova et al 50Gebre et al 47Giller et al 14Gitari et al 51HHerren 2Holger et al 70IIradukunda et al 52Isaboke et al 53JJagwe et al 218Janssens et al 54Jassogne et al 188Jefwa et al 6Jefwa et al 55Jemo et al 56Jemo et al 57Jeng 58Jogo et al 219KKabiligi et al 190Kabunga et al 220Kagabo et al 189Kagabo et al 249Kamira et al 59Kamiri and Mathias 191Kanonge et al 60Kantengwa et al 221Kantungeko et al 61Kanyana et al 62Kanyange et al 63 294
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan AfricaKanyaruguru and Niyongere 64Karamura et al 65Karltun et al 30Karltun et al 66Kasereka et al 222Katharina et al 257Katunga et al 192Keating and Carberry 1Kebede and Belay 67Kihara et al 68Kimana et al 223Kimaru-Muchai et al 27Kiplagat et al 69Kiptot 250Klapwijk and van Wijk 193Koala 224Koala et al 194Koech-Njeri et al 71Kopa-Kamanga and Darley 72LLagerlöf et al 73Langyintuo 17Lindiro et al 74Lukuyu et al 75Lutta 225Luuk 186Lyimo et al 76Lynam 24Lyonga and Fonbah 77MMaass and Metre 78Maass et al 13Macharia et al 251Manzeke et al 79Mapenzi and Musale 80Mapenzi Assani and Musale 81Masiga et al 7Mauyo et al 82Mbakaya et al 83Mbikayi 84Mbosso et al 226Mengesha and Tadele 9Mfune et al 85Mgenzi 245 295
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan AfricaMilambo 195Miriti et al 86Mkondambiri et al 227Mosnier et al 12Mowo et al 29Mpiira et al 88Mtetwa 89Mubasi et al 90Muchunguzi et al 91Mudyazvivi 228Mugabe et al 252Mugabo et al 92Mugwe et al 93Muhati 94Mukantwali et al 229Mukashema and Veldkamp 196Muke et al 95Mukuralinda et al 87Munthali and Mazuma 96Munyahali et al 97Muriuki et al 98Musana et al 100Musana et al 99Musoni et al 101Mutware et al 230Muzira et al 253Mwabi 104Mwaura et al 254NNabahungu et al 105Nakato et al 106Nambangia 107Nambiro et al 231Ndabamenye et al 109Ndabamenye et al 108Ndayisaba et al 110Ndimubandi and Orshoven 197Ndirigwe et al 112Ndirigwe et al 111Ndofunsu et al 113Nebiyu et al 114Nebiyu et al 115Ngaboyisonga et al 232Ngaboyisonga et al 117Ngama et al 118Ngamau et al 119 296
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan AfricaNgetich et al 120Ngezahayo 121Ngwira Robert 233Nibasumba et al 122Nibasumba et al 198Niko et al 123Niko et al 124Niyongere et al 125Niyuhire et al 234Njeru et al 116Njoroge et al 126Njukwe et al 127Nkuba et al 129Nkuba et al 128Ntamwira et al 131Ntamwira et al 130Nuwamanya et al 102Nuwamanya et al 103Nwoke et al 132Nyanga 255Nyberg et al 133Nziguheba et al 134Nzohabonayo et al 135Nzungize et al 179OOchieng et al 136Ocimati et al 141Ocimati et al 137Ocimati et al 139Ocimati et al 140Ocimati et al 138Odendo et al 235Odundo et al 142Okalebo et al 143Okoboi et al 144Omenya et al 145Onyegbule et al 146Otinga et al 147Ouma et al 18Ouma et al 199Ouma et al 236 297
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan AfricaPPablo 10Pali et al 256Perdomo 259Phiri 200Polepole 148Pypers et al 201Pypers et al 4RRamathani et al 149Remans et al 22Rietveld et al 150Roing et al 151Roux et al 28Ruganzu et al 152Rukundwa 237Ruraduma 153Rurangwa et al 155Rurangwa et al 154Rushemuka et al 156Rusike et al 21Rusinamhodzi et al 202Rutikanga et al 157SSaka et al 203Sanginga et al 158Sarr et al 159Sayi et al 238Schulte-Geldermann et al 161Schulte-Geldermann et al 160Schulte-Geldermann et al 8Serpantie and Rakotondramanan 204Sikyolo et al 162Simbare et al 163Sirivihauma et al 164Smith et al 239Ssamula et al 165Sunderland 166Swennen et al 5 298
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan AfricaTTakoutsing et al 240Taremwa et al 205Taremwa et al 241Taulya et al 167Tegegne et al 206Tilahun 207Tinzaara et al 258Tossah et al 168Tumwesigye 169UUkozehasi et al 208Uwimana et al 242VVan Asten et al 11Van Damme and Ansoms 243Van Noordwijk et al 3Van Rikxoort et al 16Van Schagen et al 25Vandamme et al 170Vigheri and Fina 172Vigheri et al 171Vosatka et al 173WWaha 209Wairegi and Van Asten 20Waweru et al 175Waweru et al 174YYusuf et al 176Yusuf et al 177ZZagabe 210Zhe et al 244Zingore and Adrian 15Zozo et al 178 299
    • Challenges and Opportunities for Agricultural Intensification of the Humid Highland Systems of sub-Saharan Africa 300