Common beans (Phaseolus vulgaris L.) are the most important legume staple food in Kenya coming second to maize. In Central Highlands of Kenya, the 0.4-0.5ton ha-1 output is below the genetic yield potential of 1.5-2ton ha-1 partly due pests and diseases. Plant parasitic nematodes (PPN) have been reported to cause yield losses of up to 60% on beans. Though bean production is important in the Central highlands of Kenya, information on PPN associated with the beans in the region is lacking. This study was therefore undertaken to establish the diversity of PPN associated with common beans and to assess the root knot nematode damage on beans in the region. The study covered 50 farms (32 in Kirinyaga and 18 in Embu Counties) distributed in eight localities namely Kibirigwi (L1), Makutano (L2), Kagio (L3), Mwea (L4) and Kutus (L5) in Kirinyaga County and Nembure (L6), Manyatta (L7) and Runyenjes (L8) in Embu County and covering three Agro Ecological Zones (AEZs); UM2 (L1, L2, L3 & L4), UM3 (L5, L7 & L8) and UM4 (L6) AEZs. Manyatta (L7) and Nembure (L6), had the highest and second highest gall indices, respectively, while Kibirigwi (L1), Makutano (L2) and Mwea (L4) had some of the lowest gall indices. The most common PPN in bean roots were Meloidogyne spp. Pratylenchus spp. and Scutellonema spp. with a frequency of 94.38%, 78.25% and 59.13%, respectively. This further confirm the importance of these nematodes in bean production systems. Upper Midland 3 (UM3) AEZs and UM4 had higher nematode population densities and diversity than UM2. Disease severity and nematode composition and distribution were notably low in the irrigated areas Kibirigwi, Kagio and Mwea compared to rain-fed areas such as Makutano, Nembure and Manyatta.
Host range of mungbean yellow mosaic virus (mymv) and influence of age of see...Jayappa Singanodi
Among twelve different plant species belonging to two families viz. Leguminosae and Solanaceae, only leguminous crops such as soybean (Glycin max (L.) Merr.), Pigeonpea (Cajanuscajan (L.) Millsp.), Black gram (Vigna mungo (L.) Hepper), Horse gram (Macrotyloma uniflorum (Lam.) Verdc.) and French bean (Phaseolus vulgaris L.) were transmitted with MYMV. Seedlings with early inoculation recorded highest per cent transmission. 93.33 per cent transmission was recorded in ten days old seedlings followed 80, 66.66, 46.66 and 33.33 per cent transmission were recorded by 15, 20, 25 and 30 days old seedlings, respectively.
Host range of mungbean yellow mosaic virus (mymv) and influence of age of see...Jayappa Singanodi
Among twelve different plant species belonging to two families viz. Leguminosae and Solanaceae, only leguminous crops such as soybean (Glycin max (L.) Merr.), Pigeonpea (Cajanuscajan (L.) Millsp.), Black gram (Vigna mungo (L.) Hepper), Horse gram (Macrotyloma uniflorum (Lam.) Verdc.) and French bean (Phaseolus vulgaris L.) were transmitted with MYMV. Seedlings with early inoculation recorded highest per cent transmission. 93.33 per cent transmission was recorded in ten days old seedlings followed 80, 66.66, 46.66 and 33.33 per cent transmission were recorded by 15, 20, 25 and 30 days old seedlings, respectively.
Maize Lethal Necrosis: Perspective from the U.S. MidwestCIMMYT
Perspective from the U.S. Midwest on MLN, presented at the International Conference on “MLN Diagnostics and Management in Africa,” organized by AGRA (Alliance for Green Revolution in Africa) and CIMMYT, 12-14 May, 2015
Aspects of the ecology of fruit flies in ugandaBrian Isabirye
Fruit flies cause about 40% fruit loss in Africa, and about 73% in Uganda. Design of IPM strategies for fruit flies requires knowledge of their biology. Was limited to Nakasinga, 2002; Nemeye, 2005; Okullokwany, 2006. It is not clear how: Diversity has been shaped by hosts, distribution and envital variability.
Highly cryptic and inter-intra-specific morphological variation (Clarke et al., 2005; Drew et al., 2008) among Bactrocera spp. turns out.
Will change in climate alter the suitability and distribution of species?
Evaluation of fungicides for their efficacy against seed-borne fungi of Sorgh...ICRISAT
Sorghum germplasm exchange has played a significant role in crop improvement programmes by providing wide genetic diversity world over. However, there is an inherent risk of introduction of new exotic pathogens or new/more virulent races of a pathogen into new areas. The basic principle of plant quarantine is to regulate the movement of seed material to mitigate the associated pest risk. Salvaging, a process of disinfecting infected seed, is an important quarantine strategy to prevent the introduction of new pathogens or virulent races into new areas.
Cotton is the major cash crop of South Asian countries. Due to its large cultivation, it is susceptible to various fungal, bacterial and viral diseases. Out of viral diseases, Cotton leaf curl virus (CLCuV) is the most devastating viral disease of cotton. It is caused by begomovirus of family geminiviridae and spread by ubiquitous whitefly (Bemisia tabaci). Due to the vast destruction caused by this virus in 1992 and 2001, farmers and scientists tried to tackle this disease through various techniques and methodologies. All these techniques are not fruitful because this virus is not easy to handle. This is because of the structure and environmental conditions in which virus survives. RNAi technique is the natural defense mechanism against viruses in plants, animals, and fungus. Biotechnologists used this technique for their own benefit. They manipulate the viral genome through this technique and made the plant resistant to disease. They diminish the expression of viral genome by DNA methylation and by post-transcriptional gene silencing (PTGS). In DNA methylation, a methyl group is attached to a gene of viral coding protein and restricts its transcription. In PTGS, dsRNA molecule is produced by the cell itself or can be inserted in the cell from outside. This dsRNA form dicer with microRNA and cut the mRNA of virus which is to be translated for disease-causing infectious protein. Thus, by using the RNAi technique, the viral genome of begomovirus is degraded and its expression is suppressed.
Genetic Variability, Heritability and Genetic Advance of Kabuli Chickpea (Cic...Premier Publishers
The present study was carried out to assess the extent of genetic variability among yield and yield related traits in selected kabuli chickpea genotypes. Forty-nine kabuli chickpea genotypes were studied for thirteen traits at Debre Zeit and Akaki using 7x7 simple lattice design in 2018 cropping season. Combined analysis of variance revealed that there was a significant difference among genotypes for all traits studied, indicating the presence of considerable amount of variability among genotypes. High Phenotypic coefficients of variation and moderate genotypic coefficients of variation value were shown for number of pods per plant and number of seeds per plant, respectively, indicating the possibility of genetic improvement in selection of these traits. High broad sense heritability coupled with high genetic advance were obtained for hundred-seed weight (91.88 and 23.81), number of pods per plant (68.07 and 28.13), number of secondary branches (80.92 and 27.80), number of seeds per plant (67.86 and 31.840), grain yield (62.33 and 24.42) and harvest index (75.70 and 28.17), respectively. This indicates that these characters could be improved easily through selection.
MLN Incidence and Impact in Uganda, presented at the International Conference on “MLN Diagnostics and Management in Africa,” organized by AGRA (Alliance for Green Revolution in Africa) and CIMMYT, 12-14 May, 2015
We evaluated the oviposition preference and damage capacity of Spodoptera frugiperda on the different phenological stages of corn. Tests were performed at the Assis Chateaubriand Agricultural School (07º10'15" S, 35º51'13" W, altitude 634 meters), municipality of Lagoa Seca, Paraíba State, Brazil, in two areas of 500 m2, with CMS maize hybrid strain and maize intercropped with bean with the spacing of 0.80 x 0.40 m. Eggs and caterpillars were collected weekly on 50 plants randomly sampled in five spots. Height and number of leaves per plant, and damage from caterpillars of S. frugiperda were recorded using the scale, the rangers were., 0) no damage, 1) leaf scraped, 2) leaf pierced, 3) leaf torn, 4) damage in cartridge, 5) cartridge destroyed. The average number of clutches did not differ significantly among the three phenological stages of the culture, but average clutch size (number of eggs) was significantly smaller for the stage of 4-6 leaves. However, there was a significant interaction with respect to the number of clutches between position in the plant (lower, middle, and upper) and phenological stage, and between leaf surface and phenological stages. There were significant differences among tillage systems for corn in monoculture and corn intercropped with bean.
ABSTRACT- Corynespora leaf fall (CLF) disease of rubber incited by the fungal pathogen Corynespora cassiicola is
one of the major threats for natural rubber cultivation in rubber growing regions of India. The CLF disease occurs
regularly in rubber plantation during dry period after re-foliation and intensity rise during March to April and subsides
during wet months. Study was undertaken to investigate on survival mechanism of the pathogen in rubber plantations over
the seasons. The results of the studies revealed that the pathogen survived up to 11 days in infected leaf litter and showed
good growth on potato dextrose agar medium. The pathogen was able to survive on intact infected leaves on the plant and
also on plant debris as thick dark brown dormant mycelium under the bark of dried infected twigs.
Key Words: Corynespora leaf fall, Corynespora cassiicola, Hevea brasiliensis, Survival
Ijaar vol-15-no-5| Analysis of the population structure 2015 Puccinia gramini...Innspub Net
N Wheat (Triticum astevium) production in Kenya has been severely affected by stem rust Ug99 and its related race groups. The consequence of not controlling this disease is steep decline in the crop production thus creating food insecurity to over 70% of the small-scale holder farmers who depend on it as a source of food as well as income. The causative agent of the disease Puccinia graminis f. sp tritici (Pgt) has been studied by researchers globally because of its rapid evolution of races within lineage overcoming existing resistant genes. Understanding the population structure will highlight the predominant race(s) as well as their geographical distribution. This information is required to enable breeding for resistant wheat varieties. The objective of this study was to characterize the population structure of Puccinia graminis f. sp tritici population in 2015. Using 10pgt Simple Sequence Repeats (SSR) markers 104 single uredenial-pustule samples were analysed. Minimum spanning network pattern was composed of five Simple Sequence Repeats multi-locus genotypes (SSR-MLGs) that were organized around three nodes based on samples chosen from wheat growing fields with the reference isolates; races TTKSK and TKTTF. In addition to this, non-parametric DAPC analysis showed the presence of single population made up of two predominant races from clade I (Ug99 race group) and clade IV-B (race TKTTF/TTTTF). Analysis of molecular variance (AMOVA) according to Bayesian Information Criterion showed clustering was majorly based within populations (0.576%) rather than among clusters (0.441%).
Whitefly is a known pest of economic importance in the cassava production systems of Africa. This pest has been reported to cause losses to cassava through direct feeding damage as well as vectoring cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Serangium parcesetosum is a known predator of whitefly (Bemisia tabaci) and previous screenhouse and laboratory studies reported that temperature affected the reproduction and survival of this predator. However, these findings lacked precision since they did not depict the field situation. In that regard, it was imperative to initiate a study to help understand the influence of abiotic factors especially temperature and rainfall on the population of S. parcesetosum in the cassava growing fields of Uganda. The study was conducted in two agro-ecological zones of Uganda, namely; North Western Savannah Grassland (Lira) and the Kyoga Plains (Kamuli) in the first rains of 2017. Results revealed that temperature caused an increment of 3.5%, 9.1% (Kamuli) and 1.1%, 1.8% (Lira) for mean adult and larvae S. parcesesotum per plant respectively. On the contrary, rainfall caused a decrease in the population of S. parcesesotum in Lira. Generally, the effect of both temperature and rainfall on the predator population in the field was minimal.
Types and Percentations of Parasitization Egg Parasitoids Spodoptera frugiper...AI Publications
Corn (Zea mays L) is the main commodity of agricultural crops in Indonesia. There are two groups of corn that are cultivated, namely ordinary corn (food corn) and sweet corn. Food corn is mainly used as a raw material for making food, which is used as a raw material for making animal feed raw materials and other industrial products. Easy cultivation, can grow in various conditions, stable selling prices and easy to market are the main driving force for high interest of the farming community to cultivate it. Spodoptera frugiperda larvae are polyphagous and attack many plant species. S. frugiperda larvae feed on more than 350 species of plants in 76 families. S. frugiperda is a typical migratory pest and this migratory behavior is an adjustment strategy to find a more profitable habitat. S. frugiperda is one of the most dangerous invasive pests due to its short life cycle. An adult female lays 900 – 1200 eggs in her life cycle. The purpose of the study was to inventory and analyze the egg parasitoid of S. frugiperda and the percentage of parasitization The analysis of the types of egg parasitoids of S. frugiperda was carried out through an inventory and identification process, while the percentage of parasitization was carried out using a randomized block design consisting of 5 treatment groups of eggs from 5 regions and three replications. The results of the inventory and identification contained two types of parasitoids, namely: Telenomus sp. and Trichogramma sp. The highest percentage of total parasitization was from Manado City at 85% and the lowest was from Bolaang Mongondow at 5%. Telenomus sp. higher percentage of parasitization than Trichogramma sp. Parasitization percentage of Telenomus sp. on eggs of S. frugiperda the highest came from Manado by 63% and the lowest came from Tomohon by 3%, while the percentage of parasitization of Trichograma sp. The highest came from Manado at 22%, and the lowest came from Bolaang Mongondow Regency at zero percent. In conclusion, there are 2 types of egg parasitoids in S. frugiperda eggs, namely the parasitoid Telenomus sp and the parasitoid Trichogramma sp., the percentage of parasitization of Telenomus sp. on eggs of S. frugiperda the highest sample from Manado and the lowest sample from Tomohon. Percentage of parasitization of Trichograma sp. the highest sample of S. frugiperda eggs from Manado, and the lowest sample from Bolaang Mongondow.
Maize Lethal Necrosis: Perspective from the U.S. MidwestCIMMYT
Perspective from the U.S. Midwest on MLN, presented at the International Conference on “MLN Diagnostics and Management in Africa,” organized by AGRA (Alliance for Green Revolution in Africa) and CIMMYT, 12-14 May, 2015
Aspects of the ecology of fruit flies in ugandaBrian Isabirye
Fruit flies cause about 40% fruit loss in Africa, and about 73% in Uganda. Design of IPM strategies for fruit flies requires knowledge of their biology. Was limited to Nakasinga, 2002; Nemeye, 2005; Okullokwany, 2006. It is not clear how: Diversity has been shaped by hosts, distribution and envital variability.
Highly cryptic and inter-intra-specific morphological variation (Clarke et al., 2005; Drew et al., 2008) among Bactrocera spp. turns out.
Will change in climate alter the suitability and distribution of species?
Evaluation of fungicides for their efficacy against seed-borne fungi of Sorgh...ICRISAT
Sorghum germplasm exchange has played a significant role in crop improvement programmes by providing wide genetic diversity world over. However, there is an inherent risk of introduction of new exotic pathogens or new/more virulent races of a pathogen into new areas. The basic principle of plant quarantine is to regulate the movement of seed material to mitigate the associated pest risk. Salvaging, a process of disinfecting infected seed, is an important quarantine strategy to prevent the introduction of new pathogens or virulent races into new areas.
Cotton is the major cash crop of South Asian countries. Due to its large cultivation, it is susceptible to various fungal, bacterial and viral diseases. Out of viral diseases, Cotton leaf curl virus (CLCuV) is the most devastating viral disease of cotton. It is caused by begomovirus of family geminiviridae and spread by ubiquitous whitefly (Bemisia tabaci). Due to the vast destruction caused by this virus in 1992 and 2001, farmers and scientists tried to tackle this disease through various techniques and methodologies. All these techniques are not fruitful because this virus is not easy to handle. This is because of the structure and environmental conditions in which virus survives. RNAi technique is the natural defense mechanism against viruses in plants, animals, and fungus. Biotechnologists used this technique for their own benefit. They manipulate the viral genome through this technique and made the plant resistant to disease. They diminish the expression of viral genome by DNA methylation and by post-transcriptional gene silencing (PTGS). In DNA methylation, a methyl group is attached to a gene of viral coding protein and restricts its transcription. In PTGS, dsRNA molecule is produced by the cell itself or can be inserted in the cell from outside. This dsRNA form dicer with microRNA and cut the mRNA of virus which is to be translated for disease-causing infectious protein. Thus, by using the RNAi technique, the viral genome of begomovirus is degraded and its expression is suppressed.
Genetic Variability, Heritability and Genetic Advance of Kabuli Chickpea (Cic...Premier Publishers
The present study was carried out to assess the extent of genetic variability among yield and yield related traits in selected kabuli chickpea genotypes. Forty-nine kabuli chickpea genotypes were studied for thirteen traits at Debre Zeit and Akaki using 7x7 simple lattice design in 2018 cropping season. Combined analysis of variance revealed that there was a significant difference among genotypes for all traits studied, indicating the presence of considerable amount of variability among genotypes. High Phenotypic coefficients of variation and moderate genotypic coefficients of variation value were shown for number of pods per plant and number of seeds per plant, respectively, indicating the possibility of genetic improvement in selection of these traits. High broad sense heritability coupled with high genetic advance were obtained for hundred-seed weight (91.88 and 23.81), number of pods per plant (68.07 and 28.13), number of secondary branches (80.92 and 27.80), number of seeds per plant (67.86 and 31.840), grain yield (62.33 and 24.42) and harvest index (75.70 and 28.17), respectively. This indicates that these characters could be improved easily through selection.
MLN Incidence and Impact in Uganda, presented at the International Conference on “MLN Diagnostics and Management in Africa,” organized by AGRA (Alliance for Green Revolution in Africa) and CIMMYT, 12-14 May, 2015
We evaluated the oviposition preference and damage capacity of Spodoptera frugiperda on the different phenological stages of corn. Tests were performed at the Assis Chateaubriand Agricultural School (07º10'15" S, 35º51'13" W, altitude 634 meters), municipality of Lagoa Seca, Paraíba State, Brazil, in two areas of 500 m2, with CMS maize hybrid strain and maize intercropped with bean with the spacing of 0.80 x 0.40 m. Eggs and caterpillars were collected weekly on 50 plants randomly sampled in five spots. Height and number of leaves per plant, and damage from caterpillars of S. frugiperda were recorded using the scale, the rangers were., 0) no damage, 1) leaf scraped, 2) leaf pierced, 3) leaf torn, 4) damage in cartridge, 5) cartridge destroyed. The average number of clutches did not differ significantly among the three phenological stages of the culture, but average clutch size (number of eggs) was significantly smaller for the stage of 4-6 leaves. However, there was a significant interaction with respect to the number of clutches between position in the plant (lower, middle, and upper) and phenological stage, and between leaf surface and phenological stages. There were significant differences among tillage systems for corn in monoculture and corn intercropped with bean.
ABSTRACT- Corynespora leaf fall (CLF) disease of rubber incited by the fungal pathogen Corynespora cassiicola is
one of the major threats for natural rubber cultivation in rubber growing regions of India. The CLF disease occurs
regularly in rubber plantation during dry period after re-foliation and intensity rise during March to April and subsides
during wet months. Study was undertaken to investigate on survival mechanism of the pathogen in rubber plantations over
the seasons. The results of the studies revealed that the pathogen survived up to 11 days in infected leaf litter and showed
good growth on potato dextrose agar medium. The pathogen was able to survive on intact infected leaves on the plant and
also on plant debris as thick dark brown dormant mycelium under the bark of dried infected twigs.
Key Words: Corynespora leaf fall, Corynespora cassiicola, Hevea brasiliensis, Survival
Ijaar vol-15-no-5| Analysis of the population structure 2015 Puccinia gramini...Innspub Net
N Wheat (Triticum astevium) production in Kenya has been severely affected by stem rust Ug99 and its related race groups. The consequence of not controlling this disease is steep decline in the crop production thus creating food insecurity to over 70% of the small-scale holder farmers who depend on it as a source of food as well as income. The causative agent of the disease Puccinia graminis f. sp tritici (Pgt) has been studied by researchers globally because of its rapid evolution of races within lineage overcoming existing resistant genes. Understanding the population structure will highlight the predominant race(s) as well as their geographical distribution. This information is required to enable breeding for resistant wheat varieties. The objective of this study was to characterize the population structure of Puccinia graminis f. sp tritici population in 2015. Using 10pgt Simple Sequence Repeats (SSR) markers 104 single uredenial-pustule samples were analysed. Minimum spanning network pattern was composed of five Simple Sequence Repeats multi-locus genotypes (SSR-MLGs) that were organized around three nodes based on samples chosen from wheat growing fields with the reference isolates; races TTKSK and TKTTF. In addition to this, non-parametric DAPC analysis showed the presence of single population made up of two predominant races from clade I (Ug99 race group) and clade IV-B (race TKTTF/TTTTF). Analysis of molecular variance (AMOVA) according to Bayesian Information Criterion showed clustering was majorly based within populations (0.576%) rather than among clusters (0.441%).
Whitefly is a known pest of economic importance in the cassava production systems of Africa. This pest has been reported to cause losses to cassava through direct feeding damage as well as vectoring cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Serangium parcesetosum is a known predator of whitefly (Bemisia tabaci) and previous screenhouse and laboratory studies reported that temperature affected the reproduction and survival of this predator. However, these findings lacked precision since they did not depict the field situation. In that regard, it was imperative to initiate a study to help understand the influence of abiotic factors especially temperature and rainfall on the population of S. parcesetosum in the cassava growing fields of Uganda. The study was conducted in two agro-ecological zones of Uganda, namely; North Western Savannah Grassland (Lira) and the Kyoga Plains (Kamuli) in the first rains of 2017. Results revealed that temperature caused an increment of 3.5%, 9.1% (Kamuli) and 1.1%, 1.8% (Lira) for mean adult and larvae S. parcesesotum per plant respectively. On the contrary, rainfall caused a decrease in the population of S. parcesesotum in Lira. Generally, the effect of both temperature and rainfall on the predator population in the field was minimal.
Types and Percentations of Parasitization Egg Parasitoids Spodoptera frugiper...AI Publications
Corn (Zea mays L) is the main commodity of agricultural crops in Indonesia. There are two groups of corn that are cultivated, namely ordinary corn (food corn) and sweet corn. Food corn is mainly used as a raw material for making food, which is used as a raw material for making animal feed raw materials and other industrial products. Easy cultivation, can grow in various conditions, stable selling prices and easy to market are the main driving force for high interest of the farming community to cultivate it. Spodoptera frugiperda larvae are polyphagous and attack many plant species. S. frugiperda larvae feed on more than 350 species of plants in 76 families. S. frugiperda is a typical migratory pest and this migratory behavior is an adjustment strategy to find a more profitable habitat. S. frugiperda is one of the most dangerous invasive pests due to its short life cycle. An adult female lays 900 – 1200 eggs in her life cycle. The purpose of the study was to inventory and analyze the egg parasitoid of S. frugiperda and the percentage of parasitization The analysis of the types of egg parasitoids of S. frugiperda was carried out through an inventory and identification process, while the percentage of parasitization was carried out using a randomized block design consisting of 5 treatment groups of eggs from 5 regions and three replications. The results of the inventory and identification contained two types of parasitoids, namely: Telenomus sp. and Trichogramma sp. The highest percentage of total parasitization was from Manado City at 85% and the lowest was from Bolaang Mongondow at 5%. Telenomus sp. higher percentage of parasitization than Trichogramma sp. Parasitization percentage of Telenomus sp. on eggs of S. frugiperda the highest came from Manado by 63% and the lowest came from Tomohon by 3%, while the percentage of parasitization of Trichograma sp. The highest came from Manado at 22%, and the lowest came from Bolaang Mongondow Regency at zero percent. In conclusion, there are 2 types of egg parasitoids in S. frugiperda eggs, namely the parasitoid Telenomus sp and the parasitoid Trichogramma sp., the percentage of parasitization of Telenomus sp. on eggs of S. frugiperda the highest sample from Manado and the lowest sample from Tomohon. Percentage of parasitization of Trichograma sp. the highest sample of S. frugiperda eggs from Manado, and the lowest sample from Bolaang Mongondow.
Evaluation of rice genotypes for resistance to the stalk-eyed fly (Diopsis lo...Innspub Net
Globally, rice production is limited by abiotic and biotic factors. Of the insect pests attacking rice, the stalk-eyed fly is the most abundant. Major rice growing districts in Uganda are affected, and varieties grown by farmers are susceptible. The objective of this study was to identify sources of resistance to stalk-eyed flies among improved rice genotypes in Uganda. Fifty genotypes from the Africa Rice Centre, IRRI, South Korea and the National Crops Resources Research Institute (NaCRRI) in Uganda were screened under cage and field conditions at NaCRRI. Trials were laid out in an alpha lattice design, with 3 replications, for both experiments. Natural infestation (D. longicornis or D. apicalis) was used in the field while cage trials utilized artificial infestation with D. longicornis. Data on deadhearts were collected from seedling to tillering stages, at 7, 14, 21 and 28 days. Analyses of variance were performed using restricted maximum likelihood. Infestation levels for 31 (62%) rice genotypes were the same under both field and cage conditions, 4 (8%) genotypes showed higher susceptibility in the cage than in the field and 15 (30%) were more resistant in the cage than in the field. Genotypes NERICA 4, TXD306, NM7-22-11-B-P-1-1 and K85 were identified as the most resistant varieties. F3 genotypes (GSR IR1- 5-S14-S2-Y1 x K85, Gigante x NERICA4, NERICA4 x Gigante, NERICA1x NERICA4, NERICA4 x NERICA6, and NERICA4 x SUPA) were also found resistant. These genotypes were recommended for release and further advancement, respectively.
Achievements and outcomes in implementation of Napier smut and stunt resistan...ILRI
A presentation prepared by Pallangyo B., Maeda C., Nsami E., Proud J., Hanson J. and Katagira F. for the ASARECA/ILRI Workshop on Mitigating the Impact of Napier Grass Smut and Stunt Diseases, Addis Ababa, June 2-3, 2010.
Genetic Variability and Morphological Diversity among Open-Pollinated Maize (...Premier Publishers
A study to characterize and determine the magnitude of genetic variation among 60 open-pollinated maize varieties was conducted at two contrasting locations in Sierra Leone during the 2015 wet cropping season. Results revealed that traits such as grain moisture content, anthesis-silking interval, plant and ear heights, number of ears harvested, field weight and grain yield showed moderate to high values of the components of genetic variation while days to 50% anthesis and silking revealed low values of the components of genetic variation. The first two PCA axes explained 54% of the total variation, of which the first principal component (PC1) accounted for 35% and PC2 contributed 19% of the total variation. The cluster diagram grouped the genotypes into seven main clusters and results suggest that crosses involving clusters I and V with any other clusters would produce segregants with low grain yields while the crosses between clusters IV, VI and VII would be expected to manifest higher heterosis and could result in segregants with higher grain yields. There was significant genetic variability observed among the genotypes evaluated thereby suggest the scope to bring about traits improvement of genotypes through direct selection and hybridization.
Insect pest diversity of standing crops and traditional pest management in ag...AI Publications
The mountain farming communities of the Garhwal Himalaya rely on a conventional approach to agriculture to meet their subsistence needs. The resilience of local crop varieties plays a significant role in crop productivity in the indigenous agricultural system. In such circumstances, the protection of the crop from insect pests becomes paramount. Traditional ecological knowledge plays a crucial role in safeguarding standing crops from production losses in an environmentally benign and sustainable manner. The investigators in this study have surveyed the Mandakini valley to document the indigenous practices undertaken by the farming folks to protect the crops from pest infestation in the region. These practices are discoursed here and, further, look into the potential of natural predators as bio-control. The findings indicated that pests from the order Coleoptera had the most species, followed by Lepidoptera and Hemiptera. Most of the pests in the study site were serious defoliators, damaging the young foliage of the crops. Some entirely fed upon their roots-stems, while the rest were leaf miners and sapsuckers, thus compromising the overall well-being of the plant. In a developing country like India, there is a lack of reliable data that sheds light on the annual crop losses incurred by these pests. Thus, it becomes pertinent to compute an overall estimate of crop losses at various stages of crop production, from seed storage to post-harvest times.
Influence of fertilizers on incidence and severity of early blight and late b...Innspub Net
The potato (Solanum tuberosum) production in the Far North Region, Cameroon is confronted with, diseases and pests. To improve the production of this plant, a study was carried out in Mouvou and Gouria to evaluate the impact of fertilizers on the development of late blight and early blight diseases of this plant. The experimental design used was a completely randomized block with 4 treatments: Mycorrhizae (MYC), NPK (20-10-10) chemical fertilizers, chicken droppings (CD) and a control (T). The plant material used was a local variety of potato (Dosa). Disease incidence and severity and rainfall were evaluated. Area Under Disease Progress Curve was calculated. At 60 DAS, mean incidences recorded for fertilizers were 5.7, 3.6, 1.8 and 0.8 % respectively for control, MYC, NPK and CD. In general, early blight severity decreased from 22.1% at 45 DAS to 0.3 % at 60 DAS. The highest AUDPC value of late blight at Mouvou site was observed in NPK treatment while potato in CD treatment had the lowest. The lowest AUDPC value of early blight was observed in CD treatment at both sites. AUDSIPC value for late blight was significantly higher in NPK treatment in both sites. The highest value of AUDPSIC of early blight was recorded in MYC treatment, 45 DAS in both sites. The average rainfall was higher in the Gouria site (716.5mm) than in Mouvou site (679 mm). The CD treatment can be recommended to the farmers for the phytosanitary protection of potatoes.
Fall armyworm infestation and management practices on maize fields of smallho...INNS PUBNET
Fall armyworm (FAW) is native to America and is currently affecting maize production in different parts of Africa, and recently reported in Tanzania. In the present study, FAW infestation levels and their associated management practices were investigated in 90 maize fields in the 18 villages in Arusha, Kilimanjaro and Manyara regions. Infestation levels were assessed using a scale of 0 (no damage) to 9 (100% damage), while the management practices information was collected through a survey and questionnaires from 210 maize growing farmers in the 18 villages. Results showed that all fields were infested by FAW at low (1-4) to moderate (5-7) damage levels. Arusha scored the highest (66.59% and 5.422) significant mean incidence and severity (P<0.05) respectively, followed by Kilimanjaro (52.96%, 4.756) and Manyara (52.64%, 3.989) regions. Variation in damage levels was also observed among villages, with means incidences ranging between 35.57% and 79.55%, and mean severity ranging between 2.333 and 7.267. Variation between regions and villages can be associated with farmer’s knowledge and FAW management practices. About 84.3% of farmers reported synthetic pesticides as the main management option, although the majority did not effectively apply them. Farmer’s recommendations include awareness creation on the FAW management, provision of effective pesticides and resistant maize varieties, and government intervention in the overall management of FAW. From the findings it is evident that sustainable integrated management strategies against FAW is urgent needed and this study serves as a stepping stone for the development of sustainable management options.
Similar to Diversity of plant parasitic nematodes associated with common beans (Phaseolus vulgaris) in the Central Highlands of Kenya |IJAAR (20)
Bioaccumulation of Lead (Pb) content in three species bivalves in Jakarta Ba...Innspub Net
Environmental pollution by heavy metals has become a serious problem in Jakarta Bay. Mobilization of heavy metals as a result of anthropogenic activities has caused the release of heavy metals into the environment, one of which is Pb. Several methods already used to clean up the environment from these kinds of contaminants, but most of them are costly and difficult to get optimum results. In addition heavy metal pollutans in the waters are very stable and tend to be persistent. Recently, bioaccumators is an effective and affordable technological solution used to extract or remove inactive metals and metal pollutants from contaminated soil and water. This technology is environmental friendly and potentially cost effective using bivalves. These study objectives to analyzed the Pb content of three species of Jakarta Bay bivalves. The results showed that Pb content in the Eastern and Western Season bivalve tissue was significantly lowest in P. viridis (0,166 ± 0,016μg/g dan 0,161 ± 0,155μg/g) compared the Pb concentration in A. antiquata (0,264 ± 0,015μg/g dan 0,247±0,044μg/g), and M. meretrix (0,270 ± 0,016μg/g dan 0,240 ± 0,053μg/g). In this study also showed that the concentration of heavy metal Pb in the bivalve shell of P. viridis was significantly lower than that of two species (A. antiquata and M. meretrix). Pb content in the Eastern Season bivalves did not significantly different from that in the Westerrn Season. This is caused by a weather anomaly where the rainy season occurs almos throughout year of 2020. The Pb content in the bivalves shell was significantly higher than in the body tissues. It is because Pb can replace calcium ions in the formation of animal bones or bivalve shells.
Interaction on the diet and substrate on the growth of Archachatina marginata...Innspub Net
Nine hundred juveniles of Archachatina marginata aged about two weeks, with an average live weight of 2.25 g with an average shell length of 20.12mm were monitored in culture for six (6) months on five types of substrates [S1 (soil collected in a cassava plantation: Manihot sp.), S2 (S1 with 10% oyster shell meal), S3 (S1 with 10% sawdust), S4 (S1 with 5% oyster shell meal and 5% sawdust) and S5 (uncultivated forest soil). Four diets including two industrial (D1 and D 2 of 12% and 16% calcium respectively) and two based on fodder (D3 and D4 based on leaves and fruit of the papaya (Carica papaya) on the one hand and a mixture of papaya leaves and taro (Xanthosoma maffafa) on the other hand, were used. In order to determine the best combinations inducing the best growth performance, 20 combinations were formed at the rate of 45 spat for each combination; three replicas of 15 spat each. This study showed that the combination of diet and livestock substrate influences the growth of Archachatina marginata. Although the best feed is D1 (74.68 g and 7.94cm) and the best substrate is S2 (77.12 g and 7.79cm), the best combinations are D2S3 (69.37 g and 7.47cm), D1S4 (74.68 g and 7.94cm and D4S2 (77.12 g and 7.79cm). The combined effect of the high level of dietary calcium and that of the culture substrate does not promote good growth of snails. This work will help improve the production of African giant snails and provide important data for anyone wishing to engage in the breeding of these animals.
Nutritional assessment status of adult patients with multiple sclerosis: A na...Innspub Net
No previous research has assessed the nongenetic factors, especially the nutrition status of MS patients in Arab countries. Hence, this study aims to assess the nutritional status of MS patients among Arab adults. This study is a nationally representative cross-sectional study using a structured, online self-administered, validated quantitative food frequency questionnaire (FFQ) from 13 Arab countries. All data analyses were performed using STATA 16.0 and R for statistical computing version 4.0.4. A total of 813 participants were surveyed, most of the MS participants were female (68.4%), married (58.5%), non-smoker (72.6%) and 53.3% were diagnosed with MS for up to five years. MS participants did not consume the DRI of both the macro and the micronutrients including the energy requirements, except the dietary intake of the sodium which was insignificantly different from the DRI. Results also showed that most participants rarely consumed the main food items including bread, cereals, and most types of meat. While, more than 50% of the participants consumed fruit, vegetables, all types of chicken, fish, fresh soup, rice, and egg up to 3 times per month. On the other hand, milk and milkshake were consumed rarely; while, tea and herbal teas were the most common beverages. Nutrient deficiencies are very common among MS Arab patients. The finding of this study can establish a base for the development of a nutritional program for MS patients in accordance with the recommended DRI.
Evaluation of Talisay (Terminalia catappa) nuts by-productsInnspub Net
Sensory evaluation or analysis is an invaluable tool in determining the consumers’ acceptability of a product developed and eventually its market success. This is a sequel test after the chemical analysis and microbiological procedures have been conducted. The study determined the level of acceptability of the by-product of Talisay (Terminalia catappa) nuts specifically; Talisay Nuts Polvoron, Glazed Talisay Nuts, and Sugar-coated Talisay Nuts using sensory evaluation as to appearance, taste, aroma, sweetness, and texture. The responses of the food inclined participants are described yielding from the Hedonic Tests conducted and statistically treated. Results concluded that the developed products are remarkably acceptable and marketable.
Germination and seedling growth of Moringa oleifera, Moringa stenopetala and ...Innspub Net
A germination test was carried out to identify plants that can germinate and survive in polluted soil (with and without ash) collected 2.5km east and 2.5km west, 20km west and 55km west (control) of the BCL Cu/Ni mine smelter in Selebi-Phikwe, Botswana. The experiment was carried out using Phaseolus vulgaris, Moringa oleifera and Moringa stenopetala. Soil acidity and heavy metal stress reduced germination percentage, coefficient rate of germination, root and shoot growth and dry weight, root: shoot, vigour index and tolerance index of all species. Percentage reduction followed the order 2.5km west < 20km west < 2.5km east < 55km west. Phaseolus vulgaris, Moringa oleifera and Moringa stenopetala germinated in all soils. Their ability to germinate in polluted soil indicates tolerance to heavy metal and soil acidity stress and so they have potential for use in phytoremediation of polluted soils around the mine. Phaseolus vulgaris had the highest overall germination performance but there was no significant difference between the Moringas. Application of coal fly ash increased all the germination parameters and so coal fly ash has potential for use in amending polluted soil around the mine for phytoremediation purposes.
Identification and marketing of Marantaceae in the Ndjolé area, in central Ga...Innspub Net
The forests of the Congo Basin cover an area of 200 million hectares, of which just over 10% is in Gabon. In this country, crop products and non-timber forest products (NTFPs) are abundant because of its favourable climate. There is significant biodiversity and great potential for non-timber forest products. This study is interested in the identification and the supply chain of the Marantaceae, one of these NTFPs of plant origin in central Gabon, whose exploitation is national. Through a survey of the main actors in the sector and field visits in the locality of Bifoun, it emerges the existence of three large groups of exploited marantaceae, whose harvest and transport are mainly done by women, in various containers. The storage of this NTFPs does not exceed four days, with the risk of losing its commercial value due to drying out. The uses of this resource are multiple: processing cassava, cooking food, making handicrafts, etc. The income it provides to producers is mainly use towards small family expenses but helps to monetize the rural world. The difficulties inherent in the distance from harvesting points, the low price of the product and the impossibility of long-term storage of the marantaceae leaves constitute a brake on the development of this activity. It would therefore be wise to envisage the domestication of the species listed for a sustainable use of this plant genetic resource.
Ethnobotany of Oyster nut (Telfairia pedata) in Northern Tanzania | JBES 2022Innspub Net
Telfairia pedata (Sims) Hook is an important native climber plant commonly grown in East Africa. It bears nuts which are eaten either raw or cooked and is consumed mostly by expectant mothers, and as cooking oil. The survey was conducted between September 2019 to February 2020 in Sambaa, Meru, and Pare communities of Lushoto, Bumbuli, Arumeru and Same Districts, Northern Tanzania to assess the ethnobotany of T. pedata from a sample of 346 respondents using semi-structured questionnaires. Results indicate that, 21% of respondents used T. pedata for cooking with other staple foods while 18% claimed that the nuts are used by pregnant and lactating mothers for medicinal and breast milk stimulation and nine (9) percent indicated that the nuts are used for cultural and ritual purposes. Despite its importance, the cultivation of T. pedata in the study area is declining and the gap why such decline is experienced needs to be answered in further studies. Secondly, respondents within the 36-50 age groups reported the greatest diversity of uses of T. pedata 51% compared with those aged below 36 years old 21% signifying that the traditional knowledge known by younger aged groups may be declining. Thus, this gap of traditional knowledge between the groups should be addressed in order to improve utilization and conservation of this seriously declining yet important nut in the study area and other places of Tanzania.
The amphibian’s fauna of a West African forest relict near a hydroelectric Da...Innspub Net
This study reports the amphibian’s fauna sampled from the Biodiversity Conservation Area of the hydroelectric dam of Soubré city (southwestern Côte d’Ivoire). This study aims to provide a better understanding of the diversity of amphibians in this relict forest of 200 ha, in order to assess the ecological health of this ecosystem for conservation and sustainable management perspectives. During dry season (from 26 February to 4 March 2018) and rainy season (from 17 to 23 June 2018), we recorded 14 species of anurans grouped into eight genera and six families. The study sites comprise an amphibian fauna consisting mainly of savannah specialists and degraded forest (64.28% of total species richness). Based on the IUCN Red List, all species recorded are of least concern. Also, these species are well distributed in the different regions of Côte d’Ivoire and Africa. Thus, it is necessary to monitor the ecology of the species and to protect subsequently the different habitats of this area.
Genetic parameter estimates and diversity studies of upland rice (Oryza sativ...Innspub Net
Dearth of well-articulated information on genetic parameter estimates and diversity of upland rice limits the genetic improvement of rice. This study assessed the genetic parameter estimates and genetic diversity among 40 rice accessions using 26 agro-morphological traits. The trial was conducted in 2020 at the Njala University experimental site using 5 × 8 triple lattice design. The agro-morphological traits were analyzed using various multivariate and genetic parameter estimate techniques. Classification based on qualitative and quantitative traits grouped the germplasm into ten and five distinct clusters, respectively. Genotypes Buttercup-ABC, Buttercup-RARC, Jewulay, NERICA L4, Ndomawai, Sewulie and Painipainie produced earliest days to heading (81.8–97.2 days) and maturity (111.2 – 120.7 days). Genotypes Jasmine (3.036 t.ha-1), Rok 34 (3.238 t.ha-1) and Parmoi (2.663 t.ha-1) exhibited the highest grain yields. Principal component analysis (PCA) of qualitative traits exhibited four principal components (PCs) with eigenvalues > 1.0 and cumulative variation of 68.04%, whilst the PCA of quantitative traits had five PCs accounting for 81.73% of the total genetic variation. The findings indicate the presence of enough variability that could be exploited for the genetic improvement of rice varieties and the studied traits can be used for selection. Leaf blade length and width, culm diameter at basal internode, culm length, days to 50% heading, flag leaf girth, panicle number per plant, grain yield, and 100 grain weight had high heritability and genetic advance indicating the presence of additive gene action. Findings are relevant for conservation, management, short term recommendation for release and genetic improvement of rice.
Valorization of the duckweed (Spirodela polyrhyza) in the feeding of mono sex...Innspub Net
In order to evaluate the effect of Spirodela polyrhiza using in diets of Oreochromis niloticus fingerlings, an experiment was conducted on the farm “Awara” in the village of Agongo in Sèmè – Kpodji during 70 days. The initial average weight of fry is about 1g. The stocking density was 13 fry / m². Three experimental diets made with local by-products were tested: T0 (0% S. polyrhiza Meal), T1 (5% S. polyrhiza Meal) and T2 (mixed feed composed of 70% T0 and 30% fresh S. polyrhiza). At the end of the experiment, the survival rate was 100% for all treatments. The best zootechnical parameters were obtained with T1 with a final average weight of 11.67 ± 2.52 g and a consumption index of 1.17 ± 0.30. The highest gross profit margin was also obtained with T1. The lowest economic profitability was obtained.
Anthropogenic noise reduces bird species richness and diversity along a Rur-u...Innspub Net
Urbanization is increasing rapidly in all parts of the world to accommodate the increasing human population but it is having a drastic effect on native flora and fauna. The present study was carried out across a three stage urbanization gradient in and around the city of Bilaspur, Chhattisgarh. Observations were made from September 2019 to February 2021 at the selected three sites during COVID 19 pandemic. Point count method was used for bird surveys and Sound pressure (Noise) measurements were made across the three selected sites. The Avian diversity was measured by total species richness, Fisher’s alpha diversity index and Shannon-Wiener diversity index. The Urban centre recorded the highest sound pressure and lowest Avian species richness but as we moved away from the urban centre the noise levels reduced and the avain species richness increased towards the rural areas. This is mainly due to many avian species avoiding urban areas because of increasing noise levels. We also found that the urban bird community is dominated by a few species whereas the rural bird community was much more diverse.
Construction health and safety model towards adoption | IJB 2022Innspub Net
This study aimed to assess the safety and health of contractors in Zamboanga Del Norte, Philip-pines, in terms of workforce, workplace, and work implements. It also aimed to evaluate compliance with occupational health and safety standards regarding occupational safety and health training, a health and safety plan, civil works activities, and heavy equipment operations. It combined quantitative research with a self-created questionnaire that explains and forecasts concepts that can be applied to other people and locations and objectively measures the variable(s) of interest, selected, constructed, and standardized with validity and reliability in mind. The findings revealed that respondents only partially adhered to construction safety and health in personnel, workplace, and work equipment. Occupational health and safety criteria were partially met in occupational safety and health training, health and safety plans, civil works activities, and heavy equipment operations. The Level of Compliance for construction safety and health was also partially met. As a result, it is advised that construction companies will adopt the revised construction safety model.
Chemical composition of essential oil compounds from the callus of fennel (Fo...Innspub Net
Fennel (Foeniculum vulgare Miller.), a herbaceous, perennial and aromatic from Apiaceae family, which is used for pharmaceutical, food, health and cosmatic are cultivated in different parts of Iran and much of the world. In this study, the amount of trans-anethole in callus gained from tissue culture of fennel six belonging to different regions of Iran and Turkey have been compared. Tissue culture is a randomized trial. Factor of evaluating in the first node (hypocotyl) has been as explants and hormonal composition of 2,4-D+Kinetin and NAA+BAP was used for callus induction. Callus extracts were extracted by using organic solvent and finally the effective compound was determined, using GC/MS. The results show that the highest percentage of essential oil compounds in callus of E,E 2,4-Decadienal of 46.22% and cineole were 1,8 of the 35.17 percent, respectively. Our results indicate that the derived callus from fennel plants in the MS environment and with herbal hormone has been able to produce volatile compounds.
Evaluation of some maize (Zea mays L.) genotypes for resistance to stem borer...Innspub Net
The field experiments were conducted at Agricultural Research Corporation (ARC) , Kassala and Gash Research Station Farm, Takro of, Sudan. During the two winter seasons (2016/017 and 2017/018) respectively to evaluate some grain maize genotypes for resistance to stem borer and identify the most tolerance of these genotypes to Stem Borer infestation. Thirteen (STB.G1, STB.G2, STB.G3, STB.G4, STB.G5, STB.G6, STB.G7, STB.G8, STB.G9, STB.G10, STB.G11) maize genotypes were used in this study: with two check of maize variety (check. 1(Mugtama45) and ckeck. 2 (Var.113),). The experiments were arranged in Randomized Complete Block design (RCBD) with three replications. The data collected were used in this study were : Germination percentages, plant population, plant height, ear height, ear length, days to 50% Tasselling, days to 50% silking, ear length, ear diameter, cob diameter, number of rows/ear, number of kernels/row, 100 Kernel weight and Yieldkg/ha. Results showed that the most encouraging genotypes (STB.G 11, STB.G10, STB.G 4, STB.G 6 and STB.G8) of maize production at Kassala state were obtained a high value for potential of grain yield (4132, 3723, 3611, 3302 and 3264kg/ha) respectively, and for the most important of yield components. Among the traits considered, the yield (kg/ha) was the most promising as an indicator of tolerance to stem borer infestation.
Impact of climate change on wheat yield using remote sensing technique | JBES...Innspub Net
The present study demonstrates the ability of GIS and RS in capturing the spatial temporal data. The changing climatic conditions in the country effects the agriculture. The impacts of climate change are not only restricted to the agricultural productivity of the Pakistan but changing climate also impose destructive impacts on the Land use change practices. Three districts of Punjab i.e. Attock, Multan and Gujrat were selected for analysis of climatic effect on wheat production. The time span that is used for analyzing the change in these areas was from 1999-2014. Climatic changes are not always negative ones but sometimes climatic changes are favoring the increased agricultural production. As the change in temperature and rainfall pattern affects the crop conditions, which changes the net production. It is concluded that for real time prediction of crop yield satellite remote sensing could be used for timely management of food crisis in Pakistan as well as in the world.
Extreme weather events and their impact on urban crop production: A case of K...Innspub Net
Extreme weather events are anticipated to increase the existing challenges and generate new combination of vulnerabilities, especially in developing countries. The agricultural sector is the most vulnerable due to overreliance on unpredictable rainfall. This study examined the impact of extreme weather events on urban crop production and the adaptation strategies applied by the farmers. Secondary data were collected through a literature survey and primary data were collected using structured interviews, observations and focus group discussions. A total of 108 crop farmers were interviewed in two wards of Kinondoni District. The Statistical Package for Social Sciences (SPSS) version 20 was used to analyze the data and Pearson Chi-square was used to test the statistical significance between variables. The study observed that, farmers perceived extreme weather events including floods (39%), extreme temperatures (36%), and drought (25%). These extreme weather events affected negatively crop production leading damaging of crops and low yields (38%), outbreak of crop pests and disease (38%), drying of water sources (20%), and loss of soil fertility (4%). Crop farmers used various adaptation strategies such as crop diversification (28%), the use of pesticides (23%), changing of cropping patterns and planting calendar (16%), irrigation practices (18%) and replanting (10%). The study recommends for adoption of new farming systems such as vertical farming systems for better output with the use of limited water and land resources.
Effectiveness of community forest association and water resource users’ assoc...Innspub Net
Catchment degradation has continued to occur globally albeit the presence of Community Forest Associations (CFA) and Water Resource Users Associations (WRUA). Similarly, Kilungu catchment area in Kenya is under the management of the Kenze (CFA) and upper Kaiti (WRUA). This paper examined Kenze CFA and Upper Kaiti WRUA activities by exploring their effectiveness in discharging their statutory functions. This was achieved by carrying out, an exploratory descriptive survey. Data was collected through questionnaires, focus group discussions, 10 key informants’ interviews and direct observations. Descriptive analysis was used. Information was presented in fig.s, tables and percentages. Results showed that upper Kaiti WRUA as more effective in catchment management at moderately (31%) and highly at (37%) as compared to CFA moderately (29%) and highly (5%). In terms of discharging of their statutory functions, Upper Kaiti WRUA was better at a rating of 27% (good) and 23% (very good) as compared to Kenze CFA which was rated at 3% (good) and 6% (very good). This study results implied that Upper Kaiti WRUA was more effective in all aspects of ensuring catchment management as opposed to CFA. In conclusion, a strategy of seizing the opportunities presented by the CFA of being empowered to perform all its activities as required by law with emphasis on the timely preparation and implementation of management plans and WRUA’s continuous improvement should be prioritized. The study recommends new initiatives that improve on the CFA and WRUA activities in order to effectively discharge on their statutory functions.
Smallholders socio-economic characteristics of oil palm value chain: Constrai...Innspub Net
The study on the Smallholders Socio-Economic Characteristics Oil Palm Value Chain: Constraints and Prospects was conducted in the Littoral region of Cameroon with the used of multi-sampling technique. The study made used of secondary and primary data sources. Data that were collected through survey involved the distribution of structured questionnaires to a sample of 400 smallholders who were purposively selected from two sub-divisions. The data collected through these questionnaires were analysed using Statistical Package for Social Science and Micro Soft Excel, and the interpreted resulted were presented using descriptive method, pie charts and in tables. Results indicated actors in the value chain were faced the constraints of inadequate capital, inadequate storage facilities, and fluctuation in market prices, inadequate roads, among others. Results further indicated that the activity was important as it provided opportunities such as job creation, health enhancement, education enhancement, income amelioration among others to the actors in the value chain.
Liming leads to high bean and maize yield on a strongly acid tea soil | IJAAR...Innspub Net
Acid soils are very common in tea zones. These soils have a pH below 5.0. Below this pH, not only do the soils exhibit toxicity of aluminum and manganese but are deficient of calcium, magnesium, phosphorus and molybdenum, hence becoming chemically infertile. Liming is one cheap way of reclaiming these soils. The staple food crops in these tea soils are maize and beans. However the effect of different liming levels on bean (Phaseolus vulgaris L.) and maize (Zea maiys, L.) yield on acid tea-growing ando-humic Nitisol had not before been investigated. A study was therefore conducted to determine the crop response to liming and the appropriate liming level for maize and bean crops in a tea zone soils. The experiment was carried out in Embu County, Kavutiri and Kianjokoma areas, Agro-Ecological Zone (AEZ) UM1. A randomized complete block design with four replications of each lime treatment was used at each site. Lime at rates of 0 (L0), 2.4 (L1), 6 (L2), 8 (L3) t/ha was broadcasted on to 4m x 4m plots and mixed into 0-15cm of soil. There was a significant response to liming for both maize and beans. The maximum maize and beans yield was attained at around liming level L2 (pH 5.5). Above this pH, yields started to decline. The study clearly shows the benefits of soil liming on strongly acid tea soils and also the importance of accurate lime applications.
Total phenolics and total flavonoids of extracts from freshwater Clam (Corbic...Innspub Net
The ethanol, ethyl acetate, and hexane extracts of the freshwater clam (Corbicula fluminea) were studied for the total phenolics and total flavonoids. Total phenolics and total flavonoids of the extracts were evaluated using Folin-Ciocalteau and Aluminum chloride colorimetric methods respectively. The findings showed that the total phenolics of the ethanol extract (1.67±0.28mg GAE/g of dried sample) were substantially higher than the total phenolics obtained from the ethyl acetate (0.70±0.00mg GAE/g) and hexane extracts (0.56±0.23mg GAE/g). While the total flavonoids in the ethyl acetate extract displayed a slightly higher total flavonoid (43.84±0.92mg QE/g of dried sample) relative to ethanol (30.41±1.34mg QE/g of dried sample) and hexane extracts (20.28±0.00mg QE/g of dried sample). Using ethanol, the highest yield for extraction was obtained. Ethanol is the best solvent among the three – ethanol, ethyl acetate, and hexane in terms of extraction yield and total phenolics. In addition, it can be inferred that the presence of significant amounts of phenolics and flavonoids suggests that freshwater clam is a promising source of antioxidants that provides nourishing proteins and oxidative stress remedies
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Diversity of plant parasitic nematodes associated with common beans (Phaseolus vulgaris) in the Central Highlands of Kenya |IJAAR
1. Int. J. Agron. Agri. R.
Waceke Page 62
RESEARCH PAPER OPEN ACCESS
Diversity of plant parasitic nematodes associated with
common beans (Phaseolus vulgaris) in the Central Highlands of
Kenya
J. W. Waceke*
Department of Agricultural Science and Technology, Kenyatta University, Nairobi, Kenya
Article published on January 30, 2018
Key words: Meloidogyne, Pratylenchus, Gall index, Disease severity, PPN densities
Abstract
Common beans (Phaseolus vulgaris L.) are the most important legume staple food in Kenya coming second to
maize. In Central Highlands of Kenya, the 0.4-0.5ton ha-1 output is below the genetic yield potential of 1.5-2ton ha-1
partly due pests and diseases. Plant parasitic nematodes (PPN) have been reported to cause yield losses of up to 60%
on beans. Though bean production is important in the Central highlands of Kenya, information on PPN associated
with the beans in the region is lacking. This study was therefore undertaken to establish the diversity of PPN
associated with common beans and to assess the root knot nematode damage on beans in the region. The study
covered 50 farms (32 in Kirinyaga and 18 in Embu Counties) distributed in eight localities namely Kibirigwi (L1),
Makutano (L2), Kagio (L3), Mwea (L4) and Kutus (L5) in Kirinyaga County and Nembure (L6), Manyatta (L7) and
Runyenjes (L8) in Embu County and covering three Agro Ecological Zones (AEZs); UM2 (L1, L2, L3 & L4), UM3
(L5, L7 & L8) and UM4 (L6) AEZs. Manyatta (L7) and Nembure (L6), had the highest and second highest gall
indices, respectively, while Kibirigwi (L1), Makutano (L2) and Mwea (L4) had some of the lowest gall indices. The
most common PPN in bean roots were Meloidogyne spp. Pratylenchus spp. and Scutellonema spp. with a frequency
of 94.38%, 78.25% and 59.13%, respectively. This further confirm the importance of these nematodes in bean
production systems. Upper Midland 3 (UM3) AEZs and UM4 had higher nematode population densities and
diversity than UM2. Disease severity and nematode composition and distribution were notably low in the irrigated
areas Kibirigwi, Kagio and Mwea compared to rain-fed areas such as Makutano, Nembure and Manyatta.
* Corresponding Author: Waceke J.W wanjohi.waceke@ku.ac.ke
International Journal of Agronomy and Agricultural Research (IJAAR)
ISSN: 2223-7054 (Print) 2225-3610 (Online)
http://www.innspub.net
Vol. 12, No. 1, p. 62-68, 2018
2. Int. J. Agron. Agri. R.
Waceke Page 63
Introduction
Common beans (Phaseolus vulgaris L.) are the most
important legume staple food in Kenya providing up
to 65 percent of the country’s national dietary protein
intake and 32 percent of caloric intake (Wortmann &
Allen 1994). Due to their capacity to fix nitrogen they
are frequently used in maize cropping systems as an
intercrop and reduces dependence on inorganic N
fertilizers (Rheenen et al., 1981). In the central
highlands of Kenya, though bean production is an
importance economic activity where it covers over
40000 hectares and, the yield of 0.5ton ha-1 is far
below the genetic yield potential of 2ton ha-1 (Katungi
et al., 2010). These low yields are attributed to low
soil fertility, diseases and insect pests as revealed by a
study conducted in 2015 in parts of the region
(Mwaniki 2015). The bean diseases were ranked as
the most important (87.5%), followed by low soil
fertility (52.5%), insect pests (50%), lack of quality
seed (17.5%), low market prices (12.5%) and erratic
weather patterns (10%) (Mwaniki, 2015). Although a
study on the distribution and population densities of
PPN associated with beans in Western Kenya revealed
that PPN are a big threat to bean production (Karanja
et al., 2003), studies conducted in the central
highlands of Kenya often overlook the impact on PPN
on beans production. In other regions, plant parasitic
nematodes have been reported to cause yield losses of
up to 60% with root knot nematodes being rated as
the most important (Talwana et al., 2016; Kavuluko et
al., 2010; Kimenju et al., 1999). In addition to direct
pathogenic effects on plants, the nematodes act
synergistically with other plant pathogens and pests
to form disease complexes that further impact
negatively on the crops. The nematodes also suppress
nodulation and therefore affect nitrogen fixation
(Kimenju et al., 1999). Information on PPN
associated with common beans in Central Highland of
Kenya is lacking. Further, due to the growing
importance of bean production in the region, it is
imperative that a study be undertaken assess the
diversity of PPN associated with beans in an effort to
applying sound management and control strategies.
This study was therefore undertaken to establish the
occurrence and diversity of plant parasitic nematodes
associated with common beans and assess the root
knot nematode damage on beans in the Central
highlands of Kenya.
Materials and methods
Study Area
The study was conducted in Kirinyaga and Embu
Counties in the Central Highlands of Kenya. These
counties lie on the foot of Mt. Kenya at 1280 - 2500m
above sea level. The climate is cool and humidsub-
humid with an annual mean temperature of 20-21C.
This region has a bimodal rainfall pattern with peaks
in May and November and a hot dry spell between
January and April. Average annual rainfall for this
area is 1250mm in the higher altitudes. In lower
altitudes the rainfall decreases and the rainy seasons
become shorter. Soils are deeply weathered volcanic
types mainly andosols in Upper Midland 2 (UM2) and
nitosols in Upper Midland 3 (UM3) and Upper
midland 4 (UM4) agro-ecological zones (AEZ)
(Jaetzold and Schmidt, 1983).
The study covered 50 farms (32 in Kirinyaga and 18
in Embu Counties) distributed in eight localities
namely Kibirigwi (L1), Makutano (L2), Kagio (L3),
Mwea (L4) and Kutus (L5) in Kirinyaga County and
Nembure (L6), Manyatta (L7) and Runyenjes (L8) in
Embu County. The farms were concentrated in the
UM2 (L1, L2, L3 & L4), UM3 (L5, L7 & L8) and UM4
(L6) AEZs where cultivation of bean is most common.
Though bean production is mainly rain fed, farms in
three localities; L1, L3 and L4 irrigate their crops
since most of them are under Kibirigwi and Mwea
Irrigation Schemes. In most farms, beans were inter-
cropped with maize.
Sampling
Samples were collected in the middle of the short rain
season October - November 2015. Ten bean and soil
samples per farm were taken at mid-season when the
bean plants were in the early poding stage. The farms
were selected with the assistance of the County
Executive Committee (CEC) offices in charge of
agriculture in the two counties. The plants were
gently dug out with a hand hoe taking care not to
damage the roots. Soil adhering on the roots was
3. Int. J. Agron. Agri. R.
Waceke Page 64
gently shaken off into a plastic bag, then the root
system was separated from the shoot system and
cleaned before assessing the gall index and extracting
the nematodes. The soil samples for each farm were
bulked, mixed thoroughly before taking a 1000cm3
for nematode assays
Assessment of disease severity
Nematode damage on the bean plant was assessed by
visually rating the roots for galls using the Bridge and
Page (1980) gall rating of 0-10 where 0= No knots on
roots; 1= Few small knots that are difficult to find;
2=Small knots only but are clearly visible and main
roots clean; 3= Some larger knots are visible and
main roots clean; 4=Larger knots pre-dominate but
main roots clean; 5=50% of roots infested and
knotting on parts of main root and reduced root;
6=Knotting on main root; 7=Majority of main roots
knotted; 8=All main roots knotted but few clean roots
visible; 9=All roots severely knotted and plants
usually dying and 10=All roots severely knotted and
no root system and plant usually dead.
Extraction of Nematode from bean roots
The cleaned root systems from each farm were cut
into 1cm long pieces, were well mixed before taking
two 5g sub samples. One sub -sample was oven dried
for 72 hours at 60C while the second one was used
for nematodes extraction using Maceration-Filtration
method (Hooper et al., 2005). The nematodes were
harvested after 48 hours and concentrated into 20ml
in vial bottles. Nematode population from each
sample was determined using a 1ml aliquot of a well-
mixed suspension pipetted into a Hawksley’s
nematode counter and enumerated under a Leica MS
15 dissecting microscope. Counting was repeated in
three aliquots and the mean recorded. Nematodes
extracted from the roots were expressed per gram dry
root weight. Nematodes were identified to genus level
using the morphological features. A photographic
record of the nematode genera was obtained using a
digital camera (Leica DFC 280) mounted on a
compound microscope.
Nematode extraction from the soil
Nematodes were extracted from a 200cm3-soil sub-
samples using the Modified Extraction Tray method
(Hooper et al., 2005) Nematode suspension from the
tray was sieved through a 38m sieve every day for 3
days. The nematodes were backwashed into a beaker
and concentrated into a 20ml suspension and placed
in vials. Nematodes were enumerated under a
dissecting microscope and density and frequency of
occurrence determined.
Results and discussion
Nematode galling index
The most distinct symptom of nematode damage on
the bean plants was root galling by Meloidogyne spp.
Root Knot nematode damage levels varied in the 8
localities with Manyatta (L7) and Nembure (L6),
having the highest and second highest gall indices,
respectively. Kibirigwi (L1), Makutano (L2) and Mwea
(L4) had some of the lowest gall indices of 1.17, 1.25
and 1.3, respectively, that differed significantly
(p<0.05) from those in locality 7. Farms in localities
3, 5 and 8 had gall indices of 1.5 (Fig. 1).
‡ Gall index according to Bridge and Page (1980) galling
scale of 0-10 where 1= No galls; 2=1-5%; 3=6-10%; 4=11-
20%; 5=21-30%; 6=31-40%; 7=41-50%; 8=51-75% and
9=76% of root system and 10=All roots severely knotted
and no root system and plant usually dead.
Fig. 1. Mean Gall indices‡ on bean roots from farms
in eight localities of Kirinyaga and Embu Counties.
The significantly higher RKN gall indices Manyatta
could be due to the mixed crop farming (beans,
tomatoes, squash, egg plants) that is a common
practice in the area with most of the crops grown
being good hosts to root knot nematodes (Silva dos
Santos et al., 2012; Waceke & Chege In Press;
Weselmael & Maurice 2012). Further, the high RKN
disease severity in Manyatta and Nembure could be
4. Int. J. Agron. Agri. R.
Waceke Page 65
attributed to the susceptibility of the bean varieties
grown in the areas. GLP 2 (Rose coco), GLP24 and
GLP1004 bean varieties that are commonly grown in
the area are more susceptible to RKN than GLP 585
(Wairimu) and GLP 92 (Mwitemania) (Omwega et al.,
1989; Silva dos Santos et al., 2012; Weselmael &
Maurice 2012) grown in other localities. The relatively
low galling indices some localities could be due to the
relatively poor bean host of RKN namely GLP 585
(Wairimu) and GLP 92 (Mwitemania) that are grown
in the area besides the high use of pesticides and
organic and inorganic fertilizers. Farming in these
localities is semi – commercial unlike in other areas
where farming is purely subsistence.
The high nematode damage and population densities
could be due to poor agricultural practices (low or no
fertilizer or agricultural inputs and continuous bean
cropping (twice a year)) in the areas. This contributes
to the build -up of nematode levels over the seasons
beyond damage thresholds (Omwega et al., 1989). In
farms where fertilizers (organic or inorganic) were
used, lower gall indices were recorded. It has been
reported that application of organic amendments and
fertilizers increases growth and vigor of nematode
infected plant thus allowing the host to tolerate
nematode attack (Rheenen et al., 1981) while organic
matter in the soil allows nematode antagonists to
compete successfully and attack nematodes (Waceke
and Waudo 2002).
Diversity and Density of PPN associated with beans
roots
The most common plant parasitic nematodes
encountered in bean roots were Meloidogyne spp.
Pratylenchus spp. and Scutellonema spp. with a
frequency of 94.38%, 78.25% and 59.13%,
respectively (Table 1).
Table 1. Percent Frequency of occurrence of plant parasitic nematodes in bean roots obtained from 8 localities in
Kirinyaga and Embu Counties.
Nematode genus Kibirigwi Makutano Kagio Mwea Kutus Nembure Manyatta Runyenjes
Meloidogyne 100 100 100 78 98 85 100 94
Pratylenchus 80 86 88 37 93 84 80 78
Scutellonema - 63 24 62 90 74 80 80
Hemicycliophora 26 - 21 - - - - -
Hemicycliophora spp was present in two localities;
Kibirigwi and Kagio with a frequency of occurrence of up
to 26%. Meloidogyne, Pratylenchus and Scutellonema
spp. have been reported to be the major nematode
genera associated with beans in different parts of the
country and so the findings of this study corroborates
with the findings by Kimenju et al., 1999.
Roots of bean supported higher densities of
Meloidogyne spp than Pratylenchus spp.in all the
localities except Nembure where the density of lesion
nematodes was more than double that of the root
knot nematodes (Table 2). The differences in the
densities of the two nematodes in bean roots could be
attributed to the difference in their mode of feeding
(lesion nematodes are migratory endoparasites while
root knot nematodes are sedentary endoparasites and
to the susceptible bean genotype. The bean genotypes
grown in the area are more susceptible to root knot
nematodes than lesion nematodes (Waceke et al.,
2007; Waceke and Chege 2017 In Press).The
relatively high densities of Pratylenchus in Nembure
could be attributed to the presence of coffee and
maize in most of the farms where beans were
intercropped with them (Waceke and Arim 2017; Arim
et al., 2006; Katungi et al., 2010). Coffee and maize are
good hosts of Pratylenchus spp and coffee being a
perennial crop, it support the continuous growth and
reproduction of the lesion nematodes. Further, lesion
nematodes are polyphagus except P. goodeyi which
infects only bananas. The impact of the two
ectoparasites; Scutellonema and Hemicycliophora on
bean production needs to be further investigated.
Overall farms in Kutus, Runyenjes and Manyatta had
some of the highest nematode densities in bean roots
while Mwea, Kibirigwi and Kagio had some of the
lowest densities (Table 2).
5. Int. J. Agron. Agri. R.
Waceke Page 66
Most of the farmers in the irrigation schemes
concentrated in Mwea and Kibirigwi localities are semi
commercial farmers and use pesticides, organic and
inorganic fertilizers and practice good crop husbandry in
their production systems that could have reduced the
nematode population (Wortmann & Allen 1994).
Disease severity and nematode composition and
distribution were notably low in the irrigated areas (L1,
L3 and L4) compared to rain-fed areas (L2, L5, L6, L7
and L8). This supports the observation that disease
severity is more pronounced under conditions of water
stress (Rheenen et al, 1981; Wortmann & Allen 1994).
Table 2. Mean Nematodes densities per g dry root weight of bean root in 8 localities in Kirinyaga and Embu Counties.
Nematode genus Kibirigwi Makutano Kagio Mwea Kutus Nembure Manyatta Runyenjes
Meloidogyne 33.6 76 47 18.4 113.4 36.2 97.4 104.8
Pratylenchus 8.4 16.6 16.2 12.6 29.8 84 17.4 34.8
Scutellonema - 13.8 2.4 6.8 20.6 7.4 20.2 12.8
Hemicycliophora 5.2 - 4.2 - - - - -
Total 47.2 106.4 69.8 37.8 163.8 127.6 135 152.4
Diversity and density of PPN in soil
Eleven PPN genera namely Meloidogyne spp.
Pratylenchus spp. and Scutellonema spp.,
Helicotylenchus spp., Paratylenchus spp.,
Tylenchorynchus spp., Tylenchus spp.,
Hemicycliophora spp., Hoplolaimus spp., Trichodorus
spp. and Xiphinema were encountered in bean
rhizosphere soils (Table 3) underscoring the importance
of PPN in crop production systems. Pratylenchus spp,
Meloidogyne spp, Scutellonema spp and Paratylenchus
spp, some of the most frequently encountered had an
overall percent occurrence of 100%, 97%, 73% and 63%,
respectively (Table 3). All the 11 genera were present in
three of the localities; Kibirigwi, Kutus and Nembure.
This could be attributed to the diversity of the crops
grown in these localities (Katungi et al., 2010). Kagio
had the lowest diversity of nematodes with seven out
of the 11 genera being isolated from the farms in this
locality (Table 3).
Table 3. Percent frequency of occurrence of PPN in soil obtained from 8 localities in Kirinyaga and Embu Counties.
Nematode genus Kibirigwi Makutano Kagio Mwea Kutus Nembure Manyatta Runyenjes
Meloidogyne 100 100 100 78 100 100 100 100
Pratylenchus 100 100 100 100 100 100 100 100
Scutellonema 70 63 51 78 81 78 80 60
Helicotylenchus 80 38 23 22 82 62 40 21
Paratylenchus 50 78 50 57 46 60 80 81
Tylenchohynchus 70 25 - 38 82 40 62 42
Tylenchus 81 18 - 12 48 79 60 -
Hemicycliophora 31 16 22 - 63 15 - -
Hoplolaimus 33 - - 36 46 23 60 96
Trichodorus 72 24 - - 100 62 63 40
Xiphinema 30 17 50 20 65 38 19 43
Six of the 11 genera; Meloidogyne, Pratylenchus,
Scutellonema, Helicotylenchus, Paratylenchus and
Xiphinema were encountered in all the farms
underscoring the importance of PPN in agriculture. The
rich biodiversity could be due to mixed cropping systems
in most of the localities (Kavuluko et al., 2010).
The three localities in Embu (Nembure, Manyatta &
Runyenjes) had some of the highest nematode
densities in the soils and nematode diversity (Table 3)
while Kagio and Mwea had some of the lowest
densities (Table 4).
Table 4. Mean population densities of dominant plant parasitic nematodes recovered from 200cm3 of soil samples.
Nematode genus Kibirigwi Makutano Kagio Mwea Kutus Nembure Manyatta Runyenjes
Meloidogyne 266 227 184 158 264 838 602 487
Pratylenchus 272 224 201 175 222 491 359 285
Scutellonema 38 75 28 60 77 155 174 69
Paratylenchus 34 74 29 37 27 101 97 92
Helicotylenchus 80 43 11 8 72 72 18 14
Total 690 643 453 438 662 1657 1250 947
6. Int. J. Agron. Agri. R.
Waceke Page 67
The high nematode densities in these areas could be
attributed to the mixed cropping practiced in the
area while the low nematode densities in Kagio and
Mwea could be attributed to the application of
pesticides and other inputs. Crop production in this
area is done on a semi- commercial basis and so
application of pesticides and other inputs is
relatively a more common practice than in other
study areas. Some of the farms in these areas were
formerly rice paddies and therefore the flooding
previously done could have contributed to the low
nematode densities. It is notable that these areas
had also the lowest nematode diversity (Table 3).
High counts of lesion nematodes (Pratylenchus spp.)
recovered from both the soil and root samples further
confirm their association with bean plants. (Wortmann
& Allen 1994)). Scutellonema spp., found in most of the
localities is a polyphagous genus associated with a wide
range of plant species including maize and beans
(Rheenen et al., 1981). Dominance of Meloidogyne
species in all the localities may be attributed to the
presence of beans, a suitable host and other alternative
hosts (including weeds) and continuous cropping. The
wide diversity of nematodes identified from the
sampled farms could be due to mixed cropping systems
(Rheenen et al., 1981).
Considering the AEZs in relation to the species
composition and structure of the nematode
communities, UM3 and UM4 had higher nematode
population densities. This could be due to differences
in soil properties and mixed cropping systems
common in these AEZs as previously reported by
(Wortmann & Allen 1994). Disease severity and
nematode composition and distribution were notably
low in the irrigated areas Kibirigwi, Kagio and Mwea
compared to rain-fed areas such as Makutano,
Nembure and Manyatta. This supports the observation
that disease severity is more pronounced under
conditions of water stress (Rheenen et al., 1981).
Conclusion
Manyatta (L7) and Nembure (L6), had the highest
and second highest gall indices, respectively while
Kibirigwi (L1), Makutano (L2) and Mwea (L4).
The study revealed high densities of lesion nematodes
(Pratylenchus spp.) and root knot nematodes
(Meloidogyne spp) in bean roots and soil. Upper
Midland 3 (UM3) AEZs and UM4 had higher nematode
population densities and diversity than UM2. Disease
severity and nematode composition and distribution
were notably lower in the irrigated areas compared to
areas where bean production relies on rain
Recommendation
Continuous production of susceptible bean varieties
should be minimized to reduce PPN population build
up and minimize the detrimental effects on the beans.
Further selection of the varieties to be grown in the
area should be done carefully. Appropriate measures
should be incorporated in the bean production
systems to reduce the high densities of lesion
nematodes (Pratylenchus spp.) and root knot
nematodes (Meloidogyne spp).
Acknowledgement
I acknowledge the Rockefeller Foundation for funding
this project, the farmers for allowing the collection of
samples from their farms and Kenyatta University for
providing office and laboratory spaces.
References
Bridge, Page. 1980. Estimation of Root-Knot
Nematode Infestation Levels on Roots Using a Rating
Chart. Tropical Pest Management 26(3), 296-298
Hooper DJ, Hallmann J, Subbotin SA. 2005.
Methods for extraction, processing and detection of
plant and soil nematodes. In: Plant Parasitic
Nematodes in Subtropical and Tropical Agriculture
2nd edition. Luc. M., Sikora, R. A. and Bridge, J.
(Eds), pg 53-80. CAB international, Oxfordshire U.K.
Jaetzold R, Schmidt H. 1983. Farm Management
Handbook of Kenya. Vol. III Ministry of Agriculture
Nairobi Kenya.
Karanja NK, Kimenju JW, Macharia I, Muiru
DM. 2003. Plant parasitic nematode associated with
common bean (Phaseolus vulgaris L.) and integrated
management approaches. African Crop Science
Journal 11, 503-510.
7. Int. J. Agron. Agri. R.
Waceke Page 68
Katungi E, Farrow A, Mutuoki T, Gebeyehu S,
Karanja D, Alemayehu F, Sperling F, Beebe S,
Rubyogo RC, Buruchara R. 2010. Improving
common bean productivity: an analysis of socio-economic
factors in Ethiopia and Eastern Kenya. Baseline Report
Tropical legumes II. Centro Internacional de Agricultura
Tropical - CIAT. Cali Colombia.
Kavuluko JM, Gichuki C, Waceke JW, Runo
SM. 2010. Characterization of root-knot nematodes
(Meloidogyne spp.) from selected legumes in Mbeere
District Kenya using isoenzyme phenotypes. In
“Transforming Agriculture for improved livelihoods
through Agricultural Product Value Chains: The
Proceedings of the 12th KARI Biennial Scientific
Conference”8- 12th Nov 2010 Nairobi Kenya Pg. 92- 97.
Kimenju JW, Karanja NK, Macharia I. 1999.
Plant parasitic nematodes associated with common
beans in Kenya and the effect of Meloidogyne
infection on bean nodulation. African Crop Science
Journal 7, 503-510.
Mwaniki A. 2015. Assessment of Bean Production
Constraints and Seed Quality and Health of
Improved Common Bean Seed. African Crop Science
Journal 13, 116-121.
Omwega CO, Thomason IJ, Roberts P, Waines
CG. 1989. Identification of new sources of resistance
to the root knot nematodes in Phaseolus. Crop
science 29, 1463-1468.
Rheenen HA, VanHassebach OE, Mungai SGS.
1981. The effects of growing beans together with
maize on incidence of bean diseases and pest.
Netherlands Journal of Plant pathology 87,193-199.
Silva dos Santos LN, Alves FR, Belan LL,
Cabral PDS, Matta FP, Junior WCJ, Moraes
WB. 2012. Damage quantification and reaction of
bean genotypes (Phaseolus vulgaris L.) to
Meloidogyne incognita race 3 and Meloidogyne.
javanica. Summa Phytopathol Botucatu 38, 24-29.
Talwana H, Davis KG, Waceke JW, Sibanda Z,
Manzanilla-Lopez R, Kimenju JW, Nessie DL,
Masawe C. 2016. Agricultural nematology in East and
Southern Africa: Problems, Management Strategies
and Stakeholder linkages. Pest Management Science
72, 226-245.
Waceke JW, Arim JO, Waudo SW, Kimenju
JW. 2007. Impact of some soil fertility management
practices on lesion nematodes of maize in Kenya.
First Biennual Meeting of the Regional Universities
Forum for Capacity Building In Agriculture, 23-27
April 2007, Mangochi, Malawi pp 179-186.
Waceke JW, Arim OJ. 2017. Management of lesion
nematodes on maize using green and cattle manures in
the Central Highlands of Kenya. International Journal of
Agriculture, Environment and Bioresearch 2(6), 52-66.
Waceke JW, Chege FN. 2017. Response of
common beans to a mixed population of Meloidogyne
javanica and Meloidogyne arenaria (Root Knot
Nematodes) In Central Highlands of Kenya. In Press.
Waceke JW, Waudo SW. 2001. Effect of time on
efficacy of organic soil amendments against
Meloidogyne incognita on okra. East Africa
Agriculture and Forestry Journal 67(1), 19-29.
Wesemael WM, Maurice M. 2012. Screening of
common bean (Phaseoulus vulgaris L.) for resistance
against temperate root-knot nematodes (Meloidogyne
spp). Pest Management Science 68, 702-708.
Wortmann CS, Allen DJ. 1994. Africa bean
production environments: their definition,
characteristics and constraints. Network on Bean
Research in Africa, Occasional Paper Series No.11,
CIAT, Dar-es-saalam.