This document summarizes disease control and pest management strategies for cassava production. It discusses the need to increase cassava yields to meet growing demand. The main challenges are poor adoption of improved varieties and threats from pests and diseases. It outlines the major cassava pests and diseases found across different regions. Effective management requires an integrated approach considering genotype, environment, and agronomic practices. Clean planting material and surveillance are important to control diseases like cassava mosaic and brown streak viruses.

2. Disease Control and Pest Management in Cassava Production Lava Kumar , R. Hanna, P. Kulakow, J. Legg, E. Kanju, P. Ntuhunguru and N. Mahungu International Institute of Tropical Agriculture E-mail: L.kumar@cgiar.org; www.iita.org

5. Genotype Environment Management Biotic stresses Abiotic stresses GEM factor on cassava yield Pests Diseases Planting material E Cassava yield M G

8. Cassava die-back caused by Collectotricum gloeosporioides Leaf spots caused by Collectotricum gloeosporioides

9. Cassava bacterial blight (CBB) Xanthomonas axonopodis pv manihotis Leaf spots caused by Cercospora caribea

10. Brown leaf spot Cercospora henigsii Super Elongation ( Sphaceloma manihoticola- Elsinoe brasilensis) Source: E. Alvarez, PD 87

11. Severe mottling and leaf distortion on indicator clone Secundina grafted on infected stake (leaves from buds on rootstock show no symptoms) Source: Dr L.A. Calvert, CIAT Frog skin disease (FSD)

13. Whitefly ( Bemisica tabaci ) Pest and important virus vector Sooty mould

14. The viruses of cassava in Africa African cassava mosaic virus (ACMV) Indian cassava mosaic virus East African cassava mosaic virus (EACMV) South African cassava mosaic virus (SACMV) East African cassava mosaic Cameroon virus East African cassava mosaic Malawi virus East African cassava mosaic Zanzibar virus East African cassava mosaic Kenya virus EACMV-Uganda (recombinant virus) Cassava brown streak virus ( Ipomovirus ) Cassava brown streak Uganda virus Cassava Ivorian bacilliform virus* Cassava Kumi virus* Cassava ‘Q’ virus* Cassava common mosaic virus* ( Potexvirus ) CMGs CBSV

15. ACMV only ACMV+EACMV

16. ACMV+EACMV ACMV+EACMV

17. Movement of CMBV’s in SSA Source: Ndunguru et al. 2005

19. CMG Distribution - 2004

22. Farmer yields of improved and local varieties by state in SS and SE Nigeria

23. Cassava Mosaic Disease Severity Year of cloning Mean log(CMD severity) Genetic gain/year = 0.44% CMD decreased by 30.8% y = -0.0044x + 9.1817 R 2 = 0.1741 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 1970 1975 1980 1985 1990 1995 2000

26. Cassava brown streak disease

28. CBSD CBSD disguise ready detection

29. Near normal tubers, but server damage to root quality

33. CBSV CBSUV Two viruses

34. Difficult to diagnose CBSD

35. Cassava brown streak disease CMD CBSD CMD+CBSD

36. Simple diagnostics developed at IITA for simultaneous diagnosis of CMD and CBSD Lanes 1 to 4: CBSV infected samples Lane 5: Healthy cassava Lane 6: CMD infected cassava Lane M: Molecular weight marker (100 kb ladder) M 1 2 3 4 5 6 7 1 2 3 4 5 6 7 M 1 2 3 4 5 6 7 1 2 3 4 5 6 7 M CBSV-S1/S2 + CMB CBSV-L1/L2 + CMB Sap DNA & RNA Sap DNA&RNA EACMV ACMV CBSV

37. USAID project

39. Spiraling whitefly ( Aleurodicus dispersus ) Watch-out for new pests

43. Awareness creation

44. Planting material Tubers Starch Ethanol Quality planting material is fundamental to increase cassava productivity Quality planting material to manage biotic threats Poor quality No management Poor yield Crop Management Increase in yield Good quality

49. Knowledge on pathogens and their distribution Essential needs for germplasm monitoring Availability of diagnostic tools Capacity (human skills and infrastructure) Guidelines: FAO, IPPC, IAPSC, NPPO Funds

51. Scheme for CBSD-free planting material Variety No. of tested Number CBSV-free 1 MM06/0011 20 TC 15 2 MM06/0024 20 TC 10 3 MM06/0138 20 TC 3 4 MM06/0131 20 TC 3 5 MM06/0019 20 TC 9 6 MM06/0079 20 TC 11 7 MM06/0013 20 TC 1 8 MM06/0045 20 TC 20 9 MM06/0012 20 TC 20 10 MM06/0023B 20 TC 8 11 MM06/0139 20 TC 2 12 MM06/0124 20 TC 4 13 MM06/0112 20 TC 3 14 MM06/0076 20 TC 6

56. Sustainable production of quality planting material Need for sustainable clean seed systems Individual farmers, farmer groups Tertiary multipliers  1-2ha/ site  2ha/ site NGO’s, farmer groups Secondary multipliers Primary multipliers Research stations, NGO’s  10ha Foundation stock Research stations

58. IITA Campus - Ibadan Thanks for your attention [email_address] www.iita.org