Indigenous Knowledge and Management of Yam (Dioscorea Cayenensis –Dioscorea Rotundata Complex) Pests and Diseases in Northern Benin.

Yam (Dioscorea spp.)production in Northern Benin is severely affected by pests and diseases resulting in poor yields and cultivars diversity loss in spite of the importanceof thiscommodity.In order to develop efficient integrated pestsand diseases management approaches, twenty seven (27) villages of the yam production zone of northern Benin were surveyed using participatory research appraisal to document farmers’indigenous knowledge, and traditional management practices of yam pests and diseases. Results indicated that farmers have good knowledge of the yam pests and diseases that were even reported as the third most important production constraints in the study area. Among the pests and diseases nematodes, termites, mealybugs and wilt diseases were the most signaled. Farmers surveyed have traditional methods for mealybugs but nothing for the other pests and diseases apart from the use of resistant/tolerant cultivars. An undetermined disease locally called Ban was reported as expanding at alarming rate throughout villages and yam fields seriously affecting the food quality of the tubers. Urgent intervention zones were identified with multivariate analysis and recommended to the national protection service. The sensitization of the yam producers of the necessity of treating both soil and tuber seeds before planting, the development and the use of pests and diseases tolerant cultivars were proposed as management strategies. Also, the extension of the study to other yam producing regions of the country for identifying more cultivars tolerant to pests and diseases was recommended.

Production Constraints and Farmers’ Cultivar Preference Criteria of Cultivated Yams (Dioscorea Cayenensis - D. Rotundata Complex) in Togo.

Fifty (50) villages randomly selected throughout agroecological zones in Togo were surveyed, using participatory approach, to identify and prioritize factors that affect production and farmers’ varietal preference criteria of Guinea yam (Dioscorea cayenensis-D. rotundata complex). A total of nineteen (19) constraints of varying importance across agro-ecological zones were identified among which the most important were insects’ damages on both leaves and tubers, nematodes attack on tubers, drought, soil poverty and wilting. For the majority (78.94%) of the constraints, the use of tolerant cultivars remains the most sustainable, economically profitable and environment preservative solution. Farmers’ cultivar preference criteria identified are many (24 in total). Among them, high productivity, good quality of pounded yam, resistance to drought and adaptability to all types of soils are the most important. A perfect match is noted between enumerated constraints and identified preference criteria. The knowledge of farmers’ selection criteria is of capital importance for breeders and also extension services for eventual yam cultivar exchange between agroecological zones in Togo.