Diversity, distribution and management of yam landraces (Dioscorea spp.) in Southern Ethiopia

Abstract

Yam (Dioscorea spp.) is widely grown in many parts of Ethiopia and plays a vital role in local subsistence. Nevertheless, its diversity has not been studied in detail. A survey covering 339 farm households and eight districts was conducted in the major yam growing regions of Southern Ethiopia to investigate the diversity and distribution of yam landraces using structured and semi-structured questionnaires. A total of 37 named landraces were recorded, with a range from one to six (mean 2.9) on individual farms. Farmers’ decisions regarding the number and type of landraces maintained was influenced by tolerance of the landraces to drought, their maturity time and market demand. Most landraces had limited abundance and distribution, and only a few dominant landraces were widely grown. There was also variation amongst districts with respect to diversity, distribution and abundance of the landraces found. In the majority of the localities surveyed, farmers reported a decreasing trend in the number of landraces maintained on individual farms and in the overall yam production. Besides, in those limited areas where yam production is expanding, farmers are increasingly relying on a few selected landraces that mature early. Findings of this study suggest that local farmers in Wolayita and Gamo-Gofa zones maintain considerable yam diversity that remains to be further explored for sustainable utilization and conservation of the available genetic resources.