Loss of cultivars in Yam (Dioscorea spp.): Case studies from Northern Ghana

Abstract

Yam, Dioscorea spp. is endemic to the West African sub-region, with nine species cultivated in Ghana. D. rotundata is the most popular of the yams in terms of area cultivated and usage. Study conducted in northern Ghana tried to determine reasons for loss or maintenance of landraces, as well as the best farmer practices that ensure their conservation, in four communities in northern Ghana under the traditional cultivation methods. The study also provided information on the diversity of yam landraces that are currently under cultivation. Field studies involved focus group discussions, using the four square analysis after Grum et al. (2008). Farmers identified 50 types of D. rotundata under cultivation. On average, older farmers cultivated a greater number of landraces than younger farmers. Ten traditional, cultural practices associated with yam cultivation were also identified by farmers, for ensuring diversity of yams within their farms. Threatened landraces were usually planted on very small farm areas by few households. Cultivation of some yam landraces was discontinued, mainly because of decreasing soil fertility and vulnerability to drought.