On-Farm Evaluation of Promising Dioscorea alata Genotypes in the Forest – Savannah Transition Zone of Ghana

Dioscorea alata (L) is growing in importance in Ghana due to its long shelf life and its demonstrated potential use as a functional food to supplement the fiber and mineral needs of consumers. Research and development efforts on D. alata in Ghana are therefore on the ascendency. To exploit the genetic diversity of the crop, 49 genotypes of D. alata including 14 from IITA were evaluated on-station for three years. Using a selection pressure of 90%, the 4 best lines were evaluated on-farm under farmer-managed conditions in 12 environments in the Forest Savannah Transition agroecology of Ghana. The experimental design used was RCB with 3 replications in 3 locations for 4 years in the Forest-Savannah Transition agroecology. A local variety D. alata cv Matches was used as check. Highly significant (p < 0.01) differences were observed in pre-harvest factors such as virus and anthracnose tolerance. Postharvest factors such as yield, tuber texture, taste, aroma, and after-taste were also highly significant with texture being a very important in choice of materials by farmers. Genotypes TDa_00/0046 was the best genotype amongst the four genotypes evaluated, followed by TDa_01/0029, TDa_01/0004 and TDa_00/0003. The local check had good sensory attributes than some of the improved genotypes. Genotype TDa_00/0046, however, had sensory similar attribute to the local check. It is therefore the best candidate for release as a variety in Ghana.