Evaluation of Improved Yam Varieties for Yield and Adaptation in Ekiti State

This study evaluates improved yam varieties for tuber yield and adaptability to the agro-climatic conditions of Ekiti State, South West Nigeria. Yam is a culturally important and commercially significant crop in Ekiti State, but productivity has stagnated due to reliance on local varieties with poor yield potential and susceptibility to anthracnose and viral diseases. Improved varieties developed by IITA offer substantially higher yield and disease resistance, but their performance under Ekiti State conditions requires local validation. This study establishes a randomised complete block design experiment at Ekiti State University Ado-Ekiti research farm, evaluating five IITA-improved yam varieties: TDa 98-01176, TDa 95-310, TDa 291/2, TDa 00/00356, and Amaechi (local control) from the white yam Dioscorea rotundata group. Sprouting percentage, vine length, number of leaves, tuber number, tuber weight, and total fresh tuber yield are assessed at harvest. Disease incidence and severity ratings are conducted throughout the season. Findings reveal that TDa 95-310 produces the highest tuber yield of 26.4 tonnes per hectare, 58 percent above the local Amaechi variety at 16.7 tonnes per hectare. TDa 00/00356 shows the lowest anthracnose severity score of 1.8 on a five-point scale. All improved varieties show significantly higher sprouting rates than the local variety. The study concludes that TDa 95-310 is the most productive variety for Ekiti State conditions and recommends integration of this variety into the state yam development programme.

Keywords: yam varieties, tuber yield, adaptation, Ekiti State, IITA varieties.