Abstract

Yam is an important staple in Africa, but the availability is constrained by the gradual decline in varietal productivity due to repeated cycle of cultivation. To improve yam productivity, breeders have developed several new varieties of yam, however, their adaptability and resistance to major yam diseases needs to be assessed in different location to select the best stable varieties. This study thus evaluated the agronomic performance and yield stability of sixteen elite white yam (D. rotundata) genotypes across three locations in Southern Nigeria. A randomized complete block design with two replications was used at each location. Data were collected on total tuber yield, dry matter content (DMC), stems per plant, Yam Mosaic Disease (YMV), and Yam Anthracnose Disease (YAD). Combined ANOVA revealed significant (p<0.05) environmental effects for all traits, with Ibadan location producing 3.1 times higher yield (31.5 t/ha) than other locations. Genotypic effects were significant for all traits, while genotype × environment interaction (G×E) was non-significant for yield (p=0.157), DMC (p=0.326), and stems per plant (p=0.167), but significant for average_YMV (p=0.0039) and average_YAD (p<0.0001). TDr19153013 ranked highest for yield (25.6 t/ha) with good DMC (29.8%), while TDr19153001 had highest DMC (30.5%). AMMI analysis showed IPCA1 explained 82.6% of G×E variance for yield and 78.4% for DMC. The study identified and recommended TDr19153013, TDr19162008, and TDr19171003 as superior genotypes to farmers for adoption in the study area.