Genotype – genotype × environment (GGE) biplot analysis of winged bean for grain yield

The winged bean is an underutilized legume that is adapted to the tropics. It has good prospects as a significant multi-purpose food crop including human nutrition, cattle feed, and environmental protection. However, little research attention has been given to the crop to address the identified constraints, especially low yield in Nigeria. To improve its yield potential, GGE biplot analysis was used to identify high-yielding and stable winged bean genotypes, previously collected from the continent of Asia, and Nigeria for yield improvement. Twenty winged bean genotypes were being evaluated under the rainfed condition at three locations (Ibadan, Ile-Ife, and Kishi) for two years, comprising six environments. The obtained results showed that the seed yield (SY) ranged from 805.61 kg.ha⁻¹ (Ibadan) to 1,096.35 kg.ha⁻¹ (Kishi), with SY of 988.42 kg.ha⁻¹ across the locations. The winged bean reached its first flowering, 50% flowering, 50% podding, and 70% physiological maturity in 74, 80, 93, and 137 days after being planted, respectively across the locations. The GGE biplot analysis showed that the principal component (PC) axes captured 71.5% of the total variation, where PC1 and PC2 were responsible for 36.6% and 34.9%, respectively. Genotype, environment, and their interaction had a significant effect on SY. Environments IB20 and IF20 were adjudged the most ideal environments to discriminate between the genotypes. Genotype Tpt-12 was identified as high-yielding and stable. Tpt-12 would be recommended for commercial farming in southwestern Nigeria. The selected high-yielding winged bean genotypes are hereby recommended as promising parental lines for the grain yield improvement in the winged bean improvement programs.