The adaptation of winged bean (Psophocarpus tetragonolobus (L.) DC.) in Papua New Guinea

Abstract

Thirty genotypes of winged bean were grown in five diverse environments in Papua New Guinea in order to estimate the genotypic, environmental and genotype-environmental variance of grain yield and pod number per plant, seed number per pod, 20-seed weight, pod length and shelling percentage. A maximum grain yield of 2200 kg ha^-1 was realized. Environmental and genotypic variance contributed 69.9 and 0.3% respectively to the overall variance of grain yield. A significant genotype x environment interaction for grain yield was adequately explained by joint regression analysis. Correlation studies emphasized the importance of testing genotypes in both the highlands and lowlands. Variation in grain yield was largely due to fluctuations in pod number. Grain yield and pod number showed strong negative genetic correlations with seed number per pod, 20-seed weight and pod length.