Genotype x Environment Interaction and Grain Yield Stability Analysis of Soybean (Glycine max (L.) Merrill) Genotypes in Western Ethiopia

The performance of the genotypes depends on the genetic potential of the crop and the environment in which the crop is grown. The present study was aimed to identify and release of stable high yielding and medium maturing soybean variety with better agronomic performance in western Ethiopia. To this end, seventeen soybean genotypes including the standard check, Korme, were evaluated at three locations (Bako, Gute and Boshe) for two consecutive main cropping seasons (2017-2018). Additive main effect and multiplicative interaction (AMMI), Genotype and Genotype by environment (GGE) interaction biplot and regression analysis were computed using R- statistical software to identify stable genotype across locations in both years. The environment, genotype and genotype x environment interaction (GEI) effects were highly significant (p<0.001) based on combined analysis of variance and additive main and multiplication interaction (AMMI) model. The three models revealed similar result in that PM-12-20, PM-12-32, PM-12-18 and PM- 12-39 were stable and widely adapted genotypes. However, the genotypes PM-12- 31, PM-12-45 and PM-12-43 had higher regression coefficient (bi) value showing that these genotypes were sensitive to changes in environmental conditions and tend to give high yield at a favorable environment. Genotype PM-12-37, now named as Billo-19, was relatively stable and high yielding thus released for the western Ethiopian and other areas with similar agro-ecologies.