Yield Stability Analysis of Soybean Varieties (early set) in Western Oromia, Ethiopia

Abstract

Over the decades, very limited early maturing soybean varieties were developed and released in Ethiopia. This experiment was conducted to  identify adaptable, high yielding and stable variety (s) among the released but potential early maturing soybean varieties for Western Oromia. The  influences of genotype by environment interaction on grain yield of soybean varieties were also examined. Seven early maturing soybean varieties  were evaluated at Bako for two years (2016 and 2017), at Billo and Gute during 2016, and at Chewaka and Uke during 2017 main cropping seasons.  Combined analysis of variance showed that grain yield was significantly (P< 0.01) affected by environments, genotypes and their interactions;  accounting for 51.1, 35.9 and 12.2% variations, respectively. The first two principal components (IPCA1 and IPCA2) were used to create a  two dimensional Genotype and Genotype by Environment (GGE) biplot and explained 84.49 and 9.1% of the total sums of squares of G x E  interaction, respectively. Soybean variety Nyala was identified as the most stable and high yielding genotype in the test environments. In addition,  Boshe and Coker-204 also showed better stability & high yield performance, whereas variety Nova was identified as the least stable and low  yielding. Therefore, among early set soybean varieties, Nyala, Boshe and Coker-204 were recommended for further demonstration and large scale  production in the test environments and similar agro-ecologies of western Oromia.