GENOTYPE X ENVIRONMENT INTERACTION AND YIELD STABILITY FOR COMMON BEAN (PHASEOLUS VULGARIS L) IN RAYA VALLEY, TIGRAY, ETHIOPIA

Abstract

Nine common bean genotypes were evaluated at two different environments in Raya valley of southern Tigray, Ethiopia for three consecutive years during 2016-2018 main cropping seasons. The aim of the study was to determine the effect of G × E interaction and to identify the best adaptable varieties for selection environments and yield stability. The study was conducted using a randomized complete block design with 3 replications. Combined analysis of variance for grain yield and most of yield component traits showed highly significant (p ≤ 0.01) differences among the genotypes, environments and for GEI effects. This indicated that the tested environments have an influence on the selected varieties differentially responded to the changes in the test environments. As a result, environment two was identified as more favourable to common bean production, despite some varieties were showed good performance in some traits at both locations. But, no single variety is found that generally superior in all evaluated traits across all locations and years. However, the varieties “Nasir, SAR-119, Awash-2 and SAR-125” were the better performed with yield from combined analysis of 20004.47 kg/ha, 1979.83 kg/ha, 1843.1kg/ha and 1791.49 kg/ha, respectively, followed by genotypes of Awash-1 [1548.93 kg/ha] and Awash Melka [1525.11 kg/ha]. Generally, the application of combined analysis facilitated the visual comparison and identification of superior genotypes, thereby supporting decisions on common bean variety selection and recommendation in tested environments.