Abstract:
There are several production constraints which impede the maximum yield production of sorghum genotypes by farmers. The presence of genotype by environment interactions (GEI) and low stability of genotypes across locations are among the constraints. This study was conducted with the objectives of testing the stability of sorghum genotypes and estimating the magnitude of GEI for grain yield and their effects among correlation of yield related traits in different agro-ecologies of Amhara region. Nine sorghum genotypes were tested at six different locations in randomized complete block design with three replications during 2016 main cropping season. The main effects of location and genotype and GEI were very highly significant (P<0.001) for grain yield evaluated. The highest average grain yield was recorded from the genotype Melekam (4340 kg ha-1) followed by Mesay (3655 kg ha-1) and Girana one (3508 kg ha-1) across locations. The highly significant GEIs indicated that genotype performance was inconsistent across testing locations. Some univariate and multivariate stability statistics such as Kang’s yield stability index YSI, Additive Main Effects and Multiplicative Interaction (AMMI) Stability Value and GGbiplot model methods were conducted. Genotypes Melekam and Girana one were selected based on high yield and stability value for univariate stability parameters. Based on estimated AMMI parameters, Girana one and Melekam were best for grain yield and stability. Based on GGE biplot Melekam is recommended for most of locations because it was the winning genotype in most locations. Mesay had best association and was the winning genotype for location Belesa hence, it is recommended for this location. Generally, based on estimated AMMI, GGE biplot and univariate stability parameters, Melkam and Girana one showed best performance and stability across tested environments and are recommended genotypes for the test locations and similar environment areas. Finally, I suggest and conclude their was genetic variation among the genotypes and the diversity of the growing conditions which were significantly different in yield potential that showed the mean yield of genotypes differed across locations.
Key words: GEI, AMMI, ASV, YSI and GGE biplot, lowland, sorghum