Grain Yield Stability of Ethiopian Mustard (<i>Brassica carinata</i> A. Braun) Genotypes Using AMMI Analysis in the Highlands of Bale, Southeastern Ethiopia

Abstract

The presence of significant G*E for quantitative traits such as yield can seriously limit the feasibility of selecting superior genotypes. Thus, the purpose of this study was to investigate grain yield stability and genotype X environment interaction for fifteen Ethiopian Mustard genotypes (Brassica carinata A. Braun) conducted in the highlands of Bale, Southeastern Ethiopia for three consecutive years (2018 to 2020) at two locations, Sinana and Agarfa. Randomized Complete Block Design with four replications was used. The combined analysis of variance for grain yield indicated highly significant interaction (P<0.01%) for genotypes, genotype X environment interaction, and environment. The analysis of variance for AMMI for grain yield revealed highly significant interaction for genotypes, genotypes X environment interaction, and environment. It was observed that 44.84% of the variation in grain yield was accounted by environment, 37.54% for genotypes by environments, and, 17.62% was for genotypes. The first and the second IPCA components with degree freedom of 34 was accounted for 67.64% of the interaction effect and revealed the two models were fit. Genotype G12, G11, G8, and G1 showed the lowest AMMI Stability Value (ASV) indicating stability. Furthermore, Genotypes G11, G12, G5, and G8 have the lowest GSI value indicating high stability. However, out of these genotypes, G11 showed a high mean grain yield with a yield advantage of 25.8% and showed the lowest GSI value compared to overall genotypes and the checks used in the study. Therefore, G11 was identified as a candidate genotype to be verified in the coming main season of 2022/23 for possible release for the highlands of bale zone, Southeastern Ethiopia, and similar agro-ecologies.