Genotype by Environment Interaction for Agro-Morphological Traits and Grain Yield Stability in Barley (Hordeum...

Barley production in the Ethiopian highlands is constrained by soil acidity and the lack of acid-tolerant genotypes. This study evaluated the effects of environment, genotype, and their interaction on barley performance and identified suitable genotypes for acidic soils. Ten barley genotypes, including eight accessions, one local variety, and one released cultivar, were tested under acidic and lime-treated soil conditions using a randomized complete block design. The results on the additive main effects and multiplicative interactions (AMMI) analysis showed that environment explained 60.45% of the total variation, genotype 32.38%, and genotype by environment interaction accounted for 7.18%. The first and the second interaction principal component axes were significant and cumulatively accounted for 80.59% of the total interaction variance. Analysis of the first two principal components showed that E7 and E8 in the Gumer district, representing fully limed and unlimed soils, respectively, contributed most to the genotype by environment interaction. In contrast, E5 and E6 in the Hulla district, representing unlimed and fully limed soils, respectively, contributed least, while E1-E4 had moderate effects. Grain yields in limed environments consistently exceeded the grand mean of 2.79 t ha^-1, whereas the unlimed environments produced substantially lower yields across. The first two AMMI components identified genotypes G1, G3, G9, and G10 as superior performers, combining high yield with stability. Therefore, expanding the cultivation of improved variety, G9, and further evaluating genotype G1, G3 and G10, and lime application could improve barley production and food security in the southern highlands of Ethiopia.