Yield Stability for Some Selected Drought Tolerant Sorghum Genotypes in Dry Lowlands of Ethiopia

Sorghum [Sorghum bicolor (L.) Moench] called as camel of crops due to high tolerance of prolonged drought, has been cultivated for millennia. Thus, this study aimed to identify high yielding and stable drought tolerant sorghum genotypes in the dry lowland areas of Ethiopia. The field experiment was conducted during the 2016 cropping season using a randomized complete block design with three replications across six environments. The combined analysis of variance result revealed highly significant (P≤0.01) difference among genotypes (G), environments (E) and genotype by environment interactions (GEI) for grain yield. Melkam was found to be the highest yielding genotype followed by Meko-1 with mean grain yield of 3650 and 2932 kg ha-1, respectively. GGE bi-plot stability model was used to identify stable genotype for partitioning the GEI into the causes of variation and the best multivariate model in this study. The first two principal components explaining significant shares 97.83% (PC1=93.26% and PC2=4.57%) of the total variation caused by GGE for gran yield. Besides, the which-won-where bi-plot classified the study areas into a unique (same) mega-environment with the winning genotype Melkam. Therefore, the GGE biplot identified Melkam variety as stable and high-yielding genotype owing to consistent performance across the test environments (dry lowland agro-ecologies) of Ethiopia.