Grain Yield Performance and Stability Analysis of Sesame (Sesamum indicum L.) Genotypes in Western Tigray, Ethiopia

The experiment was carried out in three different locations (a total of 7 environments) of Western Tiray, Ethiopia from 2011-2013 cropping seasons and thirteen sesame genotypes were evaluated. The objective of this study was to estimate the stability of sesame genotypes and to determine the association of the stability parameters and sesame seed yield. The design was a randomized complete block design with three replications and a total plot size of 14m2. The Additive Main effects and Multiplicative Interaction (AMMI) model for grain yield noticed significant effects of the genotypes (37.3 % sum of squares (SS)), environments (29.5 % sum of squares) and Genotype x Environment interaction (25.9 % SS). The AMMI model extracted five significant interaction principal component analysis (IPCA) with a total of 96.9 % SS and 90.3% corresponding degrees of freedom. According to the total rank value (TR), G12, G11 and G4 were the furthermost stable and widely adapted genotypes respectively, where as G8 and G9 were the furthermost unstable genotypes. Grain yield was positively associated with all of the ranks of stability parameters at different significance levels. Grain yield (GY) had significant and positive correlations with YSI, Pi, S1 and CV. Regarding to the inter-parameter correlation coefficients, neither of the stability parameters were negatively correlated among each other. Environments E1, E2, and E4 were unfavorable environments; while E5, E6 and E7 were favorable environments and E3 was moderately favorable environment for most of the genotypes.