Application of AMMI for Grain Yield Stability Analysis in Large Speckled Bean Genotypes Grown in Midlands of Bale Zone

Genotypes–environment interaction was studied for grain yield of seventeen large speckled bean genotypes at Goro, Ginnir and Dellomena in the midlands of Bale zone for two consecutive years 2016 to 2017 main cropping season. Randomized complete block design with four replications was used for this study. Plot size of 6.4m2 (4 rows at 40cm spacing and 4m long) was used at all the tested locations. Yield stability is one of the setbacks facing plant breeders in developing widely adapted varieties with superior yield. The present study was carried out to investigate theeffect of genotype by environment (GxE) on the yield stability of speckled common bean using seventeen genotypes in six environments (Locations x years combination). The combined analysis of variance for mean grain yield revealed that highly significant variation for year, environment, genotypes, and Genotype by environment interaction. It revealed that 34.16% of the total variation was attributed to environment effect followed by genotypes 11.84%, and genotypes by environment interaction 2.97%. On the other hand the AMMI analysis for the grain yield revealed that 69.75% of the variation was due to environment effect followed by Genotypes (24.18) and GE (6.07%). AMMI 1 component explained 61.64% of the total interaction sum squares whereas AMMI 2 accounted for 38.36% of the variation. Of the tested genotypes G5 and G11 showed consistent stability across the testing environments showing slop value close to unity and deviation from regression near to zero with high mean grain yield. Therefore, these two genotypes were identified as candidate varieties to be verified in the coming cropping season for the possible releases in the midlands of bale zone and similar agro-ecologies