Performance and adaptability of common bean genotypes at different agro-ecological environments in Kagera region

Abstract

Sixteen common beans (Phaseolus vulgaris L.) genotypes were used to study the genotype by environment interaction and grain yield stability. The randomized complete block design was used with three replicates. Data on yield were analyzed using additive main effects and multiplicative interaction (AMMI) model, genotype plus genotype by environment interaction (GGE) biplot model was used to display graphical representation of the yield data and the yield stability index (YSi). The analysis of variance of the AMMI model indicated that environments accounted for 56.9% of the total sum of square; genotypes effect explained 9.2% and the G x E interaction effect accounted 8.9% of the total sum of squares for the 16 genotypes tested across three environments and were all significant (P < 0.01). The average grain yield were 2.7, 1.38 and 1.20 t ha-1 for Karagwe, Bukoba and Muleba respectively. According the results, the GGE biplot revealed that, the genotypes SSIN 1240, SAB 659 and DAB 219, SMR 101, SMC 162 and DAB 602 showed greater stability with the average closer to the overall average of the tested genotypes. Therefore they are recommended to be used as varieties or parents for further improvement of available cultivars. Key words: Adaptability, Phaseolus vulgaris, Kagera, genotypes, environment.