Genotype x environment interaction: adaptation of wheat in the non-conventional areas in Kenya
Eight wheat genotypes were planted in seven environments in 1989 and 1990 to test the significance of genotype x environment interaction and the adaptability of wheat genotypes in non-conventional wheat growing areas in Kenya. Yield component factor analysis was tested to find the best yield predictors among seven yield-related traits. Analysis of variance was carried out in each of the seven environments and combined over all the environments. Correlation and path effect analyses were performed on all the eight genotypes. Stability tests were also carried out on all the parameters. Significant genotype x environment interactions were observed among the genotypes on most of the variables tested. Stability tests showed that Mbuni recorded higher mean seed yield than the grand mean in five of the seven environments but its stability was low (b=~.55, S~a =300.43). ST 46 recorded the highest mean seed yield over all the environments and was relatively stable (b=1.21). CM 64593 was the most stable for seed yield among the genotypes tested and was well adapted but its yield performance was below the grand mean. This study suggests that wheat can be grown economically in the non-conventional areas in Kenya. The factors identified to have high direct correlation with yield were tillers per plant, plant height, spikelets per head, seeds per head and kernel weight. Plant height and tillers per plant showed high total correlation with yield. Maturity was indirectly correlated through other factors.