Seed yield is a complex quantitative trait, hence the knowledge of interrelationship between contributing characters and yield is pre-requisite to plan meaningful crop improvement program. A total of 64 bread wheat genotypes were planted at Werer Agricultural Research Center during 2019/20 to assess associations of traits and their direct and indirect effects on grain yield under both optimum and drought stress conditions. Under optimum condition biomass yield, harvest index, fertile tiller plant-1 and spike length showed positive and highly significant correlation with grain yield at genotypic and phenotypic level. Under stress condition the same four traits including number of spikelets spike-1 showed positive and highly significant correlation with grain yield at genotypic and phenotypic level. In the path coefficient point of view, under optimum condition, biomass yield (0.864, 0.819) followed by harvest index (0.627, 0.626) exerted the highest positive direct effect on grain yield at genotypic and phenotypic level respectively. Under stress condition biomass yield (0.784, 0.765) and harvest index (0.405, 0.214) exerted strong and moderate positive direct effect on grain yield at genotypic and phenotypic level respectively. This suggests that biomass yield and harvest index having significant positive correlation and high direct effect on grain yield indicated the true relationship and the direct selection of the genotypes through these traits is effective for yield for the area.
Keywords: Bread wheat, correlation, path coefficient, drought stress