Early generation selection in durum wheat

The F₂ generations of 10 crosses of durom wheat were screened under irrigated condition. The F₂ plants were categorised as high, medium and low yielders on the basis of yield/plant. The 150 F₃ and 150 F₄ families of these plants were evaluated In augmented design In normal and late sown conditions. The contingency χ² test revealed close correspondence in the yleid performance of F₂ plants and F₃ families under late sown condition, and F₃ and F₄ families under both conditions. However, such correspondence was not witnessed in F₂ vs. F₄ performance. The narrow-sense heritability estimates for different characters exhibited marked variation across environments and crosses. Two crosses, HD 4571 x JU 12 (85.7%) and HD 4502 x POW 109 (70.0%) exhibited high heritability under normal sown conditions for days to heading and 1000-grain weight, respectively. However, maximum heritability for grain yield was recorded in the cross HD 4571 x JU 12 (43.2%). In late sown condition yield/ear and grain no/ear showed low to moderate narrow-sense heritability estimates, while other characters exhibited high heritability estimates.