Comparative response of yield components in hexaploid triticale x breadwheat derivatives to contrasting soil phosphorus levels

The response of 23 derivatives of hexaploid triticale x bread wheat crosses at two contrasting levels of soil phosphorus was examined. High phenotypic variability was recorded in the two P environments for all the traits except early growth vigour (normal P level) and spikes/plant (P deficient). Grain yield/plant, followed by numberof tillers and spikes/plant, early growth vigour, and leaf area index were most sensitive to phosphorus-deficiency, which caused delayed heading and maturity and increased specific leaf weight. The heritability for grain yield was low under both the phosphorus levels, which necessitates the use of indirect selection parameters. The overall character association and path coefficient analysis revealed that selection for higher 1000-grain weight and increased number of spikes/plant in both the environments, whereas that for relatively taller plants under phosphorus deficiency could be useful for improvement in grain yield.