Response of Wheat Genotypes to Sowing Time and Different Environments

Assessing grain yield of a set of cultivars in multi environmental trial, changes are commonly observed in the relative yield performance of genotypes with respect to each other across environments. Understanding the causes of G × E interaction, establishing specific breeding objectives and to identify desirable genotypes ninteen wheat genotypes along with a check cultivar were evaluated under normal and late sowing conditions for yield quantification, heritability and selection response. Analysis of variance showed highly significant differences (P<0.01) for spikes m^-2, grain yield and harvest index, while significant differences (P< 0.05) were observed for spikelets spike^-1 and grains spike^-1. Rest of the traits showed non-significant differences. The environmental component revealed highly significant differences (P<0.01) for all the traits except for grain weight spike^-1, which exhibited significant differences (P< 0.05). However, the GxE interaction showed significant differences (P<0.01) only for harvest index. Our results indicated that some bread wheat genotypes performed well under late sowing conditions. Therefore, these genotypes can be used for late sowing in multiple cropping regions or they could effectively be utilized in breeding program to transfer these characters to those varieties which do not perform well under late sowing. Heritability estimates for all yield contributing traits were greater in magnitude under late sowing condition revleaved that selection will possibly be more effective under late sowing environment to reduce the existing gap between normal and late sown wheat crop.