Effect of Weather in Relation to Dates of Sowing and Varieties on Productivity of Wheat (Triticum aestivum L.)

To assess the effect of thermal and radiation regimes on wheat a field experiment consisted of three dates of sowing starting from 20th November at fortnightly interval up to 20th December and three varieties of wheat, was carried out at Students Instructional Farm, C.S. Azad University of Agriculture and Technology, Kanpur (U.P.). The results showed that the wheat crop matured in 119 ± 8 days. Crop sown on early date took more thermal time as compared to other dates of sowing. The day length and bright sun shine hours also affected the occurrence of different phenophases of wheat cultivars. The heat use efficiency decreased with delay in sowing. The dry matter production was linearly related with accumulated heat units and HTU. Weather parameters viz., cumulative evaporation rate (r² =0.925), mean temperature (max.) (r² =0.912), mean temperature (min.) (r² =0.833) and cumulative heat (r² =0.590) were significantly positively correlated with the grain yield.