Evaluation of Wheat Varieties for Terminal Heat Stress under Varying Environments

Climate change and global warming have increasingly become relevant factors in recent years in determining the success of wheat production under heat stress conditions. Throughout its growth period wheat crop requires varying degrees of temperature to achieve ideal growth. Any variation from optimal temperature adversely affects plant growth and development. Many places where wheat is grown have high temperatures at the time of grain filling which is a major constraint on yield potential. A field experiment was conducted during the Rabi season of 2020-21 at Student’s Instructional Farm of Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya, Uttar Pradesh to evaluate the performance of wheat varieties under heat stress conditions. The treatment for the experiment consisted of sowing on three different dates i.e. D1 (30th November), D2 (15th December), D3 (30th December). It was observed that time of sowing decreased substantially almost all the yield components measured viz; number of ear bearing tillers per plant, number of grains per ear, ear length (cm), grain yield per plant (g), biological yield per plant (g), which caused severe reduction of yield in V1 (PBW-343) and V2 (HD-2967). This reduction was caused due to onset of high temperature during crop growth and particularly grain filling. Variety V3 (Halna) reduced the detrimental effect of heat stress by improving physiological traits which ultimately helped in obtaining higher yield.