Mitigation Strategies of Heat Stress in Wheat (Triticum aestivum L.) through Adjustment in Sowing Temperature and Application of Bio-regulators

Abstract

ABSTRACT Global warming, as a result of climate change, may destructively affect wheat yield potentially increasing food insecurity and poverty. The field experiments were laid out during two consecutive rabi seasons of 2016–17 and 2017–18 at Sri Karan Narendra Agriculture University, Jobner, Jaipur, Rajasthan, India, to enhance wheat growth, quality, and productivity. The present experiment consisted of three sowing at different thermal environments (22°C, 20°C and 18°C) in main plot and eight foliar sprays of bio-regulators (control, water spray, salicylic acid @ 100 ppm, salicylic acid @ 200 ppm, thiosalicylic acid @ 100 ppm, thiosalicylic acid @ 200 ppm, thioglycolic acid @ 100 ppm, and thioglycolic acid @ 200 ppm) in subplot were set in a split-plot design with four replications. The pooled data indicated that crops are sown at 20°C (D2) attained maximum growth parameters i.e. (total number of tillers per square meter and plant height), heat indices (GDD and CTD), quality parameters (chlorophyll content of flag leaf stage, crude protein content in grain and protein yield), and yield (grain, straw and biological), also proved significantly superior over D1 (sowing at 22°C) and D3 (sowing at 18°C). The data further indicated that the above parameters were measured significantly higher in B4 (SA @ 200 ppm), which excelled over rest of the treatments. Therefore, enhancement in yield requires improved agronomic practices i.e. application of SA @ 200 ppm along with crop sowing at 20°C temperature in order to sustain enhanced productivity under heat stress.