Comparative response of rice cultivars to elevated air temperature in Bhabar region of Indian Himalaya: status on yield attributes.

Increasing atmospheric temperature is the consequence of global warming, which is expected to influence crop growth and development, resulting in declining productivity in the tropical agriculture system. The selection of temperature tolerant crop cultivars with higher productivity to meet the future demand of the world expanding human population requires a thorough understanding of crop growth feedback to increasing temperature. Therefore, a field experiment was conducted during season of 2012 and 2013 to understand the response of yield and yield-related traits of eleven rice cultivars to elevated temperature grown inside field mounted temperature gradient tunnel (TGT) in the Bhabar region of the Indian Himalayas. The elevated temperature significantly impacted growth and yield and yield-related traits, especially tillers, panicles, filled and chaffy grains, grain, and 1000 grain weight, yield, and harvest index of all the cultivars during both years. The cultivars, IET 21404 and IET 21577, were reported to produced more tillers in 2012, whereas IET 21411 and KRH 2 had a maximum 2013. Likewise, maximum panicles were reported in IET 21404 and IET 21577 in 2012, while IET 21411, IET 21582, and KRH 2 in 2013 under elevated temperature. The highest grain filling under high temperature in 2012 was found in IET 21577, then IET 21404; however, IET 21411 and IET 21405 were the highest filled grains in 2013. Consequently, the cultivars IET 21577 and IET 21404 were reported as more tolerant towards yielding higher grain weight and Harvest Index. This study offers an opportunity to screen temperature tolerant cultivars with increased productivity for fulfilling the demand of rice-dependent regions in future changing climatic conditions.