Studies on thermal use efficiency, heliothermal unit and photothermal unit of rice (Oryza sativa L.) cultivars under varying crop growing environment

A field experiment was conducted during kharif season2018 entitled “Studies on thermal use efficiency, heliothermal and photothermal unitof rice (Oryza sativa L.) cultivarsunder varying crop growing environment.” in sandy loam soil of N.D. University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.). The experiment consisted of nine treatment combinations comprised of three transplanting dates viz. July 15th, July 25th and August 04th and three varieties viz., NDR-97, NDR-2064 and BPT-5204. Results reveal that different phenophases of rice markedly varied with only dates of transplanting but also different weather variables which ultimately create the different crop growing environment to harvest the yield accordingly. Highest thermal use efficiency (TUE) was recorded in crop growing environment on July 15that all the stage, followed by July 25th, among the cultivars highest thermal use efficiency was recorded with BPT-5204, followed by NDR-2064.Maximum heliothermal unit was recorded in crop growing environment on July 15th at both the stages vegetative and reproductive stage followed by July 25th. Maximum photothermal unit was recorded in crop growing environment on July 15th at both the stages, followed by July 25th at vegetative and reproductive stage and among the cultivars in BPT-5204.