Effect of high temperature and nitrogen stress on growth attributes of rice cultivars

A field experiments were conducted in a Temperature Gradient Tunnel (TGT) at the MB-4C farm of ICAR-Indian Agricultural Research Institute, New Delhi, during 2019 and 2020, focusing on rice crops. This study aimed to evaluate the impact of varying temperature conditions and nutrient treatments on the photosynthetic performance of rice at different growth stages, including tillering, panicle initiation, booting, flowering, and ripening. The results revealed significant variations in photosynthetic rates, with maximum values observed in treatments with higher nutrient levels (N1V6, N1V4) and minimum rates in nutrient-deficient conditions (N0V2, N0V1). Notably, treatment N1V6 consistently exhibited the highest photosynthetic rates across all growth stages. Additionally, the investigation of chlorophyll content (chl a+b) across various treatments N1V3 had the highest values at all growth stages, while N0V1 recorded the lowest. Overall, the findings underscore the critical role of temperature and nutrient management in optimizing photosynthetic efficiency and enhancing rice productivity in the face of changing climatic conditions.