Impact of Weather Variables on Phenophase and Yield of Kharif Rice (Oryza sativa L.) in Central Zone of Kerala

Rice is the most commonly consumed crop worldwide, serving as a staple food for almost half of the global population. A field experiment was conducted at the Agricultural Research Station, Mannuthy, Kerala Agricultural University, Kerala during kharif season 2023 to assess the impact of weather variables on the growth, development and yield of two short-duration rice varieties, Jyothi and Manuratna. The study revealed that the duration of phenophases varied significantly depending on planting dates and weather conditions. Jyothi variety took longer duration to reach physiological maturity compared to Manuratna. Maximum and minimum temperatures during active tillering to panicle initiation (P2) and heading to 50% flowering (P5) stages had a negative influence on phenophase duration for both varieties, while rainfall positively impacted the duration of active tillering (P1) and physiological maturity (P6). Grain yield varied significantly with planting dates. The higher temperatures during critical growth phases have resulted in reduced yield. Bright sunshine hour positively influenced the yield during 50% flowering to physiological maturity in Manuratna.