Agricultural Research Journal

Climate change is having significant and observable impacts on both ecosystems and livelihoods, particularly in agricultural regions like Kerala. This study utilized the GFDL CM3 climate model to project future climatic conditions under RCP 4.5 and RCP 8.5 scenarios, indicating a marked temperature increase across the region. By mid- to late-century, the northern zone is expected to experience a temperature rise of 4°C to 6°C, while the southern zone may see a rise of 2°C to 4°C under both scenarios. The implications of these temperature changes on rice phenophases were examined using the CERES-DSSAT model, calibrated with data from a split-plot design experiment involving two rice varieties (Jyothi and Jaya) and five planting dates. The study focused on three key phenophases: transplanting to panicle initiation, panicle initiation to anthesis, and anthesis to physiological maturity. The results showed that under projected future climate conditions, the duration from transplanting to panicle initiation for Jyothi reduced from 31-41 days (base period) to 29-31 days, and for Jaya from 38-51 days to 37-39 days. Additionally, the duration from panicle initiation to anthesis generally decreased, except in Idukki where it increased by 2-5 days. The period from anthesis to physiological maturity also shortened, dropping from 34-41 days to 31-33 days for both varieties. The consistent reduction in the total crop duration was linked to the projected temperature increases of 1°C to 6°C, with 1°C warming accelerating rice maturity by 4-6 days. These shortened crop durations could have adverse effects on rice production.