A field experiment was conducted during the rabi season of 2021-22 at Research farm of Navsari Agricultural University, Navsari to study the thermal indices for green gram cultivars. The thermal indices viz., growing degree day (GDD), photothermal unit (PTU), heliothermal unit (HTU), photothermal index (PTI) and thermal use efficiencies were worked out concerning green gram phenology under the different environments condition. The result revealed that the high units of thermal indices viz., GDD, HTU, PTU, and PTI were observed in cv. GBM-1 followed by cv. CO-4 under the third sowing date. The HUE was reported higher in cv. CO-4 (1.212 kg ha-1 ℃ day-1) followed by cv. GM-7 (1.040 kg ha-1 ℃ day-1) under the third sowing date. The correlation between thermal indices viz., GDD, HTU, PTU, and harvest days and seed yield were founded significant which means the temperature and sunshine hours significantly influenced the seed yield and duration of phenophases.

An investigation on climate change impact on green gram was conducted at Agronomy farm, NAU, Navsari, Gujarat during the rabi seasons of 2021-22. The calibrated and validated DSSAT CROPGRO simulation model was used to determine the productivity of green grams under various climate change scenarios. In this experiment, the effects of CO2 concentration, solar radiation and maximum and minimum temperatures on green gram productivity were examined individually and in combination. According to the sensitivity of the DSSAT CROPGRO model, under the conditions of projected climate change, the best case scenario for its favourable impact on green gram yield was a rise in CO2 concentration (600 ppm), along with solar radiation up to a certain level (1 unit), which may nullified the adverse effect of increases in temperature on green gram productivity.