Evaluation of Thermal Indices in Relation to Phenology of Green Gram (Vigna radiata L.) under Different Growing Environments of Navsari Region of South Gujarat

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.