Chickpea Phenology and Yield Related to Agrometeorological Indices Under Different Temperature Regimes

Agrometeorological variables have a major impact on crop development and yield, known as crop phenology. The phenology of chickpea under various thermal regimes was evaluated in a field experiment during the rabi season of 2019–2020 at Ishwardi, Pabna district of Bangladesh. Three chickpea cultivars (V1 = BARI Chola 5, V2 = BARI Chola 10, and V3 = BARI Chola 11) were planted under irrigation in four temperature regimes (D1 = November 5, D2 = November 20, D3 = December 5, and D4 = December 20). Early sowing on November 5 had a larger growing degree day (GDD), 2135.5 C days from sowing to harvest, and later sowing on December 20 had a lower GDD (1743.4 C days). From planting to harvest, V1 required a greater GDD (1971.5C days) while V3 required a lower GDD (1805.8 C days). Average heliothermal unit (HTU) varied from 11764.07 C day hrs (D4) to 13879.4 C day hrs (D1). Variety V1 required 13757.85°C day hrs HTU, while V2 and V3 required 13347.05°C day hrs and 11636.8 °C day hrs, respectively. The number of days needed from planting to harvest under D1, D2, D3, and D4 growing conditions were 136.3, 122.6, 118.6, and 107.4 days, respectively. Growth and yield were better for V1 and V2 under D1 settings, but they were lower under D3 conditions, while V3 was better under D2 conditions. BARI Chola 11 among the genotypes was harvested much more quickly and produced more effectively in late-sowing conditions. Physiological maturity and grain yield can be predicted with 92% and 99% accuracy, respectively, using cumulative GDD and HTU. Therefore, the study recommended that different thermal conditions and cultivars' reactions to heat utilization and economic yield have a substantial impact on chickpea cultivar yields.