Thermal Indices Requirement of Kharif Groundnut (Arachis hypogaea L.) Varieties under Different Sowing Window in Western Maharashtra, India

An agro-meteorological investigation was undertaken during the kharif season of 2017 and 2018 at the Department of Agricultural Meteorology Farm, College of Agriculture, Pune, Maharashtra State (India). The experiment was laid out in split plot design with three replications. The treatment comprised of four varieties viz., V1: JL-501, V2: RHRG-6083 (Phule Unnati), V3: TAG-24 and V4: JL-776 (Phule Bharati) and four sowing windows viz., S1: 25rd MW (18th to 24th June), S2: 26th MW (25th June to 01st July), S­3: 27th MW (2nd to 8th July) and S4: 28th MW (09th to 15th July). Results showed that the higher GDD was observed in 26th MW sowing window with variety JL-776 (1826 and 1723) and RHRG-6083 (1763 and 1690) followed by variety JL-501 and TAG-24, whereas, higher heat use efficiency (0.088 and 0.100 g/GDD) at peg formation to rapid kernel growth stage was observed under 26th MW sowing window (S2) with variety JL-776 (V2) during 2017 and 2018, respectively. The highest HTU was observed in 26th MW sowing window in variety JL-776 (8254 and 6924) and RHRG-6083 (8171 and 7074) followed by variety JL-501 and TAG-24, whereas, higher heliothermal use efficiency (0.0200 and 0.0309 g/HTU) at peg formation to rapid kernel growth stage was observed under 26th MW sowing window (S2) in variety JL-776 (V2) during 2017 and 2018, respectively. Higher PTU (4818.42 and 4890.75) was observed under 26th MW sowing window (S2) in variety JL-776 (V2) this was followed by var. RHRG-6083, JL-501 and TAG-24 whereas, higher photothermal use efficiency (0.0284 and 0.293 g/PTU) at physiological maturity was observed under 26th MW sowing window (S2) with variety JL-776 (V2) followed by variety RHRG-6083, JL-501 and TAG-24 during 2017 and 2018, respectively.