Genotypic variation in pigeonpea response to sowing time and nutrient use efficiency in rabi season

An experiment was conducted during the 2023-24 Rabi season at the Siddapur Research Farm, Regional Agriculture Research Station, Warangal, Telangana, to evaluate the effects of sowing dates and pigeonpea genotypes on yield, nutrient uptake and nutrient use efficiency. The soil was mildly alkaline (pH 7.9) with low nitrogen (260.3 kg ha⁻¹), low phosphorus (29.1 kg ha⁻¹), moderate organic carbon (0.64%) and high potassium (316 kg ha⁻¹). Sixteen treatment combinations, arranged in a split-plot design with three replications, included four sowing dates (D1-2nd fortnight of September, D2-1st fortnight of October, D3-2nd fortnight of October and D4-1st fortnight of November) and four pigeonpea varieties (V1-Telangana kandi-1 (WRGE-93), V2-Telangana kandi-2 (WRGE-121), V3-Warangal kandi-1 (WRGE-97) and V4-WRGE-182). Crops sown in late September (D1) achieved the highest seed (1392 kg ha⁻¹) and stalk (4151 kg ha⁻¹) yields, with peak nutrient uptake at flowering (60.8 kg ha⁻¹ nitrogen, 2.41 kg ha⁻¹ phosphorus, 105.6 kg ha⁻¹ potassium) and harvest (82.2 kg ha⁻¹ nitrogen, 3.67 kg ha⁻¹ phosphorus, 120.3 kg ha⁻¹ potassium). Nitrogen and phosphorus use efficiencies were highest in September (86 and 70, respectively) but declined through October and November. Among genotypes, WRGE-182 outperformed others, producing the highest seed (1181 kg ha⁻¹) and stalk (3801 kg ha⁻¹) yields, with superior nutrient uptake at flowering (58.5 kg ha⁻¹ nitrogen, 2.41 kg ha⁻¹ phosphorus, 114.0 kg ha⁻¹ potassium) and harvest (73.4 kg ha⁻¹ nitrogen, 2.57 kg ha⁻¹ phosphorus, 111.7 kg ha⁻¹ potassium).WRGE-182 also showed the highest nitrogen (73) and phosphorus (59) use efficiencies, followed closely by WRGE-121 (72, 58) and surpassing WRGE-93 (66, 53) and WRGE-97 (59, 48). In contrast, crops sown in early November (D4) and genotype WRGE-97 recorded the lowest yields, nutrient uptake and nutrient use efficiency.