Nutrient uptake of capsicum (Capsicum annuum var. grossum L.) as influenced by different nitrogen and potassium fertigation levels under poly house

Abstract

The experiment was conducted in a naturally ventilated poly house at Water Technology Centre, Horticulture Farm, Rajendranagar, Hyderabad during rabi 2019-20 to find out the optimum N and K fertigation schedule for capsicum (Capsicum annuum var. grossum L.) crop. The experiment comprised of three replications in Factorial Randomized Block Design (FRBD) with two factors {i.e. N levels (4), K levels (3) } and twelve treatments Viz; N fertigation levels of 0 %, 120 % (216 kg N ha-1) , 150 % (270 kg N ha-1), 180 % (324 kg N ha-1) and K fertigation levels of 0 %, 80 % (96 kg K2O ha-1), 100% (120 kg K2O ha-1) respectively. The 100 % RDF was 180, 90 and 120 kg N, P2O5 and K2O ha-1. The source of N was urea, P was single super phosphate (SSP) and K was white muriate of potash (MOP). A common dose of P was applied to all the treatments. The N and K were applied through drip fertigation on every fourth day during different crop growth stages. In the fertigation programme, during crop establishment stage (10 DAT to 14 DAT), 10 % of N and K2O were applied in two splits. During vegetative stage, (15 to 46 DAT) 30 % of N and 20 % of K2O were applied in eight splits. During flower initiation to fruit development (47 DAT to 74 DAT) 20 % of N and K2O were applied in seven splits. From fruit development till final harvesting stage (75 DAT to 154 DAT) 40 % of N and 50 % K2O were applied in 20 splits. Then the fertigation schedule was completed in a total of 37 splits. The soil of the experimental site was sandy loam in texture with low in available nitrogen (166.5 kg ha-1), medium in available phosphorus (81.1 kg P2O5 ha-1) and low in available potassium (245.4 kg K2O ha-1). Irrigation was scheduled at 0.8 Epan based on pan evaporation data. The total water applied to the crop was 414.8 mm. The highest total nitrogen, phosphorous, potassium uptake was noticed by application of 180% of recommended N (324 kg N ha-1) and 100% of recommended K2O (120 kg K2O ha-1) at all the growth stages of capsicum in poly house during rabi season. The total nitrogen uptake by capsicum ranged from 0.92 to 4.39 kg N ha-1 at 30 DAT, 5.52 to 17.02 kg N ha-1 at 60 DAT, 25.66 to 58.85 kg N ha-1 at 90 DAT and 61.78 to 137.64 kg N ha-1 at final harvest respectively. The total phosphorous uptake by capsicum ranged from 0.04 to 0.22 kg P ha-1 at 30 DAT, 0.53 to 2.46 kg P ha-1 at 60 DAT, 1.09 to 2.91 kg P ha-1 at 90 DAT and 3.10 to 11.37 kg P ha-1 at final harvest respectively. The total potassium uptake by capsicum ranged from 0.24 to 1.76 kg K ha-1 at 30 DAT, 2.26 to 7.11 kg K ha-1 at 60 DAT, 7.93 to 18.03 kg K ha-1 at 90 DAT and 13.17 to 28.43 kg K ha-1 at final harvest respectively.