Vol. 11, Issue 4 (2022)

Author(s):
B Gouthami, M Uma Devi M, K Avil Kumar and V Ramulu

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. The total water applied to the crop was 414.8 mm. Based on correlation studies, it was noticed that plant height at 60 DAT, number of leaves plant^-1 at 150 DAT, number of branches plant^-1 at 90 DAT, LAI at 120 DAT, SPAD chlorophyll content at 60 DAT, dry matter production at final harvest and quality parameters strongly influencing the capsicum fruit yield. Also, nitrogen uptake at final harvest, phosphorous and potassium uptake at 120 DAT have highly influenced the fruit yield.