International Journal of Plant & Soil Science

The experiment was carried out at wetlands farm, Tamil Nadu Agricultural University, Coimbatore, during summer, 2023 in a Randomized block design with ten treatments and replicated thrice. The main objective of this study is to find out the effect of varied dose of basal nitrogen & phosphorus and foliar application of conventional urea, super nano urea and nano DAP on rice fallow cotton under High Density Planting System (HDPS) on growth parameters. Cotton variety CO 17 was taken up for the study with RDF of 150:50:50 NPK Kg ha^-1. The experimental details viz., T₁- control (without N&P) K alone, T₂- RDF (150:50:50 NPK Kg ha^-1), T₃- 50% RDN&P,100% K+ conventional urea @ 1% and nano DAP @ 0.5% at 25 DAS, T₄- 50% RDN&P,100% K+ conventional urea @ 1% and nano DAP @ 0.5% at 25 DAS and 45 DAS, T₅- 50% RDN&P,100% K+  SNU(Super Nano Urea) @ 0.25%  and nano DAP @ 0.5%  at 25 DAS (Days After Sowing) and 45 DAS, T₆- 50% RDN&P,100% K+ SNU @ 0.25%  and nano DAP @ 0.5%  at 25 DAS, 45 DAS and 65 DAS, T₇- 50% RDN&P,100% K+ SNU @ 0.5% and nano DAP @ 0.5% at 25 DAS and 45 DAS, T₈- 25% RDN&P,100% K+ SNU @ 0.5% and nano DAP @ 0.5%  at 25 DAS 45 DAS and 65 DAS, T₉- 50% RDN&P,100% K+ SNU @ 1% and nano DAP @ 0.5%  at 25 DAS, T₁₀- 50% RDN&P,100% K+ SNU @ 1% and nano DAP @ 0.5%  at 25 DAS and 45 DAS. The experimental results revealed that, among all the treatments, T₁₀ significantly registered the increased plant height (112.33 cm) and highest leaf area index (4.11) and enhanced light interception (91%). Based on the experimental results, it is concluded T₁₀ i.e., reduced application of basal nitrogen and phosphorus (50% RDN&P + 100% K) with super nano urea foliar spray @ 1% and nano DAP foliar spray @ 0.5% at 25 DAS and 45 DAS found to be the optimal dosage for increased growth parameters under high density planting system in rice fallow cotton.