Effect of fertilizer and growth regulator on yield and yield attributing characters of cotton under high-density planting system

The productivity of cotton is stagnant and high-density planting system (HDPS) is the option for increasing productivity, so currently identifying genotypes in the region suited for HDPS along with canopy management to be tested so that enable to reduce the productivity gaps in the rain fed and irrigated farming as well as the diversified cotton growing areas. The present study was carried out to evaluate the effect of growth retardant and nitrogen levels on plant canopy architecture and enhancing productivity under HDPS. Three nitrogen levels (Recommended dose of nitrogen (RDN), 125 % RDN and 150 % RDN) and 3 levels of growth regulators (No growth regulator, mepiquat chloride (MC) at 20 g/ha at 60 days after sowing (DAS) and MC at 60 & 75 DAS) were studied across two HDPS suited genotypes (GISV-272 and GSHV-180) for three consecutive years (kharif 2019 to 2021). The experiment was laid out in split plot design with three replications at Research Farm of Main Cotton Research Station, Navsari Agricultural University, Surat. The plant height, number of sympodia and mean length of sympodia were significantly influenced due to nitrogen level; while, plant height, mean length of sympodia and plant width were significantly influenced due to genotypes. The growth retardant, MC significantly altered plant height, mean length of sympodia and plant width providing ample space for growth and development to both the genotypes under HDPS. The yield attributing traits and seed cotton yield were influenced greatly by the genotype and nitrogen levels. In this study, GISV 272 and 125 % of recommended nitrogen level under HDPS in rain fed region of Gujarat showed better performance and economics.