Influence of different nutrient management approaches on growth and yield of Bt cotton in a vertisol

Abstract

The field experiment of Bt cotton to evaluate different nutrient management practices was conducted on Vertisol during kharif 2016. The experiment was laid out in RBD design and replicated three times. The experiment consisted of eight treatments involving STCR, modified STCR and STL approaches, blanket recommendation and control. The soil of the experimental site was alkaline in reaction, non saline and low in available nitrogen and high in available phosphorus and potassium.Growth attributes (plant height, number of monopodial and sympodial branches and dry matter production) and yield attributes, namely, number of bolls per plant (48.0), boll weight (4.83 g boll-1), seed cotton yield per plant (189.4 g ) and seed cotton yield per hectare (36.2 q ha-1) were higher with 100 per cent application of nutrients through STCR equation to attain target yield of 40 q ha-1 compared to STL approach and blanket recommendation and the former was on par with those recorded under modified STCR approach (application of 50% P, full dose of N and K of STCR equation).Among different nutrient management approaches to achieve maximum productivity 100 per cent application of nutrients based on STCR approach was the best. Next best approach was application of 50% of P that prescribed for STCR approach and full dose of N and K. Thirdly, soil test based NPK±25% is better compared to blanket recommendation and STL-NPK based on (L, M and H).