Evaluation of the Effect of Urea and Nanourea on Growth Pattern of Rainfed Bt Cotton (Gossypium hirsutum L.)

A field experiment was conducted to evaluate the effect of different levels of nitrogen through Nanourea and commercial urea with different time of nitrogen application on Bt Cotton (Gossypium hirsutum L.) Fifteen treatment combinations consisting of five different levels of nitrogen through nano urea and commercial urea such as (125% of RDN through nano urea, 100% of through nano urea, 75% RDN through nano urea, 100% RDN through commercial urea and control plot (No nitrogen)) were applied in three split applications of nitrogen at 30,60,90 DAS (40%,40%,20%), 30,60,90,120 DAS (25%,25%,25%,25%), 30,60,90,120 DAS (30%, 30%,20%,20%) were evaluated in split plot design with three replications. The highest absolute growth rates (AGR) for both plant height and dry matter in the context of application of nitrogen through commercial urea were observed during specific growth intervals: 61-90 days after sowing (DAS) for plant height (1.350 cm day-1 plant-1) and 91-120 DAS for dry matter (2.374 g day-1 plant-1). Similarly, when considering split application of nitrogen, the application of nitrogen at 30,60,90 DAS (40%,40%,20%) showed the highest AGR for plant height (1.054 cm day-1 plant-1) during 61-90 DAS and for dry matter (2.158 g day-1 plant-1) during 91-120 DAS. Furthermore, various growth parameters such as CGR, RGR, NAR, and LAI also exhibited their maximum values under both different levels of nitrogen and the mentioned split application of nitrogen.