A field experiment was conducted at Main Agricultural Research Station (MARS), University of Agricultural Sciences, Raichur to investigate the effect of nano nitrogen on growth, yield and economics of
Bt cotton during the
kharif season 2022. The experiment was laid out in split plot design with three main plots consists of different doses of nitrogen: M1 -100% N, 2022, M2 -75% N, and M3-50% N, 2022 and five subplots with different concentrations of nano nitrogen (S1: Spraying of 0.4% nano nitrogen at flowering & boll initiation stages; S2: Spraying of 0.4% nano nitrogen at flowering, boll initiation & boll development stages; S3: Spraying of 0.6% nano nitrogen at flowering & boll initiation stages; S4: Spraying of 0.6% nano nitrogen at flowering, boll initiation & boll development stages; S5: Control (without spraying) and replicated thrice. The results revealed that significantly higher plant height, sympodial branches, dry matter accumulation, seed cotton yield, gross returns, net returns was recorded by 100% N (176.9cm, 27.1, 430.31 g plant
-1, 3388 kg ha
-1, Rs. 271024 ha
-1 and Rs. 188736 ha
-1respectively) followed by 75% RDN (168 cm, 26.7 and 426.91 g plant
-1, 3376 kg ha
-1, Rs. 270112 ha
-1 and Rs. 188291 ha
-1 respectively) which found
on par with each other. However higher BC ratio of 3.30 was recorded by 75% RDN followed by 100% RDN (3.29) which found comparable with each other.
Among the sub plots, foliar application of nano urea @ 0.6 per cent each at 90, 100 and 135 DAS has recorded significantly higher plant height (180.8 cm), sympodial branches (28.5), dry matter accumulation (429.42 g plant-1), gross returns (Rs. 278784 ha-1) net returns (Rs. 195414 ha-1) followed by foliar application of nano urea @ 0.4 per cent each at 90, 100 and 135 DAS (173.3 cm, 28 and 428.52 g plant-1, 3465 kg ha-1, Rs. 277238 ha-1 and Rs. 194768 ha-1respectively) which found comparable to each other. However higher BC ratio of 3.36 was recorded by foliar application of nano urea @ 0.4 per cent each at 90, 100 and 135 DAS followed by foliar application of nano urea @ 0.6 per cent each at 90, 100 and 135 DAS (3.34).
