Growth, nutrient uptake and profitability of Bt cotton (gossypium hirsutum l.) influenced by spacing and nutrient levels Jat R. D., Nanwal R. K. Department of Agronomy CCS, Haryana Agricultural University, Hisar-125 004, Haryana, India Online published on 4 August, 2017. Abstract A study was conducted at Research Farm, Department of Agronomy, CCS Haryana Agricultural University, Hisar during kharif 2010. The soil of experimental field was sandy loam in texture and slightly high in pH. Soil was tested low in organic carbon and available nitrogen and medium in available phosphorus and high in potassium. The experiment was conducted in split plot design with three replications. The combination of three spacings (100 x 40 cm, 100 x 50 cm and 100 x 60 cm), two times of N fertilizer application viz., T1:50% at flowering and 50% at square formation and T2:25% as basal, 37.5% at flowering and 37.5% at square formation, were kept in main plots, while three nutrient levels viz., F1–131.2:45:45 NPK (kg/ha) F2–175.0:60:60 NPK (kg/ha) and F3–218.7:75:75 NPK (kg/ha) were kept in sub-plots. Maximum plant height was recorded at closer spacing of 100 x 40 cm. Maximum sympods/plant were recorded in wider spacing (100 x 60 cm) which were significantly higher than closer spacing (100 x 40 and 100 x 50 cm). Weight/boll (g) was recorded non-significant in spacing manure. Time of N fertilizer application had a significant effect on plant height and sympods/plant. Maximum plant height and sympods/plant were recorded with three split applications of N fertilizer. Maximum plant height was recorded at a NPK fertilizer dose of 218.75:75:75 (125% RDF) kg/ha followed by 175:60:60 (100% RDF) kg/ha. Spacing (100 x 60 cm) exhibited significantly higher available N, P and K in soil than closer spacing. The maximum available N, P and K in soil was observed with two split doses of N application as compared to three split doses of N application. Significantly higher available N, P and K in soil after harvest of crop was found with 125% RDF, which is significantly superior over 75 and 100% RDF. Total cost of cultivation, gross returns, net returns and benefit: cost ratio were significantly higher with spacing of 100 x 40 cm followed by spacing of 100 x 50 cm with three split applications of N fertilizer and 100% of recommended dose of fertilizers. Cost of cultivation was significantly better in fertilizer levels with 125% of recommended dose of fertilizers. Top Keywords Bt cotton, Economics, Fertilizer levels, Growth, Spacing. Top |