Growth, yield components, and yield of Bt Cotton (Gossypium hirsutum L.) as Influenced by irrigation methods and nutrient levels

摘要

A field experiment was carried out during kharif season of 2009-'10 at Agriculture College Farm, Bheemarayanagudi, Karnataka (India), to study the response of Bt cotton to different irrigation methods and nutrient levels. The growth parameters such asplant height, number of monopodial branches per plant, sympodial branches per plant, total dry matter production, leaf area per plant and leaf area index (LAI) were, significantly influenced by different irrigation methods and nutrient levels. Among theirrigation methods conventional furrow method of irrigation, and among fertilizer levels 125 per cent RDF resulted significantly higher growth components. Yield components such as number of bolls per plant, mean boll weight and seed cotton yield per plant (58.52, 4.11 g and, 147.77 g plant'respectively) were significantly superior with conventional furrow irrigation method. Among different fertilizer levels, 125 per cent of the recommended dose of fertilizers (RDF) recorded significantly higher seed cotton yield per hectare (2591 kg ha~(-1)), seed cotton yield per plant (143.33 plant~(-1)), mean boll weight (3.73 g), number of bolls per plant (57.34), over 100 per cent and 75 per cent of RDF. Among the irrigation methods conventional furrow irrigationhas shown significantly higher seed cotton yield (2466 kg ha~(-1)) compared to alternatively alternate furrow irrigation (AAFI) (2313 kg ha~(-1)) and alternate furrow irrigation (AFI) (2233 kg ha~(-1)). However, it was on par with alternate furrow irrigation (AFI) + mulching (2387 kg ha~(-1)). Conventional furrow irrigation with 125 per cent RDF recorded significantly higher gross returns and net returns (79,090 and 54, 058 Rs. ha~(-1), respectively) compared to 100 per cent RDF (74, 470 and 50, 247 Rs. ha~(-1), respectively) and 75 per cent RDF (68, 390 and 45, 027 Rs. ha~(-1), respectively).