Bio-efficacy of glufosinate ammonium on weed control and yield of cotton (Gossypium hirsutum)

A field experiment was carried out at Instructional farm, Mohanpur, West Bengal, India during the rainy season of 2016 and 2017 to study the bio-efficacy of glufosinate ammonium 13.5% SL (15% w/v) herbicide on weed control, growth and yield of Bt-cotton hybrid (Gossypium hirsutum L.). The experiment was conducted in 3 times replicated randomized block design (RBD) comprising 7 weed-control treatments, viz. 4 doses of glufosinate ammonium 13.5% SL (15% W/V) @ 300, 375, 450 and 525 g/ha, paraquat dichloride 24% SL @ 500 g/ha, hand-weeding (weed-free control) and weedy control. The weed-free treatment by frequent hand-weeding showed maximum growth parameters, yield attributes and yield of cotton. Among the herbicidal treatments, the post-emergence application of glufosinate ammonium 13.5% SL (15% W/V) @ 525 g/ha was found to be the alternative of hand-weeding in respect to weed-control efficiency, growth and yield of cotton. This treatment also realized the highest net return (₹ 41,689/ha) and benefit: cost ratio (2.11), followed by glufosinate ammonium 13.5% SL (15% W/V) @ 450 g/ha.