Integrated Weed Management in Rainfed Soybean (Glycine max (L.) Merr.)

A field experiment was conducted during rainy (kharif) season of 2007 at Akola, Maharashtra to study the efficacy of different weed management practices against weeds in rainfed soybean. Broadleaved weeds were predominant (65%) in the experimental field than grass weeds (35%). The highest weed control efficiency (77.1%) was achieved with pre-emergence application of imazethapyr 75 g ha⁻¹ + in situ mulching with weeds after hand weeding 30 days after sowing (DAS). Hoeing twice at 20 and 40 DAS + hand weeding 30 DAS was the next best treatment with weed control efficiency of 74.3%. The seed yield decreased by 62.3% due to season-long weed-crop competition. Pre-emergence application of imazethapyr 75 g ha⁻¹ + in situ mulching with weeds after hand weeding 30 DAS gave the highest seed yield (2270 kg ha⁻¹) and was significantly superior to other treatments except hoeing twice at 20 and 40 DAS + hand weeding 30 DAS, postemergence application of imazethapyr 75 g ha⁻¹ + in situ mulching with weeds after hand weeding 30 DAS, and preemergence application of imazethapyr 75 g ha⁻¹ + mulching with crop residues 30 DAS. Pre-emergence application of imazethapyr 75 g ha⁻¹+ in situ mulching with weeds after hand weeding 30 DAS gave the highest net return ( 22 568 ha⁻¹) and benefit:cost ratio (1.79) compared to other treatments.