Efficacy and economics of integrated weed management in groundnut (Arachis hypogea L.)

Weed management is an important and expensive step in groundnut production. Field experiments were conducted in the early and late wet seasons of 2017 to evaluate the effectiveness and profitability of weed management using hoe weeding, herbicides or their combination in groundnut production. Butachlor and propaben at 2.0 kg a.i (active ingredient) ha-1 each followed by (fb) supplementary hoe-weeding (shw) at 6 weeks after sowing (WAS) significantly reduced weed cover and biomass with subsequent increase in groundnut pod yield similar to hoe-weeding treatments and better than either herbicide applied alone. The highest groundnut pod yield (1485.7 kg ha-1) and revenue ($1639.2) in the early season was obtained with three hoe weeding passes. However, in the late season, the highest groundnut pod yield (1146.3 kg ha-1) was obtained with propaben plus hoe-weeding and the highest revenue ($1264.8) obtained with butachlor plus hoe-weeding. Although three hoe-weedings gave the highest revenue in the early season, the gross margin and cost-benefit ratio obtained with hoe weeding treatments was lower than those of herbicides fb shw. This study showed that integrated weed management with butachlor or propaben and fb shw will improve weed control, productivity and profitability of groundnut production. Multiple hoe weeding, however, did not guarantee the highest profit but rather increased the cost of production.