Integration mulches with atrazine for weed management in corn

Abstract

The use of cover crops can contribute to the reduction of the dose required for weed control. The aim of this work was to assess the growth of weeds and productivity of corn from different degrees of black oat cover and velvet bean and atrazine doses. Two experiments were conducted in the experimental area, both was conducted in randomized blocks in a split plot design with four replications. In the main plots were randomized, four straw levels (0, 0.75, 1.5 and 3 times the amount originally produced) oat (Exp 1) or velvet bean (Exp 2). In the subplots were randomized to four doses of atrazine (0, 2100, 4200 and 8400 g ha-1). It was evaluated the weed density and crop yield. The utilization of straw species coverage on the ground, even at high levels, was not enough to exercise total control of weeds. Atrazine was not effective in weed control only in the treatment with 2100 g ha-1 of the herbicide and no velvet bean straw on the ground, but the straw of this species realized suppressive effect, supplementing the effect of the herbicidal dose. Levels in 2775 and 5550 kg ha-1 of velvet bean straw reduce the productivity of corn. Integrating the use of oat or velvet bean straw with low dose of atrazine (2100 g ai ha-1), results in effective weed control systems and more suitable cropping systems in the environmental aspect, both by reducing the use of herbicides as taking advantage of the benefits of no-till system.