Abstract

CONSTANTIN, Jamil et al. Desiccation systems prior to no-till corn sowing and weed control. Cienc. Rural [online]. 2009, vol.39, n.4, pp. 971-976. ISSN 0103-8478.  http://dx.doi.org/10.1590/S0103-84782009000400003.

The adequate timing for cover crop management before sowing is fundamental for the success of no-till corn. This research aimed to evaluate the effects on corn growth and yield of three burndown systems before no-till sowing, combined with three weeds control methods after crop emergence, in areas with high density of weeds. Treatments were arranged in a factorial scheme (3x3) + 1, randomized block design and five replications. The three burndown methods evaluated were: (1) burndown right before crop sowing ("AP"); (2) burndown seven days before crop sowing ("7 DAS"); and (3) antecipated burndown ("MA"), composed of herbicide application, at 25 days and 1 day before crop sowing. After corn emergence, weed control treatments were: (1) no control; (2) manual weeding; and (3) mesotrione + atrazine + mineral oil applied at post-emergence, and an untreated check, with no burndown and no post-emergence weed control. The burndown system MA improved weed control after crop emergence compared to AP and 7 DAS. Delay of corn growth occured in areas where AP burndown was used. Regardless the method of post-emergence weed control, the highest grain yields were registered in MA, with gains from 593 to 1060 kg ha^-1.

Keywords : Zea mays; herbicides; integrated mangement; no till.