Mixtures of Herbicides and Time of Application to Control Commelina Benghalensis in Maize and Off-Season

Abstract

The objective was to evaluate the effectiveness of herbicides in mixtures with glufosinate in maize and the effect until soybean sowing. Also, to evaluate the effect of time of application on the effectiveness of these herbicides in the off-season. Experiment 1 was conducted in two areas planted with maize. Experiment 2, in the off-season, after maize harvesting and before soybean sowing. In experiment 1, the treatments consisted of the application of atrazine alone or mixed with glufosinate, glufosinate alone or mixed with s-metolachlor, atrazine/s-metolachlor, mesotrione, atrazine/mesotrione, tembotrione, terbuthylazine, carfentrazone and 2,4-D, in addition to the untreated control. In experiment 2, treatments were arranged in a 9 x 3 factorial design (herbicides x application times). Glufosinate alone or in mixtures with two doses of atrazine, s-metolachlor, mesotrione, atrazine/mesotrione, carfentrazone and 2,4-D were applied, in addition to the untreated control. The three application times were 20 h, 4 h and 12 h. Weed control was evaluated in both experiments, and maize agronomic performance in experiment 1. In general, greater efficiency was found for herbicide mixtures, especially for those with a combination of pre- and post-emergence effects. The herbicides did not affect the agronomic performance of maize in experiment 1. Regarding the time of application, no effect was detected on the action of the herbicides. Mixtures of herbicides are recommended for an effective control until soybean sowing, with emphasis on those with pre- and post-emergence effects on C. benghalensis, regardless of the time of application.