DOSES DE HERBICIDAS PARA SUPRESSÃO DE Panicum Maximum CONSORCIADO COM MILHO

Abstract

Panicum maximum stands out as one of the main forage grasses used in integrated agricultural production systems in the Brazilian Cerrado, especially in crop-livestock integration. Among the available cultivars, BRS Quênia and BRS Zuri show high productive potential, adaptability to the edaphoclimatic conditions of the Cerrado region, and good response to management practices. The objective was to evaluate reduced rates of herbicides for the suppression of forages of the genus Panicum maximum, such as the cultivars BRS Zuri and BRS Quênia, aiming at intercropping, as well as the influence of this management on weed dynamics and on the succeeding soybean crop. Field experiments were conducted for each cultivar at the experimental area of IF Goiano, Rio Verde Campus, using a randomized block design with four replications. Treatments consisted of six subdoses of the herbicides glyphosate (0, 48, 96, 240, 480, and 960 g a.e. ha-1) and nicosulfuron (0, 2.5, 5, 12.5, 25, and 50 g ha-1), in addition to maize in monoculture. Biometric and productivity assessments were carried out for the soybean, corn, and forage crops, as well as evaluations of the density and dry mass of the weeds present in the experimental area. The results showed that the BRS Quênia cultivar exhibited lower competition with maize, while BRS Zuri required differentiated chemical management and stood out for its high dry matter production. The herbicide glyphosate, at rates above 480 g ha-1, eliminates the forages, while nicosulfuron provides moderate control. In both experiments, a reduction in weed dry matter and density was observed in plots with forage presence, mainly due to the suppressive effect of the forage grasses. It is concluded that adopting integrated management strategies enhances the productive efficiency of intercropped systems, contributing to the sustainable intensification of agriculture in the Cerrado.