Use of nicosulfuron in the management of Megathyrsus maximus ‘BRS Zuri’ intercropped with maize

The intercropping between maize and tropical forage crops is a commonly used alternative in production systems. However, it is necessary that the management be performed adequately in order to avoid yield losses of crops by interspecific competition in the initial phase. The application of subdoses of selective herbicides to maize is a possibility to suppress forage growth, avoiding competition. Thus, the objective was to evaluate the effects of subdoses of the herbicide nicosulfuron on the development of Megathyrsus maximus cv. BRS Zuri intercropped with maize and how this simultaneous cultivation influences the weed population, the biometric and productive variables of maize and forage crops. The treatments consisted of six subdoses of the herbicide nicosulfuron (0, 2.5, 5, 12.5, 25 and 50 g ha-1) and maize in monoculture. The results indicate that the presence of the forage BRS Zuri suppressed weed growth and development. The dose of 50 g ha-1 caused phytotoxicity in hybrid B2360PW corn plants. The presence of the forage crop negatively interfered in the maize grain yield. Herbicide doses did not suppress forage growth, since height and biomass were high. These results indicate the need for adjustments in the dosage, in the choice of maize hybrid and in the moment of herbicide application, aiming at minimizing possible interference of the forage in the performance of the maize crop.