Determination of tembotrione subdoses in the intercropping between Megathyrsus maximus cv. BRS Zuri and corn

Abstract

In recent years, the integration of agricultural production systems has been increasing exponentially in arable areas in Brazil. In the intercropped system with corn, forages can be managed with herbicides subdoses in order to avoid crop yield losses due to competition established during the coexistence period. Although it is an available alternative, studies with forages widespread in recent years are still scarce in the literature. This research evaluated the effects of tembotrione subdoses on the suppression of the forage Megathyrsus maximus cv. BRS Zuri, intercropped with corn, and how this association reflects on the dynamics of weeds, on the productivity components of corn and on the yield of the forage. The experiment was carried out under field conditions in a randomized block design, with four replications. The treatments consisted of six tembotrione subdoses (0; 3.78; 7.56; 18.9; 37.8; 75.6 g a.i. ha^-1), in addition to corn in monoculture. The results indicate that the intercropping between corn and the forage BRS Zuri reduced weed infestation. No yield losses were observed for either crop during the intercropping period. The subdoses of the herbicide tembotrione were not sufficient to suppress the growth of Megathyrsus maximus, given the high values ​​of plant height and forage yield, suggesting that the forage plants detoxified the applied herbicide. Therefore, it is necessary to carry out studies related to the adjustment of the dosage taking into account the climatic conditions and time of application.