SUBDOSES DE HERBICIDAS NO DESEMPENHO PRODUTIVO DO CONSÓRCIO ENTRE MILHO E Urochloa brizantha

Abstract

Increasingly, the intercropping between maize and forage species has been adopted by farmers, which are managed with herbicide subdoses that are used in the crop integration system for pasture formation. However, the responses to this management in both maize and forage have presented different responses depending on the herbicide used, the region and the climatic conditions. In this research, corn productivity, weed population dynamics, and yield and quality characteristics of the Urochloa brizantha pasture were evaluated in three cuts when it was formed after harvesting corn treated with mesotrione and tembotrione subdoses. The subdoses tested for mesotrione were: 0; 9,6; 19,2; 38,4 and 57,6 g ha-1 and for tembotrione were: 0; 3,78; 7,56; 15,12 and 22,68 g ha-1 . Corn and forage were also tested in monocultures. In a consortium, weed species Alternanthera tenella (ALTTE), Commelina benghalensis (COMBE) were of relative importance (IR) and were not controlled by herbicides. Yield of maize grains was not affected by forage, but forage yield (FY) of grass was reduced by maize. In the dry period of the year the FY of pasture formed by the consortium resembled FY of monoculture. However, the effects on the components of silage quality came from the coexistence promoted with maize when compared to the single control.