Efeito do consórcio de milho com panicum maximum na comunidade infestante e na cultura da soja em rotação

Abstract

This work aimed to study the effects of corn and colonião grass (Panicum maximum cv Aruana) intercropping on weed infestation and soybean crop in rotation. This research was carried out under field conditions from December 2008 to April 2010 at the UNESP Campus of Jaboticabal, São Paulo, Brazil. The experiment was arranged in a randomized block design in split-plots, with four replications. Two forms of sowing (hand-sowing and on-line sowing) of colonião grass and four amounts of seeds (200, 400, 600, and 800 points of cultural value - PCV) were studied, plus three additional treatments with the single species. Intercropping did not affect vegetative growth and corn yield, when compared to single corn. In the harvest of corn grains, there was more dry matter and plant density of colonião grass when 800 PCV were sown. However, before soybean sowing, dry matter production did not differ between the intercropping treatments. Thus, the sowing of 200 PCV of colonião seeds, hand-sowing and on-line sowing, was sufficient to maintain an adequate amount (9.1 ton ha -1) of mulch on the soil. Prior to soybean sowing, weed infestation in the single corn treatment was higher than during intercropping and the single forage treatment (hand sowing and on-line sowing). The same was observed after the installation of the crop for weed density. Corn and colonião grass intercropping did not influence the characteristics evaluated in the soybean crop cultivated in rotation. No difference was observed between intercropping and corn in monoculture for soybean yield.