Modalities of application and tank-mix combinations of herbicides on corn under conventional and narrowed spacing

Abstract

Narrowing the distance between sowing lines is a practice that may help corn crop as a competitor against weeds, but little is known about weed chemical control under such conditions. Therefore, the objective of this research was to evaluate the efficiency of different combinations of herbicides and modalities of post-emergence application on weed control in corn cultivated under conventional (0.90 m) and narrow (0.45 m) spacing between rows. Treatments evaluated included the association of atrazine+nicosulfuron+mesotrione, atrazine+nicosulfuron, atrazine+mesotrione and nicosulfuron+ mesotrione, applied in unique or sequential application, and controls (handweeded control and without handweeded control). In general all treatments were considered as selective for corn and did not affect yield components and grain yield. Results concerning weed control for sequential applications were considered as satisfactory in most treatments up to corn harvest, what was considered as an indicative that such modality presents a longer effective period of weed control considering the evaluated treatments.