Manejo de plantas daninhas em milho RR com herbicidas aplicados em isolado ou associados ao Glyphosate

Abstract

The objective of this work was to evaluate the efficiency, selectivity, and yield components of RR maize as a function of the application of different herbicides, in isolated or in a tank mix. A randomized block design with four replications was used. The herbicides were: atrazine + simazine, atrazine + s-metolachlor, s-metolachlor, glyphosate, ammonium glufosinate, nicosulfuron, mesotrione, tembotrione; 2,4 -D in pre and post-emergence, some in isolates and others in tank mix, plus two controls (weeded and infested). Herbicide phytotoxicity to SYN SupremoVIP3 corn and papaya and million control were evaluated at 7, 14, 21 and 28 days after application of the treatments and at the harvest of the crop, in addition to the determination of yield components. The glyphosate + 2,4-D and glyphosate + mesotrione tank mixture caused the highest phytotoxicity, except for those treatments after 14 DAT, there was no phytotoxicity to the crop with the other herbicides. Most of the herbicides showed good control of the million and the papuã, except for the mixture of glyphosate + 2,4 -D in the pre-harvest. The post-emergence glyphosate + (atrazine + simazine) tank mix demonstrated the highest grain yield. It is concluded, therefore, that depending on the association of herbicides, there may be a synergistic effect both for weed control and crop phytotoxicity, with productivity being the main variable influenced.