ALTERNATIVES OF CHEMICAL MANAGEMENT OF SOURGRASS IN SOYBEAN CROP

Abstract

The resistance of weeds to herbicides demands new strategies of chemical management of the intraspecific community, considering their capacity of interference in cropping systems. The objective of this study was to evaluate the efficacy of ACCase inhibitors applied in a mixture or sequential with the herbicide 2,4-D, as alternatives for control of sourgrass. The experimental design was in randomized blocks, with eleven treatments and four replications, between 2015 and 2016. The compounds were determined by the herbicides cletodim, haloxyfop-p-methyl, fenoxaprop-p-ethyl, quizalofop-p-ethyl and fluazifop-p-butyl in mixture or sequential with 2,4-D, in addition to glyphosate-associated applications of graminicide and paraquat in all treatments, Visual evaluations were carried out at 5 days before sowing (DBS) and with 0; 10; 20; 40; 50 and 65 days after sowing (DAS) to determine the sourgrass control. The application of the herbicides cletodim and haloxyfop-p -methyl in mixture or sequential with 2,4-D do not differ in the control of the sourgrass plants. The application of the herbicides fenoxaprop-p-ethyl, quizalofop-p-ethyl and fluazifop-p-butyl in sequential with the herbicide 2,4-D at higher control compared to the use thereof in a mixture with 2,4-D. The herbicide fluazifop-p-butyl in mixture with 2,4-D is not indicated for the control of sourgrass.