Revista Brasileira De Herbicidas 2018; 17(2): 1-7
Sourgrass response to mixtures of haloxyfop and glyphosate with synthetic auxinic herbicides
In Brazil, weed resistance to glyphosate is increasing for both broadleaf and grass species in the same area, making necessary to develop effective management strategies. The objective of this study was to determine the efficacy of the herbicide haloxyfop-p-methyl plus glyphosate in Digitaria insularis (sourgrass) when mixed with auxin mimics herbicides. The experiments were carried out in two locations, Mogi Mirim/SP and Indianópolis/MG, in a randomized complete block design, with four replications. The herbicide treatments were: haloxyfop-p-methyl (124 g ai ha-1); haloxyfop‑p‑methyl + halauxifen-methyl + diclosulam (124 + 30.6 g ai ha-1); haloxyfop-p-methyl + dicamba (124 + 560 g ai ha-1); haloxyfop-p-methyl + 2,4-D (124 + 1000 g ai ha-1); haloxyfop-p-methyl + halauxifen-methyl (124 + 5 g ai ha-1) and haloxyfop-p-methyl + diclosulam (124 + 25 g ai ha-1) and untreated without application. All herbicide treatments were applied with glyphosate at 1440 g ai ha-1. The applications were performed when sourgrass plants were in 4 to 6 tillers. Halauxifen-methyl did not adversely affect the control of sourgrass when applied with haloxyfop-p-methyl and glyphosate, resulting in a control of 82 and 100% for Mogi Mirim and Indianópolis, respectively. However, the control of sourgrass with haloxyfop-p-methyl plus glyphosate was not acceptable when mixed with dicamba or 2,4-D, with controls inferior than 70%. In mix populations of broad-leaves and grass areas, halauxifen-methyl may be a good option to be applied associated with haloxypop-p-methyl and glyphosate to control these weeds without diminishing performance.
431