Efficacy of halauxifen-methyl formulations to control volunteer soybean DAS-444Ø6-6 (Enlist E3TM)

Abstract

Volunteer soybean control is a fundamental requirement, mainly because of the rust inoculum disease present in these plants. Several herbicides are available that will control volunteer soybean in the vegetative growth stage, however farmers may delay application of control measures until the flowering growth stage, where the control can be more difficult With the introduction of 2,4-D tolerant soybean (DAS-444Ø6-6 - Enlist E3TM), other methods of chemical control need to be identified. The objective of this research was to determine the efficacy to control volunteer DAS-444Ø6-6 soybean using alternative herbicides. A field experiment was conducted in Cascavel-PR, using a randomized complete block design, with three replications. Herbicides treatments applied were halauxifen-methyl + pyroxsulam at 5 g a.i. ha-1 + 18 g ai ha-1, halauxifen-methyl + diclosulam at 5 g a.i. ha-1 + 25 g ai ha-1 and halauxifen-methyl + 2,4-D at 5 g a.i. ha-1 + 783 g ai ha-1, and the standard paraquat 400 g ai ha-1. The treatments were applied post emergence to soybean at the R2 growth stage. Paraquat and the treatment formulations containing halauxifen-methyl provided effective control of volunteer DAS-444Ø6-6 soybean sprayed at advanced growth stage (R2).