Management of Digitaria insularis in soybean pre-sowing desiccation by ACCase alternative herbicides and its impact on soybean carryover.

The objective of this study was to evaluate the use of alternative herbicides to ACCase inhibitors to control Digitaria insularis (sourgrass) during pre-sowing soybean desiccation. Two field experiments were conducted with two temporal replicates under different climatic conditions, with the following treatments: imazethapyr + glyphosate, clethodim + fluroxypyr, chlorimuron + glyphosate, imazapic + imazapyr, mesotrione + atrazine + glyphosate, tembotrione + atrazine + glyphosate, nicosulfuron + atrazine and imazamox + glyphosate, all of which were composed of a sequential application of glufosinate ammonium. The water stress conditions in experiment 1 compromised the efficacy of acetolactate synthase enzyme (ALS) inhibitor herbicides in the control of sourgrass. Even under water restriction conditions, the treatments containing mesotrione + atrazine + glyphosate and tembotrione + atrazine + glyphosate provided control greater than 80%. In experiment 2, the combination of ALS inhibitors with glyphosate proved to be a great alternative for the management of sourgrass control. All treatments showed no significant phytotoxicity in soybean for either experiment.