Toxicity assessment of commercial herbicide formulations to Eisenia andrei (Bouché, 1972) in oxisols.

The use of long-residual herbicides can have adverse effects on terrestrial ecosystems. This study assessed the acute and chronic toxicity and avoidance behavior of Eisenia andrei earthworms exposed to nominal concentrations of clomazone, indaziflam, and sulfentrazone, using recommended commercial formulations for sugarcane cultivation. The formulations included Gamit® 360 CS (360 g L-1 of the active ingredient - a.i. - clomazone), Boral® 500 SC (500 g L-1 of a.i. sulfentrazone), and Alion® (500 g L-1 of a.i. indaziflam). Boral® 500 SC induced avoidance at concentrations as low as 1 mg kg-1, while Gamit® 360 CS and Alion® exhibited higher avoidance at 50-75 mg kg-1 and 75-100 mg a.i. kg-1, respectively. Reproduction tests showed significant impacts from Gamit® 360 CS (EC50: 0.572 mg kg-1, EC10: 0.2144 mg kg-1) and Boral® 500 SC (EC50: 0.3941 mg kg-1, EC10: 0.134 mg kg-1). Acute toxicity tests indicated moderate toxicity for Gamit® 360 CS (LC50: 184.12 mg kg-1) and Boral® 500 SC (LC50: 1000 mg kg-1). Gamit® 360 CS reduced biomass at all concentrations, while Boral® 500 SC influenced only at higher levels (500 and 1000 mg kg-1). Results suggest significant acute risks with Gamit® 360 CS, while chronic exposure raises concerns for both Gamit® 360 CS and Boral® 500 SC, indicating potential long-term risks. Alion®'s acute effects were inconclusive, but chronic exposure hints at a possible risk. These findings provide crucial insights for environmental agencies establishing protective limits against herbicide exposure to non-target soil invertebrates.

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.

Pre-harvest desiccation strategies of soybean culture: a scenario without paraquat.

The objective of this study was to evaluate the use of diquat, glufosinate ammonium, saflufenacil and flumioxazim, positioned alone and/or combined, in the pre-harvest desiccation of soybean crops. For this purpose, a field experiment was conducted, with application of the treatments in the phenological stage R 7.2 of soybean. At 3 DAA, the herbicides diquat and their combinations with flumioxazin and ammonium glufosinate, at all doses, resulted in defoliation and desiccation percentages greater than 90%. At 5 DAA, only the flumioxazin and glufosinate ammonium treatments, alone, did not show indices for harvesting. At 10 DAA, only the control differed from the other treatments in relation to desiccation, demonstrating the need to apply desiccants to enable harvest. The results indicate that the combination of herbicides may represent an alternative to reduce doses and increase the efficacy of isolated products through synergism, in addition to operational gains.