CONTROLE SEQUENCIAL DE Eleusine indica NA CULTURA DA SOJA EM DIFERENTES ÉPOCAS DE APLICAÇÃO

Abstract

The soybean crop (Glycine max (L.) Merr.) faces significant losses caused by weed interference, highlighting goosegrass (Eleusine indica), whose resistance to glyphosate has intensified in Brazilian producing regions. The objective of this study was to evaluate the efficacy of three treatments with the herbicides — Ammonium Glufosinate (Liberty®), Glyphosate (Zapp Qi 620), and the association Glufosinate + Flumioxazin (Liberty® + Sumyzin®) — applied at different sequential intervals in the control of E. indica in the soybean crop, in Correntina-BA. The experiment was conducted in the 2024/2025 crop year, in a randomized block design, in a 3 × 6 + 1 factorial scheme, with four replications. The factors consisted of three herbicide treatments and six intervals between sequential applications (1, 3, 5, 7, 10, and 14 days after the application of the initial management), plus an additional treatment (control without application). The control efficacy was visually evaluated at 7, 14, 21, 28, 35, and 42 days after application (DAA), on a scale from 0 to 100%. Data were subjected to analysis of variance with the F-test at 5% probability, comparing the means by the Scott-Knott test at 5%. There was a significant interaction (P<0.01) between herbicides and application intervals in all evaluations. In short intervals (1 day), Glyphosate presented superior performance from 21 DAA onwards, reaching 98% of control, due to its systemic action. In long intervals (14 days), the association Glufosinate + Flumioxazin was the most efficient, maintaining 92% of control at 42 DAA, while Glyphosate and Glufosinate alone reached 83% and 79.75%, respectively. It is concluded that the efficiency of the sequential control of E. indica depends on the interaction between the mechanism of action of the herbicide and the interval between applications, with the association Glufosinate + Flumioxazin being the most robust strategy for plant management in advanced stages and for areas with a history of resistance.