Respostas da soja a aplicação de doses de saflufenacil em isolado ou associadas ao glyphosate simulando resíduos dos herbicidas em tanque

Abstract

Some herbicides, like saflufenacil, can persist as residues in sprayer tanks even after cleaning, inducing phytotoxicity symptoms in sensitive crops. This study simulated potential damage from tank residues of saflufenacil, applied alone or in combination with glyphosate, to soybeans. The experiment employed a randomized block design with four replications. Treatments included: glyphosate (1440 g ha⁻¹) alone; eight doses of saflufenacil alone (1.09, 2.17, 4.38, 8.75, 17.50, 35.00, 52.50, and 70.00 g ha⁻¹); glyphosate combined with each of these saflufenacil doses; and a weed-free control. Phytotoxicity was evaluated at 7, 14, 21, 28, and 35 days after treatment (DAT). Soybean physiological parameters were assessed at 21 DAT, and grain yield components were measured at harvest. Increasing saflufenacil doses caused progressively greater phytotoxicity symptoms, both when applied alone (above 4.38 g ha⁻¹) and in combination with glyphosate (above 2.17 g ha⁻¹). The highest saflufenacil doses, whether applied alone or with glyphosate, negatively impacted soybean physiological variables and grain yield components. Soybeans tolerated saflufenacil applications up to 2.17 g ha⁻¹, applied alone or combined with glyphosate, without significant grain yield loss.