Ácido salicílico e acibenzolar-S-methyl como atenuadores de fitointoxicação causada pelo chlorimuron-ethyl na cultura da soja

Abstract

Salicylic acid (SA) and acibenzolar-S-methyl (ASM) can be used as biotic/abiotic stress attenuators in plants, thus, there are few studies that reduce the negative effects of herbicide use on plants. Therefore, this study aimed the effect of SA and ASM as attenuators of phytointoxication caused by chlorimuron-ethyl in soybean crop. The experiment was carried out in a greenhouse in a randomized complete block design with five replicates. The treatments were not studied V3-V4 in the soybean crop were: control (without herbicide, without SA and ASM); SA (1.0 mM); ASM (1.0 mM); SA 7 days before application of the herbicide + chlorimuron-ethyl (1.0 mM + 100 g ha^-1 respectively); ASM 7 days before application of the herbicide + chlorimuron-ethyl (1.0 mM + 100 g ha^-1, respectively); chlorimuron-ethyl (100 g ha^-1); SA in syrup mixture + chlorimuron-ethyl (1.0 mM + 100 g ha^-1, respectively) and ASM in syrup mixture + chlorimuron-ethyl (1.0 mM + 100 g ha^-1, respectively). After three hours of application and at 3, 7, 14, 21 and 28 days after application (DAA), electron transport rate (ETR) evaluations were performed. On the same days the symptoms of phytointoxication and the estimation of leaf area (LA) were evaluated. At 28 DAA, plant height and dry shoot biomass were measured. The application of SA and ASM, before or in combination with chlorimuron-ethyl herbicide, reduced phytointoxication symptoms, maintained ETR indexes close to the control treatment, and minimized the reductions of LA, height and dry biomass. The application of SA and ASM attenuated the stress caused by chlorimuron-ethyl in soybean crop.