Efficacy of herbicides inhibitors of synthesis of carotenoids in the control of crabgrass species

Abstract

The sugarcane sector currently is difficulties in the weed management in areas with occurrence of crabgrass (Digitaria spp.) is very high. The objective of this study was to evaluate the efficacy of herbicides inhibitors of synthesis of carotenoids in three species of Digitaria horizontalis, Digitaria ciliaris, Digitaria nuda. The experiment was conducted in greenhouse in a completely randomized design with four replications. Dose-response biossays for each species were performed with increasing doses of isoxaflutole (112.5 g i.a. ha^-1) and clomazone (1200 g i.a. ha^-1) applied in pre-emergence, represented by 0; 12.5; 25; 50 and 100% of the dose recommended (N) for use in sugarcane cultivation. The efficacy of the treatments on the different crabgrass species was verified through the evaluation of the visual control score performed at 14, 21 and 30 days after application (DAA) and shoot dry mass (SDM) at 30 DAA. The herbicides isoxaflutole and clomazone provided high levels of fitointoxication and reduction in SDM, demonstrating the efficacy of these herbicides for the crabgrass plants. There was a difference in sensitivity in the lower doses of herbicides used as a function of each species.