CONTROLE DE CAPIM-AMARGOSO PELO HERBICIDA CLETHODIM ISOLADO E ASSOCIADO A OUTROS INIBIDORES DE ACCase

Abstract

The natural difficulty of controlling adult plants of sourgrass with the presence of resistant resistances, use or use of herbicide alternatives for the best control. The objective of this work was to evaluate the effectiveness of clethodim isolated and associated with other ACCase inhibiting herbicides in the control of sourgrass. For this, two experiments were conducted, one in a greenhouse (first experiment) and another in the field (second experiment). In experiment 1, in adult plants originating from rhizomes, three doses of clethodim (120, 192 and 240 g ha-1) were sprayed and as statistics of clethodim (120 g ha-1) with three dosages of fenoxaprop (55, 88 and 110 g ha-1) and haloxyfop (60, 96 and 120 g ha-1); and in experiment 2, in perennial plants in addition to evaluating the effectiveness of the aforementioned herbicides, associated with clethodim three doses of quizalofop-p-ethyl (25, 40 and 50 g ha-1). After herbicide application, control scores were assigned at 7, 14, 21 and 28 days after application (DAA). At 50 DAA, collect a green aerial part of the plants to assess the plants' ability to regrow. Regardless of the experimental condition (greenhouse or field), up to 28 DAA, the herbicides were used without sourgrass control, but clethodim (120 g ha-1) did not provide a control above 90% of the plants not field. No treatment achieved or definitive control of the species D. insularis. However, a regrowth of the plants was suppressed effectively with the application of higher doses, or when increased as doses of the other ACCase inhibitors, fenoxaprop, haloxyfop and quizalofop in association with clethodim (120 g ha-1). It concludes that clethodim (240 g ha-1) or clethodim + haloxyfop almost reached the definitive control of adult sourgrass plants.