The objective of this work was to evaluate the efficiency of the herbicide glyphosate used alone, in combination with chlorimuron-ethyl and quizalofop-p-tefuril as well as the effect of the addition of mineral oil to control adult Digitaria insularis plants in a no-tillage field. Two experiments were conducted under field conditions from November 2005 to February 2006 and from November 2006 to January 2007, at Jaboticabal, São Paulo State, Brazil. Experiments were set in randomized blocks with four replications. In the first experiment (2005/06) it were tested eight combinations among glyphosate (0.72; 1.44; 2.16 and 2.88 kg ha-1), chlorimuron-ethyl (0 and 10 g ha-1) mineral oil (0; 0.5 and 1.0 L ha-1) and an infested, untreated control. In the second experiment (2006/07) it were tested six associations among glyphosate (1.44; 2.16 and 2.88 kg ha-1), quizalofop-p-tefuril (0 and 120 g ha-1), quizalofop-p-tefuril (120 g ha-1) alone and combined to three (0; 0.72 and 1.44 kg ha-1) glyphosate doses, sprayed 15 days after the first application, besides an infested and untreated control. In 2005/06, plants sprayed with higher glyphosate doses, alone or combined with chlorimuron, showed severe injuries, with a control classification ranging from good (71 to 80%) to very good (81 to 90%). Over time plants tillered and showed their recovery potential and the inefficiency of the herbicides to control this weed species. The addition of mineral oil to glyphosate and chlorimuron solution did not entrance its efficiency. In the other experiment, the quizalofop alone or associated with glyphosate, combined to sequential application of glyphosate 1.44 kg ha-1, resulted in the best weed control.
sourgrass; Brazilian cerrado; desiccation; chemical control
