Controle e susceptibilidade de capim-braquiária e capim-ruziziensis ao glyphosate e fluazifop-p-butil

Abstract

This study aimed to evaluate the control and susceptibility of signalgrass and ruzigrass in initial growth under different rates of glyphosate and fluazifop-p-butil. The treatments were distributed in a 2 × 6 factorial design, with five repetitions, being two grasses: Brachiaria decumbens cv. Basilisk (signal-grass) and B. ruziziensis (ruzigrass) with six doses of herbicides: 0.00; 0.25; 0.50; 1.00; 1.5 and 2.00 times the commercial dose recommended by manufacturers. At 7, 15, 21, and 30 days after herbicide application (DAA) were evaluated the intoxication in signalgrass and ruzigrass, visually. The glyphosate toxicity was of 100% in both plants, signalgrass and ruzigrass, even at the lowest dose (90 g ha-1), so it can control effectively these species in early growth stage. It was observed that the plants exposed to fluazifop-p-butil showed regrowth only in the doses to 100 g ha-1 and 50 g ha-1 for signalgrass and ruzigrass, respectively. These results confirm the effectiveness of this herbicide molecule in the control of these two species from doses of 200 g ha-1 and 100 g ha-1 for signal grass and ruzigrass, respectively.