Field Sandbur (Cenchrus pauciflorus) Control in Pastures Using Gramxone, Roundup Ultra, or Touchdown
Keywords:bermudagrass, efficacy, dry matter, grassbur, glyphosate, paraquate, sandbur, sulfosate
Field studies were conducted during the 1997 and 1998 growing season to eval uate Gramoxone (paraquat), Roundup Ultra (glyphosate), or Touchdown (sulfosate) for field sandbur control, 'Coastal' bermudgrass tolerance, and effect on bermuda grass yield. All herbicides were applied within eight d of bermudagrass cut except in 1998 when herbicides were applied 17 d after cutting. Roundup Ultra at 0.5 and 1.0 pt/A controlled 90% field sandbur while Touchdown at 0.5 and 1.0 pt/A controlled 89%. Gramoxone control of field sandbur ranged from 61 to 94 %. Bermudagrass injury (stunting) was greater with the 1.0 pt/A rate of RoundupUltra or Touchdown. Injury was less than 10% in most instances when herbicides were applied within 8 d of bermudagrass cut. When herbicides were applied 17 d after bermudagrass cut, bermudagrass injury varied from 11 to 93% and resulted in some bermudagrass death. Coastal bermudagrass yield was not affected by any herbicide treatments applied within 8 d of cutting when compared with the untreated check.