Tuesday, November 14, 2006
172-7
Evaluation of Mesotrione as a Preemergence Herbicide in Established Turfgrass.
James D. McCurdy1, J. Scott McElroy2, and Greg K. Breeden1. (1) University of Tennessee, Knoxville, TN 37996, (2) 2431 Joe Johnson Dr, University of Tennessee-Knoxville, University of Tennessee, Plant Sciences Dept./ 252 Plant Sciences Bldg, Knoxville, TN 37996-4561
Prodiamine is a preemergence herbicide utilized for crabgrass (Digitaria spp.) control in established turfgrass systems. Mesotrione controls crabgrass both pre and postemergence; however, lack of soil residual limits its use as a preemergence herbicide. The addition of mesotrione to prodiamine could potentially delay the application of prodiamine thus providing postemergence crabgrass control and extended preemergence control. Research was conducted to evaluate mesotrione (0.28 kg ai/ha + 0.25% v/v NIS ) and prodiamine (1.12 kg ai/ha), applied alone or in mixture. Applications were made every two weeks from March 15 to May 24. As was expected for prodiamine alone, crabgrass control decreased as application dates progressed from March to May. Conversely, for mesotrione alone, crabgrass control increased from March to May application dates due to its activity as a postemergence or late-preemergence herbicide. Prodiamine + mesotrione tank-mixtures provided consistent crabgrass control across all applications dates. Prodiamine + mesotrione would be an effective tank-mixture in situations where prodiamine alone was not applied in a timely fashion.