Bermuda suppression in zoysia?

Bermudagrass is one of the most difficult species to control due to its extensive stolon and rhizome system, aggressive growth, and tolerance to management and environmental extremes. It is even more difficult to control selectively in another warm season grass, thus it can be a problem wherever zoysiagrass is grown as the desirable turf. Recent research by Scott McElroy and his colleagues at University of Tennessee shows that adding Turflon Ester (triclopyr) to Acclaim (fenoxaprop) increases bermudagrass suppression while increasing safety to the zoysia (Table 1). Adding Turflon maintains the Bermuda suppression of Fusilade, but dramatically improves the safety on zoysia. Three applications of each treatment were made at 28 day intervals starting in early June in this study. Separate stands of zoysia and Bermudagrass were used at this study with the zoysia mowed at either 0.5 inch or 2.0 inch and the Bermudagrass mowed at 3 inches. Our work in selectively controlling creeping bentgrass and Poa trivialis within another grass indicate that mowing heights have a dramatic effect on control and safety. Even though this may also be the case in warm-season grasses, the Tennessee results indicate that Turflon added to either Fusilade or Acclaim has the ability to suppress Bermudagrass in zoysia. The full report is available online in the Journal of Applied Turfgrass Science at http://www.plantmanagementnetwork.org/sub/ats/research/2006/triclopyr/.