Effects of Grooming and Trinexapac-Ethyl Applications On Zoysiagrass Fairways in the Transition Zone.

New zoysiagrass (Zoysia spp.) cultivars are increasingly being used on many golf courses as an alternative to bermudagrass (Cynodon spp.) as they requires less irrigation and  fertility to produce a high quality fairway turf. Data outlining the best management practices for zoysiagrass fairways in the upper transition zone is limited. A two-year study was initiated in 2008 at the University of Tennessee (Knoxville, TN)  evaluating the effects of grooming and trinexapac-ethyl (TE) on  six  zoysiagrass cultivars (‘Diamond’, ‘El Toro’, ‘Cavalier’, ‘Zorro’, ‘Zenith’, and ‘Royal’). The experiment was arranged as a strip-split plot design; cultivar served as the whole plot treatment. Grooming served as the strip-plot treatment; plots were either mowed (1.27 cm) with a walk-behind reel mower equipped with groomers set to a depth of 0.952 cm or mowed (1.27 cm) with a reel mower not equipped with groomers. TE served as the split plot treatment; plots received monthly applications of TE at 4.47 g a.i.ha^-1 per hectare or no TE. Digital image analysis was used to quantify percent cover, turfgrass color, and turfgrass quality. Grooming had no significant effect on percent cover, turfgrass color, or turfgrass quality in 2008. ‘El Toro’ (7.5, 6.8, and 7.1, respectively) and ‘Royal’ (7.1, 7.0, and 6.9, respectively) yielded higher turfgrass color ratings than ‘Diamond’ (5.9, 5.9, and 4.9, respectively) and ‘Zorro’ (5.9, 5.8, and 4.8 respectively).  TE increased turfgrass color ratings for each cultivar compared to the control until 22 October 2008.  These data suggest that trinexapac-ethyl applications to ‘Diamond’, ‘El Toro’, ‘Cavalier’, ‘Zorro’, ‘Zenith’, and ‘Royal’ cultivars of zoysiagrass will improve color in the fall. Grooming treatments had no effect on the zoysiagrass in 2008.