New Bermudagrass Cultivar Performance Under Simulated Athletic Traffic.

New bermudagrass (Cynodon spp.) cultivars offer improved cold tolerance, but little is known about how these cultivars tolerate foot traffic when maintained under athletic field conditions. Therefore, a two-year field study was conducted at the University of Tennessee Center for Athletic Field Safety in Knoxville, TN to evaluate the traffic tolerance of four hybrid bermudagrass (C. dactylon x C. transvaalensis) cultivars (‘Latitude 36’, ‘Patriot’, ‘NorthBridge’, and ‘Tifway’) and two improved common bermudagrass cultivars ('Riviera’ and ‘Hollywood’) maintained as athletic field playing surfaces. The experiment was arranged as a split plot design with cultivars receiving the factorial combination of overseeding with perennial ryegrass (Lolium perenne; 0 kg PLS ha^-1 or 593 kg PLS ha^-1) and variable mowing height (1.2 cm or 2.2 cm). All plots were subjected to a total of 24 simulated traffic events (STE) annually using a CADY traffic simulator beginning on 20 Aug. 2012 and 19 Aug. 2013 and applied three times each week. Digital image analysis was taken after every three STE to measure percent green cover. Percent green cover data were analyzed using non-linear regression techniques to determine the rate at which green cover was lost in response to traffic. In both years, all cultivars lost cover faster when maintained at 1.2 cm compared to 2.2 cm. Additionally, non-overseeded plots lost cover at a higher rate than those receiving overseeding. Non-overseeded ‘NorthBridge’ and ‘Latitude 36’ maintained at 2.2 cm lost cover at a lower rate than ‘Tifway’ and ‘Patriot’ maintained at the same height each year. These data indicate that traffic tolerance of ‘Latitude 36’ and ‘NorthBridge’ exceeds that of Tifway and Patriot bermudagrass. Additionally, mowing at 2.2 cm coupled with perennial ryegrass overseeding can improve traffic tolerance compared to maintained, non-overseeded turf at lower heights of cut. These results can help athletic field managers improve traffic tolerance on athletic fields.