Evaluation of Mowing Practices and Perennial Ryegrass Overseeding for Existing and Potential Bermudagrass Varieties for Athletic Fields.

Bermudagrass (Cynodon dactylon L. Pers.) is one of the most widely used turfgrass’ on sports fields in the south and transition zone. Tifton varieties such as ‘Tifway’ and ‘Tifsport’ are among the most popular choices for athletic fields. In recent years many new Tifton varieties have been developed. In addition, alternative mowing practices such as grooming are also coming into increased practice. With the limited budgets of many sports fields these varieties and mowing techniques should be assessed in an overseeded and not overseeded turfgrass stand. A two year study was performed at the University of Tennessee Knoxville, TN to compare eight Tifton bermudagrass varieties and how they perform under simulated athletic field traffic. The varieties used were ‘Tifway’, ‘Tifsport’, ‘Tifton 11’, and five experimental varieties, ‘2004-76’, ‘2004-83’, ‘2004-78’, ‘ST-5’ and ‘2004-77’. Over the period of this study each variety was subject to two mowing treatments and an overseeded or not overseeded treatment. Each plot was mowed, or mowed plus groomed three days a week until trafficking was initiated in the late fall. Overseeding was done with perennial ryegrass (Lolium perenne L.) on 22 September 2006 and 1 October 2007 at 67 g m^-2. After each trafficking event digital image analysis was performed to measure turfgrass quality, color, and percent green cover. Surface hardness was measured using the Clegg impact hammer. Results showed that mowing practice had no major effect on turfgrass quality and percent green cover in 2006, but in 2007 greater percent cover and quality were shown in the groomed treatments.   At the end of the season, when overseeded, experimental ‘ST-5’ bermudagrass and when not overseeded, experimental variety ‘2004-78’ bermudagrass had the greatest turfgrass quality and percent green color.