Mowing and Overseeding Practices Affect the Traffic Tolerance of ‘Tifway' Hybrid Bermudagrass Athletic Fields in the Transition Zone.

Bermudagrass (Cynodon spp.) athletic fields are often overseeded with perennial ryegrass (Lolium perenne) to improve aesthetic and functional quality during late fall and early winter.  Data outlining the effects of mowing and overseeding on the traffic tolerance of ‘Tifway’ hybrid bermudagrass is limited. A study was conducted at the University of Tennessee (Knoxville, TN) in 2007 and 2008 to investigate the effects of mowing and overseeding on the traffic tolerance of ‘Tifway’ hybrid bermudagrass. The experiment was arranged as a split-plot design with three replications. Mowing practice (reel mower equipped with groomers set to a depth of 1.90 cm,   reel mower without groomers, and a rotary mower) served as the whole plot treatment.  All mowers were set to a height of 2.2 cm, and mowing treatments were applied three times per week. Overseeding rate served as the sub-plot treatment. Five different rates of perennial ryegrass were evaluated: 0 kg ha^-1, 224 kg ha^-1, 4448.51 kg ha^-1, 672.77 kg ha^-1 and 897.02 kg ha^-1. Plots were subjected to a minimum of 17 games of simulated traffic applied with a CADY traffic simulator in both years.  Digital image analysis was used to quantify percent cover, turfgrass color, and turfgrass quality. Trend analysis was used to separate overseeding treatment means. Overseeding rate had a significant linear effect on turfgrass cover under simulated traffic After 17 games of simulated traffic in 2007, percent cover for plots overseeded at 0 kg ha^-1 measured 72% compared 93% for plots overseeded at 897 kg ha^-1. A similar response was observed in 2008. A significant mower treatment by year interaction was reported for percent cover data on 15 out of 17 rating dates. These data suggest that increases in overseeding rate can improve the cover of Tifway hybrid bermudagrass athletic fields under simulated traffic.