Performance of Winter Overseeded and Colorant-treated ‘Tifway’ Bermudagrass Receiving Weekly Irrigation and Simulated Traffic

Abstract

Municipal water restrictions across the southern and southwestern United States have created additional challenges for maintaining safe playing surfaces on recreational turf facilities. In recent years, many cities within these regions have begun to impose irrigation restrictions during winter months. Although winter overseeding has been regularly practiced in these areas, interest and use of colorants as an alternative to overseeding has grown due to decreasing water availability and budget concerns. Data on relative performance of colorant-treated vs. overseeded dormant turf would be of interest to turf managers, because colorants may be more cost-effective and require less water than winter overseeding. The objectives of this 2-year field study were to evaluate effects of winter treatments on performance (green cover, surface hardness, and soil moisture attributes), turfgrass injury resulting from simulated traffic, and spring transition of ‘Tifway’ bermudagrass (Cynodon dactylon L. × Cynodon transvaalensis Burtt-Davy) under a 1-day per week irrigation schedule. Treatments included 1) untreated bermudagrass, 2) fall colorant-treated bermudagrass, 3) perennial ryegrass (Lolium perenne L.) overseeded bermudagrass, and 4) turf-type annual ryegrass (Lolium multiflorum Lam.) overseeded bermudagrass. In both years, treatment differences were detected for percent green cover, soil volumetric water content (VWC), percent visual turfgrass injury, surface hardness, and percent bermudagrass transition. Percent green cover and visual turfgrass injury levels were similar between annual and perennial ryegrass in year 1, whereas loss of green cover and greater turfgrass injury were noted in annual ryegrass during the spring of year 2. Residual benefits of fall colorant applications extended into February of year 1, but dissipated by late December of year 2, likely due to higher rainfall and warmer temperatures, which prevented full bermudagrass shoot dormancy. Overseeding reduced bermudagrass spring transition by up to 50% compared with untreated and colorant-treated plots. Fall colorant treatments did not accelerate bermudagrass transition compared with untreated plots. Results of the study demonstrate that environmental differences from season to season can impact the relative benefits derived from colorant applications, as well as the performance of annual and perennial ryegrass.