SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/49194
include a perennial ryegrass test established in the fall of 2010 to assess the wear tolerances among 88 perennial ryegrass entries maintained under close height of cut (0.375 inch). In 2011, the following perennial ryegrass entries provided the best wear toler- ance: 2NJK, APR-2036, BAR Lp 10970, DLF LGD-3022, GO- PR60, IS-PR 479, JR-192, and PST-2A G4. Many of the more wear tolerant entries exhibited higher shoot densities and better overall turfgrass quality under close height of cut. This wear study will continue over the next three growing seasons. A new wear trial was also established in the fall of 2011 to assess the wear tolerance of 82 Kentucky bluegrass cultivars. These entries will be assessed for their wear tolerance over the next four growing seasons begin- ning in the spring of 2012. Sponsor: National Turfgrass Evaluation Program Efficient Irrigation for Recreational Turf in New England: Evapotranspiration and Crop Coefficients, by J. Scott Ebdon, PhD and Michelle DaCosta, Ph.D. This is a relatively new test that was planted in the fall of 2009 to measure evapotranspiration (ET) losses from pure stands of Kentucky bluegrass (Touchdown) and perennial ryegrass (Exacta) maintained at sports grass height of cut (1.25 and 2.5 inch), and creeping bentgrass (Memorial) main- tained at fairway (0.375 inch) and greens height (0.125 inch). Dif- ferent N fertility rates including 2 and 4 pounds per 1,000 ft2 are also being compared. Daily and monthly crop coefficients (Kc) de- rived from reference ET values from weather stations and actual turf ET are being measured during the summer irrigation season. Crop coefficients are values used to estimate ET rates for specific crops, in this case, for various turfgrass species and cultivars. After 2 years of study the effect of N and height of cut within the species had little influence on ET and Kc values. However, Kentucky bluegrass as a species exhibited significantly higher ET and higher Kc values than perennial ryegrass, and in turn, peren- nial ryegrass exhibited higher ET rates and Kc values than golf turf. In other words, Kentucky bluegrass used more water than perennial ryegrass which used more water than creeping bentgrass. When the study is completed in 2013, these results should provide reliable Kc values that can be used to assist turf managers in applying irrigation water more efficiently to sports and golf turf in the cool-humid New England region. Sponsors: New England Regional Turfgrass Foundation and the United States Golf Association. Improving Winter Hardiness of Perennial Ryegrass, by Michelle DaCosta, Ph.D. and J. Scott Ebdon, PhD. Perennial rye- grass is a cool-season turfgrass species that is widely used on ath- letic fields due to its rapid establishment and superior traffic tolerance. Compared to other cool-season turfgrasses, however, perennial ryegrass can be susceptible to freezing injury in northern climatic regions. In one study, we evaluated different perennial rye- grass accessions with varying levels of freezing tolerance, and iden- tified specific protective compounds that were associated with better freezing tolerance. Based on this research, we have con- ducted additional studies to exploit the accumulation of protective compounds during cold hardening in perennial ryegrass. For ex- ample, we determined that exposing plants to mild drought stress www.stma.org SportsTurf 9