Matching varieties with site characteristics
The University of Massachusetts (UMASS), Amherst, Mass., introduced its July Turfgrass Identification and Selection Workshop this way, “The ultimate performance of a stand of turf depends on matching turfgrass species and varieties with site characteristics, intended use and maintenance level. Knowing what you have is the key to knowing how to manage it.”
Consider all the options. The National Turfgrass Evaluation Program (NTEP) “is designed to develop and coordinate uniform evaluation trials of turfgrass varieties and promising selections in the United States and Canada. Test results can be used to determine if a cultivar is well-adapted to a local area or level of turf maintenance.” That data is posted on the NTEP Web site, www.ntep.org. Test plots are located at multiple sites across the U.S. Compare the data from those sites that most closely match your field conditions, and take advantage of field days to see the test plots and discuss them with turf researchers.
Dr. J. Scott Ebdon, associate professor in the department of plant, soil and insect science at UMASS, oversees the university’s NTEP trials. Ebdon says, “We see the tremendous diversity between species in the tolerance to stress and to wear, with similar diversity taking place within the cultivars of a single species. By using the NTEP data, sports field managers can pick the right species and the right cultivars to get what they want.
|Photo by Mary Owen.||Photo by Mary Owen.|
|A close-up view of the mowing height trials being conducted on Kentucky bluegrass test plots at UMASS.||Wear tolerance trials at UMASS are being conducted by Dr. J. Scott Ebdon.|
|Photo by Mary Owen.||Photo courtesy of Mike Boekholder.|
|Participants of the UMASS Turfgrass Selection Workshop inspect the wear tolerance trials.||This photo, taken April 4, 2008, shows the raised test plots of Sovereign and Patriot bermudagrasses grown on a 90/10 sand profile as spring green-up is beginning.|
“Wise species and cultivar selection includes balancing strengths and weaknesses. One cultivar may have strong early spring green-up, but not do well in the heat of summer. Another cultivar may be strongest in summer performance. The same type of data shows which cultivars rate highest in resistance to specific insects and diseases. Tapping into the NTEP research on all these performance ratings will guide their choices.
“In some instances, three or four cultivars of a single species will give the best results. In others, two or three cultivars in each of two species will do better. Over the course of a field’s life, they may introduce 10 to 12 different cultivars by continually overseeding with new introductions that rate highest in the specific characteristics they want. The best-adapted cultivars will gradually take over.”
Pushing the envelope in turf selection may not provide the quality sports field managers are after, according to Ebdon. He says, “It also could cost more in water, fertilizer and pesticides than working with cultivars better adapted to their conditions. With tight budgets and limited staffing, many turf managers are focusing on keeping the maintenance as low as possible. Selecting the turfgrasses best adapted to their environmental conditions and field use patterns can help them achieve that.”
Mike Boekholder, head groundskeeper for the Philadelphia Phillies at Citizens Bank Park, is a prime example of specific field-focused research. He keeps up to date on NTEP testing at Penn State and at Rutgers, works with his sod supplier on varietal changes they are making and considering, and networks with other sports field managers on their turf programs. He has developed his own test plots in a sod nursery just across the street from the stadium. Currently, he’s testing six blends of bluegrasses and three bermudagrasses.
“We want the best turf for our multiuse field. It has to be adaptive to what we do, providing top playability for the Phillies and withstanding all the other events we put on it, including a major concert each year. We work with a blend of 10 to 12 bluegrasses, with the specific varieties changing over the years based on what we’ve identified as key performance factors they will add to the blend overall,” Boekholder says.
“The increased cold tolerance of some of the newer bermudagrass varieties makes them a workable option for our region of the transition zone. Tony Leonard converted the Philadelphia Eagles field to Patriot bermudagrass in the spring of 2007. He’s getting very good results with it, and reports the heating system is not an issue in its success. We’re evaluating the bermudagrasses along with the bluegrasses in our test plots, so we’ll have the information collected as we review all the options.”
|Photos on this page by Alan Greene.|
|This multisport practice field at Trotwood Park in Winter Springs, Fla., is being prepared for the sprigging of SeaDwarf paspalum.|
|The same practice field at Trotwood Park in Winter Springs, Fla., after the turf was established.|
Boekholder notes that bermudagrasses generally are more durable and user-friendly for the intense wear of football and soccer. He classifies the newer bermudagrass varieties as impressive in terms of their early green-up and ability to take the typical winters of the region: not extremely harsh or overly mild. He says, “Our Riviera test plot was 100 percent ready to go on April 22, just slightly behind our bluegrass plots. All three bermudagrass plots have retained their color into late October or early November.
“These grasses are so different from cool-season turf and from the old bermudas; the biggest challenge is getting out of the comfort zone to adjust to new management practices. Overseeding is one example. We worked with a local Patriot bermudagrass field, overseeding in late September as we would have with the older varieties of bermuda. The Patriot was so aggressive that time of year, it was hard to get the seed through the dense turf. We could have gone in a week or maybe two to three weeks later with acceptable results. So, the better plan would be to retain greater flexibility, letting the weather dictate the timing each season. On fields with soccer the single fall sport, and only limited spring practices, overseeding might not be needed. The dormant bermuda could be painted green for spring use, with the paint doubling as a liquid growth blanket for faster warm up.”
The synthetic turf industry has worked hard to put out a good product. They’ve listened to the complaints about the first generation of carpets and focused on bringing many of the attributes of natural turfgrasses into the development of their improved offerings.
Most sports field managers now acknowledge that there is a place for synthetic surfaces within the field mix, and that the synthetics can become a tool to preserve the natural grass fields by bearing much of the wear during adverse conditions and overuse situations.
Looking outside the box for solutions will be key to the retention of natural turf fields.
Consider the costs of a synthetic field installation compared to sprigging that same field with bermudagrass. How many years of sprigging would it take to equal those dollars? The questions of safety and playability remain. How much turf cover will the field retain by the end of the fall playing season? How does that change if the field is overseeded with a cool-season turfgrass, retaining the dormant bermuda as a cushion? How much turf cover will be in place for early spring season play if the field is bermuda only? How does that differ if the field is overseeded? What percentage of the field surface will require sprigging? How much downtime is available for the sprigs to take hold and fill in? Is that sufficient to provide full-field turf cover at the beginning of the fall season?
Boekholder says, “Those are the kinds of questions sports field managers need to have the answers for in anticipation of the synthetic field challenge. That makes researching all the options even more important. We need to be realistic in presenting the long-term costs of natural turfgrass management and include the long-term maintenance costs of the synthetic surfaces to provide a more accurate comparison.”
Experimentation has always been part of the program for Chuck Pula, parks and recreation director for the city of Winter Springs, Fla. Firmly grounded in the warm-season turfgrass zone, he and Parks Superintendent Alan Greene have consistently applied out-of-the-box strategies to match the best grasses to all of their sites.
For over five years, they’ve been working with bermudagrasses and paspalums on the sports fields, comparing the pros and cons of each variety. Their first installation of SeaIsle 1 paspalum on the football field of Torcaso Park provided the wear resistance they were after, plus early and late-season color retention. They experimented with overseeding perennial ryegrass one season and were able to remove it for the spring transition with solar salt. They gained little in playability and extended color by the process, so they no longer overseed that field.
The game fields within Central Winds Park are Tifway 419 bermudagrass overseeded with perennial ryegrass. A 28-acre addition, adjacent to the park, was dedicated to eight practice fields and has SeaDwarf paspalum, which has provided better wear resistance. Trotwood Park has four multiuse fields for soccer, lacrosse and football, and three for baseball and softball. Pula says, “These fields are a native sandy soil and were originally Bahiagrass, but it couldn’t stand up to the level of use. Seeking a sturdier turf, we cored and sprigged SeaDwarf paspalum in two of the practice fields. It performed well, and we were considering converting the two other multiuse fields to it.
“At that point, the reclaimed water supply level dropped, and we had an extended period with no irrigation on the practice fields. Common bermudagrass infiltrated the paspalum. We tried to eliminate it in those fields with solar salt applications and with spot applications of Roundup, but it was an ongoing battle. So, we decided to switch strategies and encourage it instead, letting the two turf types coexist on those fields and spread onto the others.
“The outcome has been great. The paspalum serves as a base, with the common bermuda flowing over the top. The SeaDwarf holds color longer in the fall and comes back faster in the spring. The common bermuda on the other practice fields has basically taken over there. It’s the tougher grass when water is severely limited.”
Budgets are an increasing consideration with Florida’s Proposition I referendum cutting city funding statewide, and the gas costs, housing issues and overall economy producing fewer dollars coming into the state. “We’re exploring every step we can take to reduce costs,” says Pula. “By encouraging the common bermuda on the practice fields, we’ve been able to reduce the fertilization program to two applications of slow-release 15-0-15, the first at green-up and the second at midseason. We’re aggressive with our IPM program on weeds and insects, but have had no disease problems and less need for aeration, and we don’t overseed with rye.”
They’re also experimenting with Aloha paspalum, installing it at a park site with midlevel turf usage in the playgrounds and around the basketball courts. Pula says, “It was the newest variety at the time, so we wanted to see what it would do for us. Our experimentation has clearly shown there’s no one perfect turfgrass for every situation. It’s all about exploring the possibilities to find the best fit for the specific needs of specific fields and continually fine-tuning the program to achieve your goals with the least possible expense.”
Suz Trusty is a partner in Trusty & Associates, a communications and market research firm located in Council Bluffs, Iowa.