Zenith zoysia grass covers both the infield and outfield in this parks and recreation baseball field.

When selecting seed, there’s much to consider. The results of testing conducted under the parameters of the National Turfgrass Evaluation Program (NTEP) provide key information to help determine if a cultivar is well adapted to the local area, anticipated field use and level of maintenance. With NTEP’s report postings of 2010 test data for several grass species in June and July 2011, some new cultivars drew attention for their performance, while results on some cultivars already on the market sparked new interest for specific uses. Additional testing by university researchers is also taking place at multiple sites across the nation, with seed companies closely following the performance of their current and potential varieties.

Dr. Leah Brilman, director of research and technical services for Seed Research of Oregon (www.sroseed.com), reports the introduction of a new turf-type annual ryegrass, Annuity. “Its primary use is to assist in transition and overseeding and quick establishment under cool soil situations,” Brilman says. “The other news is the NTEP report on Yukon, our seeded bermuda developed for cold tolerance. At mowing heights ranging from .5 to 1.5 inches, it not only holds color later in the fall and survives harsh winters; it also greens up early in the spring. It can be seeded as early as April, much earlier than sprigging or sodding could take place. Water use can be trimmed by as much as 25 percent as compared to hybrid bermudas. For sports field managers, its excellent performance in wear tolerance, shear strength and divot recovery are especially important. It’s in full production now.”

Jacklin Seed’s new Gly-Ryes, JS501 and Replay, are put to the test as glyphosate is applied over the area to eradicate Poa annua.

Promotion of Zenith zoysia grass seed to the sports field market is new to the U.S., according to Dr. Tim Bowyer of the Patten Seed Company (www.pattenseed.com). Zenith, a three clone synthetic variety, is the first hybrid zoysiagrass cultivar that can be established by seed. It’s also available as sod. Patten Seed first introduced it to the landscape market, then to golf courses and now to sports fields.

“Zenith seed costs approximately 10 percent of sod costs for the same area,” says Bowyer. “Spread is slow unless managed for grow-in, but with proper fertility, adequate moisture and hot weather, the rate of spread is good. Once established, it tolerates extreme heat and cold, performing well in a wide geographic region from Tennessee to Long Island, N.Y., in Ohio, Kansas and Illinois, and west to California and Oregon. It’s similar in quality to bermuda in density and serviceability, yet with lower fertilization and water needs and less frequent mowing required, maintenance costs are reduced. On one municipal baseball field in Illinois, the only visible wear was on a small section of the turf base paths after 200 games there this past spring.”

Bowyer notes overseeding is not recommended, as the competition will inhibit or postpone green-up in the spring, and suggests spraying with green colorant instead for early or late season color. He says, “Zenith will go dormant during extreme drought, but it greens up quickly when moisture is available. Sod is the best choice for in-season repair of wear areas, so consider establishing a small on-site sod farm maintained under field conditions.”

New this year is Cezanne RZ, a tall fescue that exhibits rhizomatous traits that enable it to fill in worn areas. Murray Wingate, turfgrass marketing and sales manager for Lebanon Turf Products (www.lebanonturf.com), says, “That attribute, combined with excellent density and very good traffic and drought tolerance, make it a good fit for sports fields. The medium leaf texture and dark green color provide the aesthetics of top-quality fields with the durability and lower inputs typical of tall fescues. It also has excellent brown patch resistance. It’s now available in our Winning Colors Plus mix, too.”

Wingate notes 2011 is the first full year on the market for Shiraz Kentucky bluegrass. He says, “It’s quick to establish, with a deep green color that holds well into the winter and gives rapid green-up in the spring. It shows strong tolerance to both shade and drought and performs well with close mowing.”

Wayne Horman, director for Scotts Professional Seed (www.scottsproseed.com), says, “While we’re not rolling out new varieties this year, some of the bluegrass cultivars that had limited availability are in good supply for 2011. One of those is Avalanche, an aggressive Kentucky bluegrass that produces a dense cover that stands up to traffic. It performs well in blends and mixes, and is excellent for overseeding existing fields.”

Another cultivar is Jump Start, a drought, heat and wear-tolerant bluegrass with resistance to a wide range of diseases. Horman says, “Jump Start has quicker germination than most bluegrasses, though it doesn’t establish any faster. In many 50-50 blue-rye mixes, the rye germinates so much faster that the results are close to 95 percent rye and 5 percent blue in actual cover. Jump Start’s quick germination gives it a competitive advantage in mixes and for overseeding.”

Thermal bluegrass, which started as a grass for the south, is now being used in a broader area, from a football stadium in Kansas City to multiple major league baseball ballparks. Horman says, “It’s also 20 percent of the mix in our Thermal MVP (80 percent bluegrasses and 20 percent perennial ryegrasses), used for establishing new athletic fields and overseeding existing fields during the heat of the summer, and in Thermal Sports Turf (50:50), developed for wear tolerance and rapid fill-in.”

Barenbrug USA (www.barusa.com) introduced RPR (Regenerating Perennial Ryegrass) in January 2010. With pseudo-stolons for regeneration, RPR exhibits the superior wear tolerance required for the traffic on heavily used sports fields. Christiaan Arends, turf product manager, says, “We’ll have the first crop of the new RPR Bargamma this year. It’s from the same breeding program as our previous RPR varieties, and is a great addition to incorporate into the lineup.”

Arends notes that a number of the bluegrasses in their Turf Blue program, including Barimpala, Barrari, Barduke and BAR VV 0709, are, “exceeding the researcher’s expectations” in the Michigan State University Traffic Tolerance Trial. Arends says, “They’re surpassing all others in both the blend and monostand categories, continuing to exhibit good turf cover throughout continuous game simulation. With their rapid spring green up, their performance in early May was just as strong as it was last fall.”

Arends reports new trials with overseeding of the company’s SOS (Super Over Seeding) system are underway in Texas, North Carolina, Oklahoma and three locations in Florida. He says, “SOS combines our turf-type annual ryegrass Panterra and Panterra V with perennial ryegrasses, adapting those varieties and percentages of each cultivar to match the specific climatic parameters of the region. For overseeding of bermudagrass, the selection of varieties also considers the speed of the spring transition that best meets anticipated field use. I visited most of the sites this summer and the quality of the annual rye is very good. I think we’re getting very close to the point where there will be no reason to use the perennial rye anymore in seasonal overseeding of the bermudagrasses, unless they want the cool-season turf to linger into the very late spring or early summer. The fast establishment also makes SOS a great choice for overseeding the cool-season grasses in the fall, when quick cover is needed to alleviate wear.”

Mark Grundman, senior technical manager for Jacklin Seed by Simplot (www.simplot.com/turf/jacklin/), reports on a major new introduction for 2011, the company’s first two cultivars in a series of perennial ryegrasses that can tolerate rates of glyphosate that obliterate Poa annua. He says, “The first of Jacklin’s Gly-Ryes are JS501 and Replay. They are not transgenic glyphosate-resistant varieties, often called GE (genetically engineered) or GMOs (genetically modified organisms). The tolerance trait that blocks the plant from the glyphosate mode of action was discovered in a natural mutation and bred and hybridized to produce varieties with a higher degree of glyphosate tolerance and better turf quality. They can withstand .25 pound of acid equivalent per acre. (That’s between 8 to 12 fluid ounces of glyphosate product, depending on the formulation.)

Because the Gly-Ryes are a natural product, certain precautions are needed under specific weather conditions and growth stages, but that’s a small concession for the big benefit of wiping out an infestation of Poa annua.”

Also new is Jacklin’s CSI-Rye, a fine-textured, high shoot density perennial ryegrass that spreads laterally by developing reproductive tillers, allowing it to repair wear areas. Grundman says, “Its top growth is as much as 50 percent slower than standard perennial ryes, greatly reducing mowing time and costs. It has a deep green color that blends well with our elite Kentucky bluegrasses. Its disease resistance is comparable to other ryes. The seeding rate is significantly reduced, requiring only 3 pounds per 1,000 square feet.”

Jacklin’s 4-Season Kentucky bluegrass hit the market in late 2010, so it has had the opportunity to show its deep green color and early spring green up and growth in actual playing conditions. Grundman says, “Our Rush Kentucky Bluegrass was bred specifically for competitiveness with Poa annua, even under close mowing conditions. It’s an aggressive grass, even during the cool periods when most Poa infestations occur, so it keeps the Poa at bay. We’ve been developing customized mixes for some Chicago area sports fields, combining Rush, 4-Season and CSI-Rye with excellent results.”

Hollywood is the new seeded bermuda available this fall. “It has exceptional cold tolerance,” says Grundman. “It can take several hard frosts before it goes off-color, so sports fields get active growth longer into the fall season. It has early spring green up, too, and can be seeded when soil temperatures are in the 70s, earlier than most other cultivars.”

Overseeding strategies

Whatever the varieties chosen, overseeding strategies will focus on maintaining turf cover. In ongoing research at Iowa State University, graduate student Andrew Hoiberg and Dr. Dave Minner have been tracking the results of high-volume seeding rates, testing both continuous and single seeding applications with Kentucky bluegrass, perennial ryegrass and turf-type tall fescue to form a seed bank to create and sustain turf cover during intense traffic. Hoiberg says, “In the second year of testing, we’re again finding the ability of the seeds to form a bank is fairly limited, though at the end of the traffic season, some reserve seed remains. Based on initial results, our suggestion for the greatest overall turf cover is for application early in September using at least half of the total seed available, followed by additional applications spread throughout the traffic season to form a transient seed bank.”

The author is a contributing editor for SportsField Management.