Source: www.TurfMagazine.com
Research turns to varieties that require fewer inputs
These days, golf course superintendents are in need of turfgrasses that can perform with fewer inputs—less water, pesticides, fertilizer, etc. Turfgrass researchers and breeders are working to identify and improve those types of grasses.
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Jeff Nus, manager of research with the USGA’s Green Section, says the program has started spending a larger proportion of its research funds on turfgrass physiology, breeding and genetics.
One area the USGA is paying particular attention to is the development of cool-season grasses with greater salt tolerance. “We think that’s very important, because more and more golf courses, especially in the Southwest and the West, are being required by code to use effluent water, which typically has a much higher salt content,” Nus explains.
In many cases, that means breeding salt-tolerance into cool-season grasses. “Perennial ryegrass is one that we’re looking at, Kentucky bluegrass is another. We’re also looking for lower water use in both of those species,” says Nus. “We need to identify those genotypes which possess those abilities, and then identify the genes for that. Then we need to use either conventional breeding or molecular breeding techniques to get those genes into grasses that have high quality.”
New technologies and techniques have helped speed up the breeding process, he explains, citing as examples work being done at Rutgers and Utah State to screen grasses by testing them not only out in the field, but also in greenhouse settings. While conventional breeding is still the mainstay of producing new turfgrasses, molecular genetics techniques have taken hold in the turfgrass breeding industry.
“For example, with creeping bentgrass there has been a species identified of ‘thermal’ Agrostis scabra that is tolerant of very high soil temperatures, because it grows right around geothermal vent sites. The idea is to identify the genes and physiological processes, and insert those genes through molecular genetics into varieties that we already have on the market,” Nus explains. “We’re trying to gain the benefits that Mother Nature has already given us in organisms that have evolved over millions of years.”
Because of their native habitats, warm-season grasses have evolved over thousands of years to be more salt-tolerant than cool-season grasses. Seashore paspalum, for instance, is accustomed to growing around saltwater, but it nonetheless took years of research to produce the seashore paspalum grasses that are now available.
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One grass that’s piqued the interest of researchers is inland salt grass, which was found in the inland mountain regions, where there also is a lot of natural salt buildup. “Right now, that grass would seem to be destined for use in roughs, but that was also the case with buffalograss years ago, but clearly there are types now that can be mowed at fairway heights. So, it would be unfair to characterize the long-term use of inland salt, or any other grass we’ve just begun to work with, as being suited only for roughs. Clearly there is potential there—we don’t want to limit ourselves in the way we think about those grasses,” says Nus.
Kevin Morris, executive director of the National Turfgrass Evaluation Program (NTEP), says, “There is definitely increased emphasis in specific traits. Researchers are taking traditional species, such as perennial ryegrass, and screening them more for better drought tolerance or salt tolerance. It’s not as easy to breed for those things: it’s usually a longer process with more genetics involved than just selecting grasses that have a dark green color or better density.”
While people still want grasses that are dark green and dense, if a grass can perform well with less water and other inputs, “maybe it doesn’t have to be the absolute darkest or the densest around,” says Morris. “We’re still going to evaluate appearance, but we’re changing our program [NTEP] a bit to look at those other traits, as well.” He adds that because there are so many attractive grasses on the market these days compared to 25 years ago, scientists have a good place to start when looking to further refine traditional grasses with specific low-maintenance characteristics.
While there is a lot of interest in less-traditional grasses such as seashore paspalum that promise low-maintenance or salt-tolerance attributes, Morris encourages superintendents to learn more about the particular cultivars before using any grass at their course. “Some of these grasses have been planted at a number of golf courses without really ever having been evaluated in independent trials,” he explains. “There are some advantages to paspalum, and some of them can be planted wall-to-wall on golf courses. I think they can work quite well in a number of situations, particularly on courses using effluent water, but people are still learning to manage these grasses. It’s not the same as bermudagrass, and there’s still some question about its cold-weather hardiness. We really don’t know how far north these grasses can be used.”
Morris says there is growing pressure in the form of local and state regulations and federal voluntary programs to use less water in turfgrass irrigation. He explains. “I think golf course superintendents have responded well, they’ve reduced irrigation a lot over the years and installed more out-of-play areas using native grasses.”
While in the past, the development of high-quality turfgrasses for golf courses has helped to drive funding and innovations throughout the landscape industry, Morris points out that residential watering restrictions have pushed that segment forward, and in the future, golf courses may benefit from grasses being designed for non-golf use. “That work will pay off for the golf industry,” he says. While the landscape industry is under the most pressure to reduce water use, it’s a certainty that the golf industry will soon face that same pressure, and will need improved grasses to comply.
Even in the few areas of the country where there currently are no watering restrictions or effluent mandates, superintendents are interested in these types of grasses, says Nus. “Operating expenses on golf courses are being scrutinized more than ever,” he points out. That includes the cost of purchasing municipal water and the expense of pumping water out of a well. While superintendents continue to look for ways to keep costs down, researchers continue their quest to develop turfgrasses that will help achieve that goal, grasses that are dark green and dense, but can perform well with fewer inputs.
Patrick White is a freelance writer and editor who is always on the lookout for interesting and unusual stories.