06/06/1996

Research Looking for Green, Green Grass of Golf

AUBURN, Ala.- Managing golf putting greens in hot weather can give golf course managers a bad case of the blues. Researchers at Auburn University, however, are trying to cure those blues by finding the perfect green.

Beth Guertal, assistant professor of agronomy and soils at AU, is heading a study evaluating new, more heat tolerant grasses for use on putting greens.

"Many courses pride themselves on creeping bentgrass putting greens," she said." Bentgrasses, however, are cool-season grasses adapted to the northern United States. The hot, humid climates of the southeastern United States can exert a toll on creeping bentgrass greens, and their putting quality may decline rapidly as temperatures rise during the summer."

Previous research and experience has shown that hybrid bermudagrasses are the best adapted grasses for putting greens in warm, humid regions. However, few bermudagrass cultivars with turf quality similar to bentgrass have been identified or developed for use on putting greens.

In 1994, Guertal established a study to identify new bermudagrasses for use on southern putting greens. The study evaluated both cultivars and ecotypes. The study is funded in part by the Alabama Agricultural Experiment Station, the United States Golf Association, the Alabama Turfgrass Association and the Alabama and Gulf Coast chapters of the Golf Course Superintendents Association.

A cultivar, Guertal explained, is a "cultivated variety - one that has been selected through breeding, evaluation, and research as a superior type. Ecotypes, or variants, are usually first observed as an 'off-type' when certain plants within a cultivar demonstrate growth or appearance different from the normal cultivar."

Tifgreen and Tifdwarf are two commercial cultivars released by the Georgia Agricultural Experiment Station and commonly used in the Southeast. Variants often are found in plantings of these cultivars, some of which may have potential as new putting green material. To learn more about the potential of these cultivars and ecotypes for putting greens, Guertal planted grasses on both native soil and United States Golf Association (USGA) putting greens.

"Native soil is soil that is found naturally at the putting green location and has not been amended with sand or foreign soils," Guertal explained. "USGA greens are typically built using approximately 80-90% sand and 10-20% organic amendments."

The research greens were planted with sprigs (stolons) of Tifgreen, Tifdwarf, their ecotypes and other bermudagrass cultivars collected from golf course greens and turf breeders throughout the southeastern United States. Among the grasses evaluated were ecotypes collected from two greens on the Country Club of Mobile golf course, one from the Gulf State Park golf course in Gulf Shores, two new bermudagrass cultivars from the Georgia Agricultural Experiment Station (T596 and TW72) and two African bermudagrasses from the Oklahoma State University turf breeding program.

The grasses were planted in plots located at the AU Turfgrass Research Unit in Auburn. Mowing heights of one-eighth inch and three-sixteenths inch were used to find out if the grasses could withstand close mowing heights.

"One criteria we used for evaluation was how quickly the plots established themselves(rate-of-cover), because the sooner greens are established, the sooner they can be used for play," said Guertal. The grasses also were evaluated for fall color, fall seedhead production, spring greenup and spring seedhead production.

"Color is important because golfers desire a green appearance. Over-abundant seedhead production is an undesirable trait because seedheads are unsightly and affect the putting quality of the green," Guertal explained.

The study has helped identify some new varieties that may have commercial potential and also has allowed golf course superintendents to compare new cultivars to established ones. In addition, the research has shown that there are distinct differences in the way these grasses respond to the different putting green soils.

All the grasses tested established themselves more rapidly on the native green than on the USGA putting green. Bermudagrass grown on the USGA putting green, however, was usually darker than grasses grown on native soil. Seedhead production was greater on the USGA greens.

Tifdwarf, T596 and a Tifdwarf ecotype from the Mobile country club were greener than other grasses. Unfortunately, the Mobile country club ecotype was the only grass to produce a profusion of seedheads in the fall. Two grasses never produced seedheads -- an ecotype selected from the Number 9 green of the Mobile country club and the Georgia cultivar TW72.

"When all factors are examined," said Guertal, "Georgia's new bermudagrass cultivar TW72 shows excellent promise as a bermudagrass for putting greens. Of selected ecotypes, the best performance was demonstrated by selections from a Gulf Shores course and the Number 9 green of the Mobile country club."

Future research will examine how cultural practices, such as mowing height and traffic intensity, affect these grasses. In addition, work will be done to evaluate fertility and waterholding aspects of native soils versus USGA greens.

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News from:

Office of Ag Communications & Marketing

Auburn University College of Agriculture
Alabama Agricultural Experiment Station
3 Comer Hall, Auburn University
Auburn, AL 36849
334-844-4877 (PHONE) 334-844-5892 (FAX)

Contact Jamie Creamer, 334-844-2783 or jcreamer@auburn.edu
Contact Katie Jackson, 334-844-5886 or smithcl@auburn.edu

June 6, 1996