The Doctor Says
Turfgrass is a major contributor to playability and enjoyment of the golf game. Species and variety selection, together with turfgrass management, determines playability and how specific golf courses are is perceived by golfing visitors. The most exciting design can be ruined by poor turfgrass selection and management. However, by the same token, every design can be enhanced by “excellent” turfgrass conditions such that the golfing experience is not only rewarding, but perhaps, even extraordinary.
The most important statements that can be made in a discussion like this are:
- There are no perfect grasses; some species perform better in specific environments and under certain management regimes than others;
- The key in the decision process is to understand the environmental stresses that will be placed on the turfgrass and how they influence performance. It is essential to know how specific grasses respond to stressful and non-stressful situations;
- It is important to know and understand the expectations of the golfers, i.e. whether the “WOW” factor is important; and
- What will be the management expertise available to oversee the golf course?
The golf green is obviously the most important part of the golf course. Golfers will tolerate greater variation and less quality anywhere on the golf course other than the greens. Dr. James B. Beard stated in his book “Turf Management for Golf Courses” that greens represent only 1.75% of the golf course area, but play a role in 75% of all golf strokes. Appropriately then, while the greens encompass a small percentage of the golf course area, they receive the most attention, intensive management and resources. Thus it stands to reason that species selection for greens should have priority.
(Cynodon dactylon, C. transvaalensis and C.transvaalensis x C. dactylon)
Within the Cynodon genus there are numerous varieties available. All of the improved varieties adapted to golf greens trace their heritage to interspecies crosses between C. dactylon and C. transvaalensis. the current varieties are mutasnt selections from Tifgreen, Tifdwarf golf greens or in the case of TifEagle an intentional mutation caused by cobalt radiation.
Within these varieties there are two primary groupings; namely ecotypes similar to Tifdwarf and ecotypes with a much more dwarf morphology (ultradwarf) such as MiniVerde™. TifEagle is in the ultradwarf category, but differs from other ultradwarf varieties and Tifdwarf ecotypes in that rather than being selected from golf greens, it was intentionally bred, developed and released by the US Department of Agriculture and the University of Georgia. TifEagleand MiniVerde™ are maintained under the International Turfgrass Genetic Assurance Program (ITGAP).
All of the current seashore paspalum varieties were selected from golf courses or coastal areas. Although several varieties have been released by university breeding programs, none to date have been developed by conventional plant breeding methodology. Seashore paspalum varieties have significant differences in salt tolerance, disease susceptibilities / tolerance, growth habit and rate, but little difference in golf green performance.
A recent study at Florence, South Carolina did not find significant differences among 6 commercially available varieties in regard to green speed. There were differences in disease reaction, but no variety significantly outperformed the others in both dollar spot and rhizoctonia tolerance (Alejandro Canegallo, MS Thesis, Clemson University 2006). Unfortunately, there is little objective data available to document other varietal characteristics, consequently, seashore paspalum variety selection is usually based on golf course experience.
The Best Choice?
Which then, bermudagrass or seashore paspalum, is the best choice for golf greens in tropical climates? Under ideal conditions, the best bermudagrass variety will have superior putting quality when compared to the best seashore paspalum variety. However, neither species is consistently the “best” choice. Under normal conditions in most regions, either species can be managed to produce a superior golf green.
For example, Bangkok Golf Club changed their greens to an ultradwarf bermudagrass in 1999 and the Golf Course Superintendent, Gavan Wilson, achieved superior putting surfaces during the entire year even with between 9,000-10,000 rounds per month. Similarly, Cameron Thompson, Superintendent at Amata Springs Country Club in Thailand, has produced an excellent putting surface with seashore paspalum. On most golf courses management has a greater influence on greens surface quality than grass species. However, species adaptation to environmental stress determines the management difficulties or obstacles that must be overcome to produce consistently high quality putting surfaces.
Conditions where bermudagrass has an advantage over seashore paspalum:
- putting surface smoothness
- tolerance to scalping
- low insect preference
- putting uniformity during the day
- mower up-keep
- Chemicals available for weed control
Conditions where seashore paspalum has an advantage over bermudagrass:
- high rainfall
- environment poor to moderate drainage
- long periods of cloud cover
- low quality, high saline water
- low fertility striping
Situations where bermudagrass and seashore paspalum are considered relatively equal:
- disease pressure (varies with specific diseases & fertilization or bermudagrass has a slight advantage)
- thatch management growth regulator use (e.g. Primo)
- quantity of water use
- management expertise
- tree shade tolerance
- traffic tolerance
The majority of golf courses SE can be successful with greens planted to either bermudagrass or seashore paspalum varieties. Both can provide a high quality putting experience. However, when a species is selected that is less adapted to the golf course environment or golfing expectations, there will be a lower margin of error for management. For example, if the decision is to use bermudagrass because of its putting quality and the golf course has extended days of cloud cover, turf health will be a critical issue and must be a management priority. If, on the other hand, seashore paspalum is selected because of extended periods of cloud cover but golfing expectations are for the greens to be in ultradwarf bermudagrass tournament condition throughout the day, every day, then surface smoothness and greens speed will be the critical issue and thus the management priority. Bermudagrass and seashore paspalum each have unique advantages and disadvantages. The majority of their disadvantages can be overcome, or significantly improved, by skilful golf course superintendents.
Dr. Earl Elsner was a faculty member at the University of Georgia (1969-1981), then Director of the Georgia Seed Development Commission (1981-2001). Since 2001, he has served as technical agronomist with Manderley Turfgrass International, which oversees the international sales and distribution of numerous US patented turfgrass varieties. He worked closely with Dr. Glenn Burton and Dr. Wayne Hanna in the development of Tifdwarf in the 1960s and TifEagle in the 1990s. He has given numerous international seminars on turfgrass cultivars and genetic certification and is widely recognized as one of the leading industry authorities on turfgrass and certification programs for genetic uniformity.