Viridescent - the Asian Turfgrass Center blog

Ten Years Ago on a Golf Course in Japan: part 3

If you've flown into Narita Airport in Chiba prefecture near Tokyo, and have happened to look out the window, you may have been surprised when you flew over golf course after golf course as the plane descended. Chiba prefecture has more than 150 golf courses, placing it third among Japanese prefectures in golf course count. Only massive Hokkaido in the north, and Hyogo prefecture near Osaka, have more courses.

This map shows a portion of Chiba prefecture where there is an especially high concentration of golf courses. The satellite image was taken in the winter, so we see that the korai (Zoysia matrella) fairways and noshiba (Zoysia japonica) roughs are dormant.

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Many of the golf courses at Chiba were constructed in the golf course building boom of the early 1990's, and for these courses, there is a pesticide ban. I was a superintendent in 2000 and 2001 at Habu CC, which opened in 1996 and was thus subject to the pesticide ban. Here the inspection team from the prefectural government made a visit to inspect the course, the maintenance building, and our records. We could use wetting agents, Polyoxin-D, and phosphites; other than that there was very little in the way of chemical control products that we could use. 

One thing that I focused on, with the limited resources we had to maintain the course, was to have the central playing corridors in as good a condition as possible. We tried to have perfect greens, tees and fairways as good as they could be, and less attention was paid to the roughs, particularly in out-of-play areas. You can see here, in a view from behind the 14^th hole at Habu CC, that there are some weeds growing behind the green on this par 5.

I've sometimes had long discussions with Japanese greenkeepers about the philosphy of balance in golf course maintenance. If resources for maintenance are limiting, I've always strived to make green perfect and the playing corridors as good as possible. In Japan, there has historically been the idea that there should be balance on a course, and that all of the areas should be maintained. 

Balance is alright if you have enough resources to maintain every square meter at a high level, but if those resources are not there, then striving for balance is a sure way to have mediocre conditions all over the course. I think every course has the resources to make their greens perfect, and I am fine to let some out-of-play areas be a little less-maintained if I can ensure the greens will be excellent. This is still a challenge in Japan, because many courses were built in mountainous areas in a bubble economy and are inherently expensive to maintain. Maintenance budgets then get cut again and again, and it is very difficult to maintain these courses with the desired balance. I was lucky in my work, to be a foreigner, and to have an American boss. In this situation it was easier, culturally, to focus our maintenance efforts on the playing corridors.

Fertilizer and Weeds at Park Grass

An article I wrote with Dr. Frank Rossi about the Park Grass experiment at Rothamsted has recently been published in the USGA Green Section Record. (Download the article here). This experiment has been ongoing for more than 150 years and it involves fertilizer treatments applied to grassland and the many measurements that have been made over the years on the experimental plots. One of these measurements is the botanical composition of the plots, and the results are amazing.

When nitrogen in the form of ammonium sulfate is applied as the only fertilizer, finer grasses predominate and weeds are not present. When potassium is applied, dandelions and other weeds proliferate. Lime also causes an increase in weedy species. 

The recommendations for complete fertilizers along with lime treatments that are commonly made for for cool-season lawns and other general turf areas are probably contributing to an increase in weed abundance as well. Is it possible that less fertilizer could also lead to less weeds and less herbicide use? That is certainly something to consider, and Dr. Rossi and I suggest that the results of the Park Grass experiment are worthy of further attention from turfgrass managers.

Sandcapping or topdressing: which is better?

I have often advocated sand topdressing rather than sandcapping for golf course fairways and roughs. Why? Because sandcapping at the time of construction makes for a much higher construction cost, higher maintenance cost, and invariably leads to deteriorating playability over time. Conversely, a sand topdressing program provides better playing conditions, easier maintenance, and all for a much lower cost. I am not referring to drainage. Drainage is required for both a sandcapped system and a topdressed system. But sandcapping is not drainage.

Sandcapping a turfgrass area with 10 to 15 cm of sand has a high upfront cost and then forces higher maintenance costs as well, for that sandy rootzone will require more fertilizer, more irrigation water, and more surface organic matter management than would an area not sandcapped. And what happens if the organic matter is not controlled? See below. What used to be a fine zoysiagrass is now a mixture of cowgrass and sedges. A layer of organic matter built up at the surface creates a perfect growing environment for weeds that thrive in wet soils. And all that sand underneath? One might as well bury money in the ground. Once the organic layer builds up over the sand, there is no benefit whatsoever to having the sandcap.

Dr. Alec Kowalewski has recently published some intriguing articles that show just how effective sand topdressing can be as an alternative to sandcapping. Not only does he demonstrate the substantial cost benefits of a topdressing (or built-up over time sandcap) program compared to a sandcap installed at the time of construction, his research also shows how turf quality improves and drain line spacing can be extended when a topdressing program is implemented. 

"Preliminary findings from this research," he wrote, "suggest that as little as 1/2” (1.25 cm) of sand can be used to improve athletic field playability by substantially decreasing the surface moisture content." His results show that once 2.5 cm of topdressing sand has been applied, drain line spacing at 3.9 meters provided sufficient drainage and surface stability. After a 5 cm topdressing layer was established, and assuming surface slope is at 1% or greater, then drain line spacing could be extended to more than 6 meters while still producing the desired surface conditions.

For full details, see:

Kowalewski, A. R.; Crum, J. R.; Rogers, J. N. III. 2010. The built-up sand-capped athletic field system. MSU Turfgrass Science Program. April 7. p. 1-7.

Kowalewski, A. R., J. N. III Rogers, J. R. Crum, and J. C. Dunne. 2010. Sand topdressing applications improve shear strength and turfgrass density on trafficked athletic fields. HortTechnology. 20(5):p. 867-872.

Kowalewski, A. R., J.R. Crum, J. N. III Rogers, and J. C. Dunne. 2011. Improving native soil athletic fields with intercept drain tile installation and subsequent sand topdressing applications. Soil Sci. 176(3): p. 143-149.

With sandcapping at the time of construction there is a high upfront cost, turfgrass and playing conditions that deteriorate, and there will be the need for a disruptive and costly renovation to remove the organic layer that will invariably develop at the surface. Planting grass onto native soils and then topdressing with sand results in lower construction costs, lower maintenance costs, and better playing conditions over time with longer intervals between disruptive renovation projects. It is the surface conditions that matter for the playing of sports on grass, and topdressing with sand is a proven method to create the desired surface conditions.

Turfgrass Research at the University of Tennessee

I visited the East Tennessee Ag Research and Education Center in Knoxville yesterday to see many of the turfgrass experiments now underway. This large facility has vast swaths of turfgrass plots sweeping down to the Tennessee River.

What really caught my eye, and is now under construction and nearly ready for planting, is an exciting new research center. The Center for Safer Athletic Fields is a partnership between Astroturf® and the University of Tennessee. Dr. Jim Brosnan explained how these 60 miniature athletic fields and other research plots at the Center have been designed for many interesting experiments. From the press release announcing this Center:

The unique outdoor research facility will comprise 60 small-scale athletic research fields constructed from a variety of playing surfaces. UT turfgrass scientists will compare the safety and performance of synthetic playing surfaces to natural grass surfaces. Field qualities will range from those employed for professional-level sports to surfaces used by schools, public parks and recreation fields. 

Some of the other research trials I saw included:

• Bluegrass evaluation plots
• Zoysiagrass variety evalution
• A multitude of weed control plots, including some really interesting pre-emergent product results, Poa annua control trials, and innovative combinations of herbicides with cultural practices to optimize weed control
• Seedhead and disease control trials
• Ultradwarf bermudagrass and seashore paspalum and zoysiagrass on putting greens

The UT Turfgrass Field Day will be held on September 15, 2011. I wish I could be there for that. Seeing the various grasses right at the end of summer, when we might expect warm-season grasses to be at their best, and cool-season grasses to be at their worst, would be an ideal time to see which grasses perform best and which maintenance practices and products perform well to create the desired playing surfaces.

Herbicide Safety on Newly Sprigged Bermuda and Paspalum

This article by Patton et al. about the safety of various herbicides on seashore paspalum and hybrid bermudagrass during establishment/grow-in will be of interest to many turfgrass managers in Asia. Entitled Sulfonylurea Herbicide Safety on Newly Sprigged Bermudagrass and Seashore Paspalum, the research project was conducted in Arkansas and Louisiana and found that foramsulfuron, halosulfuron, metsulfuron, sulfsulfuron, and trifloxysulfuron can be used to control weeds in establishing Tifway bermudagrass.

For seashore paspalum, metsulfuron and halosulfuron applied two or four weeks after sprigging and sulfosulfuron applied four weeks after sprigging provided weed control without causing too much injury to the seashore paspalum turf. The Aloha variety of seashore paspalum was used in this experiment. If you are interested in using sulfonylurea herbicides on seashore paspalum, you will want to read the article for yourself.

Honda LPGA Thailand and Asian Turfgrass Field Day

This week brings the season-opening event on the LPGA Tour to Thailand's Siam Country Club. Defending champion Ai Miyazato and #1-ranked Yani Tseng headline the stellar field. The tournament is being contested over seashore paspalum fairways (Salam variety) and hybrid bermudagrass greens (Novotek variety).

Sittichai Dusadeeporn is the Director of Golf Course Maintenance at Siam CC and will be speaking at the Sustainable Turfgrass Management in Asia 2011 conference about how he prepares the course for an LPGA tournament. And our first stop on the Asian Turfgrass Field Day will be Siam CC where we will see these grasses and just a few weeks after the tournament.

From Siam CC, we will proceed to other area golf courses to look at test plots of products and maintenance techniques applied to different grasses. Some of the highlights include:

• Control of zoysiagrass seedheads with imazapic
• Conversion to new grass using glyphosate or dazomet
• Playability of different grass types and practical use of measuring equipment
• Are pre-emergent herbicides useful in the management of turfgrass in SE Asia?
• Control of bermudagrass in seashore paspalum
• Control of seashore paspalum in bermudagrass
• Evaluation of new herbicides for weed control
• Comparison of different types of zoysiagrass
• Organic matter management in sand rootzoones

The field day will conclude at Laem Chabang International CC with a look at different nozzle types for effective spraying and the use of water-sensitive paper (always interesting!) to demonstrate that, along with a few other turfgrass equipment demonstrations and then a fun golf game around the chipping course. Michelle Wie is in Thailand now for the LPGA tournament and said "Everyone is so nice and welcoming in Thailand. I love it!" You will too, so if you are planning to attend this fun and educational conference, get your registration form submitted now to hold your place.

Research on Weed Populations in Malaysia

One of the papers I found most interesting last year was Characterizing Weed Populations in Different Turfgrass Sites throughout the Klang Valley of Western Peninsular Malaysia (Uddin et al., 2010). Weeds are one of the biggest challenges facing turfgrass managers in tropical Asia. Uddin's survey of 53 sites in the Klang Valley included seventeen athletic fields, six sod farms, nineteen residential lawns, and eleven golf courses.

In total, 79 different weed species were identified in this survey, with 63 of the species being found in lawns, 29 on athletic fields, 25 on sod farms, and 23 on golf courses. Some of the most pervasive weeds were the sedges Cyperus aromaticus and Cyperus compressus along with grasses Chrysopogon aciculatus, Eleusine indica, and Digitaria fuscescens.

In three bermudagrass fields, 37 weed species were found. In three manilagrass (Zoysia matrella) fields, there were less than half as many species present. Only seventeen weed species were found in the manilagrass fields compared with 37 in the bermudagrass fields. Wiecko (2000) wrote about the challenges of growing bermudagrass in tropical Asia and this survey confirms quantitatively what turfgrass managers in Asia see every day: bermudagrass is easily infested with weeds, while manilagrass produces a dense sward that has comparatively few weeds.

Seashore Paspalum in London?

I visited the herbarium at Kew Gardens last summer for the purpose of looking at grass specimens from Southeast Asia. I was especially interested to see what types of seashore paspalum and manilagrass were in the herbarium collections. If you read the paper in Weed Science about weeds in seashore paspalum in southern China, in which manilagrass overgrew a stand of seashore paspalum, or if you have read some of my posts at the Turf Diseases blog in which I have mentioned the challenges of trying to maintain seashore paspalum in Southeast Asia, or if you have grown seashore paspalum in Southeast Asia, you will understand that the turf-type seashore paspalum requires more inputs than other common turfgrasses in order to persist in this growing environment.

Seashore paspalum is not a new grass in Southeast Asia. The image above shows a turf-type seashore paspalum collected at Bangkok in 1927; the common type at right was collected at Koh Tao, an island in the gulf of Thailand (see image below) in 1927. Other seashore paspalum specimens in the collection were collected more than 120 years ago, from the Philippines in the 1880's.


Seashore paspalum on golf courses in Southeast Asia today, without extensive inputs, will be overtaken by manilagrass or bermudagrass. The common type of seashore papspalum with long internodes is a weed that invades wet areas on golf courses and other turfed landscapes. The turf-type of seashore paspalum, with short internodes, has been growing in the wild in Southeast Asia for over a century, but it does not spread as a weed; it grows only in a very specific niche, similar to its native habitat. The sample collected at Bangkok, according to the specimen notes, was found "on open ground in tidal swamp."

Manilagrass and hybrid bermudagrass grow aggressively in Southeast Asia and make a better general-purpose turfgrass. Turf-type seashore paspalum requires extensive inputs and constant vigilance in an attempt to replicate that "tidal swamp" environment while still producing suitable playing surfaces for golf.

Registration Open for March 2011 Turfgrass Conference

Registration is now open for the Sustainable Turfgrass Management in Asia 2011 conference, to be held at Pattaya, Thailand, on 14 to 16 March. Registration forms, speaker profiles, and the program schedule are all posted at the conference website, www.asianturfseminar.com.

The 2011 event includes sessions with renowned turfgrass expert Dr. Don Loch from Australia, Dr. Jim Brosnan who heads the turfgrass weed science program at the University of Tennessee, and a new session with talks on successful techniques used by golf course superintendens at Thailand. Philip Russell from The R&A will open the conference with a talk on Understanding Sustainable Management with a special emphasis on the economic benefits that accrue from such an approach.

The conference has been approved by GCSAA for 1.0 education points. And the classroom seminars are combined with the 5^th Asian Turfgrass Field Day, this year looking especially at weed control in all types of grass, different species of zoysiagrass and their management requirements, along with other field demonstrations at golf courses near Pattaya.

The conference venue is the Amari Orchid Pattaya, a 5-star beachfront hotel with a superb dedicated conference facility, as the hundreds of delegates from the 2009 and 2010 conferences can attest.

Organized for the Thailand Golf Association by Asian Turfgrass Center and the Thailand GCSA with support from The R&A, this event provides a wealth of practical information in a fun learning environment.

Which is a Stronger Grass, Paspalum or Zoysia?

One of the most interesting research papers I have read in the past few years is this one, entitled "Spatial and Temporal Dynamics of the Weed Community in a Seashore Paspalum Turf," by Xie et al. from South China Agricultural University. With a title like that, I expected the article to explain what weeds were found in a seashore paspalum turf, where those weeds were, and when those weeds invaded. Were the weeds at the edge of the seashore paspalum area, or were they on a high spot, or in a low area with wet soil, or were the weeds particularly intense in their invasion at certain times of the year? The actual result of this experiment, however, was somewhat unexpected, and is less related to dynamics of a weed community in seashore paspalum than it is to the fitness of seashore paspalum as a turfgrass in Southeast Asia. And this is something that everyone involved in the maintenance of turfgrass in Asia should be aware of.

The experimental results published in Weed Science found that weeds emerged most frequently during the spring and summer at the experimental site at Guangzhou. No surprise there. But what is most surprising is this, and I quote from the researchers in their article: "the seashore paspalum turf has been naturally replaced by manilagrass." Manilagrass is Zoysia matrella.

The image above shows an area at the Asian Turfgrass Center's research facility that was planted to seashore paspalum and was maintained similar to a golf course fairway for three years, with regular fertilizer and irrigation applications and mowing every two days. During that time of regular maintenance, the paspalum grew fine. But in 2009, when we implemented a reduced maintenance program, with no irrigation and reduced frequency of mowing and reduced fertilization, the Salam seashore paspalum went dormant and in some areas was completely overtaken by other grasses, such as the manilagrass as shown above.

Based on what I have seen in Southeast Asia, seashore paspalum must be provided with enough fertilizer and water to maintain a steady growth rate. If the growth of seashore paspalum is allowed to slow, then it will tend to be invaded by bermudagrass, manilagrass, and other weeds. We commonly see this on golf courses, where bermudagrass that has somehow come onto the site will gradually overtake the seashore paspalum. And the research from Weed Science, and our observations at Thailand, show that manilagrass can overtake seashore paspalum as well.

If you are growing seashore paspalum in Southeast Asia, and if you want to keep this grass as the primary species over the long-term, then be vigilant in keeping other grasses out, and by all means maintain a steady growth rate on the seashore paspalum. Use sand topdressing as the primary means to control organic matter buildup and supplement that with coring and verticutting as needed. With extensive inputs, seashore paspalum will perform well in Southeast Asia. Without intensive maintenance, however, seashore paspalum does not persist and will be overgrown by bermudagrass, manilagrass, or other plants more suited to this growing environment.