Viridescent - the Asian Turfgrass Center blog

Turfgrass Teaching and Research at Oregon State University

Last week I had the opportunity to visit Oregon State University to teach one session of Dr. Rob Golembiewski's Principles of Turfgrass Maintenance class. In the morning lecture, I spoke about turfgrass maintenance in Asia and what some of the distinguishing differences are compared with typical turfgrass management in the Pacific Northwest. In the afternoon, I met with the turf club to discuss internships, career opportunities, and some of the interesting things about working in the turfgrass industry in Asia. 

I also visited the turfgrass research farm and saw the various grasses and experimental trials. Brian McDonald is the research assistant for turf management at OSU and he showed me some of the interesting research being done with fertilizer trials, fungicides, herbicides, mowing and rolling, irrigation, grass variety trials, divot recovery, and even some seashore paspalum research. My interest in turfgrass research started when I did earthworm control and herbicide research at this farm in 1998, just before graduating from OSU. 

The amount of research being done now is impressive and I got to see a lot of Poa annua, perennial ryegrass, red thread, pink snow mold, brown blight -- all grasses or diseases that I don't see all the time when I am working with warm-season grasses. Every time I got down for a close inspection of grass disease symptoms, June the Research Cat came over to say hello. She is, I'm informed, the farm's environmentally-friendly method of rodent control.

For more information about the turfgrass program at Oregon State University, check out www.beaverturf.com.

New Information on Diseases and Cation Exchange Capacity

I've been really busy in the past month, returning to Thailand after the exciting Masters Tournament, traveling to Singapore, Vietnam, and Sri Lanka, studying, and writing. Thanks to @daisukeiw who sent me the image above of the layout for my new series in Golf Course Seminar magazine. Pitchcare Oceania have just published a panel report on cation exchange capacity (CEC) and have featured some comments from me about CEC in sand rootzones and how it can be estimated most accurately by using an equation in which the only variables are soil pH and soil organic matter content.

I've also made some international updates to the Turf Diseases website. Some of my recent posts on that site are:

Large Patch Resistance of Zoysia?

A Cornucopia of Disease in Southeast Asia

Healthy Grass = Little Disease

Potassium, Hokkaido, and Snow Mold

Turfgrass Diseases in India

What is the Most Interesting Disease in the World?

Mites, a Corpse Plant, and Native Grasses

Large Patch on Zoysiagrass

More About Seashore Paspalum

A Most Unsightly Disease

The Wow Factor, Seashore Paspalum, and Dollar Spot

Collecting Dollar Spot With Dr. Tredway in Southeast Asia

Turfgrass pathologist Dr. Lane Tredway from North Carolina State University recently made a visit to Southeast Asia for the purpose of collecting dollar spot samples. From ATC's Thailand base, we went to Vietnam, Malaysia, and the Philippines to collect dollar spot from many different grass types: bermudagrass, zoysia, seashore paspalum, carpetgrass, creeping bentgrass — even from some sedges. There is not much creeping bentgrass in Southeast Asia but we traveled to high elevations to find it at Dalat in Vietnam, at the spectacular Mount Kinabalu Golf Club in Sabah (below), and at Camp John Hay in Baguio.

Dr. Tredway has chronicled this trip in a post entitled Dollar Spot Expedition to Southeast Asia on the Turf Diseases website. 

Dollar spot is ubiquitous and is especially so on seashore paspalum turf. This project looks at the different strains of dollar spot as they are found on different grass types and in different geographical and climatic areas. The idea is that a better understanding of the dollar spot pathogen itself will allow for the development of better control measures for this disease in the future.

Two Excellent (and free) Resources about Turfgrass Diseases

Controlling turfgrass diseases is one of the most important ways turfgrass managers modify the growing environment to produce the desired playing surfaces. Two resources that I find quite useful as reference material and as a source of new information are the Turf Diseases website and the University of Kentucky's Chemical Control of Turfgrass Diseases 2011.

At the Turf Diseases site, you will find updates about disease outbreaks, control options for different diseases, new information about ongoing research, and witty banter from an interesting group of university professors. The associated page on Facebook also contains information that can help turfgrass managers in their efforts to produce better playing surfaces.

The 24 page Chemical Control of Turfgrass Diseases 2011 was written by Paul Vincelli and David Williams at the University of Kentucky and is a guide that you are likely to find useful throughout the year. Not only does this document contain the latest information about fungicides and which products are most effective at controlling specific diseases, it also discusses cultural controls of turfgrass diseases and gives suggestions on how to minimize disease intensity. There is a wealth of useful information in this free document.

Handheld or Backpack Sprayer Calibration

A session during a recent seminar at Indonesia was devoted to sprayer calibration, and particular attention was given to the calibration of large, riding sprayers. Backpack sprayers are often used in Asia, and these sprayers also require accurate calibration to avoid misapplications such as we see in this photo.

An excellent guide to hand sprayer calibration is available from Kansas State University, with the four page "Hand Sprayer Calibration Steps Worksheet" available for download. That guide, however, is in imperial units, so I offer this modification to the procedure.

As a general guideline, many products applied through a handheld or backpack sprayer will work best when applied using a spray volume of 40 to 80 mL per square meter. To find the application rate of a handheld sprayer, follow these four steps.
 
1. Measure an area nine square meters in area (3 meters by 3 meters) and mark the edges of this area.

2. Using a stopwatch, measure the amount of time it takes to spray this marked area, using the normal spraying speed and technique.

3. Now, using the same sprayer pressure, spray into a bucket or measuring cup for the same amount of time as it took to spray the nine square meters area. Measure the amount of liquid collected, in mL.

4. To find the spray volume in units of mL per square meter, divide the amount of liquid collected (in mL) by 9. To find the spray volume in units of L/ha, divide the amount of liquid collected (in mL) by 0.9.

Once you have the spray volume, you may decide to adjust the spraying technique so that the amount of liquid applied is in a more suitable range, and you can also determine exactly how much pesticide or fertilizer should be added to the spray tank in order to achieve the desired result.

The Turf Diseases Website

If you are looking for a great source of information about turfgrass diseases, the most effective methods of prevention and control, and updates on the latest turfgrass research, then you should subscribe to the Turf Diseases website. Almost all the information on the site is from university professors in the United States. I occasionally contribute an update about international turfgrass disease issues. Some of my recent posts include:

Mites, a Corpse Plant, and Native Grasses

Clouds With No Rain

Large Patch on Zoysiagrass

More About Seashore Paspalum

A Most Unsightly Disease

The Wow Factor, Seashore Paspalum, and Dollar Spot

Nozzle Selection for Spraying Pesticides and Fertilizer

One of the topics I will discuss at next week's Sustainable Turfgrass Management in Asia 2010 seminar is nozzle selection, spray droplet size, and water volume. Depending on the product (fertilizer? herbicide? fungicide?) being applied, its mode of action, and the reason for the application, one can choose the nozzle type that will produce the most effective spray pattern on the turf.

The Turf Diseases blog has some good posts on this topic, including photos that show the drastic differences in spray patterns between different nozzles and tips on improving disease control by proper nozzle selection.

Don't Neglect Your Nozzles by Dr. John Kaminski

Mazel Tov! It's Nozzle Talk! by Dr. Megan Kennelly

Should I Water That In? by Dr. Lane Tredway

I also recommend reviewing the guide to nozzle selection that Tee-Jet publishes, available for download here.

Bermudagrass White Leaf

I recently wrote about bermudagrass white leaf, a mollicute disease seen in Asia on bermudagrass, at the Turf Diseases blog. See the bermudagrass white leaf post here. If you have this problem on your grass, it will probably go away in time as healthy plants grow over the dying chlorotic plants. For more information about ATC's investigations of bermudagrass white leaf, download the Field Day Book from 2008 at the Turf Information page of the ATC website.

The Wow Factor, Seashore Paspalum and Dollar Spot

The Wow Factor, Seashore Paspalum and Dollar Spot is now posted on the Turf Diseases Blog and may be of interest to those who manage seashore paspalum in Asia.

I will be contributing some posts to the Turf Diseases Blog on topics related turfgrass diseases in Asia. For information about all types of turfgrass diseases on warm and cool season grasses, and for advice on the management of these diseases from expert plant pathologists, you will want to read the Turf Diseases Blog this year.

Zoysia Greens & Fairy Rings

Last week I visited the Sritrang Golf Course in southern Thailand's Trang province. This is a low maintenance golf course on an army base, using native grasses, including a native Zoysia matrella on the putting greens.The green fee is quite affordable, from 300 to 500 baht for visitors, depending on the day of the week. That is about US$15 for an 18 hole round on a rugged course with boldly-contoured greens; a caddy will be about US$7.

I like zoysiagrasses in Southeast Asia because they tend to perform the best with the fewest inputs. Zoysia grows better year round, is healthy in both the dry seasons and in the rainy seasons, and the zoysia tends to choke out some of the weeds that invade other grasses. Zoysia is relatively immune from diseases, and it basically just grows. If I were spending my own money to build and grass a golf course in Southeast Asia, I would in almost all cases choose a type of zoysia.

The only disease I saw on the zoysia at Sritrang was fairy ring. This is a fungus that grows in the soil and creates hydrophobic conditions in the soil. You can see the dry spots in the turf near my feet in the photo at right, and you can see the mushroom growing in the turf. These are typical symptoms of the fairy ring fungus. The best control of fairy ring is accomplished by reducing the hydrophobicity, so the use of wetting agents to reduce dry spots combined with spiking or coring the greens to improve water infiltration can help. Applying some fast-release nitrogen from a source such as ammonium sulfate [21-0-0] at a rate of 1 g N m^-2 can help to mask the symptoms of the fairy ring. And fungicides with the active ingredients azoxystrobin, flutolanil, triadimefon, polyoxin-D, or pyraclostrobin can control the basidiomycete fungi that cause the fairy ring symptoms.

But overall, zoysia is relatively foolproof in the climate of Southeast Asia, unlike seashore paspalum which is quite suceptible to diseases and dry spots and even death in extreme cases, or bermudagrass which struggles in the low light conditions of the rainy season and is prone to invasion by weeds. Zoysia is a grass you can plant to have a sustainable (low inputs, low cost, good quality) golf course in southern Thailand, and it should be used at more golf facilities throughout the region.