SUMMARY. Seashore paspalum (Paspalum vaginatum) is a prostrate, perennial turfgrass used on golf courses and athletic fields in warm-season climates. Research data on the traffic tolerance of seashore paspalum compared with hybrid bermudagrass (Cyndon dactylon · Cynodon transvaalensis) is minimal. A study was conducted in 2008 to evaluate the traffic tolerance of ‘Sea Isle 2000’, ‘Salam’, ‘Sea Dwarf’, and ‘Sea Isle 1’ seashore paspalum relative to ‘Tifway’ hybrid bermudagrass. Traffic was applied with a Cady Traffic Simulator (CTS) and traffic tolerance was assessed visually through measurements of percentage of turfgrass cover after 36, 54, 72, and 90 passes were applied with the CTS. After 90 passes (45 simulated professional football games) with the CTS, ‘Salam’, ‘Sea Dwarf’, and ‘Sea Isle 1’ seashore paspalum exhibited greater traffic tolerance than ‘Tifway’ hybrid bermudagrass; ‘Sea Isle 2000’ seashore paspalum exhibited the least amount of traffic tolerance in this study. These data suggest that some seashore paspalum cultivars may be a suitable alternative to hybrid bermudagrass on athletic fields in warmseason climates.
Dr. Joe DeFrank speaks on the Aiea Baseball field weed cleanup
In August 2010, Dr. Joe DeFrank in cooperation with Kaipo Bernie and his skilled team of landscape professionals of the Honolulu City and County Parks and Recreation Department, started a weed cleanup of the Aiea baseball field on Oahu, Hawaii. The presentation below contains Dr. DeFrank’s presentation at the Pacific Agriculture Sales and Service Turf seminars and trade show at the Pearl Country Club in Honolulu. The presentation was made on January 20, 2010 and contains a description of all the fertilizer and herbicide applications made over a 4 month period from August to the end of December, 2010.
CLICK HERE to play the video clip of the presentation
(runtime: 58 min:10 sec.)
Prior to viewing the video content, the audience should download the seminar handout to better follow the detailed discussion of procedures and results and help incorporate the materials employed and their rates of application into their own operations.
CLICK HERE to download the seminar handout of the presentation
For more information on this presentation contact:
Dr. Joe DeFrank
Professor of Weed Science – University of Hawaii Department of Tropical Plant and Soil Science
email:[email protected].
Efficacy of Sodium Chloride Applications for Control of Goosegrass (Eleusine indica) in Seashore Paspalum Turf
by James T. Brosnan, Joseph DeFrank, Micah S. Woods, and Greg K. Breeden*
Control of goosegrass is difficult in the pan-Pacific region. No herbicides are currently labeled for selective control of goosegrass in seashore paspalum turf, a species used regularly on golf courses throughout the tropics. Sequential granular applications of sodium chloride (99% sodium chloride, 1% sodium silicoaluminate, 83% 0.5 to 0.25 mm diam) at 488 kg/ha did not effectively (. 70%) control goosegrass in this study. Goosegrass injury following sequential granular applications of sodium chloride, at 488 kg/ha, subsided at 6 wk after initial treatment (WAIT). A single application of MSMA at 2.40 kg/ha plus metribuzin at 0.56 kg/ha provided 96 and 83% control of goosegrass 8 WAIT in 2007 and 2008, respectively. Sequential applications of MSMA plus metribuzin at lower rates yielded similar results. Applications of foramsulfuron did not effectively control (. 70%) goosegrass in this study, suggesting a possible tolerance to this treatment. Applications of MSMA plus metribuzin controlled goosegrass (. 70%), but induced phytotoxic injury to seashore paspalum turf. Additional research is needed to evaluate strategies for POST control of goosegrass in seashore paspalum turf that do not induce phytotoxic turfgrass injury after application.
CLICK HERE to view the complete article.
Nomenclature: Metribuzin; MSMA; foramsulfuron; goosegrass, Eleusine indica (L.) Gaertn. ELEIN; seashore paspalum, Paspalum vaginatum Swartz. PASVA.
Weather’s influence on the growth of turfgrasses
by Micah Woods, Ph.D.
[email protected]
www.asianturfgrass.com
Everyone knows that the weather has a huge influence on the growth of turfgrasses, and the weather is one thing that a golf course superintendent cannot control. I have had the opportunity to visit many cities around the world where warm-season grasses are grown, and I am struck by the differences in turfgrass species that thrive in one place and that struggle in another. For example, I have seen kikuyugrass grow well at Lanai and San Diego and at Dalat in the mountains of southern Vietnam, and I know kikuyugrass grows well at many locations in South Africa, but when it is grown at Bangkok kikuyugrass cannot compete with other grasses that grow more aggressively in the Bangkok weather.
The same differences in turf vigor are seen with other warm-season species such as bermudagrass, seashore paspalum, and zoysiagrass. I made this bubble chart to show the average weather data (climatological normals) for different cities around the world, thinking that by looking at the weather data in this way we might be able to get a better understanding of why certain grasses perform better in one area but do not thrive in another.
These data are from the climatological normal tables on the Hong Kong Observatory website and the bubble charts were created using the ggplot2 package in R. If you are interested in seeing these plots on a monthly basis, please go to www.blog.asianturfgrass.com where I have already uploaded the files for May and June average weather and I will be uploading a new bubble chart around the first of each month until April of next year, showing how the average weather for different world cities changes throughout the year on a monthly basis.
The EPA Tier 4 standard and the impact on the Turf Industry
The Environmental Protection Agency’s Tier 4 diesel engine emission reduction mandate will soon have an impact on your business. Tier 4 compliant Turf Equipment, in the 25 to 74 horsepower (hp) category, manufactured after January 2013 will be better for the environment and healthier for everyone, but it will also cost more.
Understanding the financial implications of various compliance options – today – will allow you to evaluate all of your options, in advance, so you can make the most beneficial decision for your business.
The EPA Tier 4 Standard is about cleaner air!
All US regulated emission standards, including Tier 4 for off-road diesel engines, are extensions of the “Clean Air Act” (1963) which was enacted to reduce air pollution in the United States. The “tiered” mandates were put in place to progressively reduce the level of harmful emissions such as Particulate Matter (PM) and Nitrogen Oxides (NOx) that enter the air via diesel engine exhaust. The most stringent emission reduction mandate to date, is called “Tier 4”. The Tier 4 emission standard will reduce emissions of PM by 90% from current levels.
Potassium fertilizer and roots?
from TurfNet Monthly November 2004
by Micah Woods
Turfgrass professors tell us that more roots are obtained at higher potassium levels, but plant science researchers tell a different story…
Earlier this year I presented some preliminary results from the soil testing studies I have been conducting at Cornell University to a meeting of the Central NY GCSA. Many in the audience were interested to know how potassium fertilizer applications, or the withholding of potassium fertilizer from the turf, had affected the L-93 creeping bentgrass roots in the study. I did not have any final data to share at that time, but the audience’s pointed questions about rooting certainly underscored in my mind the widespread, traditional assumption that potassium plays a critical role in turfgrass rooting.
In Turfgrass Science and Culture (Beard, 1973), it is clearly stated that higher soil potassium levels yield increased root development and branching. The recently published Turfgrass Soil Fertility and Chemical Problems (Carrow et al., 2001) emphasizes the role of potassium in sand rootzones, where potassium encourages “a more extensive fibrous or branched root system.” The theory of root stimulation by potassium is propagated and promulgated anew whenever superintendents or turfgrass students are taught about turfgrass nutrition. I recently participated in an online seminar about fall fertility strategies for cool-season grasses, and sure enough, we were reminded by the instructor that a primary plant response to potassium is deeper roots with more branching.
Turfgrass professors tell us that more roots are obtained at higher potassium levels, but plant science researchers tell a different story. The definitive plant nutrition reference is Mineral Nutrition of Higher Plants (Marschner, 1995), in which Marschner wrote that mineral nutrient supply can strongly influence root growth, with nitrogen having a particularly marked effect, less so for phosphorus, and usually no effect for other nutrients.
A classic study of the effect of variable ammonium, nitrate, phosphate, and potassium supply on barley roots [Drew, 1975] found that the number and length of lateral roots were stimulated by all nutrients except for potassium. In fact, some plants have more roots when no potassium is applied [Cherney et al., 2004], perhaps because the roots explore a larger volume of soil in order to obtain the potassium that they need.
So why, I wondered, are we taught that potassium increases roots, even though the consensus among plant scientists is that potassium has little effect on roots?
Do Fairways Need A Sand Cap?
from Asian Golf Business January 2008
Must grass for golf courses always be grown only on sand? Talk to almost most professionals who deal with turf matters and they will almost always agree that sand is the ideal surface upon which to grow grass. However, one expert begs to differ – he is Micah Woods of the Asian Turfgrass Center who happens to believe otherwise and sets out to prove his case with some sound reasoning.
Six months ago, I heard an interesting comment about the turfgrass research facility being developed by the Asian Turfgrass Center. We had started to plant 33 different grass types on native soil (formerly paddy fields) near Bangkok, intending to maintain this area as a fairway turfgrass trial. We had already established these same grasses in a sand rootzone. A visitor remarked that the particular trial of turf on native soil would be the one they would like to see the outcome of, because they were not sure that these grasses could grow in anything other than sand. I was surprised to hear this, because plants will almost always grow better in soil than in sand.
There seems to be a misapprehension about suitable soils for golf courses in Asia. It is common to use sand as a growing medium for fairways (Figure 1). But this is a substantial cost, and it may not be necessary, at least during the construction phase of a golf course. In fact, I believe that many golf courses would see better and more consistent playing conditions if the fairways were not sandcapped during construction, but were regularly topdressed with sand instead.
Goldilocks and the Three Golfers
Green speeds should be matched to the contours and hole locations of greens.
By
Larry Gilhuly,
Northwest Director USGA Green Section
“The greens are too slow!” “The greens are too fast!” “The greens are just right!” No, this is not a story about three bears and a golden haired girl. It is a short story about a subject that is sure to stir emotions (usually during or immediately after a bad day of putting) – green speed. Somewhere along the road golfers have forgotten that part of the allure of the game is adapting to whatever playing conditions are found on the golf course. If the green speed of the practice green is a certain speed, then that is what the greens should be that day. Those that adapt will have a better day while those that don’t may find their score rising. But there is far more to this subject than I have space for, so let’s look at one simple part of the green speed equation – the correlation between green speed and hole locations.
Please note the chart below that shows the correlation between green speed and surface slope.
This study was conducted a few years ago as a means to educate those that wish to have excessively fast greens while not understanding the negative impact this has on the overall health of the greens and play of the game. Briefly, the % slope indicates when a golf ball begins to roll back at a player that has hit a putt from directly below a hole. While players can debate the appropriateness of a hole location when putting from above or to the side, there is universal recognition that when a ball rolls back at the player that the hole location is too severe. As you can see in the chart, a 10’ speed allows the maintenance staff to place holes up to a 3.2 – 4.1% slope. Since many greens are severely contoured and grain/wind have a major impact in Hawaii, this is a tournament green speed that should only be used for those with high skill levels unless you want 5 hour rounds. When holes are placed in relatively flat areas many have the perception that the greens are “too slow”. But place the hole on a slope (pick your favorite green) and putt downhill and downwind when the greens are in excess of this speed! Can you say – STOP!
Green speed in Hawaii has progressively gone up over the years with the introduction of new ultradwarf bermudagrasses and an improved understanding of seashore paspalum maintenance practices. Focus should be on overall green smoothness and a good understanding of the relationship between green speed and hole locations. Without this understanding the three bears will continue to be an issue with that defenseless game we play!
Dollar Spot Update
By: Lane Tredway
Associate Professor and Extension Specialist
Department of Plant Pathology
North Carolina State University
Dollar spot, caused by the fungus Sclerotinia homoeocarpa, is the most important turfgrass disease worldwide. Dollar spot develops all over the world, and can infect every species of grass that is grown for turf. According to some estimates, 40% of fungicide applications made to turf are for the control of this single disease. Unfortunately, this fungus develops fungicide resistance very quickly, and this severely limits the number of tools that superintendents have at their disposal to control dollar spot.
Despite its importance, very little is known about dollar spot or the fungus that causes it. We don’t know how the fungus spreads, where it survives when it’s not causing disease, the specific conditions that trigger its development, or how it develops resistance to fungicides so quickly. Heck, we don’t even know what the correct Latin name is for the Dollar Spot pathogen. We know that it isn’t really a Sclerotinia, but we don’t know what else to call it!
To fill these gaps in our knowledge, my research program has begun to focus almost exclusively on Dollar Spot, and in particular, the development of fungicide resistance. First, we need to understand how this pathogen spreads, survives, and reproduces. So for the last few years, we’ve been traveling the world to sample dollar spot populations from different turf species for genetic analysis. So far, we’ve amassed over 3000 isolates from the US, Dominican Republic, Argentina, Chile, United Kingdom, and Japan. Collecting trips to South Africa and Southeast Asia are in the plans for next year.
A few years ago, I had the opportunity to visit with Les Jeremiah on Lanai, along with Dr. Micah Woods from the Asian Turfgrass Center. We toured The Experience at Koele and The Challenge at Manele and collected samples of dollar spot from Creeping Bentgrass, Hilograss, and Seashore Paspalum. So far, we’ve learned a lot about the Dollar Spot pathogen from our work with these Hawaiian isolates.
Hydrauleak – A Method to Speed Recovery
By: Larry Gilhuly, Northwest Director
Admit it. Every superintendent has been there when it comes to the use of mowers with hydraulic fluid — a drip, a narrow line or a massive blowout. Hydraulic leaks happen with every type of mower on golf courses, with the heat of the oil causing turf loss that often results in lasting visual turf loss for weeks or months, based on the time of the occurrence. Here in the Pacific Northwest we are in the “please don’t blow” phase of mowing, as any hydraulic leak at this time of the year will require months of recovery. This occurred recently at my home course due to the failure of an equipment alarm and the fact that the crew had to mow in the dark (early AM shotguns can cause problems!). Regardless of how it happened, the response by CGCS Scott Young, his assistants Mike Cupit and Jeff Jackson and the maintenance staff, may lead to a method that you can use when a similar incident occurs — without resodding or seeding. Interested? Read on for a step-by-step method to fix the damage caused by a stream of hydraulic oil from a triplex mower on a putting green.
Once the damage had occurred on two greens in late September, it was too late to seed. With the damage being just a narrow line — not more than ¼-1/2″ wide — the idea of narrow resodding was also dismissed. After putting their heads together, the group came up with a 9-step program (not as bad as it sounds!) to bring the weak areas back to normal playing condition. Full visual recovery by the end of November is expected, or approximately 6 weeks, when growth has greatly reduced. Here is how they did it.