Course Care: Easing The Pain Of Core Aeration

10 tips for quicker recovery

By Patrick Gross, USGA Green Section

Making a clean aeration hole expedites turf recovery. The goal is to make a clean, surgical cut so that the turf heals rapidly and redirects its energy to producing new roots and leaves to fill the voids. (USGA Green Section)

 Core aerating putting greens is a lot like going to the dentist. We know it is necessary a few times each year, but we hope the experience is as quick and painless as possible. Although core aeration temporarily diminishes putting quality, the short-lived pain results in a long-term gain for turf health by reducing thatch and organic matter levels, relieving soil compaction, increasing soil oxygen levels and stimulating healthy root growth.
 Golfers begrudgingly understand these benefits but wonder why it sometimes takes so long for putting greens to recover. Core aerating greens will always result in some disruption, but there are steps that can be taken to help the greens recover as quickly as possible.
 There are dozens of methods superintendents use to aerate greens, the most popular being half-inch-diameter hollow tines, commonly referred to as conventional coring, but there are also small, pencil-sized hollow tines, high-pressure injection of water and/or sand, large-diameter drills and many others involving tines, knives, or blades of varying shapes and sizes. Each procedure has its own benefits, and it should be up to the superintendent to decide which method is best based on the prevailing climate, conditions and aeration goals for a particular golf facility. For the purpose of this article, only the standard practice of core aeration using half-inch-diameter hollow tines or larger will be discussed, along with 10 useful tips to get the maximum benefit from the procedure and restore smooth putting surfaces as quickly as possible.
1. Proper timing – This is probably the single greatest factor affecting the success of the procedure and the time necessary for recovery. Core aeration needs to be done when the turf is healthy and actively growing so greens will heal and recover as quickly as possible. From an operational standpoint, most golf facilities determine aeration dates based on a calendar so tournaments and events may be planned at least a year in advance.
From an agronomic perspective, it is best to schedule core aeration based on a temperature model because soil temperature has the most influence on turf growth rate and the ability of the holes to recover quickly. For cool-season grasses like creeping bentgrass and Poa annua, core aeration is best performed in the spring and fall when soil temperatures are consistently above 55°F and preferably between 60°F and 65°F. For warm-season grasses such as bermudagrass and seashore paspalum, core aeration is best performed in late spring and throughout the summer when soil temperatures are above 75°F. Although it is nearly impossible to predict the weather one year in advance, historical weather records along with personal experience are helpful in determining the proper timing for core aeration.
Attempting to aerate during the offseason or outside recommended temperatures can have a very negative effect on surface quality and significantly delays recovery. This is a common pitfall in northern and high-elevation climates, where the golfing season is short. As many golf facilities have experienced, attempting to aerate in the late fall when the soil is too cold runs the risk that the greens may not recover until the following May or June, depending on winter and spring conditions.
2. Fertilize three to five days before aeration – Stimulating turf growth a few days prior to aeration helps holes heal more rapidly once aeration is completed. It is best to use a soluble nitrogen source (e.g., urea, ammonium sulfate, calcium nitrate, potassium nitrate) that is readily available to the plant. Apply at a rate of half-pound nitrogen per 1,000 square feet, followed by watering the material into the turf.
3. Irrigate to provide adequate soil moisture – The greens should be irrigated one to two nights prior to aeration to bring the volumetric soil water content into the range of approximately 30 percent for the upper few inches of the root zone, or deeper if using longer aeration tines. Proper moisture content is not only important for healthy turf growth, it serves as a lubricant for the coring tines and helps to resist soil heaving and tearing of the turf. Excessive moisture should be avoided as it can result in wheel rutting by the aeration equipment and muddy conditions as soil cores are brought to the surface. Conversely, very dry conditions can result in shock and damage to turfgrass roots and contribute to a poor-quality aeration hole that is slow to recover.
4. Make a clean aeration hole – Proper equipment setup and an inventory of several new sets of hollow tines are essential for making clean holes. This will expedite recovery. The goal is to make a clean, surgical cut so that the turf heals rapidly and redirects its energy to producing new roots and leaves to fill the voids. Worn and jagged coring tines tear the turf and contribute to desiccation along hole edges, which slows recovery. The equipment should be checked and tested at least a week in advance to verify that adjustment and timing of the machine are correct and to insure that a clean vertical hole is created. Aeration tines wear down rapidly and may only last for two to three greens. The superintendent and mechanic should monitor the equipment closely throughout the aeration process so that the coring tines can be changed promptly.
5. Topdress with dry sand on a clean, dry surface – In an ideal world, the application of dry topdressing sand on a clean, dry turf surface helps the material to fill the holes as completely as possible. After the aeration cores are removed from the surface, a blower or high-pressure hose-end nozzle should be used to clear any remaining debris from the surface before applying dry topdressing sand. Dry sand moves into holes more readily, while moist sand tends to clump at the top of the aeration hole. The latter is referred to as bridging, and it requires more dragging to completely fill holes with sand. Rain or heavy dew on the day of aeration can disrupt the process and may require extra brushing, dragging, and irrigation to incorporate sand. Oftentimes, just letting the topdressing sand sit on the surface of the green for an hour or more provides enough drying so that the sand can be easily incorporated into aeration holes.
6. Fill the aeration holes completely to the surface – Partially filled aeration holes result in a bumpy surface and reduce the overall effectiveness of core aeration. The holes are going to fill up with something, and it will be more thatch and organic matter unless sand can be applied to completely fill the column. It is important to carefully set the metering device on the topdressing machine and monitor the mechanism throughout the process so that the proper amount of sand is applied to each green. Even when done properly, it is typical for sand to settle within the holes after a couple of days, leaving small depressions on the putting surface. Prepare to make a second application of sand at a lighter rate within three to five days to top off the holes and restore surface smoothness.
7. Avoid excessive turf abrasion when incorporating sand into aeration holes – Typically, a steel drag mat, brushes, or brooms are used to push sand into aeration holes. Dragging or brushing should be performed only to the point where sand has filled the holes and turfgrass leaves are visible on the surface. Excessive dragging can cause damage and abrasion to the turf and extend recovery time. For this reason, many superintendents are now using blowers to finish moving sand into aeration holes after an initial brushing is completed. Also, it is important to note that the angularity of the sand can contribute to turf abrasion during dragging and brushing operations. It is important to work with the sand supplier and an accredited physical soil testing laboratory prior to aeration and topdressing to insure that the size and shape of sand particles are compatible with the putting green root zone. A complete list of accredited physical soil testing laboratories can be found at the American Association of Laboratory Accreditation.
8. Roll the greens to smooth the surface – The use of a putting green roller after aeration and topdressing helps to eliminate surface irregularities and provide reasonable putting quality. Rolling also improves mowing quality and reduces the potential for mowers to gouge or scalp tufts of grass that have been lifted up during the dragging and brushing process.
9. Let the turf grow through the sand topdressing layer – It defeats the purpose of core aeration and topdressing to put sand down one day and then mow it off the next. This is also a surefire way to ruin mower reels. For better overall turf quality and less damage to equipment, it is best to roll the greens for one to two days following aeration and topdressing and then resume mowing at 0.005 to 0.010 inches higher than the normal cutting height. It is typical for golfers to loudly complain for several days immediately after aeration, and the tendency for superintendents is to immediately resume mowing to clean the greens of any remaining sand. Such tendencies should be avoided by both golfers and superintendents. Trying to restore pristine putting surfaces immediately following aeration and topdressing largely defeats the purpose of either practice. And when putting greens do not get the full benefit of both procedures, the result is more aggressive and/or frequent cultivation treatments needed in the future.
10. Irrigate and fertilize to stimulate turf recovery – The high volume of sand that is incorporated into aeration holes can dry out quickly and induce drought stress on greens, especially in the late afternoon. Frequent irrigation and supplemental hand watering throughout the day for several days are typically necessary to stimulate and accelerate turf recovery. A follow-up application of a soluble fertilizer five to seven days after aeration at a rate of quarter-pound nitrogen per 1,000 square feet further helps speed turf recovery and get the greens back to a smooth, dense, uniform condition.
Conclusion
These 10 points to ease the pain of core aeration may seem obvious, but unfortunately they are often overlooked. Like any simple procedure, problems tend to occur when shortcuts are taken. Aerating at the wrong time of year, not completely filling holes with sand, and not paying proper attention to fertilizer and water applications before and after aeration are frequent mistakes. The end result is prolonged recovery, and putting greens will not receive the full benefit of the procedure.
Keep in mind that despite meticulous planning, adverse weather can disrupt the process, and it is always a good idea to plan an alternate date for aeration in parts of the country where adverse weather is a concern. While golfers and superintendents never look forward to core aerating greens, following the steps in this article will make the process as painless and quick as possible.
Pat Gross is director of the USGA Green Section’s Southwest Region. Email him at pgross@usga.org.

Greens Aerification

 On Monday May 19th, we aerified the greens with a 3/8" side eject tine. Along with the aerification, the greens were verti-cut in two different directions, top dressed and fertilized with a Ultradwarf Bermudagrass granule fertilizer.

1-greens are verti-cut with a dyna blade verti cutters at 1/8" deep (below the height of cut) in two direction.
 A rule of thumb-In a years time, 24% to 30% of material (such as thatch) needs to be removed. By aerifying with 3/8" tines on 1.5 centers an estimates 8.1% is being removed, then the verti-cutting cutting removes approx. another 2.3%
2-blower comes along and helps in removing the excess material (grass clipping) that was removed during the verti-cutting.
3-greensmower mows the green to help in smoothing the surface.
4-green is aerified
5-green is top dressed (heavly)
6-dragging in the sand--after approx. 2 hours of sand sitting on the greens surface we begin dragging the sand in.
7-mow the green-if the sand has settled enough for me to be say ok, lets mow it then we do--otherwise we may wait a day or two before we start mowing the greens.
8-fertilize the greens with a granuler fertilizer-up to 3/4 pound of Nitrogen plus all the necessary micros.
9-water it in.

This whole process took us 9 hours to do. Expect the healing time to take anywhere from 10 to 14 days. Of course, that depends on temperatures, remember the 150 temperature degree rule!!!

USGA Ultradwarf Management

Going for the Gold with the Ultradwarf Bermudagrasses

This is part three of an occasional series on bermudagrass putting greens and focuses on surface management and minimizing grain.
 The first full set of ultradwarf (Champion) bermudagrass putting greens were planted in Florida in the summer of 1997. The following year, Floradwarf and TifEagle became available and were used on a few courses in Florida and the Southeast. Also in 1998, an On-Site Evaluation of Bermudagrass for Putting
Greens project was initiated and sponsored by the National Turfgrass Evaluation Program, USGA, and Golf Course Superintendents Association of America. Subsequently, there has been a steady increase in the use of the ultradwarfs, and today Champion, Mini-Verde, and TifEagle have replaced Tifdwarf as the standard
for warm-season turfgrass putting greens. Although the ultradwarfs are bermudagrasses and there was some preliminary work done as far as their management requirements, as we all know, fine tuning of best management practices occurs in the field over a period of several years. With the ultradwarfs having been in use for ten years, a sound information base now exists for producing consistently top-quality putting green
conditioning.
 It should be reiterated that every golf course is unique and “there are a lot of ways to skin a cat.” Having visited numerous facilities throughout Florida and having discussed ultradwarf putting green management programs with superintendents from the Carolinas across the Southeast to Texas, there are a number of common denominators. The following is a review of the key surface management practices being used to produce top-quality ultradwarf putting greens.

HEIGHT OF CUT IS NOT THE TOTAL ANSWER

Along with a finer leaf blade and increased shoot density, the ability to tolerate a height of cut of 0.125 inch was one of the primary criteria used in selection of the ultradwarf cultivars. As to be expected, however, heights of cut have been taken lower and lower in an effort to produce very fast putting green speeds. However, just because it can be done does not mean that maintaining the lowest height of cut possible is
necessary or even best for providing top-qualit yputting green conditioning. Time and again, university research and field experiences have shown that there is a point of diminishing return where no additional increase in speeds is achieved with further reductions in height of cut. It should also be reiterated that the continual practice of maintaining excessively low heights of cut negatively impacts general turf health and increases its susceptibility to disease and nematode pest problems.
 Thus, today, an effective height of cut in the range of 0.105 to 0.125 inch is being routinely practiced at the vast majority of facilities where top-quality ultradwarf putting greens are being maintained. Along with being able to provide medium fast to fast putting speeds, the turf has improved disease and environmental stress
tolerance. However, during extended periods of inclement weather and in the fall when preparing for the winter, slightly elevated heights of cut need to be maintained.
 The higher shoot density of the ultradwarfs compared to Tifdwarf is a positive characteristic as far as smoothness of ball roll is concerned. Yet, this also is something of a negative when it comes to speed because of the additional resistance or friction created. To compensate and maintain fast to very fast putting speeds, lightweight rolling or double cutting are considered necessary and routine practices. These practices
typically are employed three or four times per week, but at some facilities they are done on a more frequent basis. Generally, when sustained turf growth is occurring, this is not a problem, but additional care needs to be exercised to prevent excessive wear and damage to the perimeters and collars of greens.
 Having sand particles integrated into the turf canopy also aids in reducing ball-to-leaf-blade contact, which in turn helps maintain faster speeds and a smoother, truer ball roll. Thus, frequent but very light sand topdressing is another necessary and routine ultradwarf surface management practice. Throughout the growing season, lightly topdressing on a 7- to 14-day interval is the standard regime. It should further be pointed out that regular sand topdressing plays a dual rule and is needed for dilution of thatch and organic matter accumulation in the upper rootzone. While more frequent topdressing than ever before is being practiced, it is also very important to make sure that a sufficient quantity of sand is being applied annually to
achieve true dilution. Several factors, such as length of the growing season and nitrogen fertilization rates, need to be considered, but applying between 30 to 50 cu. ft. of sand per 1,000 sq. ft. annually would be suggested as a target.
 The turfgrass growth regulator Primo (trinexapac-ethyl) is a very beneficial putting surface management tool with Tifdwarf bermudagrass greens. It was initially questioned, however, if there would be any real benefi t to treating ultradwarf greens, given the fact that a very dense turf canopy already existed. Yet, it was quickly found that with suppressing vertical shoot growth, more consistent putting speeds throughout the day and from one day to the next, along with slightly faster speeds, are achieved with adherence to a regular treatment program. This has become a standard, and it should be pointed out that at a lot of courses in
Central and South Florida, weekly treatments on-virtually a year-round basis are being performed.
The only time they are stopped is just prior to the arrival of a cold front and when nighttime
temperatures of 50 degrees or colder are expected.

GRAIN CONTROL AND SURFACE GROOMING

Due to its stoloniferous growth habit, controlling grain is a major management concern with bermudagrass
greens. There is a strong argument today that with intensively managed, closely cut ultradwarf greens, the influence of grain on ball roll has been minimized to the point that this is not a concern for the vast majority of average to high-handicap golfers. Yet, very distinctive grain patterns do occur and are accentuated by more
frequent rolling and mowing regimes. Since golf, and especially putting, is highly perceptual based, it is imperative to always try to keep grain to a minimum.
 Along with promoting a dense, upright shoot growth character to minimize grain, aggressive verticutting of Tifdwarf putting surfaces has been a standard practice. This also aids in controlling thatch and organic matter accumulation. Verticutting in this manner every two or three weeks is effective, yet it also results in significant
mechanical stress and damage. It has been a standard recommendation to severely verticut Tifdwarf greens with walk-behind units in the early summer and in conjunction with core aeration replications. It was determined fairly quickly, however, that the ultradwarf cultivars do not tolerate severe verticutting and recover very slowly from this abusive cultural regime.
 Regular verticutting of ultradwarf putting surfaces, at least every couple of weeks during the growing season, is being conducted at most facilities. However, along with using the new type of blade options that cut rather than rip through the turf canopy, they are adjusted to operate at no more than 0.0625 to 0.125 of an inch below the effective height of cut. The basic philosophy of routine verticutting of ultradwarf putting surfaces has changed from aggressively removing leaf surface area, thatch, and surface organic matter accumulation, to only thinning the turf canopy and grooming an upright shoot growth habit for grain control.
 With a shallower depth of penetration with regular verticutting, it has been found that a pronounced difference in the effectiveness of the process occurs when working into the grain compared to going down grain. To compensate for this grain effect, double verticutting and going across the putting surface in one direction and then turning around and coming back down the same pass in the opposite direction is needed.
As with routine mowing, the direction of attack with verticutting should be changed with each replication. Circle verticutting is another variation being employed at a few courses in South Florida because it also varies the direction of attack into the grain pattern. While adherence to a regular verticutting schedule throughout the growing season is needed, this also needs to be closely monitored and adjustments made to make sure that excessive thinning, mechanical damage, and stress are not exerted on the turf. Furthermore,
if more aggressive verticutting is required to alleviate a severe grain problem, this should be restricted to the late spring to early summer when maximum sustained growth is occurring.
 In addition to regular verticutting, putting green mower-mounted brushes or groomer attachments are important management tools. Constantly promoting an upright shoot growth character helps keep grain in check, and with minimizing ball-to-leaf contact, a smoother, truer ball roll and faster putting speeds are
achieved. Use of brush or groomer attachments in conjunction with routine mowing is typically performed three to six times per week and in between the routine verticutting replications.

SUMMARY

 Although not discussed in this review, very careful and judicious nitrogen fertilization and irrigation are common denominators at the courses where top-quality ultradwarf putting greens are being maintained. Thus, in many respects, ultradwarf and bentgrass putting greens are managed very similarly today. There is no argument that the ultradwarfs require more intensive and careful management compared to what works successfully with Tifdwarf bermudagrass greens. This has been raised as a concern by some because of the additional commitment of time and resources required. However, on the other hand, if top-quality putting green conditioning is desired or expected, this certainly can be achieved with the ultradwarfs, and the results
justify the efforts.
JOHN H. FOY is the director

Scoreboard Landscaping

Be on the lookout, the golf course maintenance staff will be doing a landscaping project at the existing scoreboard area.
Before we got started-this is what it looked like for years and years.

These next set of pictures will show the changes in appearance happening.

Fairway Aerification

 Willow Fork CC is scheduled to have the corporate fairway aerifier in the first 2 weeks of May.  We will be using a 3/4" solid tine on 2" centers. We will be aerifying 40 acres of fairways plus an additional 70 acres with our Aerway aerifier as well.
 The fairway aerifier resembles the greens aerification, punches a round hole, the depth varies on the compaction of the soil. The rough aerifier (Aerway) makes slices in the turf again the depth varies on the compaction of the soil.
 As we are finishing up each hole a pre emergent block will be sprayed to help prevent crabgrass from moving in.
 So please be patient with us for the next 2 weeks as we are trying to get this aerification completed as quickly as possible.

Willy Plowman
Golf Course Superintendent

County OKs meaty contract to trap, process feral hogs

The Houston Chronicle posted this on Wednesday April 23, 2014.

After this article, I e-mailed Kiah Collier the author of this article, telling him our experience with the hogs here at Willow Fork.

 Locally sourced pork may be on the menu for needy Houston-area families as Harris County Precinct 3 launches its most ambitious effort to eradicate feral hogs damaging parkland and neighborhoods around the barker and Addicks reservoirs.
 Within a month, precinct employees hope to begin trapping and transporting the wild pigs to a meat processing facility in Brookshire, where they will be butchered, frozen and distributed to area food banks.
 Commissioner Court on Tuesday approved a one-year contract $217,600.00 contract with J&J Packing Co. that begins May 1. Commissioner Court also OK'd the purchase of metal panels to complete four traps to be erected near the reservoir's in west Harris County.
 The approvals were the final steps needed in Precinct 3 Commissioner Steve Radack's longstanding plan to eliminate, or at least sharply reduce, a prolific hog population in George Bush and Commissioner Bill Archer parks, home of the two reservoir's.
 "This is the beginning of the Harris County hog program in earnest," Radack declared. "As meat prices go up, we'll be giving it away."
 The commissioner for years has been looking for a way to curb the destructive beasts that have proliferated in his precinct, Texas and most other states, according to government wildlife agencies.
 In 2009, the U.S. Army Corps of Engineers vetoed another Radack plan to hire bow hunters to shoot feral hogs, saying the impact would be minimal and would not outweigh the risk to the public.

Getting rid of the past
  Radack said the rapidly multiplying pigs, have been a problem in his precinct for almost a decade, venturing into neighborhoods bordering the reservoirs to look for food, rooting up yards and damaging sports fields (failed to mention the golf course).
 Radack said trapping them and donating the meat to the hungry is a charitable solution to a pesky problem that he hopes will serve as a model for other communities.
 The question is: "Are we going to be able to make a dent and, yes I think we will," he said.
 For nearly a decade, off duty county workers and hired contractors have trapped several hundred hogs a year in the area. The current plan began to come together early last year when the precinct won a $630,000 Federal Coastal Impact Assistance Program grant to bankroll a study assessing whether hog removal improves water quality, as well as pay for four metal traps and the slaughter and processing of 2,500 pigs. "It'll will be an ongoing and continuing exercise until we get every pig in that area," said Mike McMahan, Radack special activities coordinator.
 The plan is to trap the varmints in four, 4-acres fenced structures - two in each park - where they can survive for up to several weeks, having grass, water, and room to move around. The larger traps will be more effective than the smaller ones employees have been using, McMahan said, because the pigs do not realize they are in a trap and less likely to panic and warn others. "Pigs become very aware of those situations very quickly," McMahan said. "Pigs are very smart animals."

Huge win' for charity
 Radack's office already has an agreement with the Houston Food bank to receive and distribute the meat. The agency's public policy manager, Pamela Berger, described the partnership as a "huge win for us." "From our perspective, this is kind of meat everybody wants; it's locally sourced, it's wild, it's been subject to practices that some people are now finding objectionable, and it's USDA-approved," she said. "I mean, that's the magic because, of course, we would never distribute product that has not been appropriately certified." The meat processor the county will use, J&J, is one of only a few in the state that accepts  feral hogs that has a U.S. Department of Agriculture inspector.
 The plan has its skeptics. Brian Mesenbrink, a wildlife disease biologist with the Texas Offices of Wildlife Services, the U.S. Department of Agriculture branch designated to address human-wildlife conflicts, said the agency is "not against any legal method when it comes to controlling the feral hogs," but said that the trap-and-process concept - "tried in small little operations here and there" - has proved short-lived in other places, mainly because of the cost. "It's actually very expensive," he said, noting that "you don't get to pick which ones go to market."

The 'disease aspect'
 He also warned of the "disease aspect" of such an operation, noting that feral hogs "carry quite a few" and even federal inspectors do not examine every piece of meat. "It's like Russian roulette," he said. "It's great publicity while it works, but the minute something goes wrong, the minute somebody gets sick, there's going to be all hell to pay. No one thinks about that going into it. They just see the fuzzy and warm side of it."
 Radack dismissed the disease concern, noting that hunting and eating feral hog is far from uncommon. As for the financial viability of the program, he believes the precint will be able to secure additional grant money to contnue it.

Will meet safety rules
 If not, he said, people likely will "donate to the cause" once they see the effectiveness of the program, which he noted has been approved by the Corps of Engineers.
 McMahan said the agency had to sign off on the areas where the traps will be set up to ensure they do not disturb beneficial, native plants species. "Our evaluation found that this program met our requirements and may have a positive impact on the resevoirs with regards to water quality," said Isidro Reyna, a spokesman for the Corps Galveston District. "The Corps will maintain oversight throughout the duration of the program."
 The Corps had been developing another program with the Texas Parks and Wildlife Department to form a new policy on managing hog populations in the resevoirs and elsewhere. Reyna said that has been "set aside" so that it can "evaluate the successs of the program wth Harris County."

Let's wish them the best!!!

150 RULE

 So what is the 150 rule? 

Add the nighttime and daytime temperatures together and what do you get? 

The ideal growing combined temperature is 150 degrees, with this ideal combined temperature number you get results in the growth of turf. When the combined temperatures add up below this 150 rule the grass is either in a dormant stage or growing at slow pace. The same will generally occur when temperature reach the 100 to 105 degree during the summer months.

 Here's some examples of March 2014;

Week 1-average low 51 degrees average high 66 degrees =117 degrees

Week 2-average low 62 degrees average high  71 degrees = 133 degrees

Week 3-average low 64 degrees average high 73 degrees = 137 degrees

Week 4-average low 69 degrees average high 79 degrees = 148 degrees

April 2014

Week 1-average low 52 degrees average high 66 degrees = 118 degrees

(2 morning were in lower 40's-ouch)

Week 2-average low-61 degrees average high 74 degrees = 135 degrees

Forecast for Week 3 

Average low-51 degrees average high 68 degrees = 119 degrees

So far no combined average temperatures have reached the 150 degree rule of thumb. Yes there has been a day here or there, but overall temperatures are well below where we need them to adequately maintain a good stance of turf.

Everybody hang in there before long we will be wishing for some cooler weather to come in and cool things down.

Thanks

Willy Plowman

Golf Course Superintendent