Sunday, August 20, 2017

USGA Article on factors affecting green speed

USGA COURSE CARE
Why Can't Green Speeds Remain Constant? June 17, 2016

Putting green speeds fluctuate because of factors such as temperature, humidity and the different maintenance practices.
                                   
It’s a beautiful fall day with cool temperatures and low humidity; you are playing golf and marveling at the condition of the course, particularly the pace of the putting greens. Some golfers might be inclined to just enjoy the moment. Others will wonder why the greens can’t play like this all the time. There are a myriad of variables that affect turfgrass growth and putting green speed; and, what is possible to achieve at one time of year under certain conditions may be impossible at other times.




Unquestionably, the biggest variable affecting turf health and playability is weather. Air and soil temperatures both have a tremendous impact on turfgrass growth rates. So do moisture and humidity. Rain or irrigation events, particularly when combined with a fertilizer application, can stimulate extra growth. This effect can be magnified under warm conditions with the result being increased surface resistance and reduced ball roll. Similarly, hot, humid conditions cause turfgrass leaves to retain moisture and remain fat, and this also may result in reduced green speed. Conversely, dry, windy conditions can cause the turf to wilt which can reduce surface resistance and increase putting green speeds. Putting green speed will vary from day to day merely as a result of weather influences and the seasonal changes turf undergoes.






Maintenance practices also have major effects on putting green speed. Mowing and rolling operations increase putting green speed. Applications of topdressing, needed to dilute organic matter and smooth putting green surfaces, can initially slow putting green speeds. A day or two after a topdressing application, putting green speeds often get faster than they were prior to the application. The same often is true of vertical mowing and brushing. Practices that stand the turf up aid in controlling the development of grain and can improve the quality of cut, but these practices can slow putting green speed for a day or two before stimulating an increase.




Many other factors affect turfgrass growth. Growing environments, soil conditions, and applications of plant growth regulators, plant protectants, and fertilizer are just a few. Anything that affects turf growth is likely to affect putting green speed. Golf course superintendents constantly juggle maintenance practices with the weather to maximize playability and maintain consistency. Despite our scientific training, modern equipment and experience, it is impossible to maintain a consistent putting green speed every day of the season.




The question is, why would we want golf courses to play the same way every day? Adjusting one’s game to the conditions and varying setup are some of golf’s greatest attractions. Golf courses cost a lot to maintain, and if consistency is so important, a cheaper alternative would be to move the game indoors. Golfers could use simulators and hit off of artificial surfaces into nets in climate controlled environments. This would ensure absolute consistency and eliminate the variable effects that come from wind, rain, temperature, maintenance practices, course set up, etc.




Fortunately, most golfers believe that playing the game outside in a natural setting is part of golf’s charm. Varying how courses play through setup and having to adjust one’s game based on the weather and playing conditions makes the game infinitely interesting and challenging. Rather than considering green speed and other aspects of playability as factors that should be kept as constant as possible, look at their changing effects as a blessing that continually adds interest and new challenge to a wonderful game.
 

Friday, August 18, 2017

Cart Restrictions - Cart Path Only Rulings


Lately with abundant rainfall I have been hearing a lot of questions about why we need to be cart path only when the course seems to be draining fine after the rain stops. I wanted to try and explain some of the issues involved in making the decision.


I don't ever want to inconvenience the members or take away from the enjoyment of your round of golf but CPO decisions involve more complex issues than most people realize. It's not about whether or not the carts leave ruts in the ground, but more about the long term health of the soil structure and turf. The time of year and number of rounds (carts) also plays a big part in how conservative I need to be. 

 

There are two main issues. When the soil is wet, especially on the surface, the water acts as a lubricant and allows the soil particles to compact more readily. This causes long term rooting problems as well as water infiltration problems during drier weather. When we were having dry weather back in July I was fighting a lot of these issues related to water percolation. We had a lot of localized dry spot (LDS) in high traffic areas. LDS occurs in compacted areas and the result is that normal irrigation water will not penetrate the surface and move down to the root zone. These areas then require wetting agents and manual watering which is a big job when it comes to fairways and rough.

 

The other issue during very hot and humid weather like yesterday (8/17/17) is called wet wilt and can be very detrimental very quickly. When you get a heavy downpour, followed by the sun coming back out on really hot days, the turf can't cool itself and everywhere a cart drives on wilted turf causes acute damage. Watching the radar and the storm forming yesterday, combined with high temperatures, I saw the potential for this to happen so I called it cart path only as soon as the rain started. Once the storm passed, and the threat for wet wilt passed, I reversed the cart restriction. During cooler times of the season I never would have taken action like that so quickly with just a brief rain event. We have had a lot of rain lately (10.6 inches in the past 30 days), so it wouldn't have taken much for that scenario to play out yesterday and I was overly conservative. 

 

In regards to areas getting damaged where carts can't go it's actually these same issues that contribute to those problems. Your feet actually have a higher PSI than your cart tires, plus spikes, so you will notice issues on tees and walk up areas to tees and greens due to wear and compaction even though there are no carts allowed there. All of those areas get traffic even when they are saturated and we are cart path only. Additionally, those areas do get traffic from all of the maintenance activities we do on a daily and weekly basis. These factors, combined with some disease and insect damage, is what led to turf loss on the tees on 4 and 6.

 

I'm sorry for any inconvenience these decisions cause. It's always a difficult one to make because I know that it detracts from the enjoyment of golf and makes the course play longer and harder.  As I said, I never want to inconvenience the members but I have to make sure the course remains in acceptable condition throughout the year.

LDS with wilted turf.
      


James hand watering fairway LDS in high traffic area on #1.
                      
 
Wet wilt with cart tracking at a local course. These tracks will turn brown a few days later.



   

Tuesday, August 8, 2017

Summertime Green Speeds and Height of Cut

Currently we are approaching the end of the "dog days" of summer. We are at the point where we can start to be a little less conservative with greens rolling, as well as start to lower the mowing height back to normal.

During the heat of the summer when higher temperatures and heavy downpours can come unexpectedly, we must stay on the defensive with our cultural practices. Rolling, brushing, and low mowing do damage that accumulates over time as stress increases and recuperative ability decreases due to high temperature and humidity.

Being that we are getting closer to when the turf can readily recover, I can start to push the greens more. In fact, we are planning on starting to roll some this week and lowering mowing heights gradually over the next 7 to 10 days...with the extended forecast calling for low 80's. We topdressed yesterday and John is grinding the greens mowers tomorrow in anticipation.

Currently, the greens are being mowed daily and we use a combination of growth regulators and light weekly applications of fertilizer to control growth. The speed is slower than usual due to the increased mowing height more than anything. During times of stress the height of cut is raised so the turf can produce more food for itself. Although it seems minor, raising the height from .110 to .130 creates a lot more leaf area for photosynthesis. Unfortunately that small increase, combined with the summer humidity, will cause a decrease in speed.

Last year I made the mistake of pushing for green speeds too hard and paid a price when the heat and humidity came and never let up. In that scenario the slow speeds came in late summer and fall due to the need to recover from summer thinning. I'm sorry for the reduction in speed over the last few weeks but our greens and collars have held up well for the most part and I think we are now out of the woods. That sets us up for a great fall season instead of pushing growth and recovery.

The speeds will increase over the next week or two leading up to aeration and then obviously they will be slower for a couple weeks after that. After they heal, you can expect them to get even faster throughout the fall season. We have been doing more frequent topdressing which will help with speed and firmness when the humidity and temps start to drop. We will also be doing a less aggressive aeration on the greens this fall so recovery time will be shorter than this past spring.



Thank you for your patience through this critical period of balancing health and playability.


For a detailed look at the science behind mowing heights please follow the link below.


USGA Green Section Article - Bent Grass Greens Mowing Height