It’s time for me to own it

Posted on May 11th, 2020

Thomas A. Nikolai, Ph.D.

I don’t recall the exact location or date, but sometime around the dawn of the 21st century I was attending an open discussion among prominent turfgrass scientists when Dr. Karl Danneberger of The Ohio State University sarcastically asked, “I just want to know who the hell is telling superintendents to roll their greens”?  I don’t think anyone expected an answer when a graduate student stood up and confessed “That would be me”.  It was a stunning declaration considering two other universities concluded lightweight rolling was only useful to increase green speed on a short term basis and therefore recommended it only be used for special occasions such as tournaments.

I was confident recommending rolling on a frequent basis because I had performed the most continuous lightweight rolling research to date.  Consistent results of MTF funded rolling research include decreased dollar spot, localized dry spot, and weeds with no increases in compaction or bruising of leaf tissue.  Results from other MTF sponsored research include that rolling can replace mowing during periods of the year to relief traffic stress which can lead to economic savings all while maintaining customer satisfaction.   

Due in part to those studies I was nicknamed the “Dr. of Green Speed” and I have traveled the globe and spread the word about rolling putting greens.  As I have travelled the world there has been one nagging question I get about frequent lightweight rolling which has been, “How do I stop my rolling program from injuring my collars”?  I have always respectfully poo-pooed the problem, however, it recently occurred to me that I caused this problem.  Given my enlightenment it is time for me to own this and do the best I can to solve this nagging condition of worn collars on putting surfaces.

Step one was to determine how big the problem of worn collars is in Michigan by releasing a survey with the assistance of Adam Ikamas and Carey Mitchelson.  The average results of the survey are listed below.  These results do not solve the problem, but they do provide an indication of how wide spread the problem may be and provided me enough data to sort out common practices that may exacerbate the dilemma of collars.  This will lead to further analysis of this survey and a future study at the Hancock Turfgrass Research Center.  155 people responded to this survey and I trust everyone will find the results interesting at this point.  With that said, I want to thank the Michigan Turfgrass Foundation for their support.

Questions asked and the most popular responses are offered below.

The bench setting height of cut for my greens are: (155 responses)

.110 – .120 = 29.7%

.120 – .130 = 28.4%

.100 – .110 = 20.6%

.090 – .100 =   9.7%

I certainly made a small error on the HOC surveys by making the ranges cross over at the extremes, that is, .120 has a possibility of 2 options.  My bad, but I think the results are still interesting and may assist in the worn collar issue.


The bench setting height of cut for my tees are: (154 responses)

.350 – .400 = 24.7%

.450 – .500 = 23.4%

.400 – .450 = 20.8%

.300 – .350 = 16.9%


The bench setting for my green collars are: (155 responses)

.450 – .500 = 24.5%

.350 – .400 = 21.9%

.400 – .450 = 20.0%

.300 – .350 = 15.5%


The bench setting for my fairway mowers are: (155 responses)

.450 – .500 = 36.1%

.400 – .450 = 23.2%

      > .500 = 16.8%

.350 – .400 = 14.2%


For the majority of the year my greens are mowed with a: (153 responses)

Triplex             77.1%

Walk-behind    21.6%


Which best describes your putting green rolling frequency? (155 responses)

Rolled 1 – 3 times per week      42.6%

Rolled 4 – 5 times per week      25.2%

Rolled 6 – 7 times per week      23.2%

Never rolled                               4.5%

By the way, due to over 20 years of lightweight rolling research at MSU I recommend a frequency 3 times per week to no more than 2 times per day.  


The roller type I use on most often on my putting surface is: (149 responses)

Sidewinder                   64.4%

Vibratory                     16.8%

Weighted triplex rollers   9.4%

Sidewinder & vibratory   3.4%

Pull behind                    2.7%

Fairway roller                 0.7%


If you use a sidewinder roller how do you change directions? (105 responses)

On the collar                 41.0%

On the surrounds          26.7%

On the green                 23.8%

Rotate*                          5.7%

*Comments provided about rotation included:

*Rotate changing direction on green or surrounds/never the collar.

*Rotate on the greens and collars.

*Rotate on collar, surrounds, and green and come to complete stop on greens.


The PGR program on my greens is best described as applied: (153 responses)

Every 2-weeks             39.2%

Based upon GDD         20.3%

Every week                  19.0%

Once a year at most        8.5%

Every 28-30 days            5.9%


When I apply a PGR on my putting greens I: (152 responses)

Also spray the collars                           88.8%

Try to avoid spraying the collars              7.9% 


The most worn collars on my course that surround my putting greens show:

No visible impact from my putting green rolling program                       48.7%

Very little thinning from my putting green rolling program                     34.7%

Some wear damage from my putting green maintenance program              8.7%

Noticeable thinning from my putting green rolling program                       4.7%

Show a lot of damage from my putting green rolling program                   0.7%


The PGR I use the most often on my putting greens throughout the year include: (191 selections as many choose more than one option)

Primo Maxx (includes generic Trinexapac ethyl)          59.6%             

Proxy                                                               10.4%

Trimmit                                                             7.3%

Anuew                                                               6.3%

Legacy                                                               6.3%

Cutless                                                               4.2%


My golf facility is best characterized as: (154 responses)

Private             41.6%

Public              32.5%

Semi Private     13.6%

Resort                7.1%

Municipal          5.8%

Again, thank you all for the tremendous response.  As I make time to statistically analyze the data for interactions I will get the data out through the MTF and MiGCSA.


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