Dr. Thom Nikolai, Turfgrass Academic Specialist

2009 MTF Turfgrass Research Update from Thomas A. Nikolai, Ph.D.

Turfgrass leaf-mulch study
A Kentucky bluegrass, ryegrass, fine fescue mixture maintained at a 3-inch mowing height was used to perform a leaf-mulching nitrogen study.  Three different rates of tree leaves (none, ankle height, and calf height) were mulched into plots and with a rotary mower.  Afterwards, one of two rates of fertilizer (none or .80 lbs of N from Scotts Wintergaurd) was spread over the plots.  Results indicate that mulching tree leaves into the turf is a viable option for getting rid of the leaf-litter,  grass with leaf-litter mulched into it greens-up quicker in the spring, the addition of the nitrogen (especially on the higher rate of leaves) reduces the visibility of the leaf litter which many homeowners would find favorable.

Golf Spike Studies 
My crew performed a golf cleat study for Foot Joy during the spring/early summer of 2009.  Basically, Foot Joy utilizes MSU for traction and putting green wear studies.  The results of the studies indicate that a prototype cleat actually improved traction while decreasing wear on the putting surface compared to cleats currently on the market.  My guess is we’ll see that prototype on Foot Joy soles next year.

Wetting Agent/Irrigation Study
We utilized three wetting agents and three different irrigation regimes (no irrigation, 35% ET, and 70% ET) from May-September on a creeping bentgrass putting green.  Data collected included weekly TDR (soil moisture), localized dry spot, and green speed measurements and we are currently running % organic matter.   While there were differences in the amount of soil moisture there was never any differences in visual quality or amount of green speed.  This is attributed to the fact that it rained every “F’in” day and the temperature never exceeded 60 degrees during the summer of 2009 (or at least that is how I remember it).  This study will take place again the next two years as part of Rod Toccos graduate work (Ph.D. student).

Fertilizer carrier/rate/ putting green root zone study
The study was initiated in 2009 and is a collaborative effort with Dr. Kevin Frank.  The study utilizes several differ nitrogen carriers, several different nitrogen rates, and different P and K rates on three putting green root zone mixes.  Data collection includes biweekly green speed measurements, color ratings, disease counts, soil chemical tests, percentage nutrient content in the leaf tissue, water infiltration, and percent organic matter.  This study will run through 2013 and it’s currently the master’s study for Miyuan Xiao (Nancy).  This is the coolest study ever.

Lightweight rolling studies
We performed four-separate lightweight rolling studies this past summer.  Two of the studies are being utilized by Paul Giordano (masters student under Dr. Vargas) who is attempting to determine why rolling decreases dollar spot.  One of the other rolling studies was a multi-site study performed in collaboration with Douglas Karcher at the University of Arkansas.  We will be submitting this work for publication very soon.  The final study was also part of a multi-site study (U of Tennessee, UCONN, and U of Arkansas and MSU) and it is the only long term rolling study performed on Poa annua greens with different mowing/rolling frequencies.

Putting green mowing frequency study
Single, double, and triple mowing 6-days per week on a creeping bentgrass putting green.  Data collection includes green speed measurements, quality measurements, dollar spot counts, and leaf tissue analysis. 

Functional Qualities of Turf in an Urban Environment
While I have been working on this project for most of the year we are just initiating it this month (October).  What we are doing is maintaining turfgrass on abandoned properties in several sections of Flint, MI. in an effort to quantify the environmental, economic, and social qualities of turfgrass.  Scotts Co. is providing funding (for up to three years) and all the fertilizer and pesticides and John Deere has agreed to donate mowers for the project.  I could not possibly pull this study off by myself and it will be a collaborative effort including Kevin Frank, Kurt Steinke, and Stephen Gasteyer (MSU Sociologist).

I hope Neil Young will remember….Confessions of a lightweight rolling yahoo researcher.

Article by Thomas A. Nikolai, Ph.D.
Michigan State University

Not too long ago I was watching the Top 100 Southern Rock Songs of all time on VH1. As the countdown had reached the final 5 songs I found myself wondering which Allman Brothers Band song would be the Number 1 Southern Rock song of all time.  Heck, there are so many great Allman Brothers Band tunes I was having a hard time deciding which one would be number 1.  Then, much to my surprise the Number 1 Southern Rock Song of all time was awarded to Lenard Skynard for their 1972 release Sweet Home Alabama. 

So why is any of that relevant?  Well the point is I give numerous national presentations on putting green management often with my cohort Mike Morris CGCS, Crystal Downs Country Club, Frankfort, MI.  Recurring comments from our Taking Control of Green Speed GCSAA seminar evaluation forms are attendants requesting more rolling, fertility, and mowing height studies on warm season grasses. I certainly don’t blame any  superintendent in Florida for thinking, “What the heck is this yahoo going to tell me about taking care of my warm season greens”?

This makes me think about the line “Southern man don’t need him around anyhow” from the song Sweet Home Alabama”.   Now that line is directed toward Neil Young who wrote the racially charged song Southern Man in 1970, but in relation to my putting green research I am not so certain many warm season grass superintendents shouldn’t think it applies to me as well.  So now I have been asked to write an article about green speed for superintendents in Florida.  Hmmmm, can I pull it off?

Well let’s start with some results from some of my lightweight rolling research and I’ll let each of you decide if it can be useful to your turf and/or your management of your crew.  Who knows, if it is good maybe I’ll be asked to volunteer my time to write about fertility and green speed in a future article.

First of all I have performed more lightweight rolling research than everyone else combined.  I am not bragging it is just a fact.  Beginning in the mid-90’s the  objective was to decide what the safest rolling frequency was for a putting surface without causing detriment to the turfgrass plant or increasing compaction. Too make a long story short; rolling three times per week (or every other day) resulted in:

• Noticeably increased green speeds every day (as long as the thatch is not too thick.  When the thatch is too thick residual green speed the next day drops off fast).
• No increases in compaction given the plots were on a sand topdressing program.  If the plots were not on a sand topdressing program I don’t know what the results would be, but I think it is worthy of mention.
• No decreases in water infiltration given the plots were on a sand topdressing program.
• Decreases in dollar spot (this takes several months to a year to become incredibly noticeable).
• Decreased localized dry spot.
• Decreased broad-leaf weeds (which I think means better turfgrass density).
• Decrease moss (which I think means better turfgrass density).

At this point I wanted to find different ways to use lightweight roller and address some concerns of superintendents in the south.  Step 1 was to perform a study in collaboration with Dr. John Sorochan at The University of Tennessee since I cannot perform studies in the transition zone on my own.   My thinking was there is no more difficult region to grow grass in than the transition zone (or at least that is what I am told) so if rolling could work in that area it would carry to different regions.

A treatment included in this multi-state study included alternating rolling and mowing on a daily basis throughout the season.  To clarify, mow one day without rolling, and then roll the next day without mowing and continuing to alternate on that program for the entire season.  Dr. Sorochon used a DMI Speedroller and I used the Tru-Turf vibratory roller. Results from alternating mowing and rolling on a daily basis included:

• Better turfgrass quality compared to mowing every day (no disease reduction but improved wear tolerance). 
• The same playability (green speed) compared to mowing every day.
• A possible cost saving for a golf course between $12,000 to $30,000 per year depending upon the mowing program and length of season.  I must mention that this portion of the study included a cost analysis survey written and tabulated by Dan Strunk who sent the survey to every golf course superintendent in Tennessee.  I sat on Dan’s graduate committee.

Now to get real for a minute, most superintendents would not alternate mowing and rolling on a daily basis for an entire year (though Dr. Sorochan tells me he knows of 4 courses in Tennessee that do this as a result of the study and the weak economy).  However, results from the research do provide the superintendent with a viable option for managing their putting surfaces during the most stressful period of the season.   The question the results beg the end user to ask themselves is, “If I can provide the same playing conditions during the most stressful 4-8 week period of the season and improve turfgrass quality than why wouldn’t I?   Could you do this for 2, 3, or 4 weeks to free-up some manpower for a special project?  I don’t know the answer to that, but if you take daily green speed measurements during this period you can. 

As I began presenting those results at seminars superintendents were very responsive and I began to formulate other ways to use rollers.  I responded by initiating more mowing/rolling frequency studies with the DMI Speedroller and the Graden roller.  One of the treatments included in each study was Roll every day and mow every other.  That’s right; I’ll write it again, Roll every day and mow every other.  At this point I must acknowledge the assistance of MikeMorris, CGCS  Crystal Downs Country Club who performed an identical study on his nursery green in Frankfort, MI.  Results from Rolling everyday and mowing every other include:

• Improved  turf quality compared to plots mowed every day and rolled every other
• Improved uniformity in green speed from day to day compared to all other mowing/rolling programs
• Improved uniformity in green speed through the length of the day compared to all other mowing/rolling programs
• Less dollar spot compared to mowing only with green speeds increased approximately 18-inches compared to mowing alone (that is on the day rolled and mowed and on the day not mowed and rolled) 
• No decrease in water infiltration or compaction given that the plots were on a topdressing program.

Wow, that’s a pretty cool option isn’t it?  One little caution, to my knowledge the rollers used in these studies were the lightest ones on the market so if you are going to consider rolling everyday know the weight of your roller compared to the ones listed above.   Also, superintendents with Poa annua greens that have experimented with this rolling/mowing frequency on their golf courses have informed me that it only gives accelerated great green speeds for five/six weeks (the research was performed on bentgrass greens in Michigan). Only you can know if the program will work for you on your course. 

OK, so these studies were all performed on cool season grasses far north of Florida.  So what is the point?  Well, all in all the results from these studies are not intended not to tell any superintendent “how they should manage their putting surface” but more to offer the superintendent a viable option based upon the results.  The point is that if you can make the time to take daily  green speed measurements from at least one green twice daily (one in the morning and one in the afternoon) you can make more informed cultural practice decisions that can also impact your courses playability (green speed) and pocket book.  It is not one size fits all.       

Is there a hint as to how these rolling programs might work on warm season grass?  Well, these results were interesting enough that I asked Rick Tatum, CGCS Grey Oakes Country Club, Naples, FL to perform a similar short term study on his bermudagrass greens putting course.  Rick obliged (thanks Rick you are truly cool) using his Salsco roller.  Rick had three greens which he alternated mowing and rolling on a daily basis, three greens that he rolled every day and mowed every other, and  three greens he simply mowed every day (in research we would call those three greens the check plot).   Rick performed the studies for three weeks in the summer and three weeks in the winter.  The results from both time periods were the same; there were no statistical differences in green speed among the treatments.  In all truth there was a lot of variability within treatments and I am hopeful to perform this study with Rick again this summer and am hopeful to decrease the variability.   Additionally, I hope to perform a similar study with Tim Heirs, CGCS, Old Collier, Naples, FL. on his Seashore Paspalum nursery green.  Note to Mr. Young: these are two fine southern men.

Finally, I am performing collaborative lightweight rolling/mowing height studies in 2008 with three other Universities (one having ultra-dwarf bermudagrass greens) to collect pro and con data on the long term impact numerous rolling/mowing height programs has on warm season grass pests.  We will be happy to share the results has they come in.  Now I am not certain if “Neil Young will remember a Southern man don’t need him around anyhow”.  However, I know that southern superintendents don’t need me around so I just want to thank all that I have met for your hospitality.   I hope some of my research efforts can be pertinent to your labors.

Research Reports