Page 12 - GreenMaster Spring 2022

Nancy Dykema initiated an irrigation timing study based in part upon research that concluded frequent lightweight rolling increases volumetric moisture content and decreases dollar spot.
Tying it all together, my results proved it was not only safe to frequently roll putting greens, but it was beneficial by decreasing dollar spot and localized dry spot. Paul’s research verified my findings that rolling decreased disease by increasing VMC which correlated with an increase in bacteria. Nancy’s research verified Paul’s results because among her treatments, it is clear irrigating at 10 pm daily resulted in the greater VMC which also resulted in the least amount of dollar spot.
The point is, knowing why a positive reaction occurs following a treatment leads to alternative strategies to recreate the positive reaction. The falling dominos in the scenario above has led to the question, “can we construct a green and manage the amount of water in the root zone to eliminate dollar spot and other diseases?” Enter Mike Rabe, an MSU master’s student, who will be attempting to answer that question initiating in 2022. His study, funded by Capillary Concrete, will compare USGA specification greens with overhead irrigation to sand based sub-ground irrigation greens
that run off solar power. Both putting green construction methods will have undulating surfaces and slopes up to 3% so stay tuned, but be patient for at least two years.
The frequent rolling of putting surfaces became a common practice with a handful of superintendents accepting the results of my studies and then other superintendents followed suit. Truth is, none of the agronomic benefits I discovered were necessary to make rolling acceptable. All research ever needed to do was conclude that frequent rolling was not detrimental to soil or turfgrass health because rolling smooths the surface increasing the likelihood that a good golfer can sink a 10-foot putt.
I would like to close with how I started, by quoting Sir Robert Blyth Greig. “A considerable body of knowledge has been built up by the Golfers’ Research Association of America (USGA). . . The first problem then is to get together the knowledge that does exist and make it available to all. The second problem is by scientific research to add to the existing knowledge and fill up the blanks in our ignorance.
This is an operation that shall never cease, but there is no reason why it should never begin. Judging from the success of the American Golfers’ Research Association, the small subscriptions required of each club will be many times repaid by the additional pleasure which the game will give when played under better conditions. But golfers must be patient. They must not expect quick returns. Research is slow, but it is very sure, and it pays not in fives and tens but ultimately in hundreds and thousands percent.”
I believe those words are as true today as when Sir Robert published them in 1929. To everyone who supports turfgrass research, this article is dedicated to you. While the methods may seem slow, your contributions have benefited the game and the environment, and it always will, as long as science continues to ask why.GM
Photo credits to Nancy Dykema, Research Assistant, Michigan State University. Photo credit: Sir Robert Blyth Greig, Edward Drummond Young.
Creative Commons - CC by NC. National Galleries Scotland.
12 • CGSA • GreenMaster
“... irrigating at
10pm resulted in
the least amount
of dollar spot while irrigating infrequently resulted in the most dollar spot.”