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Presented in partnership with Syngenta
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The bedknife vs. the green
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You might say Thom Nikolai, Ph.D., is obsessed with greens speed. He has published several articles and a book, and he gives seminars on the subject. But the man has his reasons.
“My premise,” says Nikolai, “is that a superintendent juggles three things when it comes to his greens: budget, playability (measured in greens speed) and turfgrass health.”
In his quest for ways to maintain playability while maintaining turf health, Nikolai tested bedknives of three different thicknesses to determine whether bedknife thickness affects greens speed or turf quality.
With the support of the PGA Tour and John Deere’s loan of nine 220 walk-behind mowers, Nikolai undertook a study at Michigan State University’s Hancock Turfgrass Research Center in May 2006.
Each of the nine mowers was used to mow a different 40-foot by 40-foot Crenshaw creeping bentgrass green. The mowers were divided into three groups, with each group using one thickness of bedknife: thin (Lowcut), medium (Tournament) and thick (Standard). The bench setting for each mower was 0.150 inch. The greens were mowed six days a week for the three weeks of the study.
To evaluate playability, the speed of each of the nine greens was measured on 12 dates with both a Stimpmeter and a Pelzmeter. Superintendents would be more likely to use a Stimpmeter, but Nikolai also used a Pelzmeter because he believes “there’s less variability with a Pelzmeter, which makes it a great research tool.”
When all three types of bedknives were compared, Pelzmeter measurements were significantly different on four of the 12 dates measurements were taken, but Stimpmeter measurements were significantly different on only two.
No matter which measurement tool was employed, when the speeds of all nine greens were compared, the speeds of greens where the thin and medium bedknives had been used were not significantly different from each other, but they were significantly greater than the speeds of greens where thick bedknives had been used.
Visual evaluation showed no significant differences in turf color at the beginning of the study, but greens mowed with the thick bedknife had significantly lower color ratings than the other greens at the end of the study.
For these results to be conclusive, the study would have to be repeated, which is unlikely given the unique opportunity to test nine mowers of the same model. Yet, there is a take-home message for superintendents.
Given the results of this experiment, superintendents might consider using a bedknife of medium thickness, which produced turf that was not significantly different in greens speed or color from turf mowed with a mower that had a thin bedknife. Medium bedknives are less expensive than thin ones, but they are also thicker and presumably will last longer than their thin counterparts. Using bedknives of medium thickness could save superintendents money without sacrificing playability and quality.
Another tip from the guy who’s working to help superintendents have affordable, playable, high-quality greens.
The Turf Resource Center’s Facts About Artificial Turf and Natural Grass is available to give readers the ability to make informed judgments when installing natural grass or artificial turf. The 30-page booklet addresses the short- and long-term health, safety and fiscal and environmental consequences that artificial turf may present. Case studies, references and scientifically documented information also are included. A downloadable, printable version of the booklet is available at www.turfresourcecenter.org, while hardcopies are available to educators and organizations with a shipping and handling fee, subject to the approval of the Turf Resource Center. For more information, contact the Turf Resource Center at 847-649-5555. Novozymes Biologicals announces plans to open a new 32,000-square-foot dry agricultural products production facility, which will triple the company’s capabilities to produce granular and soluble fertilizers for its Roots product line. The Roots line also includes micronutrients, growth enhancers, disease control and insect control products for the turf industry. The new facility in Albion, Ind., will employ 12 people, and production is expected to begin once the building is completed in 2008. |
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