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K-State Study Examines Golf Course Ball Mark Repair


Some of the most well-meaning golfers are causing the worst problems for today’s putting greens, but studies at Kansas State University suggest the solution is simple. The researchers concluded that golfers should either learn how to use their traditional ball mark repair tool correctly or consider switching to one of the newer tools on the market.

A depression results each time a ball drops onto a green’s lush bentgrass. Busy golf courses can develop more than 1,000 of these cavities every day. Such ball marks not only kill grass but also wipe out the possibility of a straight-rolling putt.

K-State Research and Extension horticulturists Jack Fry and Steve Keeley knew that, for years, golf courses have been encouraging players to repair their own ball marks. Some courses have even furnished the palm-size, double-pronged "forks" traditionally used for this task.

But a surprisingly large number of golfers have never understood the correct way to apply the tool. Instead, they use its 2-inch prongs, topped by a thumb-size grip, to dig in and lever up the smashed grass and compacted soil. Rather than helping the mark heal quickly, they often tear the plant’s roots.

"Levering seems logical, but it’s not the way the tool was meant to be used. We found that the digging and lifting actually has a more long-lasting effect than leaving the mark unrepaired," Fry said.

Researchers elsewhere have assessed how damaging ball marks can be – finding that unrepaired marks can lead to persistent scars and overall poor turf quality and play. The K-State studies were the first to take a scientific look at repair strategies.

"Our results indicate that poor technique, not the traditional repair tool, have been at fault," Keeley said. "Still, we found that the new device we evaluated is as effective, if not better, under some conditions. More importantly, the new tool is less likely to be used incorrectly."

The new tool used in the study is called a GreenFix, and it abandons the long prongs common to the traditional shape. Looking somewhat like the blades from tiny pruning shears, it’s much too stubby to create the kind of damage an improperly used traditional tool can. Its design calls for an entirely different approach: Just push the mark back into place.

"You insert the GreenFix blades at a 45-degree angle into the turf around the edge of the ball mark, and gently push in toward the center. It’s pretty simple," Keeley said.

In contrast, the traditional tool – often mistakenly called a divot repair tool – requires golfers to insert it into the edges (not the center) of a mark and use a gentle twisting (not lifting or levering) motion to bring those edges back together.

(The Golf Course Superintendents Association illustrates the tool’s correct use at http://www.gcsaa.org/resources/facts/ballmarks.asp.)

The marks the K-State researchers examined came from golf balls lobbed in with a pitching wedge on opening day of each study. The first study ran from May 27 to July 12 and the second was just over a year later from September 17 to October 29.

The researchers randomly assigned the brand-new marks to one of four treatments: (1) no repair, (2) correctly used traditional tool, (3) incorrectly used traditional tool, and (4) a putter-end GreenFix. – which also is available in a palm-size, thumb-grip version.

The two greens used were at the Colbert Hills Golf Course and K-State´s Rocky Ford Turfgrass Research Center. Both are well-established L-93 bentgrass, growing in sandy soils near Manhattan, Kan.

The researchers assessed the results of their four treatments each week on the basis of (1) scar size, (2) surface smoothness and (3) turf quality. They found:

* Every ball mark leaves a scar.

* Initially, unrepaired marks cause the poorest surface quality. After healing, they also retain a cavity shape that impairs the "trueness" of ball roll.

* For the first few days, the quality of surface is better on a well-handled traditional repair than on a GreenFix repair.

* Properly used, both repair tools can bring complete ball-mark recovery in two to three weeks.

* On greens with firmer surfaces, the scar shrinks faster and recovery takes four days less with a GreenFix than with a traditional tool repair.

* Improper use of the traditional tool doubles the time ball marks need to recover. After healing, surface quality remains reduced, and the mark leaves the largest scar.

"In the Colbert Hills study, the GreenFix tool eventually produced the best and fastest results – including the smallest scars," Fry said. "In the research center study, the properly used traditional tool and the GreenFix tool produced almost identical results."

The researchers’ complete scientific report is available in Applied Turfgrass Science at http://www.plantmanagementnetwork.com/pub/ats/research/2005/repair/.