Fraze mowing, which involves removing the grass down to soil level, has been used in agriculture for several years, and more recently, it was introduced for use on athletic fields. Now golf courses are exploring the possibilities of using fraze mowing as a regular management tool.
At the Turf Solutions II educational session on Tuesday, two researchers and two superintendents formed a panel on fraze mowing moderated by John Sorochan, Ph.D., at the University of Tennessee. Turf scientists Aaron Patton, Ph.D., at Purdue University and Jim Brosnan, Ph.D., at the University of Tennessee, discussed their experiments with fraze mowing, and superintendents Andrew Jorgensen, CGCS, and John Nachreiner spoke about their real-life experiences with the method.
Fraze mowing was developed from a method used to remove asphalt from roadways and has been used for several years on soccer pitches in Europe. In the U.S., athletic fields like the football field at the University of Tennessee are replaced annually using fraze mowing: 2 inches of grass and soil are removed and then replaced with 2-inch thick sod.
At Purdue, Patton experimented with fraze mowing on cool-season grass, removing nearly all of the creeping bentgrass and watching it grow back from 0 mm. An unexpected result was that weeds also grew back "in places you didn't know you had them," said Patton. However, fraze mowing can remove large quantities of weed seed in the soil. Kentucky bluegrass is more tolerant of fraze mowing, but recovery in perennial ryegrass is very slow — as might be expected in areas with shorter growing seasons and cooler climates — and zoysia, unlike bermudagrass, is not a good candidate for fraze mowing.
John Nachreiner, director of agronomy at Shady Canyon Country Club in Irvine, Calif., resorted to fraze mowing to correct problems caused by lateral growth of Princess 77 bermuda battling Tifway 419 bermuda. Like Jorgensen, Nachreiner was pleased with the end result, saying, "If I could do it everywhere, I would."
Both superintendents said that disposal of the massive amounts of material removed by fraze mowing was the biggest problem they faced. Jorgensen said his two-man crew filled one roll-off trailer for every 100 feet of the 22,000 square-foot tee. "It took two hours to make a mess and two days to clean it up," he said, and suggests hiring someone to clean up the debris and dispose of it properly. Nachreiner's 3-acre project took only one and a half days to complete, but cost $900 per roll-off trailer for disposal. The debris can be used for compost, and local schools or municipal parks can cover their athletic fields with the material fields. Planning ahead for debris disposal is essential.
And finally, at the University of Tennessee, Jim Brosnan is looking at fraze mowing as a means of at least reducing Poa annua on golf courses. He has tested fraze-mowed strips and found a 40% to 50% reduction in the number of Poa plants present. Fraze mowing is said to remove 80% of visible Poa seeds, and physical removal of Poa annua through fraze mowing may be part of a successful control strategy. One of the questions being explored is how often fraze mowing should be done to maintain Poa annua control.