New Fairy Ring Discovery Providing Results

By Patrick O'Brien and Christopher Hartwiger, USGA Green Section SE Region Agronomists

March 17, 2009

Fairy rings on putting greens have long been a nemesis for superintendents. Varying degrees of success have occurred over the years with fungicides, wetting agents, and cultivation programs. It's no wonder, as up to 60 different fungi can be associated with the symptoms. These fungi not only impact the turfgrass tissue and root systems, but can change the soil physical and chemical properties as well, including making the soils hydrophobic (water repellant).

Research by Dr. Lane Tredway at North Carolina State University recently made a breakthrough in that only three fungi have been associated with the fairy rings on putting greens. Just as important, his research demonstrates that once the fairy rings are observed, curative fungicide treatments will suppress the fungi, but have little impact on helping the soils return back to normal and the symptoms will persist. Most past research has focused on curative rather than preventative strategies, and most fungicides specify treatment once symptoms are observed.

Dr. Tredway set-up a research experiment in 2006 and 2007 to investigate preventative fairy ring control programs Field trials indicated that two spring applications of Bayleton at 21 to 28 day intervals effectively prevented fairy ring symptoms on putting greens when applied once soil temperatures (a five-day average ) reached 55 degrees at the two inch depth. Irrigating the product to a depth of 0.25- inch into the thatch and soil is a benefit. No added benefits were observed by adding a surfactant.

Our observations from more than 50 golf courses following this strategy were, that it was highly effective on both bermudagrass and bentgrass putting greens during the 2008 season. Dr. Tredway has made important progress with this century old issue. If you would like to learn more about this topic, read the Web update by Dr. Tredway and Lee Miller on TurfFiles: NCSU Web Site . March 27. p. 1-4. www.turffiles.ncsu.edu/PDFFiles/004051/Fairy_Ring.pdf .

Source: Patrick O'Brien 770-229-8125 or patobrien@usga.org and Chris Hartwiger 205-444-5079 or chartwiger@usga.org