Limiting turf injury from soil-inhabiting fungi can be challenging because damage to turfgrass root systems usually occurs long before visible symptoms. As such, golf course superintends typically employ an integrated program of cultural and chemical control measures to protect susceptible turf from soil-borne pathogens.
Fairy ring is one such soil-borne disease that is especially troublesome on putting greens. The flushes of growth, circular patterns of discoloration, occasional fruiting bodies and hydrophobic conditions can adversely affect the appearance and playability of putting surfaces. Unfortunately, fairy rings have been a frequent topic of conversation during recent USGA Course Consulting Service visits.
In general, fungicides are most effective when they contact the site of disease activity. It is fairly easy to spray turf foliage to control foliar diseases, but reaching pathogens beneath the playing surface can be far more difficult. Research indicates that using soil surfactants and higher spray volumes can help control soil-borne pathogens, such as fairy ring (Latin, 2002). In fact, many fungicide labels recommend carrier spray volumes from 2 to 4 gallons per 1,000 square feet. Higher spray volumes can be easily achieved by using high-capacity spray nozzles.
Although increasing spray volume from 1.5 to 4 gallons per 1,000 square feet may require mixing an additional tank or two, the potential benefits of using a higher spray volume are well worth the extra effort. So, turn up the volume to maximize each treatment and improve efficacy.
Latin, Richard. “Fairy Ring.” Turfgrass Disease Profiles. Purdue University Cooperative Extension Service, Jan. 2002. Web.
Central Region Agronomists:
Bob Vavrek, regional director – bvavrek@usga.org
John Daniels, agronomist – jdaniels@usga.org
Zach Nicoludis, agronomist – znicoludis@usga.org
Information on the USGA’s Course Consulting Service