ARS | Publication request: Resistance of closely-mown fine fescue and bentgrass species to snow mold pathogens

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 11, 2011
Publication Date: July 1, 2011
Repository URL: http://handle.nal.usda.gov/10113/56389
Citation: Gregos, J., Casler, M.D., Stier, J. 2011. Resistance of closely-mown fine fescue and bentgrass species to snow mold pathogens. Plant Disease. 95:847-852.

Interpretive Summary: Creeping bentgrass is the most desirable grass for use on golf courses in cool-humid regions of the USA. However, this grass is highly susceptible to fungi that grow under snow cover, called "snow molds", which generally kill bentgrasses unless they are treated with highly expensive fungicides. This research has demonstrated that colonial bentgrasses can be substituted for creeping bentgrass, greatly increasing resistance to snow molds, with a relatively small sacrifice in turf quality and appearance.Fine fescues, while highly resistant to snow mold fungi, had very poor turf quality and appearance on golf course fairways mowed at 1/2" height. Golf course superintendents and advisors can utilize this information to select appropriate varieties for fairway renovation with the goal of reducing or eliminating the use of fungicides for winter disease control.

Technical Abstract: Creeping bentgrass (Agrostis stolonifera) is the primary species used on golf courses in temperate regions but requires prophylactic fungicide treatment to prevent snow mold diseases. We hypothesized that fine fescues (Festuca spp.) and colonial bentgrass (A. capillaris) have superior resistance to snow mold diseases compared to creeping bentgrass. Our objective was to compare the resistance of fine fescues, colonial bentgrass, and creeping bentgrass to snow mold diseases caused by Microdochium nivale and Typhula spp. Field plots were established in two separate years on fairways of three golf courses in Wisconsin to encompass the geographic distribution of snow mold pathogens. The experimental design was a split-split-split plot arrangement with three replications. Whole plots were pathogen species, host genus were sub-plots, host cultivars were sub-sub plots, and inoculated vs. non-inoculated treatments were sub-sub-sub plots. Plots were visually evaluated each spring for disease, turf quality, and Poa annua infestation. Data were analyzed using planned contrasts. Inoculation effects depended on pathogen type and location. Creeping bentgrass always had the most snow mold damage. Fine fescues had less snow mold damage than colonial bentgrass except for one yr-location, but did not provide acceptable year-long turf quality due to P. annua invasion.