Nursery, Greenhouse, and Landscape

Grey Snow Mold on Turf Controlled by Fungus

Grey snow mold is a common disease of turfgrass in areas where there are over 90 days of continuous snow cover during the winter. Isolates of the fungus Typhula phacorrhiza, collected across southern Ontario in the spring of 1994, were evaluated in field tests over a 3-year period for suppression of grey snow mold.

In December 1994, forty-six of these isolates were applied to creeping bent grass (Agrostis stolonifera) at a rate of 200 g/m2. In December 1995, 30 selected isolates were inoculated onto a new set of plots along with grey snow mold fungi. In November 1996, 22 of these isolates were re-inoculated onto the 1995 plots. All plots were rated for injury after snowmelt, 1995-1997.

The isolates tested varied significantly in their ability to suppress disease. Significant correlations were found between the disease suppression trials for the 3 years, with several isolates showing statistically significant control of grey snow mold equal to a fungicide treatment.

Because not all of the isolates in the collection could be screened in the field tests, lab characteristics (such as growth rate and sclerotial production) were examined for their relationship to suppression ability. No strong correlations were found between these in vitro growth characteristics and field performance, so this cannot be used as a pre-screening system. More research needs to be done to determine if better performing isolates exist among the remaining 200+ isolates that haven't been tested.


Wu, C., T. Hsiang, L. Yang and L. X. Lin. 1998. Efficacy of Typhula phacorrhiza as a biocontrol agent of grey snow mould of creeping bentgrass. Can. J. Botany 76(7): 1276-1281.

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