Fairy Rings in Turf Associated with the Bird's Nest Fungus Cyathus stercoreus.

During the summer of 1998, several fairy rings with the fruiting bodies of a bird's nest fungus were observed on two greens at the University of Minnesota turf plots in St. Paul. Both greens, a 3-year-old annual bluegrass green and a 2-year-old creeping bentgrass green, were constructed of a 90% sand: 10% reed sedge peat soil mix. The fungus was identified as Cyathus stercoreus (Schwein.) de Toni (Nidulariaceae) (1). The fruiting bodies were approximately 15 mm tall and 8 mm wide. The fairy rings were irregular in shape, with a diameter of up to 50 cm, and contained up to 120 fruiting bodies per ring. On annual bluegrass, chlorotic and necrotic grass was observed at the edge of the rings in July but those damaged areas recovered in August. No symptoms were associated with the rings in creeping bentgrass. Rings were first discovered in June and early July and expanded by about 10 cm in 30 days. New fruiting bodies appeared during July and August as the rings expanded. The application of the fungicide chorothalanil did not affect the rings. This is the first report of a bird's nest fungus associated with fairy ring in turf. Reference: (1) H. J. Brodie. 1975. The Bird's Nest Fungi. University of Toronto Press, Toronto.