Ecology and Life Cycle:
Ophiosphaerella korrae is thought to survive unfavorable environments
as mycelial plaques in plant debris. The fungus is thought to move from
plant to plant by growing ectotrophically along the surface of roots
and rhizomes, and infecting cells in the root cortex. Infection in bermudagrass
occurs in the fall, with symptom development occurring in the spring.
Bluegrass infection occurs throughout the growing season during cool,
wet periods with symptoms first occurring in late spring.
Ophiosphaerella korrae is an ascomycete. It produces ascospores
in black pseudothecia, which are formed on necrotic roots, rhizomes,
leaf sheaths, and crowns. The importance of ascospores in pathogen dissemination
Links to other sites:
Spring Dead Spot in Hybrid Bermudagrass - NCSU Turfgrass Disease Note
Trends article - Spring Dead Spot Control
IPM Online: Spring Dead Spot
Disease Profiles: Necrotic Ring Spot - Purdue Extension
Ring Spot - Colorado State Extension
Ring Spot Fact Sheet - Cornell Extension
Alexopoulos, C. J., Mims, C. W., and Blackwell, M. 1996. Introductory
Mycology. 4th ed. New York, NY: John Wiley and Sons, Inc.
Butler, E.L. 2004. Development of novel strategies for control of spring
dead spot of bermudagrass. M.S. Thesis
Couch, H. B. 1995. Diseases of Turfgrasses. 3rd ed. Malabar, FL: Krieger
Smiley, R. M., Dernoeden, P. H., and Clarke, B. B. 2005. Compendium
of Turfgrass Diseases. 3rd ed. St. Paul, MN: APS Press.
Smith, J. D., Jackson, N., and Woolhouse, A. R. 1989. Fungal Diseases
of Amenity Turfgrasses. London: E & F.N. Spon Ltd.
Vargas, J. J. M. 1994. Management of Turfgrass Diseases 2nd ed. Boca
Raton, FL: Lewis Publishers.
If not otherwise cited, images and figures are courtesy of E.L. Butler,
Turfgrass Diagnostician at North Carolina State University