Spots 2 to 24 inches in diameter; typically small, light tan spots with distinctive reddish cast; pink to reddish mycelia threads extend out ¾ inch from lesions on the leaf or pink gelatinous mycelia mass; get water soaked, then tan to bleached leaves, yellowing, and shriveling from the tips, and matted my this pink mycelia
HOST GRASSES:
Major Hosts: Fine fescues, Ryegrasses, Kentucky bluegrass
Others: Bentgrasses, Bluegrasses, Tall fescue, Bermudagrass
DISEASE CYCLE:
Shoot attacking fungus; most severe during periods of slow shoot growth; typically occurs in spring and fall; Pathogen overwinters as mycelial fragments on living and dead plants; disease is spread by mycelia from infection centers during moist cool weather (60 to 75 degrees); confined to leaves and leaf sheaths; spread by water or machinery moving over infected turf; red threads are easily broken off the leaf and carried by the wind to spread the disease-next year it will likely be in another location
FACTORS THAT MAY PROMOTE DISEASE DEVELOPMENT:
Spring and fall disease; temperatures 60 to 75 degrees; high humidity; low nitrogen levels; heavy dews
CULTURAL CONTROL:
Increase nitrogen levels judiciously to sustain moderate shoot growth; maintain adequate P and K levels; raise cutting height; water deeply in morning; maintain soil pH at 6.5 to 7.0
CHEMICAL CONTROL:
Use fungicides as last resort; several protectant or systemic fungicides recommended.
| Specific Fungicide Recommendations | |||
|
Fungicide (chemical name) |
Efficacy |
Application Interval |
Example of Products (trade names) |
| Azoxystrobin | Good to excellent | 14 to 28 days | Heritage |
| Fenarimol | Good to excellent | 10 to 21 days | Rubigan, Patchwork |
| Iprodione | Good to excellent | 14 to 28 days | Chipco 26019, Chipco 26GT |
| Myclobutanil | Good to excellent | 14 to 28 days | Eagle, Immunox |
| Triadimefon | Good to excellent | 14 to 28 days | Bayleton, Accost |
REFERENCES:
Duble, R. L. 2001. Turfgrasses-Their Management and Use in the Southern Zone. Second Edition. Texas A&M University. College Station, Texas.
Emmons, R. D. 2000. Turfgrass Science and Management. Third Edition. Delmar Thomson Learning. Albany, New York.
Turgeon, A. J. 2002. Turfgrass Management. Sixth Edition. Prentice Hall. Upper Saddle River, New Jersey.
Beard, J. B. 2002. Turfgrass Management for Golf Courses. Second Edition. Ann Harbor Press. Chelsea, Michigan.
Taylor, G. R. - Editor. 2000. Turfgrass Pesticide Recommendations 1999-2000. Extension Publication SCS-1991-01. Texas A&M University. College Station, Texas.
Purdue University (http://www.agry.purdue.edu/turf/pubs/latin.htm)