eb0938
Gary Chastagner, Ph.D., Washington State University Plant Pathologist, Ralph S. Byther, Ph.D., WSU Cooperative Extension Plant Pathologist (retired), and Carrie Foss, WSU Cooperative Extension Coordinator, WSU Puyallup | |||||
Management | |||||
| Disease | Symptoms | Conditions Favoring Disease | Presence in Washington | Cultural | Fungicidal(a) |
BROWN PATCH Rhizoctonia Solani |
Brown irregular-shaped or circular | Moist, warm (above 80°). | Common in eastern Washington. Not common in western Washington. | Avoid excessive irrigation and high nitrogen fertility. | fenarimol, flutolanil, chlorothalonil, triadimefon. |
FAIRY RING Marasmius oreades |
Rings of dark green grass and sometimes dead zones, with or without tan mushrooms 1-2" in diameter. | Mild, moist. Mushrooms mostly in spring and fall. | Common on all turf-grasses in western Washington. Fairly common on turfgrasses in eastern Washington. | Open soil mechanically. Daily soakings of rings with water for one month. Keep turf well fertilized. | flutolanil |
FUSARIUM PATCH Microdochium nivale (Fusarium nivale) |
Browning and thinning of turf in large (1-8") indefinite spots. Also see Pink Snow Mold. |
Cool, wet. | Very common on bent grass and annual bluegrass in western Washington. Common in eastern Washington. | Promote air and soil drainage. Avoid excessive nitrogen. 2.0 lbs. sulfur per 1000 sq. ft. per year may help. | fenarimol, mancozeb, triadimefon. Use twice in spring and twice in fall. |
HELMINTHOSPORIUM DISEASES Bipolaris, Drechslera and Exserohilum species (Helminthosporium sp.) |
Root and crown rot resulting in yellowing and thinning of turf or tan to purple spots on leaves. | Moist. | Common on bluegrasses and rye grasses. | Water in morning; pick up clippings. Do not let grass get matted. Avoid excessive nitrogen. | chlorothalonil, mancozeb |
NECROTIC RING SPOT Leptosphaeria Korrae |
Dead circles, arches, and patches several inches to several feet in diameter. | Spring and fall in eastern Washington; spring through fall in western Washington. | On seeded and sodded bluegrass. Most common on sodded turf, 2 to 3 years after establishment. | Promote deep rooted turf by proper fertilizer and water management. | fenarimol |
RED THREAD Laetisaria fuciformis (Corticium fuciforme) |
Bleached or tan-colored irregular areas 2-24" with red fungus strands. | Cool, moist. | Very common in western Washington. Occasional in eastern Washington. | Use adequate nitrogen in a balanced NPK nutritional program. Late fall fertilizer applications especially important. | chlorothalonil, fenarimol, flutolanil, mancozeb, triadimefon. See EB1016. |
RUST Puccinia sp. |
Leaves turn yellow. Yellow to orange to reddish-brown powdery growths on leaves. | Variable. | Most common on certain bluegrasses, especially Merion. Also on perennial ryegrasses. | Increase nitrogen. Water during dry periods. Mow frequently. | Usually not necessary. if needed: chlorothalonil, mancozeb, triadimefon. |
| SLIME MOLDS | White to yellowish slimy growth, usually turning to masses of small, dark, powdery "pin-heads" on large leaves; occasionally large (1-3") gray powdery mounds. Not parasitic. | Mild, moist. | Occasional spring and fall. | Mow, rake or wash off with water. Usually disappears after 1-2 weeks. | Common turf fungicides may prevent reappearance. See EB1083. |
SNOW MOLDS Gray Snow Mold Typhula sp. |
Irregular dead, bleached areas 2-24" with a gray mold, usually under or near melting snow | Cold, wet; worse under prolonged snow cover. | Not common in western Washington. Very common in northeastern area. | Avoid late, heavy nitrogen fertilization. | Apply before snowfall: chlorothalonil, fernarimol, triadimefon, flutolanil. See EM4047. |
Pink Snow Mold Microdochium nivale (Fusarium nivale) |
Circular light brown to dark brown patches 2-12" Patches commonly bleached under snow and covered with pink fungus. Also see Fusarium patch. |
Cold, wet; worse under prolonged snow cover. | Not common in western Washington. Very common in northeastern area. | Avoid late, heavy nitrogen fertilization. | Apply before snowfall: fenarimol, mancozeb, triadimefon. See EM4047. |
| TAKE-ALL PATCH Gaeumannomyces graminis var. avenae (Ophiobolus graminis var. avenae) | Thinning and/or dying of turf in circles 4-36" followed by invasion of weeds and annual bluegrass in center. | High moisture favors disease development, but symptoms do not show until turf is under moisture stress. | Common on bentgrass in western Washington. Occasional in eastern Washington. | Use ammonium sulfate in balanced NPK (3-1-2 ratio) nutrition. Avoid high lime. 2.0 lbs. of sulfur per 1000 sq. ft. per year may help. | fernarimol. See EB0939. |
YELLOW PATCH Rhizoctonia cerealis |
Light brown to yellow patches and rings. | Prolonged moisture at 40-60°F | Common on bentgrass bluegrass and fescue | Avoid excessive irrigation and fertilization; manage to ensure deep rooting. | flutolanil |
(a)See last page for trade names of registered fungicides.
| FUNGICIDES REGISTERED FOR HOME LAWN USE IN WASHINGTON AGAINST TURFGRASS DISEASE(1) | ||
| Common Name | Trade Name | Registrant |
| chlorothalonil | Blackleaf Lawn and Garden Fungicide | Wilbur-Ellis Company |
| Cooke Daconil | Cooke Laboratory Products, Chas. H. Lilly Company | |
| Green Thumb Lawn and Garden Fungicide | Cotter & Co. | |
| Ortho Multi-Purpose Fungicide | Solaris Corp. | |
| fenarimol | *Rubigan A.S. | Dow Elanco Company |
| flutolanil | *Prostar 50 WP | Nor-Am Chemical Company |
| mancozeb | Fore Lawn Fungicide | Black Leaf Products Company |
| Maneb Plus with Zinc | Green Light Company | |
| Broad Spectrum Mancozeb Spray | Green Light Company | |
| triadimefon | Bayleton 25 Turf and Ornamental Fungicide | Miles Agricultural Chemical Division |
| Fung-away | Green Light Company | |
(1) Before you purchase any of these fungicides, read the label to make certain the package you have selected is labeled for your intended use, and then follow all lable directions and precautions.
*These fungicides are registered for use by homeowners but are not commonly found in most garden centers. Check farm and feed stores as possible sources of these fungicides. They will only be available in larger containers (1-4 lb. bags, for example).
Use pesticides with care. Apply them only to plants, animals, or sites listed on the label. When mixing and applying pesticides, follow all label precautions to protect yourself and others around you. It is a violation of the law to disregard label directions. If pesticides are spilled on skin or clothing, remove clothing and wash skin thoroughly. Store pesticides in their original containers and keep them out of reach of children, pets, and livestock.
Issued by Washington State University Cooperative Extension, and the U.S. Department of Agriculture in furtherance of the Acts of May 8 and June 30, 1914. Cooperative Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, color, gender, national origin, religion, age, disability, and sexual orientation. Evidence of noncompliance may be reported through your local Cooperative Extension office. Trade names have been used to simplify information; no endorsement is intended. Revised July 1994. Subject Code 254, 356. A EB0938