Turf Disease

Pythium Blight
Pythium Blight [cottony blight / grease spot] is a rapid spreading disease that occurs during very humid weather patterns (65+ evening temperatures followed by hot, humid days) and prolonged leaf wetness. The disease causes root and crown rot which can wipe out a lawn in a matter of days.

The grass blades will exhibit a wet or grease like appearance, starting at 1" to 3" in diameter which may combine with other patches to form larger areas of infected turf. In the morning, while dew is still present, a white cottony mass (mycelium) will form on the diseased areas. As the blade dries, the turf turns straw colored and usually starts to stick together, especially if moist conditions persist. Sometimes this disease, if the pathogen is halted due to weather, may resemble dollar spot.

Disease Development Favored by: Over watering/too much moisture High humidity Thatch build up Warm night temperatures Soil compaction Corrective Measures: Do not mow while lawn is wet Do not water in the evening Overseed in late fall with resistant turf type(kentucky bluegrass or tall fescue are recommended) Remove thatch Aerate lawn Prune trees to promote air circulation

Pythium Blight on lawn