The Ohio State University

Home LandscapeNotes Even though this has been a relatively moderate season to grow grass (low levels of disease) during the last week a wide range of samples and calls have been received with diseases active. In some areas warmer temperatures, varying amounts of rainfall and high humidity have resulted in building disease pressure. The follow is a list of what we have seen and a few comments.

Red Thread - has been wide spread on Kentucky bluegrass and perennial ryegrass especially in northern Ohio.

Rust - has been active in parts of the state for over 2 weeks and primarily on perennial ryegrass. Rust tends to be on sites with dry soils, compacted soils and slow growing grass.

Brown patch - started the last few days. Watch for if temperature rise and there are wet humid conditions. Lush and or juvenile turfgrass is the first place the disease develops. This is a common problem in over irrigated sites. Tall fescue can be especially affected. This is often confused with Pythium blight but remember that pythiun requires HOT WET conditions, high temperatures in the 80's and 90's during the days and 70 and about at night.

Dollar spot - With moderate conditions this disease is wide spread. This can be an ongoing problem on Kentucky bluegrass and perennial ryegrass and is often found in combination with red thread.

Leaf spot - various leaf spot and melting out situations have been encountered.

Posted by Joseph Rimelspach