You Are Here: Management Updates 1998 Archive May 11, 1998

Date: May 11, 1998
Category: Diseases
Subject: Yellow Patch, Fusarium Patch

The excessive rain and cool temperatures have resulted in outbreaks of two diseases in particular: yellow patch (cool season brown patch) and Fusarium patch (pink snow mold). Both diseases are favored by high N.

Fusarium patch usually appears as small greasy to coppery patches. Although the fungus is often not visible on the turf, it produces abundant spores which are easily streaked across the turf to initiate new infections especially during mowing and when water drains across the surface of the turf. Even though the rain has now stopped, there is an incredible amount of moisture in the turf. The disease is likely to remain active as long as night temperatures remain cool. This disease is sometimes confused with Pythium root rot, but that disease will show no evidence of streaking. If you store a turf sample in a plastic bag overnight, the Fusarium patch fungus will typically appear on the infected blades by morning- again telling you that it is not Pythium root rot which is strictly underground. This method can also be used to determine if fungicide applications are still holding.

Yellow patch will probably disappear rapidly with the coming warmer temperatures. It causes quite large patches of blighted leaf blades typically without a smoke ring on golf turf and lawns but rarely causes lasting injury.

Because there is so much moisture still in the turf, be on the lookout for other fungal diseases as the weather warms up. It would not be surprising to see dollar spot or possibly anthracnose if the heavy rains have left turf a little low in nitrogen.

- Submitted by: Dr. Gail Schumann