You Are Here: Management Updates 2004 Archive March 31, 2004

Date: March 31, 2004
Category: Diseases
Subject: Fusarium Patch, Crown or Basal Rot Anthracnose

Two diseases to watch for on putting greens: The current cool, rainy weather is perfect for two common diseases of putting greens and possibly tees. The fungi that cause these are present in other turf areas, but stress and frequent mowing allow them to cause disease in very low cut turf. If you see small greasy spots, it is not Pythium. It is Fusarium patch (pink snow mold). It streaks very easily just like Pythium. If you are not sure, send a sample to the Turf Disease Diagnostic Lab or put a cup-cutter sample in a plastic bag humidity tent overnight in a cool place. The fungus mycelium should be visible at the leading edge of a spot by the next morning. Spot treatments with fungicides are effective. Watch for the disease in shady areas of greens where the turf stays cool and moist longer.

If you suddenly see small patches of bright yellow Poa annua, it is probably crown or basal rot anthracnose. Pull the yellow plants straight up out of the turf and look for the charcoal black evidence of the fungus. Water in a systemic fungicide and follow that with a separate surface application of chlorothalonil. Avoid spreading the spores to new areas by washing mowers. Avoid sand topdressing until you have the disease under control. Read the fact sheet on "Why Anthracnose Is So Difficult to Control" in the Disease Fact Sheets section of this web site for other stress factors that contribute to this disease. It is important to try to correct the stresses before the heat stress. Anthracnose is a warning that you are pushing the turf too far.

- Submitted by: Dr. Gail Schumann