You Are Here: Management Updates 2003 Archive June 6, 2003

Date: June 6, 2003
Category: Diseases
Subject: Red Thread, Leaf Spot to Melting-Out, Ascochyta Tip Blight, Fusarium Patch, Take-All

We have had enough wet weather for some of the lawn diseases to develop into roughly circular patches of declining plants. Some of these plants were weakened by the severe Typhula blight/gray snow mold last winter. Active now are:

1. Red thread: Look for red threads growing off leaf tips and pink fungal growths on leaf blades when wet.
   
2. Leaf spot progressing into melting-out: When there is enough water, the leaf spots just keep accumulating until the leaf blade starts to collapse. The fungus can invade the crown and kill the plant. You can pull back the affected leaves to check the crown. If it is white and firm, the plant should recover.
   
3. Ascochyta tip blight: Look for numerous dark brown to black fruiting bodies in infected tissue. This is a short-term stress disease. Turf should recover with drier weather.
   Fungicides are usually not very effective in lawns. Recovery and regrowth should occur with the upcoming warm weather. Overseed any thin areas that do not recover.

On golf courses, Fusarium patch (pink snow mold) and take-all patch (root disease of bentgrass) have predominated the week. Take-all patch will occur even in established bentgrass if the pH is high or when we have April for two months! Again, we should see improvements in the coming week.

- Submitted by: Dr. Gail Schumann