You Are Here: Management Updates 1999 Archive October 1, 1999

Date: October 1, 1999
Category: Diseases
Subject: Red Thread, Rust, Basal-Rot Anthracnose, Fusarium Patch

The big news this week is the confirmation of the NEW FALL SPOT DISEASE OF BENTGRASS described in the previous message. The continuing moist weather is favoring a variety of fungal problems in turf. In lawns, RED THREAD and RUST are commonplace. Rust takes 10-14 days to appear after infection, so it occurs mostly on turf that is growing slowly due to compaction, drought, and/or low fertility.

ANTHRACNOSE BASAL/CROWN ROT is appearing on some golf putting greens. This disease is most common where root growth is limited and in compacted and particularly wet areas. It may occur in somewhat circular patterns or just irregularly in the turf. Both Poa annua and bentgrass are susceptible, but one species may be more affected than the other depending on the fungal strain present. The sticky spores are easily spread to other areas, so mow affected areas last or hose off the mower before moving to nonaffected areas. Chemical control is best with a tank mix of chlorothalonil plus a DMI fungicide. Plants with badly infected crowns may be slow to recover, if they do at all.

The cooler weather and abundant moisture is also allowing the return of he infamous FUSARIUM PATCH (PINK SNOW MOLD). It can appear as greasy/reddish spots, sometimes like a hydraulic fluid leak. If the spores have been spread widely by mowing, there may be a general reddish cast to the turf. As with anthracnose, the abundant spores are easily spread around. High N fertility and high surface pH (e.g. recent liming) favor the disease along with the favorable environmental conditions.

- Submitted by: Dr. Gail Schumann