You Are Here: Management Updates 2003 Archive August 7, 2003

Date: August 7, 2003
Category: Diseases
Subject: Pythium, Brown Patch, Slime Molds, Take-All, Summer Patch, Bentgrass Dead Spot, Dollar Spot

This is the last turf disease message that I will write from Amherst. The next time you hear from me, I hope to be opening my new lab at Marquette University in Milwaukee, Wisconsin. The new information will be posted on this web site when I am ready to receive samples and requests for information.

I picked a good time to leave. If you ever had any doubt that fungi like wet conditions, the past week was certainly enough to convince even the most casual observer. Pythium blight and brown patch have both been active and severe in many areas. Luckily, these foliar diseases respond well to fungicides and will both be inactive with the first night in the 50s F.

Slime molds love warm, moist conditions. Several kinds have been active. One of the most famous is the "dog vomit" slime mold that shows up lemon yellow on bark mulch and quickly turns to beige with masses of black, powdery spores. On turf, I have seen the kind that looks like small, white balls at the tips of grass blades, another that is a gold yellow with powdery white spores inside, and the most common one that starts black and slimy and becomes gray and powdery like cigarette ashes. You can read more about the dog vomit slime mold at Tom Volk's great fungi website:
http://botit.botany.wisc.edu/toms_fungi/june99.html

Other diseases that are active this week are anthracnose (when isn't it??), take-all patch on bentgrass, and some summer patch on Poa annua. Two cases of bentgrass dead spot were reported. This, so far, occurs only on young bentgrass on sand greens (<6 yrs old). It looks like ball marks and, upon a closer look, will have numerous black fruiting bodies in the leaves. It can be distinguished from dollar spot by observing the turf in the morning dew or closing a sample in a plastic bag overnight with a damp paper towel. Dollar spot produces abundant white mycelium, especially at the leading edge of the spot. Also, dollar spot is a disease of both bentgrass and Poa annua, but BDS infects only bentgrass.

If you need diagnostic services in the next few weeks, please contact the labs at URI or Rutgers. Contact information is posted on the Disease Diagnostics page. I look forward to continuing my work with you after Labor Day. Thank you for your tremendous support and many kindnesses over the years.

- Submitted by: Dr. Gail Schumann