You Are Here: Management Updates 2002 Archive June 7, 2002

Date: June 7, 2002
Category: Diseases
Subject: Dollar Spot, Anthracnose, Brown Patch, Bacterial Wilt

We are in the transition to summer weather. Dollar spot is active in some areas, and anthracnose has returned with the rain and warmer temperatures. Anthracnose responds best to fungicides in the early foliar (leaf) stage. Once it is in the basal or crown rot stage, it is difficult to control. The basal rot stage requires that a systemic fungicide is watered into the crown area and followed by a separate application of chlorothalonil to the leaves. Chemicals alone will not eliminate anthracnose if you do not correct the stress factors that have led to the disease. Avoid sand top-dressing until you have the disease under control. Hyperodes can cause similar symptoms, and they are definitely active at this time.

Take-all patch continues to be a problem on bentgrass (see last week's message). We should be done with yellow patch (cool-weather brown patch), but warm-weather brown patch could show up once we start getting warmer nights. It does not have to be very hot for brown patch as long as night temperatures stay above 59 F- especially if there is plenty of moisture as we have had from the recent rains. A sample of bacterial wilt on annual bluegrass (Poa annua) was diagnosed this week. There is no cure for this disease which generally occurs only in very compromised plants. The solution is to fix the poor soil environment and favor bentgrass which is not susceptible to the disease.

- Submitted by: Dr. Gail Schumann