You Are Here: Management Updates 2003 Archive June 23, 2003

Date: June 23, 2003
Category: Diseases
Subject: Fusarium, Take-All, Melting-Out, Red Thread, Anthracnose, Brown Patch, Pythium

The continuing wet weather has been encouraging fungal diseases. Temperature has determined which ones are most active. Cooler areas are still dealing with Fusarium patch (pink snow mold) and take-all patch on bentgrass. Leaf spot and melting-out are widespread as is red thread. It is difficult to eliminate either disease with fungicide in a lawn. Where weather is warmer and nitrogen levels are high, Fusarium blight has occurred. This disease can mimic Pythium blight with greasy leaf blades and, sometimes, some pinkish to reddish color of the affected leaves. The spores are easily streaked with mowers. Anthracnose has begun to show up, but in most areas, the rainfall seems to be keeping the grass growing quickly enough to avoid problems. Some fairly dramatic slime molds have been popping up, but they can simply be scraped away and will not infect the turfgrass. In many areas, the continued wetness has made the dead outer leaves obvious and unsightly, but with no apparent disease activity. Annual bluegrass weevils (“Hyperodes”) can mimic disease and cause yellowing of Poa annua, especially along edges of fairways.

WARNING #1: A look ahead this week suggests that we are finally going to get some days in the upper 80s and nights in the 60s. With the continuing rain through the weekend, this is the perfect situation for severe outbreaks of brown patch and, possibly, Pythium blight. These will most likely occur on putting greens and collars, tees, and perennial ryegrass lawns. It is probably best to avoid any nitrogen fertilizer applications until nights are cooler and the turf has dried out.

WARNING #2: The UMass Turf Disease Diagnostic Lab will be open next week (June 23-27), but will be closed the following week (June 30-July 4). Diagnostic services are available through Rutgers and URI. Contact information will be on my phone voicemail and this website by Friday, June 27.

- Submitted by: Dr. Gail Schumann