You Are Here: Management Updates 2002 Archive April 23, 2002

Date: April 23, 2002
Category: Diseases
Subject: Yellow Patch

Yellow patch (sometimes called cool-season brown patch) is widespread throughout New England right now. It is caused by Rhizoctonia cerealis, a different fungal species from R. solani that causes summer brown patch. Some superintendents report that yellow patch was active last fall and again this spring before the hot weather. Since the return of cool,wet weather, additional outbreaks have been reported. Perhaps the environmental conditions were optimal for disease development or the recent hot weather may have stressed the plants and made them more susceptible.

Yellow patch usually does little harm to turf, but it may persist as long as the weather remains cool and wet. High N levels in turf foliage and excessive thatch favor the disease. Many of the fungicides that are effective for hot weather brown patch are not very effective for yellow patch. Fungicides that are likely to check the disease include: azoxystrobin (Heritage), flutolanil (ProStar), and fludioxanil (Medallion). The last product is a contact/protectant only. Recovery of the turf after treatment will depend on how quickly the turf is growing. In most cases, treatment is not necessary.

- Submitted by: Dr Gail Schumann