You Are Here: Management Updates 2006 Archive June 12, 2006

Date: June 12, 2006
Category: Diseases
Subject: A 'New' Turf Disease

Yellow Rings, similar to those seen with Yellow Patch (caused by Rhizoctonia cerealis) have been showing up on putting greens from California to Massachusetts and Kansas to Canada in the last several weeks. The Yellow Rings have been described as Rhizoctonia-like in nature, but also as Fairy Ring and Necrotic Ring Spot. The symptoms, although very similar to Yellow Patch, occur under much warmer temperatures than are associated with the former disease and also occur without the darkened roots and crowns associated with ‘patch’ diseases like Necrotic Ring Spot. Many of the reports have been on push-up or older greens and the primary turfgrass affected has been Poa annua. New sand greens have not been affected, but there are reports of this new disease on creeping bentgrass. The strange weather patterns of last winter and the wide fluctuations in both temperature and moisture this spring may be responsible for the unusual growth of soil fungi. The disease has been variously named, sheath and leaf spot, Brown Ring Patch, and Waitea Patch; and the causal agent identified as Waitea circinata var. zeae, Rhizoctonia circinata var. zeae, or simply Rhizoctonia zeae. This new pathogen is also closely related to the Brown Patch fungus, Rhizoctonia solani. Although the name and cause of this new disease is academic, the control recommendations are the same as for other Rhizoctonia diseases. Apply azoxystrobin (Heritage™), fludioxonil (Medallion™), flutolanil (ProStar™), polyoxin D (Endorse™), or propiconazole (Banner Maxx™) according to the label, at the high rate, and in at least 4 gal water/ 1,000 sq ft to reach the turfgrass crowns and roots.

Submitted by: M. Bess Dicklow

DISCLAIMER - As always, it is the responsibility of the applicator to verify the registration status of any pesticide BEFORE applying it. Different states have different regulations as well. The author and the University of Massachusetts are not liable for any consequences of any pesticide "recommendations". Mention of any trade name is not to be considered endorsement of a product.

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