UMass Extension Turf Program

Bentgrass Decline, Pythium Blight, Brown Patch

Date: 
July 1, 2005
Subject: 
Bentgrass Decline, Pythium Blight, Brown Patch
Category: 

The UMass Plant Diagnostic Lab has been struggling over a number of cases of bentgrass thinning and dying. In most cases, no plant pathogenic fungi have been noted in the foliage, crown or roots. In some cases, ectotrophic root-infecting fungi, consistent with the take-all fungus, have been noted but not in significant amounts. Superintendents have had a broad spectrum of fungicide coverage with little if any response by the turf. It is likely that environmental conditions and/or cultural practices are playing a primary role. A syndrome referred to as Bentgrass Decline, largely the result of high temperatures has been written about for several years.

Pythium blight has been noted on several golf courses, and occurred in S. Deerfield during the very first heat wave. This disease does not usually occur until the hot humid days of July and August. However, its here now and will return whenever conditions are favorable (hot and humid days, with warm nights). Chloroneb, etridiazole, mefanoxam and fosetyl-al are all materials specific for Pythium blight. When Pythium is active and the grass is wet, do not mow. Pythium blight weather also means brown patch activity and you will need a different set of chemistry for brown patch management. Stobilurins, DMI’s, polyoxin (Endorse), thiophanate methyl, chlorothalonil are among materials active against brown patch. Both Pythium blight and brown patch are stimulated by high levels of nitrogen.

Submitted by: Dr. Robert Wick

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Archived Turf Management Updates contain information that is presented as it originally appeared, in an effort to preserve useful information and to illustrate changing management techniques and pest patterns over time. Some text may contain references to specific pesticide or fertilizer products. Due to the continually changing nature of the industry and pesticide regulations, some messages may contain references to products that are no longer available and/or are no longer registered for use.
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