Disease

As most people know, the Willamette Valley in Oregon is known for its beautiful summers and its very wet winters. Along with wet conditions comes disease on the golf course. The picture below is of Fusarium patch (also known as Microdochium patch), a common turfgrass disease in the Willamette Valley. Fusarium patch begins to show up on golf greens in late fall when we begin to get lengthy periods of cool wet weather. It is a significant problem on the putting surface because of its unevenness and patchy distribution. It is related to the snow molds but in this case, Fusarium does not need snow cover to begin its life cycle. It produces thousands of spores that will lay at rest in the thatch layer of turfgrass throughout the warm season, these spores will then grow when triggered by the cool temperatures. Fusarium patch can be managed by chemical and cultural control methods but the best way is to use a dedicated IPM (integrated pest management) program. A well balanced IPM program will use both chemical and cultural control methods throughout the entire year. The best cultural control method is to remove leaf wetness every day. In our environment we have dew that forms every morning almost, it is key to either mow, roll, or "mop" the greens in the morning to remove the dew and dry out the leaf surface. Chemical controls come into play when the disease really begins to take hold of your putting greens. Heavy metal fungicides were most commonly used in the control of this disease but as the years pass the golf industry is becoming more and more conscious of the environment and has moved away from these toxic chemicals. Commonly used fungicides include DMI's such as fenarimol and propiconazole, also hydrocarbons such as PCNB, and the cholronitriles such as chlorothalonil. You can see in the picture below the overall size of the patches and the significance it could cause to a rolling golf ball. Once the warm weather kicks in, any disease left on the greens will begin to heal and fill in with routine top dressing of sand.

Fusarium patch on a creeping bentgrass/poa putting green at

 Mallard Creek Golf Course in Lebanon OR.