Putting The Brakes On Microdochium Patch March 3, 2017 By John Daniels, agronomist, Central Region

The fungal pathogen Microdochium nivale can cause substantial damage despite the lack of snow cover.

Balmy weather in February has melted what little snow fell across the Upper Midwest, allowing many golf courses to open their doors weeks ahead of schedule. This fast start to the golfing season is a welcome sight for cooped-up golfers as well as facilities looking for a bump in rounds.

In areas where snow cover typically persists well into March, turf managers are rapidly adjusting agronomic programs to account for milder temperatures. Many are wondering how the recent warm weather will impact pest pressure. For example, preventative fungicide treatments made at the onset of winter to guard against snow mold damage have most certainly been depleted by the warm weather and snow melt, opening the door for infection. Of primary concern is the fungal pathogen Microdochium nivale – i.e., Microdochium patch – which is active over a broad range of temperatures from near freezing all the way into the 60s.

Be on alert for periods of cool, wet weather with extended cloud cover; these conditions favor Microdochium patch development. Also, limit leaf wetness and avoid applying excess nitrogen, to reduce the likelihood of disease. Consider applying a fungicide to areas of the golf course that have a history of Microdochium patch damage. Effective control products include: chlorothalonil, thiophanate-methyl, iprodione and the QoI group of fungicides.

Microdochium patch also can be a concern for superintendents in the South managing ultradwarf bermudagrass putting greens in heavily shaded and poorly drained sites. The risk is especially pronounced for those in the transition zone where temperatures could easily dip back down in the coming weeks. Slow-growing bermudagrass plants are vulnerable to Microdochium patch, so pay close attention should high temperatures stay below 68 degrees Fahrenheit for several days.


Central Region Agronomists:

Bob Vavrek, regional director –

John Daniels, agronomist –

Zach Nicoludis, agronomist –

Information on the USGA’s Course Consulting Service 

Contact the Green Section Staff

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