Dollar Spot Activity in Ontario

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In southwestern Ontario, rain and waterlogged soils have made it difficult to mow turfgrass, let alone begin preparations for preventive sprays to combat diseases. It seems rain and humidity has been a consistent presence in the Windsor - London area. What has been lacking is warmer, more normal, temperatures. Until now.

Much of Southern Ontario experienced temperatures that exceeded 20 degrees in the past week. The warmer temperatures, coupled with abundant leaf wetness, has triggered dollar spot activity in the Windsor area. Field observations in Windsor confirmed dollar spot activity as well as monitoring the Smith-Kerns Dollar Spot Prediction Model

It is easy to focus all of our attention to dollar spot. After all, we can visibly see the signs of infection as the white aerial mycelium can be easily observed during the morning hours. This time of year, however, it is equally important to consider management options for diseases that we can't see. Diseases that are active below the ground or lower in the turfgrass canopy.

For those managing annual bluegrass surfaces, we should consider management strategies for anthracnose, brown ring patch, and summer patch. On creeping bentgrass surfaces, we should be mindful of take-all patch, fairy ring, and Pythium root rot/dysfunction.

This is a great time of year to take advantage of the DMI class of fungicides. This class is incredibly broad spectrum and can be an umbrella treatment to control many of the diseases that are active this time of year. This also allows an opportunity to save other classes of chemistries (SDHI's for example) later in the season when dollar spot pressure is much greater.

Bayer Solutions

Mirage Stressgard is a powerful DMI fungicide that provides excellent control of both dollar spot, anthracnose, and many root affecting diseases such as fairy ring and summer patch. As the name suggests, this product is formulated with Stressgard technology to provide unmatched versatility, consistency, and satisfaction to your golf course playing surfaces. Mirage Stressgard has been tested extensively at the most respected universities throughout North America giving you unrivaled confidence in this product when you need it most. For more information on the performance of this product against tough diseases under replaced research conditions, please contact your Bayer Territory Sales Manager or email me directly at