We have received word that downy mildew was confirmed at 4 different locations in Michigan this week. The close proximity to our growing regions combined with the recent severe storms, rainfall and high humidity mean that Ontario growers should be on high alert for this disease.
The best way to manage downy mildew is with preventative fungicides. Now that the disease has been confirmed in the Great Lakes basin, apply a targeted downy mildew fungicide on a 7-day schedule. Products like Orondis Ultra, Torrent and Zampro offer a high level of downy mildew control. Always rotate between the three products to help prevent the development of resistance. Broad spectrum products such as chlorothalonil and mancozeb are useful under low-risk conditions but are no longer suitable as stand-a-lone products under current conditions.
For more information on the current status of downy mildew in North America, visit: Home – Cucurbit Downy Mildew ipmPIPE
If you suspect you have downy mildew in your crop, please notify OMAFA (Elaine Roddy, 519-401-5890). Downy mildew is a community disease. By sharing information about the status of the disease we can do a better job of managing it. We do not publish specific locations, only the county in which it is occurring.
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