While downy mildew has still not been confirmed in Ontario, recent report from Michigan indicate that levels are starting to increase in the Saginaw Bay area. At this time growers should maintain preventative downy mildew fungicide programs, especially for the late harvested crop.
Phytophthora has been identified in a pumpkin field in Norfolk county. This disease thrives under wet soil conditions. For more information, see: Phytophthora Blight of Cucurbits – August 7th, 2014.
Angular leaf spot, a bacterial disease, is present in many pumpkin fields at this time. While this is a sporadic disease of cucurbits in Ontario, under the appropriate weather conditions, it could spread a cause premature defoliation of the crop. Infections may also predispose the fruit to bacterial soft rot at harvest or in storage. Copper fungicides, such as Copper 53W and Copper Spray, will help to control the spread of this disease.