Late blight has been confirmed on tomatoes in Elgin County, Chatham-Kent, and the Regional Municipality of Waterloo. Credible reports have also been received from other areas, including the United Counties of Stormont, Dundas and Glengarry, Middlesex, and Perth County.
Recent weather has been conducive to the development and spread of late blight. Commercial growers should scout often and ensure they are using fungicides with good late blight activity in their fungicide program. When late blight is in the area, spray intervals should be shortened.
See the late blight post from July 29 for fungicide recommendations for tomatoes in Ontario.
Contact OMAFRA at 519-674-1690 or firstname.lastname@example.org if you suspect you have found late blight in Ontario.