It is important to scout your tomato fields regularly and know the symptoms of late blight. Refer to https://onvegetables.com/2010/07/13/late-blight-look-alikes/ for photos of late blight and possible look-alikes on tomato. Remember that conventional tomato growers following a regular fungicide spray program (by calendar or TOMcast) for early blight, septoria leaf spot, and anthracnose, are also protecting the crop from late blight infection. In 2009, most conventional fields survived the late blight outbreak without harm.
If late blight is found in Ontario, OMAFRA will notify the industry. If you find late blight symptoms, please notify Michael Celetti, Horticulture Plant Pathologist, OMAFRA – Guelph (519-824-4120 ext. 58910 or firstname.lastname@example.org) or Janice LeBoeuf, Vegetable Crop Specialist, OMAFRA – Ridgetown (519-674-1699 or email@example.com) or Eugenia Banks, Potato Specialist, OMAFRA – Guelph (519-826-3678 or firstname.lastname@example.org). We will collect samples to identify the strains present. Your information will remain confidential.