Tomato late blight has been confirmed in Chatham-Kent this week. Previous late blight confirmations this season have been in tomatoes in Essex and Elgin Counties and on potatoes in the Orangeville area.
Please contact me if you think you are finding late blight. If possible, samples can be taken to submit for genotyping* and research to help address this evolving disease issue. I can be reached at firstname.lastname@example.org. It’s helpful if you include photos of affected leaves (upper and lower surfaces), as well as stems and fruit if they are showing symptoms. See the tomato late blight photo gallery to review the symptoms.
* Genotyping is being conducted by Dr. L. Kawchuk, Agriculture and Agri-Food Canada, Lethbridge, Alberta, under the 2015 National Late Blight Survey project.