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.
See the late blight post from June 24 for fungicide recommendations for tomatoes in Ontario. Information for potato growers can be found in the July 13 post.
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 janice.leboeuf@ontario.ca. 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.
Previous 2015 late blight posts: July 21, July 14, July 13, June 24
* Genotyping is being conducted by Dr. L. Kawchuk, Agriculture and Agri-Food Canada, Lethbridge, Alberta, under the 2015 National Late Blight Survey project.