2012 Survey: In recent years, new strains of late blight have been detected in both the US and Canada. Some of these new strains are very aggressive on tomatoes while others have the potential to be very aggressive on potatoes or both crops. Again in 2012, OMAFRA is participating in a late blight survey organized by Agriculture and Agri-Food Canada and the University of Manitoba that is being conducted across Canada.  If late blight is detected or suspected in a tomato or potato crop, please contact Michael Celetti, OMAFRA Plant Pathologist at (519) 824-4120 extension 58910 or michael.celetti@ontario.ca or Janice LeBoeuf OMAFRA Vegetable Specialist at 519-674-1699 or janice.leboeuf@ontario.ca  as soon as possible so that we can arrange to collect samples of the disease for strain type identification and other research.

You can also collect a sample and contact OMAFRA or AAFC for pick up.  Sampling instructions can be downloaded here.  For tomatoes, if infected fruit are present, include a few with the leaf samples.  Growers are encouraged to submit more than one sample, if late blight is showing up in multiple sites (in different fields or within a field).  There can be more than one strain present in an area and we want to learn as much as we can about this evolving disease.  Information on all submissions will remain confidential and only identified to the county level in public late blight alerts and reports.

2012 Late Blight Survey Instructions and Questionnaire AAFC

Previous 2012 late blight updates: May 31, June 4, July 20, July 27,  July 30, August 16, August 21, August 22, August 29, August 30.