Late blight was reported in potatoes in Simcoe County, Ontario, Canada on July 18. Genotype testing is in progress by North Carolina State University. No other reports of late blight have been received at this time.
A map of current late blight observations can be monitored at https://usablight.org/map/. (Simcoe County is located at the southern tip of the Georgian Bay in Lake Huron.)
In Michigan, no late blight has been detected and current weather conditions indicate low to medium risk throughout the state (see above map to the right). However, following potato late blight incidences in Montcalm County last year, and abundant volunteer pressure noted in areas this season, careful monitoring is recommended.
Please contact MSU Potato and Sugar Beet Pathology at willbur1@msu.edu or (517)355-3863 or MSU Plant & Pest Diagnostics at pestid@msu.edu or (517)355-4536 for disease diagnosis and management support or visit our websites for more information.