Blightline July 21, 2014
No late blight has been reported in our region. Late blight has been reported in potatoes Portage County, Wisconsin; the late blight is not widespread. Late blight severity values generally did not increase over weekend. If severity values in your area have accumulated to 15, application of a protectant fungicide such as mancozeb or chlorothalonil on a 7-10 day schedule is recommended. Many sites have reached this threshold.
Blightline July 21, 2014 (pdf)