Blightline July 24, 2014
No late blight has been reported in our region. The recent storm caused late blight severity values to increase quickly the past three days. The threshold value of 15 has been reached at all locations except Beach, Leonard, Williston, Grand Forks and St. Thomas. At the severity value threshold of 15, weather conditions have accumulated sufficiently for late blight to occur if inoculum is present. Application of a protectant fungicide such as mancozeb or chlorothalonil on a 7-10 day schedule is recommended.
Blightline July 24, 2014 (pdf)