Blightline July 17, 2015
No late blight has been reported or confirmed in our region of ND, MN or MB. Late blight has been reported in potatoes in the provinces of Alberta and Ontario, and additional late bight has been reported in potatoes in Adams, Waushara and Wood counties in Wisconsin. Late blight severity values in our regions have increased dramatically this week due to the frequent thunderstorms and high humidity. All irrigated and non-irrigated locations have now reached late blight severity values of 15. At this threshold value of 15, accumulated conditions are conducive for late blight if inoculum is present. Growers are encouraged to apply a protective fungicide such as chlorothalonil or mancozeb, and scout fields for late blight, concentrating in areas that are wet longer such as low areas, near shelterbelts or around pivot wells.