Trace amounts of downy mildew were found in a Kent County cucumber field today by the University of Guelph, Ridgetown Campus, scout.
All cucumber growers in Ontario are advised to begin a preventative downy mildew spray program using targeted downy mildew fungicides. For more information fungicide selection, see the Ontario 2015 Downy Mildew Control Strategy for Cucumbers. Growers are also encouraged to monitor their own fields for early signs of infection (see figure 1, below).
Current weather conditions are very suitable for the spread of this very aggressive disease. Under these conditions, with downy mildew in the area, a 7-day spray schedule is warranted.