Cucurbit downy mildew has been reported on pickling cucumbers and cantaloupe in Essex County. This is the first field report for this disease in 2017.
All Ontario cucumber growers should now switch from a broadspectrum program to a 3-product rotation using targeted downy mildew fungicides.
The following products have shown the most consistent results in fungicides trials at the University of Guelph, Ridgetown and Simcoe campuses. Under high downy mildew pressure, follow a spray interval that is no longer than 7-days.
- Orondis Ultra A (mandipropamid) + Orondis Ultra B (oxathiapiprolin) + Bravo (chlorothalonil)
- Torrent (cyazofamid)
- Zampro (ametoctradin/dimethomorph)
For more information about the most effective spray rotations, see: 2016 University of Guelph Cucumber Downy Mildew Results.