University of Geluph researchers monitor Cucurbit downy mildew in Kent and Norfolk counties using spore traps.
Spore traps installed on June 7th in Ontario Canada detected no Cucurbit downy mildew until July 29, 2021.
Cucurbit downy mildew has been confirmed on cucumber at one location in Norfolk County and two additional locations in Kent County. Squash bugs are active on pumpkins and squash.
Plants in most areas are still very small and many grower will not have started their preventative fungicide programs. Now that the disease has been confirmed in Ontario, fungicides should be applied as soon as possible.
ONvegetables reports that wet soil conditions are conducive to infection by Oomycetes such as Phytophthora which can lead to extensive damage in the field, and can lead to storage rots. Workers harvesting pumpkins and squash with Phytophthora infections should sanitize their hands after handling infected fruits before handling uninfected fruit. Management of Phytophthora infestation in cucurbit fields requires a long (4-5 year) rotation.”
Symptoms of Gummy Stem Blight in winter squash include hot spots of stems with oozing lesions, and distinctive patterns on the skin of butternut squash.
“Downy mildew pressure remains high, and has now been confirmed on cucumbers as far North as Wellington county. Early detection of downy mildew this year increases the possibility of fungicide resistance.”
“Examine low lying or poorly drained areas noting any wilted or stunted plants, and look for lesions. Phytophthora usually presents as a foliar blight or a crown rot in zucchini, squash, and pumpkin, so look for dark lesions on the crown. In cucumbers and melons Phytophthora usually causes fruit and stem lesions so look for water soaked lesions with white spores developing on the fruit.”