OnVegetables publishes a weekly crop report for the Ontario region. Downy mildew, Phytophthora, and Powdery mildew on cucurbits are featured in the recent report.
“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.”
Advanced symptoms of cucurbit downy mildew on top surface of cucumber leaf (left), and dark purple sporangia on underside (right). Ridgetown, July 30.
“Powdery mildew is developing on several cucurbits, particularly squash and pumpkin. Infection with this pathogen can affect yield and fruit quality.”
Powdery vs downy mildew symptoms on pumpkin. Bottom left, appearance of early downy mildew infection of pumpkin, credit: T. A. Zitter
