OnVegetable team is tracking this year’s downy mildew epidemic and requests that growers report symptoms of downy mildew on melons (including watermelon), pumpkin, and squash. Growers also should scout for Phytophthora in cucurbits.
“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.”
Downy Mildew, Simcoe, Norfolk county July 24 (Top) and July 28th (Bottom) Top: Downy mildew lesions and sporangia on a cucumber leaf, Bottom: Downy mildew can cause defoliation, breaks in the canopy can lead to sunscald on fruit decreasing marketability.
