{"id":2427,"date":"2017-03-01T16:52:54","date_gmt":"2017-03-01T21:52:54","guid":{"rendered":"http:\/\/132.236.156.160\/cuccap\/?page_id=2427"},"modified":"2024-07-10T18:05:11","modified_gmt":"2024-07-10T22:05:11","slug":"powdery-mildew","status":"publish","type":"page","link":"http:\/\/132.236.156.160\/cuccap\/disease-management\/squash\/powdery-mildew\/","title":{"rendered":"Powdery mildew on squash and pumpkin"},"content":{"rendered":"
\"disease<\/a>

Squash leaf infected with powdery mildew. Image provided by Dr. Lina Quesada, NC State Vegetable Pathology Lab<\/p><\/div>\n

Podosphaera xanthii<\/em><\/h2>\n

Cucurbit powdery mildew is caused worldwide by the fungal pathogens Podosphaera xanthii<\/i>\u00a0and Golovinomyces cichoracearum<\/i>. Podosphaera xanthii<\/i> is more common\u00b9 and, apparently, may be the only one on cucurbits in North America\u00b2. Early symptoms of powdery mildew include small, circular, yellow lesions on leaves and petioles. Lesions quickly become covered in white spores and may appear also on the underside of the leaf. The pathogen may be entirely restricted to the undersides of leaves in areas with intense sunshine, e.g., Imperial Valley, California. As disease progresses the entire leaf and petiole surface may become covered in the characteristic white powdery powdery spores that may also be found on peduncles (stems) and fruit. Powdery mildew affects all cucurbit crops such as cucumber, melon, squash, and watermelon.<\/p>\n

Diagnostic Resources<\/h2>\n