Disease SpotlightCucurbit Downy Mildew (CDM) is a devastating disease of cucumbers, pumpkins, squash, watermelon, cantaloupe. The disease is caused by Pseudoperonospora cubensis, a water mold that favors cool nighttime temperatures (55 to 75 degrees F) along with prolonged periods of high humidity.
Management: The spores are spread in the air currents and can move large distances in a short period of time. For this reason, early detection and accurate diagnosis are critical to prevent widespread outbreaks of the disease. Although disease management relies heavily on the use of preventative fungicides, disease-resistant or -tolerant varieties of cucumbers, squash and cantaloupes are available. There are no resistant watermelon varieties. Avoid overhead irrigation and select growing sites with full sun exposure. The following resources provide detailed information of managing CDM: LSU AgCenter Louisiana Plant Disease Management Guide and National Sustainable Agriculture Information Service (organic strategies).
|IPM Resources for Vegetables and Herbs
Louisiana Plant Disease Management Guide (revised 2015)
|Plant Pathology Disease Identification and Management Series