Use a crop rotation of at least 1 year. Destroy volunteer plants. Deeply plow debris under after harvest. Avoid damaging fruit during harvest to prevent storage infection. A 5-minute immersion in warm water containing 120 ppm chlorine helps to prevent infection of healthy watermelons in storage.
Resistance is available for watermelons and cucumbers.
Watch for which races of the fungus are in the area and which races a particular cultivar is resistant to. See current recommendations for chemical control measures. Scab is a disease of cucurbits caused by the fungus Cladosporium cucumerinum . It can affect cucumbers , cantaloupe, gherkin, honeydew melon, muskmelon, pumpkin, summer squash , squash and watermelon. The disease can affect all aboveground parts of the plants.