Adventist Youth Honors Answer Book/Nature/Fungi/Downy mildew
Downy mildew refers to any of several types of oomycete that infect plants. In commercial agriculture, they are a particular problem for growers of crucifers, grapes and vine-type vegetables.
Cucurbit downy mildew (caused by Pseudoperonospora cubensis) is specific to cantaloupe, cucumber, pumpkin, squash, watermelon and other members of the gourd family. The disease is one of the most important diseases of cucurbits worldwide.