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.
The prime example is Peronospora farinosaas featured in NCBI-Taxonomy and HYP3.
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.
