Downy mildew, caused by the fungal organism Pseudoperonospora cubensis, is most destructive to cucumber and cantaloupe though all cucurbits are susceptible. Symptoms first appear as pale green areas on the upper leaf surfaces. These change to yellow angular spots. A fine white-to-grayish downy growth soon appears on the lower leaf surface. Infected [..]

see mildew. A plant disease in which the sporangiophores and spores of the fungus appear as a downy growth on the lower surface of leaves and stems, fruit, etc., caused by fungi in the family Peronosp [..]