Owing to their appearance they go by the popular name of mildews.
Fungal foliar diseases and their control, including leaf blights, downy mildews, leaf blights, downy mildews, leaf curls, mildews, leaf spots and rusts.
Chemical control Organic gardeners can use sulfur dust to control powdery mildews.
The existence of blights and mildews of cereals had been observed and recorded in very ancient times, as witness the Bible, where half a dozen references to such scourges occur in the Old Testament alone.
They are particularly susceptible to mildews and molds.