The most well-known symptom of downy mildew is the classic spot, lighter in color than the rest of the leaf, somewhat resembling an oil stain. These spots are distributed across the upper surface of the leaves, usually bordered by the veins. If you look at the underside of these infected leaves, you can see the mycelium and fruiting bodies as a whitish fuzz. These structures are responsible for the production and dispersal of new spores throughout the crop.<\/p>\n
The affected parts eventually become necrotic and die, turning a brick-red color. Leaves deposited on the ground can carry spores, which are responsible for infections the following year.<\/p>\n