Pest identification
and confirmation—Powdery mildew
Powdery mildew is often confused with downy mildew. Both downy mildew and powdery mildew produce whitish
collections of spores on the leaf surface, but similarities end there. In powdery mildew the white sporulation
covers much of both the lower and upper sides of the leaf; downy mildew spores appear mostly on the undersides
of leaves. Downy mildew spores are produced on branched stalks that look like little trees, whereas powdery
mildew spores occur in chains on a single stalk. Areas affected with powdery mildew enlarge in a circular
pattern, spreading a white, dusty growth over the whole leaf; there is no clear veinal delineation as
in downy mildew infections. Powdery mildew thrives in warm weather; downy mildew is a cool-weather disease.
|
Spores
of powdery mildew
 Spores
of downy mildew
|
