Powdery mildew—Erysiphe cichoracearum
Powdery mildew usually appears first as yellow spots on the upper leaf surface of older leaves; these
spots develop the characteristic powdery growth and symptoms spread to the undersides of leaves and stems.
Affected leaves may turn completely yellow and die.
Powdery mildew rarely becomes serious enough to require treatment.
For more information, see the Powdery
Mildew Pest Note.
growth of powdery mildew