Powdery mildew of cherry
Podosphaera clandestine (Wallr.:Fr.) Lév.
The fungus attacks young leaves and shoots and tends to cause more damage on sour cherry than sweet cherry. Infections appear as white circular lesions or patches of powdery growth on either side of the leaf or on the terminal ends of shoots (A). Severely infected leaves curl upward or blister but eventually drop as infection progresses. Towards the end of the season, small, black fungal bodies (cleistothecia) are visible within powdery mildew colonies (B). Infected fruit are deformed when infected young, or develop circular, slightly sunken lesions when infection occurs on mature fruit.
Occurs all along the east coast.
Powdery mildew is managed through a combination of fungicides, starting from petal fall and continuing through pit hardening, and the use of resistant varieties. Many fungicides used for brown rot control are effective against powdery mildew.
The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.