Powdery mildew on apple is a fungus disease caused by Podosphaera leucotricha. It can be a persistent disease of susceptible apple cultivars wherever apples are grown. It is the only fungal apple disease that is capable of infecting without wetting from rain or dew. Mildew severity and the need for control measures are related to cultivar susceptibility and intended fruit market. The table below lists the relative powdery mildew susceptibility of numerous apple cultivars.
| Apple cultivar | Powdery mildew susceptibility rating (z) | Apple cultivar | Powdery mildew susceptibility rating (z) |
|---|---|---|---|
| Arkansas Black | R | Monroe | HS |
| Ambrosia | R | Mustu (Crispin) | S |
| Arlet | S | Niagara | R |
| Baldwin | HS | Nittany | R |
| Ben Davis | S | Northern Spy | S |
| Braeburn | S | Orin | S |
| Britemac | HS | Raulared | HS |
| Cameo | S | Pinova | S |
| Chinook | S | Prima | R |
| Cortland | HS | Prime Gold | HS |
| Cox’s Orange Pippin | S | Princess | S |
| Creston | S | Priscilla | R |
| Crimson Crisp | HS | Pristine | S |
| Cripps Pink (Pink Lady) | S | Puritan | S |
| Dayton | R | Quinte | S |
| Delicious | R | Redfree | S |
| Empire | S | Rhode Island Greening | S |
| Enterprise | R | Rome Beauty | HS |
| Fuji | R | Runkel | S |
| Gala | R | Sansa | S |
| Gala Supreme | R | Scarlet O’Hara | S |
| Ginger Gold | HS | Senshu | S |
| Golden Delicious | S | Shizuka | S |
| Golden Supreme | S | Sir Prize | R |
| GoldRush | S | Spartan | R |
| Granny Smith | HS | Spigold | S |
| Gravenstein Holly | HS | Spijon | S |
| Grimes Golden | R | Stayman | HS |
| Hampshire | S | Summerred | S |
| Honeycrisp | S | Suncrisp | S |
| Idared | HS | Sundance | S |
| Jerseymac | S | Sunrise | S |
| Jonafree | R | Twenty Ounce | S |
| Jonagold | S | Wayne | S |
| Jonamac | S | Wealthy | S |
| Jonathan | HS | Wellington | S |
| Julyred | HS | Winesap | R |
| Liberty | S | Yellow Transparent | R |
| Lodi | R | Yataka | R |
| Lord Lambourne | R | York Imperial | S |
| Macoun | S | Zestar! | R |
| McIntosh | S | ||
| Milton | S | ||
| (z)
R = resistant. Control only needed under high disease pressure. S = susceptible. Control usually needed where disease is prevalent. HS = highly susceptible. Control always needed where disease is prevalent. These cultivars should receive first priority when control is required. |
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See Powdery Mildew on Apple for more information.
Data compiled by K. S. Yoder and A. R. Biggs from personal observations and the following sources:
Management Guide for Low-Input Sustainable Apple Production, A publication of the USDA Northeast LISA Apple Production Project and Cornell University, Rodale Research Center, Rutgers University, University of Massachusetts, and University of Vermont. 1990. (Apple disease management section by D. A. Rosenberger, Cornell University).
A Grower’s Guide to Apple Insects and Diseases in the Southeast. 1993. Alabama Cooperative Extension Service, Auburn University, Circular ANR-838. Ed. J. R. McVay, J. F. Walgenbach, E. J. Sikora, and T. B. Sutton.
Aldwinckle, H. S. 1974. Field susceptibility of 51 apple cultivars to apple scab and apple powdery mildew. Plant Disease Reporter 58:625-629.
Yoder, K. S., R. E. Byers, A. E. Cochran II, W. S. Royston, M. A. Stambaugh, and S. W. Kilmer. 1994. Evaluation of scab-resistant apple cultivars for cedar-apple rust and mildew susceptibility. 1992-93. Biological and Cultural Tests for Control of Plant Diseases 9:11.
Biggs, A. R., Yoder, K. S., and Rosenberger, D. A. 2009. Relative susceptibility of selected apple cultivars to powdery mildew caused by Podosphaera leucotricha. Plant Health Progress doi:10.1094/PHP-2009-1119-01-RS.