| Home > Pest management > blister spot |
| Blister spot is a bacterial disease that occurs predominantly on Mutsu apple, although it is also of minor importance on RedCort and Fuji. Small, raised, brown to black blisters occur on fruit in mid- to late July. The bacteria grow on blossoms and fruit surfaces without causing symptoms initially. Fruit are most susceptible to infection about two weeks after petal fall. The occurrence of streptomycin-resistant strains of the pathogen means there are no effective controls for this disease. |
 |
| |
Blister spot on Mutsu apple fruit. |
- For more monitoring information and evaluation of available pesticides:
Michigan Fruit Management Guide
- MSU Diagnostic Services for assistance in pest identification.
- MSU Fruit Crop Advisory Team Alert newsletters for current pest/crop conditions.
|
| This information was developed from A Pocket Guide for IPM Scouting in Michigan Apples by David Epstein, Larry J. Gut and George W. Sundin. Purchase this in a pocket-sized guide for reference in the orchard from MSU Extension (publication E-2720). |
