How to Manage Pests
UC Pest Management Guidelines
Cladosporium Fruit Rot
Pathogen: Cladosporium cladosporoides
(Reviewed 12/09, updated 12/09, pesticides updated 6/15)
In this Guideline:
Symptoms and Signs
Blackberry and raspberry plants with Cladosporium fruit rot have berries that are covered with a velvety, olive-green mycelial growth. While this growth is unsightly, it does not often damage the fruit. C. cladosporoides can occur alone or in association with lesions caused by Botrytis cinerea (the causal agent of Botrytis fruit rot).
Comments on the Disease
Cladosporium fruit rot of caneberry is primarily a postharvest storage disease. Even though these fungi cause little actual damage to fruit, the mycelial growth on the fruit is unappealing, so the fruit is unmarketable. Optimal temperature for the growth of these fungi is between 68° to 77°F (20° to 25°C), but may occur at lower temperatures during normal fruit storage.
This fruit rot is most commonly associated with fruit that is sunburned or damaged in some manner.
Practice good sanitation and manage moisture within the planting to reduce inoculum levels and the risk of infestation. Harvest regularly and carefully, removing damaged and infected fruit. Cool berries as rapidly as possible to an optimum of 32°F (0°C).
Organically Acceptable Methods
Good sanitation and harvest practices are acceptable methods in an organically certified crop.
Treat if weather conditions are favorable for the development of Botrytis and Cladosporium fungi (i.e., rain).
UC IPM Pest Management Guidelines: Caneberries
S. T. Koike, UC Cooperative Extension, Monterey County
Acknowledgment for contributions to Diseases:E. J. Perry, UC Cooperative Extension, Stanislaus County