How to Manage Pests
UC Pest Management Guidelines
Botrytis Diseases And Disorders
Pathogen: Botrytis cinerea
(Reviewed 9/08, updated 9/08)
In this Guideline:
The Botrytis pathogen commonly infects tissue through injuries and forms gray, velvety mats of sporulating tissues. Infected twigs may die back several inches. Infected blossoms often result in increased fruit drop and in injuries to the developing fruit. These fruit injuries are evident as ridges on mature fruit that result in a lower graded crop during marketing. The name "gray mold" is used to describe the disease when it occurs as fruit decay during postharvest storage.
Comments on the Disease
Botrytis cinerea is a ubiquitous fungus that causes disease on twigs, leaves, blossoms, and fruit of citrus in areas with prolonged wet and cool conditions. Generally, the organism is a minor pathogen of citrus; lemons are infected more commonly than other citrus crops.
General preventive measures, such as avoiding mechanical injury, protecting against frost and brown rot, and pruning regularly to improve air movement may help reduce the incidence of Botrytis diseases. Treatments with copper and benzimidazole fungicides before rain or fog may help to reduce the blossom and fruit phases of the disease. Under prolonged cool, wet environmental conditions, frequent treatments are required and these may not be economical. Postharvest treatments may be required in wet years to prevent fruit decay during storage and marketing.
UC IPM Pest Management Guidelines:
Acknowledgment for contributions to Diseases: