Pomegranate Diseases & Disorders
Pomegranates in California > Diseases & Disorders
The main diseases affecting pomegranate fruit are Alternaria fruit rot (Alternaria alternate), Aspergillus fruit rot (Aspergillus niger) and gray mold (Botrytis cinerea).
Alternaria fruit rot (also known as black heart) and Aspergillus fruit rot appear after rains as the flowers begin to open, and infect the internal portion of the pomegranate. Wounds must occur after flower initiation for these two infections to occur. The only exterior signs of disease would be a slight off-color in the peel, and a lighter weight due to internal decay (UC IPM website, 2011). However, this problem usually is not apparent until fruit sorting after harvest.
Gray mold (Botrytis cinerea) causes problems after harvest. While the tree is flowering, airborne spores are spread to the open flowers and enter the fruit. The disease is activated with free water, commonly during the postharvest wash and spreads when stored at room temperature. However, if a postharvest fungicide is used, it can get into the crown of the fruit to prevent infection (UC IPM website, 2011). Fludioxonil (Scholar) is registered for pomegranates and can be used to prevent gray mold (Kader 2006), as well as Fenhexamid (Judge).
For more information, see UC Statewide IPM Program: How to Manage Pests: Pomegranate and UC Postharvest Technology Produce Fact Sheets: Pomegranate
These photos are accessed from the UC ANR Repository, courtesy of UC Postharvest Technology. Photo information, including the photographer, is displayed when the larger image is viewed.