How to Manage Pests
UC Pest Management Guidelines
Aspergillus Fruit Rot
Pathogen: Aspergillus niger
(Reviewed 6/11, updated 6/11)
In this Guideline:
SYMPTOMS AND SIGNS
Aspergillus rot infections begin most commonly in the orchard following rain during flowering and early fruit development. Similar to Alternaria fruit rot, the fungus may grow within the fruit often without external symptoms. However, infected fruit generally are slightly off-color such as a paler red and may show some yellowish to brownish-red discoloration.
COMMENTS ON THE DISEASE
Colonization by Aspergillus niger is often associated with insect infestations, such as feeding by hemipterans, or other factors that cause fruit injury or cracking (e.g., bird pecking, sunburn, and russeting).
Because the fruit crown covers the blossom tissues the use of preharvest sprays are generally ineffective. Good orchard management practices, such as dust control and sanitation (removal of old fruit and dead branches), may reduce the pre- and postharvest incidence of disease. Control insect pests such as filbertworm and leaffooted plant bugs that feed on the fruit, enabling pathogen entry. Infected, but healthy-appearing fruit may be dropped to the ground by gently shaking the tree at the time of harvest. Avoid water stress and over watering that may result in fruit cracking.
Thorough sorting and grading of pomegranates for discoloration and cracking can help to avoid packing diseased fruit.
UC IPM Pest Management Guidelines: