How to Manage Pests
UC Pest Management Guidelines
Pathogen: Capnodium spp. and related fungi.
(Reviewed 9/16, updated 9/16)
In this Guideline:
SYMPTOMS and signs
Sooty mold consists of hyphae and spores of Capnodium spp. and related fungi. Sooty mold is black, somewhat felty fungal growth on the surface of fruit, leaves, or stems. Sooty molds grow on honeydew excreted by juice-sucking insects, including soft scales and whiteflies.
COMMENTS ON THE DISEASE
Sooty molds do not infect avocado and generally cause no damage. Exceptions are if leaves become so heavily covered that photosynthesis is significantly reduced, causing chlorosis and possible premature leaf drop. If fruit is noticeably fouled, it may be downgraded at the packing house.
Manage sooty mold by controlling the insects that produce honeydew. Honeydew-producing insects in avocado are often well controlled by natural enemies. Control ants, minimize dust, and avoid broad-spectrum insecticides to conserve these beneficial parasites and predators. If direct insect control is required, use selective insecticides whenever possible.
UC IPM Pest Management Guidelines:
A. Eskalen, Plant Pathology, UC Riverside
Acknowledgment for contributions to Diseases:G. S. Bender, UC Cooperative Extension, San Diego County
H. D. Ohr (emeritus), Plant Pathology, UC Riverside
J. A. Menge, Plant Pathology, UC Riverside
L. J. Marais, Plant Pathology, UC Davis
R. Hofshi, Hofshi Foundation, Fallbrook, CA
J. S. Semancik, Plant Pathology, UC Riverside
J. A. Downer, UC Cooperative Extension, Ventura County
U. C. Kodira, Plant Pathology, UC Davis