How to Manage Pests

UC Pest Management Guidelines

SYMPTOMS

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.

MANAGEMENT

Manage sooty mold by controlling the insects that produce honeydew. Honeydew-producing insects in avocado are usually 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.

PUBLICATION

UC IPM Pest Management Guidelines: Avocado
UC ANR Publication 3436
Diseases
B. A. Faber, UC Cooperative Extension, Santa Barbara/Ventura counties
G. S. Bender, UC Cooperative Extension, San Diego County
H. D. Ohr (emeritus), Plant Pathology, UC Riverside
Acknowledgment for contributions to the diseases section:
L. J. Marais, Plant Pathology, UC Davis
J. A. Menge, Plant Pathology, UC Riverside
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

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