How to Manage Pests

UC Pest Management Guidelines

SYMPTOMS AND SIGNS

Dothiorella gummosis can cause leaves and twigs on scattered branches or the entire tree to decline and die with fruit and leaves remaining attached. Portions of trunks or branches will have dead outer bark located over a sunken canker. The dead bark may exude gum; the cambial layer of wood underneath the bark may be brown to yellowish. The canker may spread up and down the cambium in grooves with some faint, shallow, yellowish brown discoloration of the underlying wood.

Dothiorella gummosis can cause rapid decline and death of a tree. Young trees are especially susceptible if the affected tissue is not removed. Often the dead bark remains attached to the tree so tightly that it is not immediately obvious that it is dead. This dead bark has a more grayish cast than healthy bark.

COMMENTS ON THE DISEASE

Unlike dry root rot, discoloring of bark by the pathogen is lighter and infected bark may ooze dark liquid. On the surface, Dothiorella cankers may have a grayish cast with dead bark that remains tightly attached.

MANAGEMENT

A minor disease, Dothiorella gummosis is usually associated with a wound or injury.

PUBLICATION

UC IPM Pest Management Guidelines: Citrus
UC ANR Publication 3441
Diseases
J. E. Adaskaveg, Plant Pathology, UC Riverside
Acknowledgment for contributions to Diseases:
J. A. Menge, Plant Pathology, UC Riverside
H. D. Ohr, Plant Pathology, UC Riverside

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