Diseases of olive (
Verticillium wilt
Verticillium wilt is caused by the soil borne fungus Verticillium dahliae. Symptoms include wilt and death of one or several branches (photo 1) of infected trees. In severe cases the entire tree may die. The fungus infects the tree through the roots, grows into the xylem and causes blockage of the vascular system. Substances produced in the plant during infection also may cause vascular discoloration, but this symptom is not always present. This is not a root rot disease, so decay of the root tissues does not occur. Resistant varieties of olive are available. There is no effective treatment once plants are infected.
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May 16, 2003