Contact Us
University of California Cooperative Extension Ventura County
669 County Square Drive, Suite 100
Ventura, CA 93003
Phone: 805.645.1451
Fax: 805.645.1474
Office Hours:
Monday - Friday from 9 a.m. to 4 p.m.
The office will be closed for the following holidays:
March 29 – Ceaser Chavez Day
May 27 – Memorial Day
June 19 – Juneteenth
July 4 - Independence Day
Olive Knot
The name comes from the fact that the disease was first identified on olives. And it can be a serious disease on olives causing severe crop loss. The causal microorganism is a bacterium which survives in the galls. The bacterium becomes active during spring rains and is moved about by wind-blown rain, insects, and possibly birds. The bacterium infects the host through leaf and flower scars and through wounds.
To control olive knot, prune all diseased tissues out of the bush. Then spray the bush with a registered fungicide. The process of pruning and spraying may have to occur several times over several seasons before the bacterial inoculum is eliminated. If your neighbor has the problem and does not follow the same therapy program, the problem may never go away.