UF/IFAS Okeechobee County Extension Service

458 Highway 98 North

Okeechobee, FL 34972-2578

Phone: (863) 763-6469

E- mail: dfculbert@ifas.ufl.edu

January 10, 2005

Feature Article - for release the week of November 9, 2003

Jack Hebb - Extension Citrus  Agent

A Homeowner’s Responsibility With Citrus Canker

Last week the Florida Department of Agriculture confirmed that a citrus grove location in our area has been identified as having citrus canker. This follows the announcement of another find in Port Saint Lucie.

After all is said and done, everyone has suspected for a long time that the presence of canker in the Treasure Coast   was just a matter of time. No one entity is more susceptible to the importation and transfer of this disease as a dooryard citrus owner. However, a homeowner is usually very proud of the various varieties of citrus that can be grown in a Florida dooryard - bragging rights belong to the gardener who can show his northern neighbors the prettiest and the best.

It’s no mistake that Florida has always had a climate conducive to growing lots of citrus.  But, Florida ’s climate has always had certain maladies that compete with a citrus tree’s ability to survive. Among the list of maladies for citrus survival, there is predominantly one that tops the list -citrus canker.

Citrus canker is a highly contagious disease that attacks the fruit, the stems, and the leaves, as well as causes lesions to the fruit. Although the disease is not harmful to humans, it can dramatically affect the health and vitality of citrus trees.

Unlike most citrus diseases, which are predominantly fungi (plant-like), citrus canker is a serious bacterial disease. It is microscopic (unseen by the human eye), and can be spread by wind, rain, humans (contact), landscaping (trimming, chipping, cutting, or pruning citrus trees), and fruit removal (peeling, buying, selling, transporting, picking, etc.).

When a disease is bacterial in nature,  the only remedies that exist for its control are decontamination (chemical antibacteriants), or sanitation (burning).  The best choice for control is decontamination by antibacteriants instead of the latter.

The latter choice (burning) involves the eradication of citrus trees within 1900 feet of the radius of an infected tree. In a neighborhood or subdivision, this would mean a substantial removal of neighboring citrus trees for many blocks.  In the case of citrus growers, it means the removal of more than 200 acres per infected tree site in contiguous groves.

For homeowners, I recommend the following measures to help control canker:

(1) If you suspect any part of a citrus tree of harboring canker, please do not remove the leaves, fruit, or limbs.  Leave them alone and promptly place a call to the canker control task force office at (800) 282-5153. The office is a division of the Florida Department of Agriculture and will promptly respond to your call by dispatching an individual to the suspected tree location who will seek your permission to view the tree.  Do Not, and I repeat, Do Not, remove suspicious citrus tree parts and transport them to another location.

(2) In neighborhoods where canker has been identified, homeowners need to wash outdoor clothing (gardening clothes) in a hot water cycle with laundry soap immediately following outdoor chores around citrus trees.  A personal disinfectant for hands can be accomplished by washing with soap and water, followed by a chlorine bleach disinfectant (sodium hydrochloride) of approximately 1 oz. of bleach to 1 gallon of water (a 200 ppm solution).

(3) Clean all landscape tools (pruning shears, clippers, etc.) that have contacted citrus trees need Clorox disinfectant at the rate of about 6 oz. of bleach to 1 gallon of water (about 1200 ppm) . Be sure to wash the implements clean before dipping in the bleach solution.

(4) Have any landscapers who work on your property (yardmen, landscapers, etc.) that prune or cut citrus trees or work around citrus trees practice the same measures as cited above.   A specific decontamination suggestions bulletin for landscapers is available.

I encourage all neighborhood residents to be on the lookout for suspicious looking lesions on their citrus trees. We need to be alert and aware, because if citrus canker is not eradicated from our area, it could destroy one of Florida ’s most important crops as well as an abundant resource that is enjoyed by homeowners across this state.

Photos and more links to information on Citrus canker can be found at the UF/IUFAS Canker website, http://canker.ifas.ufl.edu/index.asp, and the Florida Department of Agriculture’s website,  http://www.doacs.state.fl.us/pi/canker/ .

Do not bring samples of suspected canker to our office!  If you need additional information on Citrus canker, please email us at okeechobee@ifas.ufl.edu or call us at 863-763-6469.  Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, visit our Okeechobee web page, http://okeechobee.ifas.ufl.edu   The Okeechobee County Master Gardeners are available on Tuesday afternoons from 1 to 5 PM on Tuesday afternoons.  

-30-

University of Florida Citrus Canker Program Website

Florida Department of Agriculture Citrus Canker Website 

Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. Florida Cooperative Extension Service / IFAS /University of Florida. This page is maintained by Dan Culbert