Citrus Canker

Florida's Treasure Coast produces some of the finest citrus fruit in the world. We are home to many of the groves that make up the 9 billion dollar Florida citrus industry. The local citrus industry not only adds to our economy but employs thousands of local workers. We all benefit from our citrus industry, and need to do our part, whenever possible, to protect it.

A Homeowner's Responsibility With Citrus Canker

After all is said and done, everyone has suspected for a long time that the presence of canker in Martin and St. Lucie Counties 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, and 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 conducive climate for 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.). Remember that the disease is bacterial in nature and the only remedies existing for its control are decontamination (chemical antibacterials), or sanitation (fire). The best choice for control is decontamination by antibacterials instead of the latter. The latter choice (firing) involves the eradication/ 900 feet of citrus trees within the radius of an infected tree. In a neighborhood or subdivision, this would mean a substantial removal, of neighboring citrus trees for blocks, or in the case of citrus growers 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:

  • 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 local canker control force office at (772) 429-2000. 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.

  • 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 with personal hygiene washing (soap and water) followed by a Clorox disinfectant (sodium hydrochloride) of 200 ppm or approximately 1 oz. of Clorox to 1 gallon of water.

  • Landscape tools (pruning shears, clippers, etc.) need about 1200 ppm Clorox disinfectant at the rate of about 6 oz. of Clorox to 1 gallon of water. Be sure to wash the implements clean before dipping in the Clorox solution.

  • Yardmen, landscapers, etc. who prune or cut citrus trees or work around citrus trees need to practice the same measures as cited above.

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.