Citrus canker symptoms on twigs, leaves and fruit. Photo by Timothy Schubert, FDACS

Citrus canker was found for the first time in the Florida panhandle in Gulf Breeze in southern Santa Rosa County in November 2013. Since that time, citrus canker has spread widely in the Gulf Breeze area and just recently in 2020 was found in two locations in Panama City and Panama City Beach in Bay County.

Citrus canker is a serious bacterial disease that only infects citrus trees. It will not infect any other plant species nor is it a threat to human health. Severely affected trees experience substantial leaf loss and premature fruit drop and serve as a source for infecting nearby citrus. The disease spreads through wind, rain, and transportation of infected plant material from other locations.

This highly contagious disease has no cure although progression of the disease can be slowed through the use of copper-based products. This publication guides the homeowner on using copper.

Citrus canker lesions on leaves are raised, rough and visible on both sides of the leaf. Photo by Timothy Shubert, FDACS.

Not all citrus varieties are equally susceptible to this disease. Grapefruit, lemon, and lime are some of the most vulnerable while tangerine and tangelo varieties are among the most resistant.

What should you do if you suspect your citrus is infected with this disease?

  1. Look at this guide for more information and compare the symptoms on your tree to the photos. Lesions on the leaves penetrate through the leaf so they are visible on the upper and lower leaf surfaces, are rough, and have a yellow halo. The lesions look similar on the fruit and stems. Lesions (or cankers) on the stems usually indicate a longer standing infection of a year or more.
  2. Consult your local Horticulture Extension Agent to confirm the diagnosis and obtain more information and control/removal strategies.
  3. Proper removal of infected trees is recommended to prevent the spread of citrus canker but is not mandatory. The best way to dispose of infected trees is through cutting them down and burning them onsite; this ensures than none of the plant material leaves your yard to infect other areas. Consult your local burn regulations before burning. Stray leaves, branches and fruit should be raked and burned or double bagged for the trash. Please avoid disposing of any of your citrus trees by putting them by the side of the road for pickup by the county yard waste recycling or regular waste disposal. The bacterium will survive in the plant tissue and be spread to other neighborhoods in the county. You can, however, double bag infected plant material in sturdy bags and place it in the trash.

 

For more information please see:

UF IFAS Gardening Solutions: Citrus

Citrus Culture in the Home Landscape

UF IFAS Extension Online Guide to Citrus Diseases  

 

Mary Salinas
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