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What is wrong with the Sabal palm?

It’s difficult to believe that our state tree, Sabal palmetto, is presenting some difficulties. For me, Sabals are a bullet proof plant, until recently…

What is the culprit? Lethal bronzing disease (LBD)!

  • It used to be called Texas Phoenix Palm Decline (TPPD).
  • It was discovered in Florida in 2006 and is caused by a phytoplasma—a type of bacteria that lacks a cell wall and cannot be cultured with artificial media.
  • The phytoplasma is similar to, but genetically distinct from the phytoplasma that causes lethal yellowing (LY) disease of palms.
  • The LBD phytoplasma is limited to the phloem (sap) of the palm and cannot survive outside a plant or insect; therefore, it cannot be mechanically transmitted (e.g., by pruning tools or infected roots touching new roots).
  • Once a palm shows symptoms and tests positive for the LBD phytoplasma, it should be removed immediately.
  • Healthy palms near infected palms should be tested to verify that they are free of infection and injected with oxytetracycline HCl (OTC) every three to four months as a preventative for at least two years.
  • For proper management early detection is key
  • As of today, the list of palm host are:
Scientific Name Common Name
Adonidia merrillii Christmas Palm
Bismarckia nobilis Bismarck Palm
Butia capitata Pindo Palm
Carpentaria acuminata Carpentaria Palm
Cocos nucifera Coconut Palm
Livistona chinensis Chinese Fan Palm
Phoenix canariensis Canary Island Date Palm
Phoenix dactylifera Edible Date Palm
Phoenix roebelinii Pygmy Date Palm
Phoenix sylvestris Wild Date Palm
Pritchardia pacifica Fiji Fan Palm
Pseudophoenix sargentii Buccaneer Palm
Sabal Mexicana Mexican Palmetto
Sabal palmetto Cabbage Palm
Syagrus romanzoffiana Queen Palm
Trachycarpus fortunei Chinese Windmill Palm

Note: the list may grow over time!

For more information about LBD, check the UF/IFAS publication at: https://edis.ifas.ufl.edu/pp163

Figure 1.Early symptoms necrotic inflorescence infected with LBD. Courtesy: Dr. B. Bahder, UF/IFAS

Figure 2. Symptom progression of LBD in a Sabal palmetto demonstrating discoloration of older leaves first, March 2018 (left); then three months later where more, younger leaves are affected and spear leaf has collapsed (right). Courtesy: Dr. B. Bahder, UF/IFAS

Fig. 3. Late symptoms, the majority of fronds are dead. Courtesy: H. Mayer

Fif. 4. Dead Sabal after approximately four month of LBD. Courtesy: H. Mayer

Fig. 5. P. sylvestris with LBD in the Dolphin Expressway. Courtesy: H. Mayer

Fig. 6. Group of sabal palms with late stage of LBD in the Dolphin Expressway. Courtesy H. Mayer

Fig. 7. Notice the reddish coloration. It’s typical when LBD is present. Courtesy of H. Mayer

Fig. 8. Various ornamental palms displaying symptoms of LBD. Courtesy: Dr. B. Bahder, UF/IFAS