Lethal Bronzing Disease (LBD) formerly known as "Texas Palm Decline" is a devastating bacterial disease wreaking havoc on palm trees across Florida.
WHAT IS LBD?
LBD is caused by a phytoplasma, a type of bacteria without a cell wall, making it difficult to study or culture in a lab. The disease is spread primarily by a tiny sap-sucking insect called the American palm cixiidae. Once infected, the phytoplasma invades the palm's phloem (the tissue that transports nutrients), clogging its vascular system and leading to rapid decline. This cannot be spread from pruning tools, as the phytoplasma only survives in living hosts.
SYMPTOMS OF LBD ON SYLVESTER DATE PALMS
Identifying LBD early is challenging, as symptoms may not appear until 4-5 months after infection. The earliest symptom is often fruit dropping before it ripens and flower stalks turning black. The disease's hallmark sign is the "bronzing" of older lower fronds, starting at the tips and moving upward through the canopy. This bronzing can be mistaken for potassium deficiency or natural leaf decay, but LBD's progression is much faster.
The final stage occurs when the spear leaf (the central, newest frond) turns brown and collapses, signaling death of the palm's "heart"
At this point, the palm is effectively dead, even if some green palm fronds remain.
MANAGEMENT & PREVENTION STRATEGIES
For healthy Sylvester palms in areas with known LBD, quarterly injections of (OTC) can prevent infection. These injections cost $100-150 per injection and must continue every 3-4 months indefinitely. OTC is ineffective once symptoms appear.
While no palm is fully immune, some species like the Foxtail Palm, Ribbon Palm, and European Fan Palm are less susceptible to LBD.
Healthy palms are more resilient to disease. Proper watering, fertilization, and pruning practices will reduce stress thus reducing the palm's vulnerability.
CONCLUSION
If you have Sylvester Palms on your property, stay proactive. Monitor for symptoms, test periodically and contact a professional for preventative Oxytetracycline injections.
Consider planting alternative species that are less susceptible to LBD.
Jason West
Sources:
-University of Florida IFAS Extension
-The Florida Department of Agriculture