The City of Galveston'stree committeehas asked residents to be aware of a disease in palm trees called lethal bronzing. It’s moving around palms on the island south of Houston, causing them to quickly decline without a cure. As officials work to quarantine affected areas and remove infected trees, they've encouraged residents to keep a close eye on their palm trees.
The disease does not pose a risk to humans or animals. It is spread by bacteria that can only infect plants and are transmitted by insects.
"Similar to a mosquito that spreads viruses through blood from one person to the other," said Boone Holladay, theTexas A&M AgriLife Extensionhorticulture agent in Galveston County.
Holladay said the disease spreads when a small leafhopper insect takes some tissue out of one plant that has the pathogen within it, flies over to another palm and as it's feeding on that palm, spreads the disease.
According to aFacebook postby the City of Galveston,palm trees at risk on the island include the Canary Island date palm, Sabal palmetto and Queen palm. The post also listed symptoms of a tree being impacted by bronzing:
- Sudden fruit drop
- Browning leaves
- Spear leaf death
- Root rot
"Normally where there would be green leaves and you see this reddish bronzing coloration to the foliage, that is a clue for us that this palm may be infected," Holladay said.
Holladay recommended those who notice signs of lethal bronzing to contact theGalveston County AgriLife Extension office,which can help determine if the tree is suffering from normal wear and tear or at risk of lethal bronzing. If the office suspects the tree is infected, it will advise the person to have the palm tested by inspectors with the Texas Department of Agriculture.
If the test comes back positive, Holladay said getting the tree removed by a certified arborist is the next step.
"The longer that those infected palms stay in place, they’re acting as a source of spread onto other palms so the recommendation is to get those out of there as soon as possible," Holladay said.
Holladay said officials with theTexas Department of Agricultureare working to quarantine areas with infected trees. The quarantined areas help individuals know not to bring plant material outside of that area and potentially spread the disease into new locations.
"Each time we find a new positive confirmation, it spreads that quarantine zone out,” Holladay said. “We’re still in the early stages of this, so we just don’t know how vast it’s going to become at this point."
Holladay said the west end of the island is particularly at risk since almost 100% of the canopy of trees are palms. He said if that portion of the island ends up getting an infestation that flares up substantially, it will lose a lot of its shade canopy with it.
Galveston Island isn't the only area grappling with the disease as lethal bronzing has also recently threatened palms in Port Isabel, which is in far South Texas, as well as in Florida, according to data from the Texas Department of Agriculture.
While an infected tree can't be treated, Holladay said residents can take some preventative measures. He said residents can start with simply taking better care of their palms by watering during drought periods and practicing proper pruning to remove dead fronds. Other preventative measures include an antibiotic treatment called oxytetracycline and a systemic insecticide treatment.
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