According to Monica Elliott, plant pathology professor at the University of Florida's Fort Lauderdale Research and Education Center, the palm's anatomy is more similar to that of a corn plant than that of an oak tree, with each stem having a single bud or heart. Once that tissue is damaged, death is likely. "Palms cannot repair injuries to their stems, and diligent effort must be made to prevent injuries that create opportunities for insect or pathogen invasion of the trunk," she said.
Ganoderma butt rot and Phytophthora bud rot are just two of the most problematic diseases of palms. Ganoderma butt rot, caused by the fungus Ganoderma zonatum, is prevalent in Florida, where it has been found on more than 50 palm species. "Ganoderma butt rot is always a lethal disease of palms," said Elliott. "By the time symptoms develop, usually more than half of the lower trunk has been killed by the fungus," she said. In Florida, palm trees of 58 species have died from this fungus and no effective controls are known for this disease.
Phytophthora bud rot can be caused by several species of Phytophthora, and occurs in most places where palms are grown. This pathogen has been reported on palms from more than 20 countries as well as from California, Florida, Hawaii, and Puerto Rico. In total, the species of Phytophthora have a broad host range and have been reported to attack more than 25 palm species. "Bud rot is always fatal to coconut trees, but other smaller palms
Contact: Amy Steigman
American Phytopathological Society