There are 12 known diseases of palms in South Florida and the ones that kill your palms are not curable but most are preventable. 8 of the palm diseases in South Florida have no cure yet.
How Do Diseases of Palms Infect Your Palm Trees & What You Can Do To Prevent It!
All disease pathogens need 2 things to infect a palm tree, they need the right palm species and the right conditions in order to infect the palm. Pests and Diseases are opportunistic they take advantage of a weakness or opportunity to cause the damage. with proper palm tree care and by properly selecting, installing and caring for your palms you can help prevent palm diseases.
Palms suffer from leaf, crown or bud, trunk and root disease. Lots of time palm diseases are missed diagnosed as deficiencies and vice versa.
The most important part of dealing with palm disease prevention is proper cultural practices, what are cultural practices?
Cultural practices are things we can do correctly to prevent palm tree diseases and pests, such as proper selection of palm species for our landscape in the correct place if a palm tree is expected to grow 30 feet tall with a frond span of 12 fee you should not plant it 10 feet from your two story home, the fronds will always touch the walls.
Most palms do not need to much water once established, if you have a low laying are that floods all summer this can cause root rot and eventually kill it. Avoid hanging plants from palms such as orchids that require daily watering can cause palm tree trunk rot. The green fungus on palm tree trunk could be algae which is a clear indication the trunk is getting wet to often.
Palm trees in poor light or the wrong light are more susceptible to palm diseases.
Cold or frost can mimic or allow diseases to cause damage to palm, a cold frost can kill a palm in south Florida because most palms cant handle temperatures bellow 50 degrees for prolonged periods of time, a cold frost that lasts only one night can cause damage that becomes apparent 6 months later with yellowing and trunk deformation or twisting.
Wind can increase the spread of diseases of palms spreading spores around entering wounds.
Improper pruning with un-sterile equipment like pruning saws and chain saws and transmit a disease from am infected palm in your landscape when landscapers trim. You should have your landscapers sterilize their equipment between every palm they trim.
Avoid opening wounds with line trimmers at the base and roots or at the trunk level with trimmers, sheerer, saws or with nails or screws which wounds are permanent and never heal, having an open wound will allow diseases to enter palm. Even trunk injections should be avoided and used as a las resort to save the tree.
Do not over trim or pencil top palms which leads to deficiencies making palm trees more susceptible to diseases.
Lastly fertilize correctly and at the right frequency with the appropriate amount for the specific palm species and size, avoid banded fertilizer and don’t allow it to pill up around the exposed roots or trunk.
A palm tree fungus spray with a fungicide are effective primarily for foliage diseases such as leaf spot, or blight of palms to prevent further spread of the disease to healthy tissue but it does not remove the spots, damage from diseases on palm fronds are permanent until the frond falls off or is removed. Spots on palm leaves by diseases or by false smut can be misdiagnosed as deficiencies.
Confirming The Presence of Diseases of Palms
Palm tree diseases pictures do not help in actual diagnosis of the disease because so many other factors such as site, light, fertilizer could be the actual cause and not a disease only a laboratory test by submitting to the Tropical Research and Education Center Laboratory can confirm the presence of the disease.
List of 12 Palm Diseases in South Florida.
Bud Rot of Palm (NO Cure)
Calonectria (Cylindrocladium) Leaf Spot of Palm
Fusarium Wilt of Canary Island Date Palm (NO Cure)
Fusarium Wilt of Queen Palm and Mexican Fan Palm (NO Cure)
Ganoderma Butt Rot of Palms (NO Cure)
Graphiola Leaf Spot (False Smut) of Palm
Leaf Spots and Leaf Blights of Palm
Lethal Yellowing (LY) of Palm (NO Cure) Prevention with Oxytetracycline hydrochloride Trunk Injections every 4 months for life before palm becomes infected.
Pestalotiopsis (Pestalotia) Diseases of Palm (NO Cure)
Petiole (Rachis) Blight of Palm
Texas Phoenix Palm Decline (NO Cure)
Thielaviopsis Trunk Rot of Palm (NO Cure)
Source: http://edis.ifas.ufl.edu/topic_palm_diseases