Fusarium Wilt Information
In brief: Fusarium Wilt disease is caused by a fungus that naturally lives in the soil in some areas. The problem is that this fungus, Fusarium oxysporum, can be passed to the vascular system of palms that have no defense against it - typically by contaminated pruning instruments like chainsaws or handsaws. TRIMMING YOUR CANARY PALMS WITH CHAINSAWS IS NEVER RECOMMENDED - use new handsaws or new blades on pole saws. Always practice sanitary pruning practices when trimming your Canary palms. If you want to avoid the wilt disease trim off only completely dead fronds. Please bear in mind that this is a fatal, fungal infection - there are no magic sprays, giant miracle syringes, injections or chemicals that have proven effective in curing or controlling this disease. However there are some spray companies that will spray your Canary palms and claim this may or will stop the development of this disease, but it has been my experience over the last 10 years of watching this go on that this is simply not the case. Fusarium Wilt has a symptom development pattern that can vary - the symptoms can become worse and then the palm can recover somewhat. This is not uncommon when dealing with this disease but in the end the palm always dies. I have monitored dozens of Canary palms over the years that were receiving this Phosphite fertilizer "treatment" and the palms have always eventually died. The companies and people that advocate these sprays range from the well-meaning but inexperienced to the down-right dishonest. People love their Canary palms and when they become infected with the Fusarium Wilt they are willing to do just about anything to save them and this is what these unethical companies prey upon. I have noted though that these sprays are very effective in separating clients from their money! It is also important to note that spraying Canary palms for the Pink Rot fungus is not necessary. The Pink Rot fungus is a weak secondary pathogen on Canary palms and in normal circumstances does not kill Canary palms. Spraying them for this fungus also adds a powerful fungicide to the environment for no reason other than to make money. Currently I am working with a company and testing some non-toxic, organic solutions that may prove effective in controlling the disease - more on that in the future on this website. If your Canary palm is diagnosed by a qualified, experienced Horticulturist or Arborist as being positive for the disease the best course of action in a typical situation is to remove the palm in a timely manner in one piece, if possible, using a crane. If there is no crane access then remove the palm in as few pieces as possible. The practice of leaving the palm on site and cutting off the infected fronds as the palm slowly dies is not recommended. If you do this the sawdust generated, which is potential inoculum, will fall to the ground and can then infect your soil. Once the fungus is in the soil it can grow and enter other nearby Canary palms through their roots.
For more detailed information on Fusarium Wilt disease please go to this plant pathology website where Mark has an article on Fusarium Wilt disease published - CSP Labs.com and look under Articles.