What Causes Avocado Rot?
Avocado wood rot is a fungal disease caused by the pathogen Ganoderma lucidum. Spores of this fungal disease are carried on the wind and infect avocado trees through open wounds on the trunk or roots. The spores can live in soil for quite some time and also be carried to root wounds by flooding or splash back of rain. Avocado rot is more prevalent in weakened or damaged trees. Ganoderma lucidum wood rot can also infect other trees besides avocado, such as:
Acacia Apple Ash Birch Cherry Elm Hackberry Sweetgum Magnolia
While wood rot of avocado trees can kill a tree within only three to five years of the initial infection, the disease does not usually exhibit any symptoms until it is too late. Early symptoms can include wilted, yellowing, stunted or deformed foliage, leaf drop, and dead branches. In spring, the tree may leaf out like normal, but then foliage will suddenly yellow and drop. Other times rotten avocado trees may not display any foliar or branch symptoms. Ganoderma lucidum wood rot of avocado trees is also known as varnished fungus rot because in advanced stages of the disease it produces orange to red, shiny conks or shelf mushrooms from the tree’s trunk near the base of the tree. These conks are the reproductive structure of the fungal disease. The underside of the conks is usually a white or cream color and porous. In the humidity of mid to late summer, these conks release spores and the disease can spread to other trees. Interestingly, these conks or shelf mushrooms are an important herbal medicine used to treat many human ailments in traditional Chinese medicine.
How to Treat a Rotten Avocado Tree
There is no treatment for avocado wood rot. By the time symptoms and conks are noticed, the internal rot and decay of the tree is extensive. The fungus can severely rot structural roots and the heartwood of the tree without displaying any symptoms. Aerial symptoms that are noticed may be mistaken for many less serious fungal diseases. When the tree’s structural roots and heartwood are decayed, the tree can be easily damaged by wind and storms. Infected trees should be cut down and the roots should also be removed. Infected wood should be destroyed.
