Fungi are the most common form of infectious disease in trees worldwide. There are more than 2,000 species that appear and thrive only on trees, to the detriment of their hosts. These fungi are divided into two broad categories based on the mode of infection. Wood decay fungi enter a tree's vascular system as spores, germinate and grow beneath the bark. Canker fungi take advantage of broken branches and any area where living wood is exposed, such as a nick or a cut. Curing tree fungus requires different methods dependent on the category.
Prevention is the best method to treat fungal infection. Aerate the soil surrounding the tree frequently and, if the soil is prone to retaining moisture, consider adding peat moss or vermiculite to thin it out. Fungal infections thrive in standing water, so it should be avoided. Whenever branches are pruned or should the bark be broken to expose wood, the affected areas must be covered with a nonasphalt based pruning sealer. This will help ensure fungal spores do not make their way into the tree's vascular system.
Wood Decay Fungi Cure
Because wood decay fungi can go for months before the bark hiding it from sight crumbles away, it's difficult to catch in time. If caught before it progresses to the root structure and heartwood, there is a chance it can be saved. The fungus must be scraped out. Given the degree of rot, a hatchet is normally sufficient to chip out the infected wood. Solid wood surrounding the infection will be wet. This is not water; it is infected sap and must be dried out to halt the infection. Use a kerosene torch, but a heat gun will work just as well. Once the wood is dried, repeated applications of any fungicide solution that is borate-based will kill all remaining spores. After that, the exposed wood of the tree must be sealed off to prevent reinfection.
Fungal Canker Cure
As fungal canker grows on the outside of tree bark and infects the broken ends of tree limbs, the first step to curing it is stripping any bark with fungus growing on it and pruning away infected limbs. Fungal cankers are particularly vulnerable to copper sulfate, and the old Bordeaux solution is still regarded as the most effective. It should be painted across the tree's open wounds and around the bark of the infected areas daily. A week's worth of treatments will ensure no spores survive to continue the infection.