Canker Disease Affecting Oak Trees
Probably at some point you have notice that your oak tree is suffering from some unsightly cankerous looking wounds, and you question yourself what are these cankers and what is causing them in my trees. Hypoxylon cankers are prevalent and highly visible diseases affecting oak trees and other hardwoods, and these cankers are caused by one or more fungi.
Hypoxylon species are not considered as aggressive killers, instead they are usually found on trees suffering from a variety of injuries of stress. Cankers are often the straw that broke the camel’s back’ in oak trees suffering from water stress, root diseases, soil compaction, construction damage or other injuries.
Any tree infected with hypoxylon often show evidence of severe injuries on the the branches or stem and advanced decline or die-back. You can see that the bark of infected trees typically sloughs off, near injuries or along the trunk and major branches, revealing one of two types of fungal signs.
How Canker Disease Can be Identified (Symptoms and Signs)
Symptoms may initially resemble in oak trees that seen to be decline, their bud break may be delayed, leaves may be undersize, foliage may be chlorotic, scorched or wilted, and branches may begin to die-back from the top of the tree downward.
The easiest way you can identify canker disease is by the large spore bearing mats produced beneath the bark of infected trees, the stomata usually appears the year following drought, or any other severe stress cases.
Stomata will grow in size and eventually cause rupture in the bark, patches of sloughed off bark range from a few inches to many feet in size. In severe cases you can see that almost the entire oak tree will lose its bark and be covered in the fungal mats.
The stromata can vary in color it can go from tan, brown, black, or even grey depending on the tree specie. When this happens your oak tree or any other specie can die quickly, if its not already dead at the time of the stromata production.