Biscogniauxia also known as Hypoxylon Canker, is a type of fungal pathogen that attacks trees in a weakened or stressed state of health.
Unfortunately, we are seeing it more and more around Central Texas in 2024 and we are seeing it on Live Oaks although it can affect or attack most hardwoods. It is usually found in years of drought or after drought. It goes after trees stressed from lack of water. It is considered a weak pathogen in that it is not aggressive enough to invade healthy trees. Once it actively infects a tree, the tree will likely die.
Once the fungus invades a tree, the sapwood begins to rapidly decay. If the infected trees are in areas where they could cause damage if they fall, they should be removed as soon as possible. The fungus is spread by airborne spores and there is no known control for the fungus other than maintaining tree vigor and working on the health of your trees.
One way to work on better water uptake is deep root fertilization. It not only adds nutrients to the soil but breaks up the soil, allowing for better and more water penetration. The spores of this fungus are very common and can stay dormant for extended periods of time until the conditions are optimal for them to attack. The fungus will cause bark to fall off and areas will appear tan initially but eventually become dark brown or black. Unfortunately, I think we are going to see a lot of this in the coming months, but I sure hope I am wrong. Once we hit triple digit days, try to get your trees some supplemental water every 7-10 days.
