Annosum Root Rot: Identifying Characteristics
Identifying the disease:
Infected trees tend to occur in pockets, called infection centers. The trees in the center die first. As the pathogen moves through the root systems, the spot enlarges and creates a gap in the forest. Infected trees may lose many of their needles, which turn light green to yellow. As the disease progresses, roots turn into a stringy, white mass of decayed tissue. Infected trees will often be surrounded by windthrown trees that have already lost their battle with the disease. The conks at the base of tree are usually covered by leaf litter and therefore hard to see. Conks are often absent, even on trees with advanced root disease.
Susceptible trees:
Annosum root rot can affect any southern pine. Pine plantations on sandy soils with a low water table are at high risk when they are thinned and large numbers of freshly cut stumps are available for the fungus to infect.