Determination of growth loss of Pinus taeda L. caused by Heterobasidion annosus (Fr.) Bref.

The root system of 350 loblolly pine trees in 14 plots were excavated utilizing a bulldozer and evaluated according to the annosus root rot (Heterobasidion annosus) symptom expression of the roots, i. e. resin soaked and stringy. The annual increments of the healthy (<1% colonized) and diseased (<1% colonized) groups of trees were compared for each of the last five years growth. There was a significant growth difference between healthy and diseased trees for each of these last five years at about 4% per year or about 19% for the five year total.