RED HEART
The fungus, Fomes pini, is the cause of a heartrot of widespread distribution. Common names for the rot produced by this fungus are: red heart, red ring rot, or white peck. The disease is commonly associated with mature and over-mature conifers, especially Douglas fir, larch, spruce, and pine. In the southern United States, the fungus attacks all species of mature pine.
Fruiting body of redheart on southern pine.
Generally, infection of all hosts occurs through dead branch stubs. Early stages of decay caused by F. pini are characterized by a discoloration of the heartwood, often appearing light red to reddish brown. The advanced stages of heartrot appear as elongated white pockets or flecks, formed parallel to the grain and separated by apparently firm wood. Often the pockets become resin filled. On southern pine hosts, the conks are often bracket-like or hoof-shaped. The upper surface appears dull grey to dark brown, with concentric furrows parallel to the margin of the fruiting body. The lower side is a light brown to brownish gold, rimmed by a velvety golden brown margin. Swollen knots result from the living wood tissue trying to overgrow the knot where a conk is forming.
Cross section of infected tree showing rotted and decayed heart wood.
In southern forest stands, heartrot damage may be reduced by harvesting mature pines prior to the age of extreme susceptibility to fungus attack. Some degree of shade tree protection can be obtained by pruning dead and dying branches flush with the main stem. This will allow the knot to be quickly overgrown by sap wood, preventing the heartrot fungus from entering through the branch stub.