Infections spread from infected stumps to healthy trees through root grafts. Common borax powder applied in salt shaker manner to surfaces of freshly cut stumps prevents stump infection and subsequent spread to adjacent living trees. Harvesting during dry summer and fall months whenever possible lessens the possibility of new infections. This disease is a problem on seedlings. Damage to large trees is usually minor.
Symptoms first appear as irregularly circular light gray-green spots on needles in the fall.
Spots enlarge rapidly and encircle the needle forming narrow tan-brownish bands, and finally the tips of the needles die as a result of multiple infections. Many needles may be killed the first season they are infected. The fungus fruits on very small dark-brown to black colored elongated spots on the dead part of the needle. Spores are produced in wet weather and the needles may be attacked several times in one season. At least three successive annual defoliations must occur to kill longleaf pine seedlings.