Pine needle rust disease first appears as yellow spots on individual needles in spring, followed by whitish pustules or blisters which break open to discharge orange spores of the fungus. Heavy pine needle rust infection can cause defoliation. Needle rusts can affect Austrian, Scots, Virginia, loblolly, mugo, pitch, and red pines in Kentucky. A common pine needle rust is caused by the fungus Coleosporium asterum. This fungus lives on pine for part of its life, and for the rest mainly on asters and goldenrod. Destroying these alternate host plants breaks the life cycle of the fungus and controls the disease. Sulfur-containing fungicides applied to needles in spring can prevent new infections if alternate hosts are still growing nearby.
Contact your local Extension office for fungicide recommendations.
