Widely planted in temperate zones, pine trees (Pinus spp.) provide welcome deep shade in summer and winter color when deciduous trees are bereft of leaves. Although few pests or diseases affect pine trees, some pine diseases are most often fatal.
The first symptoms of pitch canker are needle dieback followed by a slightly sunken canker on the surface of the branch. The wood behind the canker will be soaked with pitch. As there is no known chemical control for this disease, pruning out the affected branches may prevent the trunk from becoming infected with the fungus. Infections of this fungus on the trunk of the tree are often fatal.
Needle blight usually affects two- to three-year-old needles which die back from their tip and leave a green base. Black-fruiting bodies with a long narrow appearance grow on the lower surface of the dead needles. Primarily an aesthetic problem, no fungicides are registered for the cure or control of this pine tree disease.
Annosus Root and Butt Rot
Affecting all species of pine, annosus root and butt rot can kill trees either gradually or rapidly. It most often infects a cut stump of a pine tree and spreads in a circular fashion to nearby pines. The crown foliage is thin on affected specimens, and fruiting bodies of fungus live on the trunk near the soil line. Infected and weakened trees blow over while still alive. To prevent the spread of annosus root and butt rot, treat freshly cut stumps with dry granular borax. Remove infected trees and do not plant additional pines within 20 feet of a pine that succumbed to the disease.