Tip blight afflicts many pine trees, especially in urban conditions. The disease is widespread in the Midwest. The fungus diplodia or sphaeropsis sapienea causes tip blight which is sometimes called Diplodia tip blight. Mature pine trees are typically affected, especially in areas of drought stress. The needles on the extremities of branches die as a result of the fungus which penetrates the needles. The fungus winters in the fallen cones and needles under the trees and emits spores in spring. Left untreated, tip blight can spread widely within the garden, park, neighborhood or nursery and cause trees to be deformed. It can also kill mature trees.
Symptoms: Dead needles at the tip and end of branches and brown patches on affected trees. Black fungus growth on needles and cones.
More information: Ohio State University Extension, Michigan State University Extension
Photo: Christine Engelbrecht, Department of Plant Pathology, Iowa State University