Eastern filbert blight— Anisogramma anomala
Eastern filbert blight occurs primarily in Oregon and the eastern U.S. Blossoms, leaves, and terminals turn brown, wilt, and die. Leaves discolor and drop prematurely. Cankers or lesions may occur on limbs or twigs, especially in the upper canopy. The fungus that causes Eastern filbert blight infects buds and young leaves and shoots through airborne spores produced during wet conditions.
Prune out infected limbs during dry weather. Remove escaped seedlings. Plant resistant cultivars and species, such as Corylus cornuta var. californica.