Nectria galligena Bres. in Strass.
Distribution: Common to northeastern US and southeastern Canada and westward, but problems usually persist only in maritime climates or where infected nursery stock was planted.
Cankers are often associated with nodes, appearing as elliptical, sunken areas.
Thomas Burr, Cornell Univ.
Cankers are often associated with nodes, often appearing as elliptical sunken areas (A). Sometimes callus production stops fungal invasion and cankers die by season's end. Other times, the fungus, walled off by callus formation during the current growing season, re-invades callus tissue when active growth resumes the following season, giving older cankers a zonate or target-like appearance (B). Enlarging cankers girdle infected twigs and branches, killing tissue above cankers. During damp weather, gelatinous white to cream-colored sporodochia produce spore masses that ooze from cankers; bright red to orange fruiting bodies (perithecia) may appear on older cankers (similar to Nectria twig blight).