Deter canker and dieback diseases - Dieback and Canker Disease

Dr. Malcolm C. Shurtleff

Canker diseases are common, widespread and destructive. They attack all woody plants, especially those low in vigor. Cankers may cause wilting and dieback of twigs and branches and structurally weaken a plant so much that it breaks in a wind, snow or ice storm. Cankers also slow the normal healing of wounds thus providing easy entry for wood-decay, wilt-producing and other disease-causing organisms.

Canker and dieback diseases are most common and easily seen on trees and shrubs growing under one or more of a variety of stresses: transplant shock, an excess or deficiency of water, prolonged exposure to temperature extremes, sudden hard freezes in mid- to late fall or spring, summer or winter sunscald, frost cracks, imbalances of essential nutrients, extensive defoliation by diseases or insects, soil compaction, changes in the soil grade, mechanical injuries (hail, wind, a heavy ice or snow load, lawn mowers, construction equipment, borers, dogs, livestock or deer), pruning wounds, root rot, nematodes, or improper digging, storage and shipping of nursery stock.

What is a canker? A canker is a dead area or lesion, usually in the bark of a woody plant, that often results in an open wound. Starting as a small, sharply delimited dead spot, usually round or oval to elongated in shape, a canker may enlarge and girdle the cane, twig (shoot), branch (limb), trunk or root.

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