Decline symptoms do not develop with grafting from dying yellow-cedar

Abstract

Branchlets from dying yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) trees were grafted on healthy saplings to determine if agents transmissible through grafts are associated with the widespread yellow-cedar decline in Alaska. A total of 216 branchlets were removed from 72 mature yellow-cedar trees that were apparently healthy, in early stages of dying, or nearly dead. These scions were grafted on 72 saplings and monitored for 5 years. The survival of grafted scions was reduced to 33% after 5 years. All surviving scions that were chlorotic when grafted became green. Chlorotic symptoms did not develop proximally to grafts in branches or generally in any of the saplings. Grafting treatment produced no detectable effect on height or diameter growth of the recipient saplings. This study produced no evidence that a graft-transmissible agent is associated with yellow-cedar decline.