Characteristics of Annosus Root Disease in the Pacific Southwest

Abstract

Annosus root disease is mainly a concern in pines and true firs in California. It is most serious on the east side of the Sierra Nevada and Cascade crest, in the mountains of southern California, and in higher elevation fir forests. Symptoms caused by the disease include crown decline and decay and resinosis of roots. Several signs of the fungus may be found. Conks are most common in stumps. Mycelial sheets on the inner bark and popcorn conks on thin-barked roots are diagnostic. Declining trees or recent mortality are best for diagnosis. Wood samples should be symptomatic but not well decayed. Laboratory procedures are available to confirm the presence of H. annosum.

Parent Publication

• Proceedings of the symposium on research and management of annosus root disease (Heterobasidion annosum) in western North America; April 18-21, 1989; Monterey, CA.

Citation

DeNitto, Gregg A. 1989. Characteristics of Annosus Root Disease in the Pacific Southwest. In: Otrosina, William J.; Scharpf, Robert F., technical coordinators. 1989. Proceedings of the symposium on research and management of annosus root disease (Heterobasidion annosum) in western North America; April 18-21, 1989; Monterey, CA. Gen. Tech. Rep. PSW-GTR-116. Berkeley, CA: Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture; p. 43-48