PHYTOPHTHORA SPECIES INCITING ROOT ROT OF CHAMAECYPARIS LAWSONIANA AND OTHER ORNAMENTALS IN COASTAL BRITISH COLUMBIA

Abstract

In the south coastal region of British Columbia about two-thirds of the Phytophthora isolates from Chamaecyparis lawsoniana affected with root rot were P. lateralis, and the remaining third comprised P. cinnamomi and an unidentified Phytophthora sp. P. cinnamomi was isolated infrequently from Taxus baccata L., T. cuspidata Sieb. & Zucc., and Rhododendron ponticum L. New host records of P. cinnamomi, in experimental infections, are Chamaecyparis pisifera Sieb. & Zucc. var. filifera nana aurea and Cornus nuttallii Aud. The unidentified Phytophthora sp. experimentally infected C. lawsoniana var. ellwoodii, C. pisifera var. filifera nana aurea, R. ponticum, R. obtusum Planch var. Hinodegiri, and C. nuttallii.