Studies of Fusarium associated with containerized conifer seedling diseases, 2. Diseases of western larch, Douglas-fir, grand fir, subalpine fir, and ponderosa pine seedlings at the USDA Forest Service Nursery, Coeur d'Alene, Idaho

Containerized western larch, Douglas-fir, grand fir, subalpine fir, and\ud ponderosa pine seedlings which displayed disease symptoms were sampled for\ud presence of Fusarium spp. Seedlings from 33 seedlots within the Northern\ud Region were sampled. Major types of diseases included post-emergence\ud damping-off, root disease (late damping-off), and cotyledon blight. Fusarium\ud oxysporum was most frequently isolated from seedlings; F. avenaceum was also\ud commonly isolated, particularly from grand fir and subalpine fir seedlings.\ud Both fungal species often produced orange sporodochia on diseased seedlings.\ud Poor production from several high elevation Douglas-fir seedlots was probably\ud due to losses from seed-borne Fusaria