Investigations were conducted to understand the epidemiology of Fusarium on containerized Douglas-fir seedlings. Types and importance of Fusarium inoculum sources, relationships between seedling infection and symptom production, amounts and types of diseases that occurred throughout typical growth cycles, and the importance of secondary pathogen spread were investigated. Levels of Fusarium...
Eighteen isolates of Fusarium comprising four species (F. oxysporum, E. avenaceum, E. acuminatum, and F. sambucinum) isolated from diseased conifer seedlings from nurseries were tested for pathogenicity on Douglas-fir germlings. Three of the most pathogenic F. oxysporum isolates on Douglas-fir germlings were also tested on ponderosa pine germlings and older...