Insect damage was extensive to Douglas-fir, ponderosa pine, western white pine, and western larch cones at most seed production areas surveyed in 1979. From 70 to 100 percent of the cones from several collecting periods were injured. Moderate damage (40-70 percent of cones injured) occurred to Douglas-fir, ponderosa pine, western...
Potential problem pests found were Armillaria root disease, pocket gopher, western pine shoot borer, and white pine blister rust. Early detection of problem pests allows management actions to be taken if needed to prevent serious impacts. Unit managers should check the areas periodically and call on pest management specialists to...
White and grand fir are both valuable components of the mixed-conifer stand structure managed for late-successional reserves in central Oregon. However, they are often short-lived species because of high susceptibility to root diseases, defoliating insects, bark beetles, and wildfire. This study focuses on the effects of root diseases caused by...
Thirty-three isolates of Fusarium acuminatum obtained from inland Pacific Northwest forest nurseries were tested for their pathogenicity on young Douglas-fir germinants under controlled laboratory conditions. Tested isolates were from forest nursery soil, roots of healthy-appearing and diseased conifer seedlings, Styrofoam and hard plastic containers, conifer seeds, 411 and adult fungus...
Forty-seven isolates of Fusarium solani obtained from the roots of diseased and healthy conifer seedlings and forest nursery soil were tested for pathogenicity on young Douglas-fir germinants under controlled laboratory conditions. Isolate virulence varied widely; a few were highly virulent whereas many were classified as non-pathogenic. Isolates from the roots...
A survey for incidence and distribution of root diseases was conducted on the Kootenai National Forest using timber inventory subcompartments as primary sample units. Root diseases were located within 23 of 75 sampled subcompartments. At least 1.1 percent of the commercial forest lands within the Forest are infested with root...
In spruce budworm damaged areas, height growth loss can be a major factor in stand development. This survey was confined to top-killed trees. Estimates on height growth loss or nontop-killed trees was not attempted. Although spruce did not have as high a percentage of trees top-killed as the true firs,...