A 3-year evaluation of Douglas-fir cones in Montana and Yellowstone National Park, Wyoming, showed the western spruce budworm, Choristoneura occidentalis Freeman, and midges were the most common and injurious insects found each year. Injury was so severe at some plots that no sound seeds could be found.
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...
An evaluation was made in 21 seed production areas and 1 seed orchard in Region 1 to identify the primary insect pests and to assess amount of injury caused. Cones from Douglas-fir, grand fir, western larch, lodgepole pine, ponderosa pine, and western white pine were collected periodically and examined. The...
Benomyl and chlorothalonil were tested on 2-0 bareroot ponderosa pine seedlings as a means to reduce impact of Diplodia tip blight at the Fantasy Farms Nursery, Peck, Idaho. Infection levels were not adequate to assess effectiveness of the fungicides. However, techniques were developed which can be used to assess efficacy...
Dwarf mistletoe is a serious problem on the Flathead Indian Reservation. Since the early 197o's, a procedure called thinning-sanitation has been applied to lightly infested stands. Evaluation of this procedure indicated that average dwarf mistletoe infection levels now range from 7 to 50 percent in larch and Douglas-fir treated 10...
Published November 1940. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog