Cones of Douglas-fir and ponderosa pine with extensive mold on external portions of scales were sampled for presence of fungi potentially pathogenic to conifer seedlings in nurseries. The major colonizers of cone scales and external seedcoats for both conifer species were Trichoderma spp. Penicillium spp. were also very common. The...
A total of 45 nondiseased containerized ponderosa pine seedlings from 10 seedlots were sampled at three different times during the growing season for root infection by Fusarium and Trichoderma at the USDA Forest Service Nursery in Coeur d'Alene, Idaho. More than 90 percent of the seedlings had roots infected with...
Needle tip dieback of 2-0 ponderosa pine seedlings at the Coeur d'Alene Nursery was investigated. Organisms associated with dieback symptoms were identified and infected trees were transplanted to determine disease effects on survival. The major fungus colonizing necrotic needles was Lophodermium nitens, a close associate of L. pinastri. The fungus...
A synthetic pheromone of the western pine shoot borer, Eucosma sonomana Kearfott, has been used
successfully as a 'mating disrupter in northern Idaho and western Montana since 1984. Infestation
levels in treated ponderosa pine plantations declined from an average of 28 percent infested in 1983
to 5.5 percent by 1986....
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...
Two blends (Natural and Phillips) of the western pine shoot borer pheromone, formulated as Hercon Luretape, were applied to six ponderosa pine plantations in northern Idaho and western Montana in 1984. The treatment was approximately 21.6 grams of pheromone per hectare. Significant reductions in damage have occurred in all treated...
Aerial application of mexacarbate and Bacillus thuringiensis Berliner was tested against pine butterfly, Neophasia menapia (F. and F.). These were applied to 40-acre plots on the Bitterroot National Forest and adjacent State and private lands during June 1973. Two concentrations of each material were tested; these were 0.15 and 0.30...
Root rot caused by Armillariella mellea creates roughly circular
disease centers of infected dead and dying trees in the younggrowth
ponderosa pine forest under study. Research objectives concerning
chemical control of the disease were: 1) to test the
effectiveness of certain chemicals in protecting living pines adjacent
to disease centers...
Armillariella mellea (Vahl. ex Fr. ) Karst. was grown aseptically
in hazel stems (Corylus cornuta var. californica) which were used in
the forest to infect 290 ponderosa pines (Pinus ponderosa Laws.)
which had been "stressed" in five different manners plus two control
groups. All trees were inoculated twice giving a...