An evaluation to establish baseline data on forest insect and disease activity near a magnesium plant under construction in northeastern Washington was initiated in 1974. The plant will emit significant amounts of sulfur dioxide. Data indicates that several fungal and insect species are at low populations. Needle retention appears normal...
Tests were conducted to determine levels of tolerance of 10 Botrytis cinerea isolates from the Flathead Indian Reservation greenhouse (Ronan, MT) to six fungicides. In vitro growth and conidial germination on fungicide-amended potato dextrose agar were used as criteria for assessing tolerance. All tested isolates were tolerant to benomyl and...
Isolates of Fusarium oxysporum, F. acuminatum, and F. sambucinum obtained from peat-vermiculite soil mixes were tested for pathogenicity on ponderosa pine, lodgepole pine, western larch, and blue spruce containerized seedlings and on germination of Scots pine and blue spruce seed. Ponderosa pine seedling were the least susceptible to killing by...
An evaluation was conducted at the USDA Forest Service Nursery, Coeur d'Alene, Idaho, to quantify the occurrence of diseases in the spring 1984 crop of containerized Engelmann spruce seedlings. The crop included 19 separate seedlots from seven National Forests in the Northern Region. An overall production rate of 94.5 percent...
Isolates of Botrytis cinerea from containerized conifer seedlings from two
nurseries in the Northern Rocky Mountains were exposed to the
dicarboximide fungicides vinclozolin and iprodione and the chlorinated
nitroaniline fungicide dicloran to evaluate occurrence and characteristics
of resistant strains. The isolates were grown on test media prepared by
incorporating the...
Mortality of western white pine transplants used to assess resistance to blister rust at the USDA Forest Service Nursery in Coeur d'Alene, Idaho was likely due to extensive root infection by Pythiva app. Severity of foliar symptom production was significantly correlated with extent of root system colonization by these fungi....
An evaluation of the efficacy of steam treatment on reducing levels of Fusarium, Cylindrocarpon, and
Trichoderma within styroblock containers was conducted at the Plum Creek Nursery in Pablo, Montana. Although levels, of both Fusarium and Cylindrocarpon were significantly reduced by cleaning, relatively high populations of both these fungi persisted after...
Investigations of containerized conifer seedling root diseases at the Champion Timberlands Nursery revealed that Fusarium oxysporum was most commonly isolated from seed, seedling roots, and styroblock containers. Amount of seed infection varied widely among the seedlots tested, but was usually below 5 percent. Runningwater rinses did not reduce amounts of...
Three hundred fifty Leach pine cells used to grow containerized conifer seedlings at the USDA Forest Service Nursery in Coeur d'Alene, Idaho, were sampled for Fusarium and Trichoderma colonization. Cells were either sampled prior to or after cleaning. Cleaning reduced Fusarium colonization from 86 percent of the cells to about...