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...
Mortality of containerized western white pine seedlings outplanted on the Bonners Ferry Ranger District, Idaho Panhandle National Forests, was probably due to extensive root infection by Fusarium oxysporum. Diseased seedlings had chlorotic foliage, needle tip dieback, and severe twisting of the needles that indicated wilting. Most root tips of diseased...
Needlecast caused by Meria laricis caused serious losses of 2-0 bareroot western larch during 1983 at the USDA Forest Service Nursery, Coeur d'Alene, Idaho. Cool, wet weather throughout the spring and summer of 1983 was ideal for disease buildup and spread. Control attempts with fungicides were largely unsuccessful because of...
Five seedlots of Colorado blue spruce and three seedlots of Black Hills spruce were sampled for Fusarium contamination. All seedlots contained some seed and/or debris with Fusarium. Levels of contamination were greatly reduced by treating seed with running water rinses for 48 hours or with chemical sterilants such as sodium...
A root disease evaluation was completed for the Ducharme logging unit near the southeast corner of Flathead Lake. Extensive root disease was found on Douglas-fir throughout the unit. The major pathogen on the site was Armillaria meilea. Black stain (Verticicladiella sp.) was isolated from one tree which was also infected...
An impact survey to determine extent and distribution of root disease centers was completed for the Nezperce National Forest, Idaho, in 1980. Lowlevel
color infrared photography was used to delineate root disease centers
within National Forest inventory subcompartments. Suspected root disease
centers were ground checked to determine associated fungi and...
Two methods attempting to stop marginal spread of a root disease center in Douglas-fir were evaluated within the Flathead Indian Reservation, Montana. The first method was to cut all living trees within a 1-chain strip outside the edge of the infestation. The second method was to uproot all trees for...
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...
Six fungicides were evaluated to control Botrytis blight of western 41 larch in seedbeds at the Coeur d'Alene Nursery. Fungicides were applied at biweekly intervals during the spring of 1982; test seedlings were inoculated with spores of B. cinerea twice during the evaluation period. Seedling mortality and height were recorded...