Longevity and germination of seed of western dwarfmistletoe (Arceuthobium campylopodum Engelm. f. campylopodum) of ponderosa
pine (Pinus ponderosa Laws.) was investigated to determine:
1) the influence of humidity and temperature on seed viability and
deterioration during storage; 2) the physiology of seed dormancy;
3) the composition of seed reserve food...
A comparative study was made of Pinus ponderosa Laws, and
Arceuthobium campylopodum Engelm. f . campylopodum to determine
(1) whether or not the parasite or parasitized tissues accumulate
abnormal concentrations of minerals, (2) whether or not there
was evidence of a blockage of mineral translocation in the phloem
because of...
A study was undertaken to determine the reliability of the formation
of a line of demarcation between paired cultures of Fomes
cajanderi Karst. as an indicator of dissimilar compatibility genotypes.
The results were applied to an assay of the number and location of
compatibility genotypes in each of four glaze-damaged,...
The Pacific Coast form of Douglas-fir in natural forest succession
is an intermediate species thriving in the Coast Range and
Cascade Mountains of the Pacific Northwest. This species constitutes
26 percent of the standing timber in the United States, and 24 percent
of the nation's annual timber harvest. Characteristics of...
This study concerns factors affecting production and survival
of ascospores of Elytroderma deformans (Weir) Darker, a needle
cast of ponderosa pine (Pinus ponderosa Laws.).
The results show that summer cooling and a reduction in host
vigor delays and diminishes the number of fertile hysterothecia
produced. Evidence is offered for classification...
Numerous isolates of Armillaria mellea were obtained within
a 250 by 450 foot Study Area in a ponderosa pine plantation in central
Oregon. These isolates were recovered from roots of armillaria-killed
young-growth pine, from large stumps of the former pine
overstory, including roots away from the stump proper, and from...
Root rot of ponderosa pine caused by Armillaria mellea was
studied in a pine forest that had been under management for 30 years
in Klickitat County, Washington. Information sources included
disease survey, detailed observation and description of specific
disease situations, and examination of roots in situ and removed.
Roughly circular...
In 1967, Lophodermella morbida Staley and Bynum, a recently described
hypodermataceous needle-cast fungus, became destructively
epidemic in a knobcone pine (Pinus attenuata Lemm.) plantation in
Del Norte County, California, and in several ponderosa pine (P.
ponderosa Laws.) plantations in western and southwestern Oregon.
This thesis presents information on this currently...
Phytophthora lateralis Tucker and Milbrath, causal agent of a serious fungus root rot of Chamaecyparis lawsoniana, has seriously damaged natural stands in southwestern Oregon forests and affected ornamentals throughout the Pacific Northwest. Progress with an effective control program in the field has been limited by lack of critical knowledge of...
Western dwarf mistletoe (Arceuthobium campylopodum Engelm.
1. campylopodum) is a parasite of ponderosa pine (Pinus ponderosa
Laws. ). The objectives of this investigation are: (a) to formulate a
mathematical description of the process of dwarf mistletoe disease
spread in a pine forest, (b) to use this description to predict the...
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...
Chamaecyparis lawsoniana, an extremely valuable timber tree
species, is highly susceptible to a serious, soil -borne root disease
caused by Phytophthora lateralis. Disease outbreaks of epidemic
proportions are continually causing high mortality in natural stands
of the host tree. Practical control measures rely on an understanding
of the many factors...
Root rot due to Armillariella mellea (Vahl. ex Fr.)
Karst. is unusually severe in ponderosa pine near Glenwood,
Washington. Isolate relations, clonal variability, vegetation
patterns, and climate were examined in relation to
severity of disease in this area.
Ninety-one isolates from 70 infection centers were
examined. Pairings of neighboring isolates...
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...
The root pathogen, Phytophthora lateralis Tucker and Milbrath,
continues its destructive spread among Port-Orford Cedars (Chamaecyparis
lawsoniana (Murr.) Parl.) of southwestern Oregon. This
thesis concerns spread of the fungus between root systems of
individual trees in a 49-year-old stand predominantly of Port-Orford-
Cedar. The contribution of root grafts to spread...
Infection courts for microorganisms invading white fir heartwood were determined to be primarily branches and basal wounds. Of 11 hymenomycetes isolated from infected trees, only four: Echinodontiurn tinctorium, Phellinus chrysoloma, Pholiota adiposa, and Hericium abietis were of major significance in terms of frequency of infection and damage caused. Two or...
The effects of dwarf mistletoe on fuel in precommercial ponderosa pine stands: Dwarf mistletoe and healthy stands were sampled by vertical planar intercept and whole tree biomass sampling techniques to measure
fuel loading in ground and crown fuels. Differences in size, distribution, and vitality of fuel were shown to depend...
The pathogenicity of A. flavus on alkali bee larvae was studied
using sample materials from three nesting sites of these soil
inhabiting bees along the Oregon-Washington state line. Soil
saprophytes of the biosphere of the alkali bee were also studied.
Field observations and direction of soil cores from bee beds...
A method is described for determining the partition coefficient, K, for radon gas
distributed between an aqueous phase and an organic solvent. The method uses
sequential extractions of radon into equal volume aliquots of organic solvent. The
radon-laden organic liquid is then counted on a liquid scintillation analyzer with alpha-beta...