In the Pacific Northwestern United States, the hop powdery mildew fungus, Podosphaera macularis, survives overwintering periods in association with living host tissue because the ascigerious stage of the pathogen is not known to occur in this region. Field experiments were conducted over a 5-year period to describe the overwintering process...
Crown gall can develop on grapevines wounded by freezing temperatures, mechanical damage or grafting. Pathogenic agrobacteria residing within the vascular system are able to initiate tumor growth in damaged plant cells. Sampling from 21 sites in Oregon vineyards and nurseries yielded diverse populations of pathogenic agrobacteria. Most of the pathogenic...
Crown gall infected and healthy Kalanchoe pinnata (Lam.)
Persoon plants were analyzed for soluble amino acids. Specifically
the amino acids in young leaf, mature leaf, stem, root, and gall
tissues were quantitatively measured. The plants were inoculated
with the bacterium, Agrobacterium tumefaciens (Smith and Townsend)
Conn., on one side of...
Crown gall can develop on grapevines wounded by freezing temperatures, mechanical damage or grafting. Increased demand for grape varieties grafted to phylloxera resistant rootstocks has led to increased incidence of crown gall at graft unions. Therefore a search for plant material that is resistant to crown gall has been undertaken....
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...
Transition matrix models are one of the most widely used tools for assessing population viability. The technique allows inclusion of environmental variability, thereby permitting estimation of probabilistic events, such as extinction. However, few studies use the technique to compare the effects of management treatments on population viability, and fewer still...
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,...