Index Catalog // ScholarsArchive@OSU

Postemergence herbicides and take-all disease in winter wheat : alterations in the incidence and severity of disease and crop growth

Creator:: Geddens, Ray M.
Abstract:: Eight postemergence herbicides were evaluated to determine their influence on the incidence and severity of take-all disease caused by the fungus Gaeumannomyces graminis var. tritici in winter wheat. Mecoprop ((+)-2-(4-chloro-2-methylphenoxy)propanoic acid), difenzoquat (1,2- dimethyl- 3,5- diphenyl -1H- pyrazolium), dinoseb amine (amine salt of 2-(1-methylpropy1)-4,6-dinitrophenol), and diclofopmethyl (methyl ester of (+)-2-[4-(2,4-dichlorophenoxy)...
Resource Type:: Dissertation
Full Text:: : Redacted for Privacy Arnold P. Appleby Redacted for Privacy Robert L. Powelson Eight postemergence

Patterns in coastal marsh vegetation of the Juneau area, Alaska

Creator:: Stone, Catherine S.
Abstract:: A vegetation study was made of four coastal marshes near Juneau, Alaska. Results confirmed earlier studies' findings in southeast Alaska that communities or assemblages of species can be identified but from marsh to marsh these assemblages appear to have no consistent relationship to each other or to environmental "factors" such...
Resource Type:: Dissertation
Full Text:: . Harry K. Phinney, Professor of Botany; Dr. C. D. McIntire, Professor of Botany; and Dr. Arnold Appleby

Systematic and reproductive studies of Mimulus (Scrophulariaceae) in the Pacific Northwest : implications for conservation biology

Creator:: Meinke, Robert James
Abstract:: The Mimulus washingtonensis complex is a group of morphologically similar species centered in the Pacific Northwest. All are rare, and most are under consideration for listing as endangered. Morphometric and pollination data were used in developing a revised taxonomy for the group. Five species and two varieties are recognized. Mimulus...
Resource Type:: Dissertation
Full Text:: our meetings. The remaining members of my committee, Drs. Gerald Krantz, Arnold Appleby, and Donald

Bioindication of air quality in forests of northern and central California using epiphytic macrolichen communities

Creator:: Jovan, Sarah
Abstract:: The unifying purpose of this dissertation was to describe, model, and map relationships between epiphvtic macrolichen communities and air quality in Ibrests of northern and central California. First, multivariate analyses were used to subdivide the large study area into three model areas with similar climate, topography, and lichen communities: the...
Resource Type:: Dissertation
Full Text:: nieiiibet's, Pat Muir, Mary Santelmann, Janet Ohmann. and Richard Dick. for their support and encouragement

A taxonomic revision of Astragalus mokiacensis and allied taxa within the Astragalus lentiginosus complex of Section Diphysi

Creator:: Alexander, J. Andrew
Abstract:: North America, with over 400 species of Astragalus (Fabaceae), is one of three major centers of diversity, all of which comprise the majority of the nearly 1750 species of Astragalus worldwide. One of the most diverse species, Astragalus lentiginosus of Section Diphysi, is a polymorphic complex of over 40 varieties,...
Resource Type:: Dissertation

Growth and replacement patterns occuring among selected dominant species associated with plant succession on Douglas fir clear-cuts

Creator:: Robinson, Myles Canby
Abstract:: Growth and replacement patterns of four successionally important species occurring on Douglas fir clear-cuts were investigated from September 1964 to June 1967. The study was carried out on the Marys Peak watershed located near Corvallis, Oregon. Species used in the study include Holcus lanatus, Senecio jacobaea, Lotus crassifolius var. subglaber,...
Resource Type:: Dissertation

Purification and properties of the polygalacturonases produced by Fusarium oxysporum f. sp. lycopersici

Creator:: Harman, Gary Elvan, 1944-
Abstract:: This study was undertaken to determine the sorts of polygalacturonases present in the culture filtrate of Fusarium oxysporum f. sp. lycopersici, to purify and characterize these enzymes, and to study any complexes that may form between polygalacturonase and carbohydrate not degraded by the enzyme. The polygalacturonase in culture filtrate consists...
Resource Type:: Dissertation
Full Text:: Mary Jo Stratton for Gary Elvan Harman ACKNOWLEDGEMENTS I wish to thank Dr. M. E. Corden for his

Anatomical studies of Pinus ponderosa Laws : infested by Elytroderma deformans (Weir) Darker

Creator:: Wirtz, Felicia Pietrykowski
Abstract:: Pine needle blight of Pinus ponderosa Laws. caused by Elytroderma deformans (Weir) Darker is recognized by changes in the needles, in the bark and in the development of the branches. Anatomical studies of the host-parasite relation have been made previously on young pine tissue up to four years of age...
Resource Type:: Dissertation
Full Text:: Elytroderma deformans hyphae occur in sieve cells of the pri- mary phloem at the base of buds (Fig. 10

The influence of pollinators on the maintenance of mixed mating in a population of the blue columbine, Aquilegia coerulea (Ranunculaceae)

Creator:: Sweet, Heather R.
Abstract:: Pollination ecology may play an important role in the maintenance of selfing in populations of self-compatible hermaphroditic plants where both selfing and outcrossing occur (mixed mating). Behavior and abundance of pollinators can influence the two major modes of selfing; autogamy (selfing within a flower) and geitonogamy (selfing between flowers on...
Resource Type:: Masters Thesis
Full Text:: the assistance that Mary Meaker and Daniel DeJoode provided in the lab. The members of the Liston

Cytotaxonomic studies in the Artemisia ludoviciana polyploid complex of the Pacific Northwest

Creator:: Estes, James R.
Abstract:: The Artemisia ludoviciana polyploid complex is a highly polymorphic assembledge of eight taxa in the Pacific Northwest, with a chromosome base number of x=9. A cytogenetic analysis of this complex was carried out to determine the sources of its variation, the types of polyploidy present, and the genetic processes active...
Resource Type:: Dissertation

Bionomics of the hop cyst nematode, Heterodera humuli Filipjev, 1934 (Nematoda : Heteroderidae)

Creator:: Sen, Arun Kumar
Abstract:: The hop cyst nematode, Heterodera humuli Filipjev, 1934 was first reported from Europe in 1894, however, very little is known with respect to the biology and economic importance of this pest. Abundant material from Oregon hop yards provided an excellent opportunity to add additional details concerning the bionomics of this...
Resource Type:: Dissertation

The genus Anthracobia Boudier (Pezizales, Ascomycetes)

Creator:: Larsen, Harold J.
Abstract:: A taxonomic revision of the genus Anthracobia Boudier is presented. The genus and eight included taxa are described and figured. A discussion of the taxonomic criteria used to delimit the genus and the species is included, and a key to the recognized taxa is given. Four imperfect states for included...
Resource Type:: Dissertation
Full Text:: is presented August 14, 1975 Typed by Mary Jo Stratton for Harold J. Larsen, Jr. TO MY WIFE AND

Variation of drought resistance and root regeneration among genotypes of Port-Orford-cedar (Chamaecyparis lawsoniana)

Creator:: Sharpe, Jodie M.
Abstract:: Drought resistance among genotypes of Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murr.) Pan., Cupressaceae) seedlings was evaluated both in the field and in the greenhouse. Field water potentials (Ψ) of 5-year-old seedlings were measured at two high-elevation plantation sites where summer drought occurs. Measurements of Ψ were compared to survival two years...
Resource Type:: Masters Thesis

Succession and certain adaptive features of plants native to the sand dunes of the Oregon coast

Creator:: Kumler, Marion Lawrence, 1941-
Abstract:: The vegetation of the Oregon coast is characterized by a variety of stages of plant succession which are repeated widely throughout the sand dune area. During the years from 1960 to 1963 the gradation of upland sand dune succession was studied on 48 plots within a 150 mile section of...
Resource Type:: Dissertation
Full Text:: . According to the ordination these communities grade from the pri- mary, herbaceous plants to the near

Drivers of Soil Fungal Communities Across Three Tropical Rainforests in Panama

Creator:: Schappe, Tyler
Abstract:: Fungi play critical roles in ecosystem processes and interact with plant communities in mutualistic, pathogenic, and commensal ways. Fungal communities are thought to be influenced by both associated tree communities and soil properties. However, the relative importance of the biotic and abiotic drivers of soil fungal community structure and diversity...
Resource Type:: Masters Thesis
Full Text:: ., Mary, B., Revaillot, S. & Maron, P.A. (2011) Fungi mediate long term sequestration of carbon and

Contracting nucleolar vacuoles in somatic tobacco cells growing in microcultures

Creator:: Johnson, John Morris
Abstract:: Contracting nucleolar vacuoles are a general and consistent feature of somatic tobacco cells growing in microcultures. Nucleolar vacuoles were studied in cells from callus tissues of two single-cell clones, H-196 and H-239, of hybrid tobacco (Nicotiana tabacum X N. glutinosa). Vacuoles periodically contracted either completely or incompletely, apparently releasing a...
Resource Type:: Dissertation

Distribution of understory species in relation to maximum and minimum tree influence in the montane forest of the Central Oregon Cascades

Creator:: Robinson, Andrew Frederick, Jr.
Abstract:: Twenty sites of uniform topography and soil were select ed in the montane forest found on the East flank of the Central Oregon Cascades. These sites were located along a vegetational gradient composed of five plant communities: Abies/Pachistima, Pinus/Ceanothus, Pinus Arctostaphylos-Purshia, Pinus/Purshia/Festuca, and Juniperus Festuca. An attempt was made to...
Resource Type:: Dissertation
Full Text:: wife, Mary Ann, for typing, reading of the manuscript, and patient understanding, I am everlastingly

A systematic study of Lathyrus vestitus Nutt. ex T. & G. (Fabaceae) and allied species of the Pacific Coast

Creator:: Broich, Steven L.
Abstract:: Eight species of Lathvrus (Fabaceae, Faboideae) endemic to the Pacific Coast of North America were the subject of a systematic investigation. Taxa studied included Lathvrus vestitus, Nutt. ex T. & G., L. laetif lorus Greene, L.. iepsonii Greene, £,. splendens Kellogg, L. polvphvllus, Nutt. ex T. & G., L. holochlorus...
Resource Type:: Dissertation
Full Text:: ArVydas Grybauskas. Mary Allcott, W. Roderick and especially James R. Griffin graciously responded to

Copper and streptomycin resistance in Pseudomonas syringae isolated from Pacific Northwest nurseries

Creator:: Scheck, Heather J.
Resource Type:: Dissertation

Forest structure and regeneration in the Tsuga heterophylla - Abies amabilis transition zone, central Western Cascades, Oregon

Creator:: Stewart, Glenn H.
Abstract:: The dynamics of stands in the mid-elevation old-growth Douglas-fir (Pseudotsuga menziesii) forests of the central western Oregon Cascade Range were investigated using stand structure analysis. Trees with different growth rates were commonly present in the same stand, which resulted often in a weak correlation between tree diameter and age. Thus,...
Resource Type:: Dissertation
Full Text:: other people helped in so many ways during my stay in the U.S.A. To Fred and Mary Swanson, Doug and

Examination of the role host-selective toxins play in fungal-plant interactions

Creator:: Andrie, Rachael M.
Abstract:: Pyrenophora tritici-repentis, causal agent of tan spot of wheat, produces multiple host-selective toxins (HSTs), including Ptr ToxA, encoded for by ToxA, Ptr ToxB, encoded for by ToxB, and Ptr ToxC. Variable distribution of these three HSTs among different isolates of P. tritici-repentis, both singularly and in all possible combinations, defines...
Resource Type:: Dissertation
Full Text:: Dr. Mary Powelson for introducing me to Plant Pathology and believing that I could tackle a Ph.D

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