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Filtering by: Creator DeRuiter, S. L. Remove constraint Creator: DeRuiter, S. L. Academic Affiliation Botany and Plant Pathology Remove constraint Academic Affiliation: Botany and Plant Pathology Decade 1960-1969 Remove constraint Decade: 1960-1969

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  • Etiological studies on foot rot of wheat caused by Cercosporella herpotrichoides Fron.

    Creator:
    Byther, Ralph S.
    Abstract:
    Abundant conidial production occurs from colonized straws and plants infected with Cercosporella herpotrichoides Fron during the cool moist months of the growing season. Experiments were designed to study the survival, inoculum potential and competitive saprophytic ability of conidia in soil. Laboratory results indicated that cool moist soil favors the saprophytic...
    Resource Type:
    Dissertation
    Full Text:
    Robert L. Powelson Abundant conidial production occurs from colonized straws and plants infected with

  • Development of the storage organ of Brassica campestris L.

    Creator:
    Larson, Ann Marie
    Abstract:
    Developmental changes in the storage organ of Brassica campestris L. were followed from the organization of the embryonic radicle and hypocotyl to the mature storage organ. Three independent primary meristems gave rise to the cortex, the stele, and the root cap-epidermis. The primary development is typical of the Cruciferae. Cambial...
    Resource Type:
    Dissertation
    Full Text:
    Development of the storage organ of Brassica campestris L

  • Physiology of senescence of the shoot apex in Pisum sativum L.

    Creator:
    Ecklund, Paul Richard, 1941-
    Abstract:
    Shoot apex senescence is defined as the collective progressive and deteriorative processes which ultimately terminate the functional life of the shoot apex. Senescence of shoot apices of Pisum sativum L. 'Alaska' as measured by cessation of stem elongation was delayed by removal of flowers and by treatment with gibberellin A₃...
    Resource Type:
    Dissertation
    Full Text:
    sativum L. AN ABSTRACT OF THE THESIS OF PAUL RICHARD ECKLUND for the (Name) Ph. D. (Degree) in

  • Comparative gibberellin relationships in tall and dwarf peas (Pisum sativum L.)

    Creator:
    Anderson, James David
    Abstract:
    Experiments were performed to determine whether a direct correlation exists between the growth rates of tall and dwarf peas grown either in the light or in the dark and endogenous gibberellin (GA) content. Three separate but related experimental approaches were utilized: (1) the determination of possible qualitative and /or quantitative...
    Resource Type:
    Dissertation
    Full Text:
    use 12 -day- old seedlings for extraction of GA's, since at t h i s a g e a l l foil]: kinds of

  • Hybridization between Arctostaphylos viscida and A. canescens in Oregon

    Creator:
    Gottlieb, Leslie D., 1936-
    Abstract:
    Arctostaphylos viscida Parry and A. canescens Eastw., two well-known and frequently encountered manzanitas in the Siskiyou Mountains in southwestern Oregon, are shown to hybridize and to produce an extensive series of morphological intermediates. The hybridization occurs wherever populations of these two species meet at contact zones of serpentine and non-serpentine...
    Resource Type:
    Masters Thesis
    Full Text:
    . chryso- phylla 3800 ?s. menziesii, lambertiana, L. decurrens, g. vaccinifolia, L. densiflora, Ç

  • Nature of resistance to Verticillium dahliae Kleb. in strains of peppermint (Mentha piperita L.) developed by irradiation

    Creator:
    Sherrod, Leslie Lynn, 1940-
    Abstract:
    Verticillium dahliae Kleb. causes a wilt disease of peppermint. Attempts to control the disease by soil fumigation, crop rotation, flaming of stubble, and deep plowing have met with only limited success. Development of resistant varieties through conventional breeding procedures is difficult because commercial peppermint is male-sterile. Several strains of commercial...
    Resource Type:
    Dissertation
    Full Text:
    Title: NATURE OF RESISTANCE TO VERTICILLIUM DAHLIAE KLEB. IN STRAINS OF PEPPERMINT (MENTHA PIPERITA L

  • Origin and distribution of polyploid Achillea (Compositae) in western North America

    Creator:
    Tyrl, Ronald J.
    Abstract:
    A cytogeographical study was made of populations of tetraploid (n=18) and hexaploid (n=27) Achillea millefolium (Compositae- Anthemideae) from the Pacific Coast states. There is a complex distributional pattern, involving overlapping ranges, mixed populations, migration of one form into areas occuplied by the other, pentaploid hybrids, and septaploid and octoploid plants....
    Resource Type:
    Dissertation
    Full Text:
    Rogue R. S. III nois R. 445 A.II! 428 l AA \--\'' A tA Medford 512 Klamath Falls OREGON

  • Factors affecting development of iris rhizome rot caused by Botrytis convoluta Whetzel and Drayton

    Creator:
    Maas, J. L.
    Abstract:
    Abundant conidial and sclerotial production occurs on iris plants infected with Botrytis convoluta Whetzel and Drayton during the cool moist months of the year. Experiments were designed to study the survival and inoculum potential of conidia and sclerotia. Basic nutritional requirements of the fungus in culture were also studied. Results...
    Resource Type:
    Dissertation
    Full Text:
    DRAYTON Abstract approved: Robert L. Powelson Abundant conidial and sclerotial production occurs on

  • The effects of DMSO on wound periderm formation in potato tuber tissue

    Creator:
    Davidson, Roy M., 1939-
    Abstract:
    A study was conducted to determine the influence of DMSO (dimethyl sulfoxide) on suberization and wound periderm formation in cut potato tuber tissue, and to determine the effectiveness of DMSO as a potato seedpiece treatment for prevention of seedpiece decay in the field. The influences of tuber storage conditions, varieties,...
    Resource Type:
    Masters Thesis
    Full Text:
    Tuber Tissue AN ABSTRACT OF THE THESIS OF Roy Merle Davidson, Jr. for the M. S. (Name) (Degree

  • The parasite Aspergillus flavus Link and other fungi of the biosphere of the alkali bee Nomia melanderi Ckll., in eastern Oregon and Washington

    Creator:
    Baker, Gerald Merritt
    Abstract:
    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...
    Resource Type:
    Dissertation
    Full Text:
    ALKALI BEE NOMIA MELANDERI CKLL. , IN EASTERN OREGON AND WASHINGTON Abstract approved: L. F. Roth The