22,622 research outputs found

    Cereal Leaf Beetle (Coleoptera: Chrysomelidae) and Winter Wheat: Host Plant Resistance Relationships

    Get PDF
    The cereal leaf beetle was introduced into North America from Europe prior to 1960. An overview of the control of the insect in North America is presented with major emphasis on host plant resistance. The length and density of the adaxial trichomes (pubescence or leaf hairs) convey resistance to wheat, and the amount of resistance can be estimated mathematically without the insect being present

    Economic Thresholds for Central European and North American Wheat Insects

    Get PDF
    The economic thresholds for implementing control of 24 wheat insect pests from Central Europe and North America are discussed. Additional studies on wheat pests are necessary to better define the existing thresholds

    Insects Taken at Japanese Beetle Traps Baited with Anethole-Eugenol in Southern Michigan in 1968

    Get PDF
    A survey of the populations of Jap.anese beetles, Popillia japonica Newman, is made each year in southern Michigan to determine the abundance and distribution of this pest insect. Since little information is available about the insects that are attracted by Japanese beetle attractants in Michigan or anywhere in the United States, a study was made of the insects captured in Japanese beetle traps

    Method for analyzing radiation sensitivity of integrated circuits

    Get PDF
    A method for analyzing the radiation sensitivity of an integrated circuit is described to determine the components. The application of a narrow radiation beam to portions of the circuit is considered. The circuit is operated under normal bias conditions during the application of radiation in a dosage that is likely to cause malfunction of at least some transistors, while the circuit is monitored for failure of the irradiated transistor. When a radiation sensitive transistor is found, then the radiation beam is further narrowed and, using a fresh integrated circuit, a very narrow beam is applied to different parts of the transistor, such as its junctions, to locate the points of greatest sensitivity

    Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (North Atlantic): American oyster

    Get PDF

    Tillering Response of \u27Monon\u27 And \u27Newton\u27 Winter Wheats Infested With Biotype L Hessian Fly (Diptera: Cecidomyiidae) Larvae

    Get PDF
    Two wheat, Triticum aestivum, cultivars that differed in their ability to tiller were infested by ovipositing Hessian flies, Mayetiola destructor, under similar controlled conditions. Since a larva typically stunts and kills the stem where it feeds and develops, tiller development of fly infested-wheat seedlings is an important plant trait relative to grain yield. \u27Monon\u27 tillered more than \u27Newton at the 0 infestation level (control). \u27Monon\u27 had about the same number of tillers at 0, 1, 2, and 3 puparia (indicative of the number of feeding larvae) per plant; and \u27Newton\u27 had fewer tillers at 0 than 1, 2, or 3 puparia per stem. However, tillering of both cultivars was less at 4 or more puparia per stem, perhaps due to the depletion of plant nutrients. In general, for both cultivars there was a decrease in leaf length, number and wet weight as the number of puparia increased per tiller

    Resistance Stability of the Secondary Tiller of \u27Caldwell\u27 Wheat After the Primary Culm Was Infested With Virulent Hessian Fly (Diptera: Cecidomyiidae) Larvae

    Get PDF
    Secondary tiller resistance of \u27Caldwell\u27 wheat, Triticum aestivum, with the H6 gene for larval resistance to Hessian fly, Mayetiola destructor, was maintained, after the primary culm had been previously infested with virulent larvae. Earlier studies showed that a primary culm infested initially with a virulent larva allowed subsequent normally avirulent larvae to survive on that cultivar; however, in our study the resistance of secondary tillers was mainained even though the primary culm was infested earlier with virulent Hessian fly larvae. This gene stability for resistance is important for optimizing wheat yield of those cultivars that possess genes resistant to the Hessian fly that are tillering and infested with different biotypes

    Spatial Concentration of Institutional Property Ownership: New Wave Atomistic or Traditional Urban Clustering

    Get PDF
    NCREIF investors acquire property in counties that meet socioeconomic filtering criteria. In contrast to atomistic predictions, these investors acquire their apartment buildings, offices, retail facilities, and warehouses in density clusters. These clusters follow a model of a negative exponential demand curve, a model that previously explained the technologically caused density gradient of urban areas. Institutional investors signal their belief that clustering of properties is a value dimension.

    Agroecological aspects of evaluating agricultural research and development:

    Get PDF
    In this paper we describe how biophysical data can be used, in conjunction with agroecological concepts and multimarket economic models, to systematically evaluate the effects of agricultural R&D in ways that inform research priority setting and resource allocation decisions. Agroecological zones can be devised to help estimate the varying, site-specific responses to new agricultural technologies and to evaluate the potential for research to spill over from one agroecological zone to another. The application of agroecological zonation procedures in an international agricultural research context is given special attention.Agricultural research., Technological innovations., Agricultural economics and policies.,
    corecore