658 research outputs found

    Economic thresholds for western bean cutworms

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    In his book, Entomology and Pest Management, Larry Pedigo discusses economic thresholds and the foundation for their development and use. He states that one type of very common economic threshold is what entomologists know as the nominal threshold. A nominal threshold is one that is based upon a person\u27s understanding of the pest\u27s biology tied together with field experience, and it is rarely based on rigorous research. Nominal thresholds tend to be static--that is, unchanging with changes in crop value, control costs, or plant development stage

    Straw biomass - potential raw material for ethanol production

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    Barley straw was found to be suitable raw material for ethanol production. Straw could be easily pre-treated with steam explosion, hydrolysed to monosaccharides and fermented to ethanol. The optimum harvesting times for bio-ethanol raw material are at grain maturity for barley straw. Potential raw material, barley harvested at full ear emergence, when straw is rich in soluble sugars, need further research

    Quantitative and Qualitative Analysis by HPLC of Major Peganum harmala Alkaloids at Different Stages of Development

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    The analysis of major Peganum harmala alkaloids (harmaline, harmine, harmol and harmalol) has shown that the content of these secondary metabolites depends on the plant development stage. The qualitative and quantitative profile of major alkaloids change significantly between stems, leaves and roots. The roots and seeds are the richest and most diversified organs in these metabolites. The concentration of the major alkaloids in all organs increases during the first three weeks and stabilizes at a constant level during vegetative growth phase and then decline at the beginning of flowering. On the scale of the whole plant, major alkaloids concentration of P. harmala varies with the developmental stage of the plant between 21.16 and 26.96 mg/g and harmine remains the most abundant molecule. Optimum exploitation of these natural products from the P. harmala plant is possible if the harvest of plant material occurs during the vegetative growth phase and at the appropriate stage for the richest organ. Keywords: Peganum harmala, Plant growth, Alkaloids, Harmine, Harmaline, Harmol, Harmalo

    Industrial benefits and future expectations in materials and processes resulting from space technology

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    Space technology transfer is discussed as applied to the field of materials science. Advances made in processing include improved computer techniques, and structural analysis. Technology transfer is shown to have an important impact potential in the overall productivity of the United States

    Boron application in red clover (Trifolium pratense L.) seed production

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    peer-reviewedThis work is part of the research project TR-31016, funded by the Ministry of Science and Technological Development, Republic of Serbia.A field trial with four red clover cultivars was established on acid soil in order to evaluate the effect of foliar boron application on seed yield. The crop received foliar boron treatment during the second growth of the second year at two applications. Although seed yield showed a significant increase in boron-treated plants in 2011 compared with control (26.0%), its relative increase was far higher in 2010 (43.2%), which had increased total rainfall amounts during flowering. Sufficient level of boron supply to red clover plants for seed production has a remarkably positive effect under conditions hampering pollination and fertilisation.Ministry of Science and Technological Development, Republic of Serbi

    Urban, Forest, and Agricultural AIS Data: Fine Spectral Structure

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    Spectra acquired by the Airborne Imaging Spectrometer (AIS) near Lafayette, IN, Ely, MN, and over the Stanford University campus, CA were analyzed for fine spectral structure using two techniques: the ratio of radiance of a ground target to the radiance of a standard and also the correlation coefficient of radiances at adjacent wavelengths. The results show ramp like features in the ratios. These features are due to the biochemical composition of the leaf and to the optical scattering properties of its cuticle. The size and shape of the ramps vary with ground cover

    The Plant Ontology facilitates comparisons of plant development stages across species

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    The Plant Ontology (PO) is a community resource consisting of standardized terms, definitions, and logical relations describing plant structures and development stages, augmented by a large database of annotations from genomic and phenomic studies. This paper describes the structure of the ontology and the design principles we used in constructing PO terms for plant development stages. It also provides details of the methodology and rationale behind our revision and expansion of the PO to cover development stages for all plants, particularly the land plants (bryophytes through angiosperms). As a case study to illustrate the general approach, we examine variation in gene expression across embryo development stages in Arabidopsis and maize, demonstrating how the PO can be used to compare patterns of expression across stages and in developmentally different species. Although many genes appear to be active throughout embryo development, we identified a small set of uniquely expressed genes for each stage of embryo development and also between the two species. Evaluating the different sets of genes expressed during embryo development in Arabidopsis or maize may inform future studies of the divergent developmental pathways observed in monocotyledonous versus dicotyledonous species. The PO and its annotation databasemake plant data for any species more discoverable and accessible through common formats, thus providing support for applications in plant pathology, image analysis, and comparative development and evolution

    Parâmetros morfoanatómicos foliares de Arundo donax e eficácia do glifosato

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    Cuticle thickness is known to affect the amount of active ingredient that reaches the target site of a post emergence herbicide and consequently its efficacy. So, this work aimed to relate glyphosate efficacy with the thickness of leaf cuticle of young and mature leaves of Arundo donax. Glyphosate was applied at different development stages of the invasive species, in spring, summer and autumn at the concentrations of 0.675; 1.350 and 2.025 g L-1. Cuticle thickness of mature and young leaf blade and leaf sheath was measured on transverse sections by light microscopy. Despite the significant differences in the cuticle thickness between young and mature leaves, this did not seem affect the efficacy of glyphosate uptake since no significant differences were observed between young and mature leaves glyphosate treatments. But herbicide efficacy was dependent of the plant development stage. Higher efficacy of glyphosate was recorded when plots were sprayed at the end of October (flowering) compared to end April and mid June applications. Mortality of giant reed was higher than 90% one year after treatment only in autumn treatments. This result suggests that other mechanisms are involved, probably the reserves carrying over to rhizomes, on herbicide efficac

    Lyophilization as a method for pathogens long term preservation

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    Lyophilization (freeze-drying) is one of the most suitable methods used for a long term preservation of pathogens. The aim of this paper was the application of lyophilization for storage of three significant plant pathogens: Fusarium graminearum, Helminthosporium gramineum, and Pseudomonas syringae pv. gylicinea, respectively. The plant material was collected continuously (during a four year period 2002-2006), depending on a plant development stage, from different localities in Vojvodina. Pathogens were isolated from diseased parts with characteristic symptoms, and placed on nutritive media specific for a certain pathogen, using standard phytopathological methods. Lyophilization was carried out in marked and coded ampoules by freezing and drying of pathogen suspension and nutritive medium. Revitalization of lyophilized isolates was done after four days. High percentage of revitalization was characteristic for all studied isolates, and it ranged from 85-92%, confirming that lyophilized pathogens would be capable of keeping viability for a long time in the collection. Besides above mentioned pathogens, there were 200 isolates in the collection, originating mostly from field and vegetable crops. Each isolate that was put into the Collection, was followed by all the necessary data such as: name of the pathogen, number of isolates, locality, host plant year of isolation, name of the researcher and other relevant data
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