Die Wirkung elektromagnetischer Stimulation auf den Keimungsprozess von Weizen     

Branko Marinkovic  Miroslav Maleševic  Jovan Crnobarac  Hans-Jürgen Schaller  Franz Götz  Olaf Röder  Goran Jacimovic 《Gesunde Pflanzen》2003,55(6):187-190

  相似文献   

Die Biophysik in der Wachstumsfunktion von jungen Maispflanzen     

Branko Marinkovic  Novica Petrovic  Jovan Crnobarac  Hans-Jürgen Schaller  Franz Götz  Olaf Röder  Goran Jacimovic 《Gesunde Pflanzen》2003,55(6):184-186

  相似文献   

Der Einsatz von Trichogramma-Schlupfwespen in Deutschland     

Olaf Zimmermann 《Gesunde Pflanzen》2004,56(6):157-166

The use of Trichogramma egg parasitoids has further increased. T. brassicae, released against the European Corn Borer Ostrinia nubilalis, holds the largest share in Germany with 11,000 hectare. For small-scale fruits crops the commercial use of T. cacoeciae and T. dendrolimi against the Codling Moth (Cydia pomonella) and the Plum Moth (Grapholita funebrana) has been expanded. Trichogramma species are also being offered for controlling the vine moths, Lobesia botrana and Eupoecilia ambiguella on grapevine in homegardens. A strain of T. evanescens is available against cabbage pests, especially noctuids. Research has been conducted on the biological control of Autographa gamma in spinach, as well as of the Pea Moth (Cydia nigricana) and the Leek Moth (Acrolepiopsis assectella) in organic farming. Trichogramma is also important for the biocontrol of exotic pests in greenhouses. These are often polyphagous pests that have been introduced together with ornamental plants, such as Duponchelia fovealis and Clepsis spectrana. The Carnation Tortrix (Cacoecimorpha pronuba) was successfully controlled by Trichogramma in the field. The use of Trichogramma has been further established for the control of storage pests. T. evanescens is used against the Indian Meal moth (Plodia interpunctella) in stored cereal products. Other target pests in storage environments are Ephestia kuehniella and Sitotroga cerealella. In addition, Trichogramma species have been tested for the control of the Common Cloths Moth (Tineola bisselliella) under laboratory conditions. The range of target pests for Trichogramma egg parasitoids has therefore increased considerably in research and commercial applications in Germany.  相似文献   

Validation of the periodicity of growth zone formation in the otoliths of four fish species from the Upper Zambezi ecoregion,southern Africa     

Geraldine C Taylor  Richard A Peel  Clinton J Hay  Olaf LF Weyl 《African Zoology》2016,51(3):153-159

In the Upper Zambezi and Okavango ecoregions, Brycinus lateralis, Hepsetus cuvieri, Schilbe intermedius and Serranochromis macrocephalus are important in subsistence fisheries, while S. intermedius and S. macrocephalus are often caught in commercial catches. Despite their importance, there is little information on their age and growth and age validation. Growth zone deposition rate in otoliths of B. lateralis, H. cuvieri, S. intermedius and S. macrocephalus was validated as annual using edge analysis in this study. Annual deposition of growth zones was corroborated by a fluorochrome marking experiment. Both methods demonstrated that one growth zone was deposited annually. Edge analysis demonstrated that the highest proportion of opaque zones was detected between August and December, most likely as a result of slow growth during lower temperature water during the preceding winter. With growth zone deposition validated as annual, future research should focus on determining the growth, maturity and mortality rates of these species, parameters which are important for their management.  相似文献   

Intensification or extensification? Factors affecting technology use in peri-urban lowlands along an agro-ecological gradient in West Africa     

Olaf Erenstein   《Agricultural Systems》2006,90(1-3):132-158

The paper analyses whether the increased use of lowlands in proximity to urban centres in West Africa is associated with technological intensification or extensification. Technologies are typified in terms of their orientation – land or labour saving – and market dependence for their procurement and reviews the factors driving and modifying their use in lowlands. The factors associated with technology use are analyzed empirically using geo-referenced lowland data around four urban centers along an ecological gradient in Côte d’Ivoire and Mali. The technologies analyzed include both external inputs (fertilizer, pesticide, herbicide, improved varieties) and crop management practices (plot level bunding, rice transplanting and rice direct seeding). Results from binomial logit models highlight the prominent positive and non-linear role of proximity to urban markets for the technological intensification of lowlands – an issue associated with factor scarcities and the transaction costs for procurement and marketing. Technology use in lowlands is also associated with the agro-ecological gradient, lowland development and non-native lowland users. A common thread linking these variables is that they modify resource scarcity and therefore intensification incentives. Lowlands are not always as valuable as they may seem and there may be limited incentives to intensify. Instances of significant lowland cultivation and intensification in the study sites tend to be associated with specific opportunities – driven by market opportunities and modified by seasonal, institutional or development-induced relative land scarcity. Market access is therefore a necessary but not sufficient factor for the technological intensification of lowland use. There is a need for better targeting of development efforts in terms of enabling lowland intensification or extensification as appropriate.  相似文献   

The occurrence of Echinococcus multilocularis in red foxes in lower Saxony: identification of a high risk area by spatial epidemiological cluster analysis     

Berke O  von Keyserlingk M  Broll S  Kreienbrock L 《Berliner und Münchener tier?rztliche Wochenschrift》2002,115(11-12):428-434

There is considerable interest in the spatial distribution of Echinococcus multilocularis in red foxes (Vulpes vulpes L.), because this parasite causes the zoonoses of alveolar echinococcosis which is potentially of high fatality rate. High risk areas are known from France, Switzerland and the Swabian Alb in Germany for a long time. In this work, the spatial scan statistic is introduced as an instrument for identification and localisation of high risk areas, so called disease clusters in spatial epidemiology. The use of the spatial scan statistic along with data about the distribution of the parasite in 5365 red foxes in Lower Saxony, that were collected during 1991 to 1997, led to the identification of another high risk area. The relative risk for this disease cluster is approximated by RR = 5.03 (CI0.95(RR) = [4.27; 6.58]) for the period of 1991 to 1994 and by RR = 4.45 (CI0.95(RR) = [3.53; 5.59]) for the period of 1994 to 1997, respectively.  相似文献   

Statistics for Veterinary and Animal Science, 2nd ed.          下载免费PDF全文

Olaf Berke 《The Canadian veterinary journal. La revue veterinaire canadienne》2007,48(8):867

  相似文献   

Encomium     

Weyl H 《Science (New York, N.Y.)》1946,103(2669):216-218

  相似文献   

Vorläufige Untersuchungsergebnisse über die Lebensweise des PappelknospenwicklersSemasia oppressana Tr. und des PappeltriebwicklersSemasia aceriana Dup.     

Olaf Anders 《Journal of pest science》1958,31(7):101-107

Ohne ZusammenfassungDie vorliegenden Untersuchungen wurden auf Anregung von Herrn Prof. Dr.-Ing. E. Schimitschek und mit Unterstützung der Landesforstverwaltungen Hessen und Schleswig-Holstein durchgeführt.  相似文献   

Silicon reduces slug feeding on wheat seedlings     

Griffin  Mark  Hogan  Brian  Schmidt  Olaf 《Journal of pest science》2015,88(1):17-24

Journal of Pest Science - Slugs are a serious pest of cereal crops, and recent emphasis in slug pest management has shifted from solely chemical towards integrated approaches. The objective of the...  相似文献