Diagnosis of the bacterial ring rot of the potato     

Walter H. Burkholder 《American Journal of Potato Research》1942,19(10):208-212

  相似文献   

Der Einfluß verschiedener N-Formen und N-Mengen auf Pflanzenertrag und Bodenreaktion in einem langjährigen Düngungsversuch: 1. Mitteilung: Einfluß auf den Pflanzenertrag     

Gerhard Kolbe  Horst Scharf 《Archives of Agronomy and Soil Science》2013,59(2):103-114

  相似文献   

Abstracts of papers presented at the 9th meeting of the international council for the study of viruses and virus diseases of the grapevine     

William B. Hewitt  Marc Fuchs  Bernard Walter  Monique Pinck  Lothaire Pinck  G. Belli  P. A. Bianco  A. Fortusini  Giovanni Granata  Anna Appiano  et al. 《Phytoparasitica》1989,17(1):57-78

  相似文献   

Structure-activity relationships of triazinone herbicides on resistant weeds and resistant Chlamydomonas reinhardtii     

Walter Oettmeier  Ursula Hilp  Wilfried Draber  Carl Fedtke  Robert R. Schmidt 《Pest management science》1991,33(4):399-409

Weeds resistant to the s-triazine herbicide atrazine also show resistance to the triazinone herbicide metribuzin. However, with highly lipophilic triazinones, thylakoids isolated from atrazine-resistant Amaranthus retroflexus (mutation at position Ser₂₆₄ of the photosystem II D-1 reaction centre protein) in general show a higher pI₅₀ value in photosystem II electron transport than those from the wild type (i.e. negative cross-resistance; ‘supersensitivity’). A quantitative structure–activity relationship (QSAR) can be established, wherein the lipophilicity of the compound plays a major role. In in-vivo experiments, it was found that the triazinone DRW2698 killed resistant Amaranthus retroflexus and Chenopodium album whereas the wild type was almost unaffected. Triazinones were further investigated in five different mutants of Chlamydomonas rheinhardtii (mutations in the D-1 protein at positions Ser₂₆₄, Ala₂₅₁, Leu₂₇₅, Phe₂₅₅, and Val²¹⁹). Inhibitory activity of all triazinones was generally enhanced in the Phe₂₅₅ mutant but decreased in the Val₂₁₉ mutant. In the other mutants, biological activity was decreased when position 3 of the triazinone was substituted by CH₃, OCH₃, SCH₃, NHCH₃ or N(CH₃)₂. However, negative cross-resistance was again observed when this position was occupied by free thiol. It is therefore suggested that these two groups of triazinones orient themselves differently within the herbicide binding niche of the photosystem II D-1 protein.  相似文献   

Biochemical and toxicological differences in the modes of action of the benzoylureas     

Rainer Neumann  Walter Guyer 《Pest management science》1987,20(2):147-156

The two insecticidal benzoylurea compounds, diflubenzuron and chlorfluazuron, show large differences in their toxicity against the larvae of insects like the tobacco budworm, Heliothis virescens, or the Egyptian cotton leafworm, Spodoptera littoralis, chlorfluazuron being about 100 times more toxic. This difference is due mainly to a much faster metabolism of diflubenzuron. Its half-life within the larvae is about 5 h, compared to about 50 h for chlorfluazuron. Chlorfluazuron is also the much better ovicide of the two, following injection of the compounds into the females of H. virescens. Again the difference in the rate of metabolism is the main cause. The rate of excretion of the parent benzoylureas is relatively low, but their metabolites are excreted very quickly.  相似文献   

Induced Disease Resistance in Plants by Chemicals   总被引：23，自引：0，他引：23  

Michael Oostendorp  Walter Kunz  Bob Dietrich  Theodor Staub 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(1):19-28

Plants can be induced locally and systemically to become more resistant to diseases through various biotic or abiotic stresses. The biological inducers include necrotizing pathogens, non- pathogens or root colonizing bacteria. Through at network of signal pathways they induce resistance spectra and marker proteins that are characteristic for the different plant species and activation systems. The best characterized signal pathway for systemically induced resistance is SAR (systemic acquired resistance) that is activated by localized infections with necrotizing pathogens. It is characterized by protection against a broad range of pathogens, by a set of induced proteins and by its dependence on salicylic acid (SA) Various chemicals have been discovered that seem to act at various points in these defense activating networks and mimic all or parts of the biological activation of resistance. Of these, only few have reached commercialization. The best- studied resistance activator is acibenzolar-5-methyl (BION). At low rates it activates resistance in many crops against a broad spectrum of diseases, including fungi, bacteria and viruses. In monocots, activated resistance by BION typically is very long lasting, while the lasting effect is less pronounced in dicots. BION is translocated systemically in plants and can take the place of SA in the natural SAR signal pathway, inducing the same spectrum of resistance and the same set of molecular markers. Probenazole (ORYZEMATE) is used mainly on rice against rice blast and bacterial leaf blight. Its mode of action is not well understood partly because biological systems of systemically induced resistance are not well defined in rice. Treated plants clearly respond faster and in a resistant manner to infections by the two pathogens. Other compounds like beta-aminobutyric acid as wdl as extracts from plants and microorganisms have also been described as resistance inducers. For most of these, neither the mode of action nor reliable pre-challenge markers are known and still other pathways for resistance activation are suspected. Resistance inducing chemicals that are able to induce broad disease resistance offer an additional option for the farmer to complement genetic disease resistance and the use of fungicides. If integrated properly in plant health management programs, they can prolong the useful life of both the resistance genes and the fungicides presently used.  相似文献   

Paul e. Nelson, 1927 to 1996     

Tammen JF  Toussoun TA  Horst RK  Burgess LW  Marasas WF 《Phytopathology》1999,89(12):1126

  相似文献   

Spatial and stochastic simulation to evaluate the impact of events and control measures on the 1997-1998 classical swine fever epidemic in The Netherlands. II. Comparison of control strategies     

Nielen M  Jalvingh AW  Meuwissen MP  Horst SH  Dijkhuizen AA 《Preventive veterinary medicine》1999,42(3-4):297-317

Using the spatial, temporal and stochastic simulation model InterCSF, several alternative pre-emptive slaughter strategies that could have been applied in the Dutch Classical Swine Fever (CSF) epidemic of 1997–1998 were evaluated. Furthermore, effects of changes in some disease-spread and disease-control parameters were studied. InterCSF simulates the spread of CSF between farms through local spread and contacts (animals, transport and persons). Disease spread is affected by control measures implemented through different mechanisms (e.g. depopulation of infected farms, pre-emptive slaughter, movement control). The starting point for the evaluation of strategies was a simulated basic scenario, which mimicked the real epidemic. Strategies were compared using epidemiological as well as economic results. Economic results were generated by a separate model (EpiLoss) that calculated the direct losses and consequential losses for farmers and related industries. The comparison of the different alternatives to the basic scenario led to some general conclusions on the Dutch CSF-epidemic. Pre-emptive slaughter seemed to be an effective strategy to reduce the size of an epidemic, if started at an early stage. Economically, pre-emptive slaughter was not as expensive as expected; the resulting smaller size of the epidemic, combined with less welfare slaughter, led to much lower overall losses. Furthermore, although large movement control areas seemed effective in reducing the size of the epidemic, the total losses were relatively high because of subsequent welfare slaughter. If infection probabilities could be reduced, for example by improved biosecurity, the resulting epidemics would be much smaller.  相似文献   

Dr. James E. Kraus     

Walter Sparks 《American Journal of Potato Research》1972,49(9):352-353

  相似文献   

SURFACE-INDUCED DEEP HYPOTHERMIA – A PRACTICAL METHOD FOR CARDIAC ARREST SURGERY IN THE DOG     

Walter E. Weirich D.V.M.  M.S.  Ph.D. 《Veterinary surgery : VS》1974,3(2):82-87

  相似文献