Landschaftspflege und landwirtschaftliche Schädlingsbekämpfung

Ohne Zusammenfassung     

Zeitschriftenschau

Journal of Pest Science -     

Estimating water use by sugar maple trees: considerations when using heat-pulse methods in trees with deep functional sapwood

Accurate estimates of sapwood properties (including radial depth of functional xylem and wood water content) are critical when using the heat pulse velocity (HPV) technique to estimate tree water use. Errors in estimating the volumetric water content (V(h)) of the sapwood, especially in tree species with a large proportion of sapwood, can cause significant errors in the calculations ofsap velocity and sap flow through tree boles. Scaling to the whole-stand level greatly inflates these errors. We determined the effects of season, tree size and radial wood depth on V(h) of wood cores removed from Acer saccharum Marsh. trees throughout 3 years in upstate New York. We also determined the effects of variation in V(h) on sap velocity and sap flow calculations based on HPV data collected from sap flow gauges inserted at four depths. In addition, we compared two modifications of Hatton's weighted average technique, the zero-step and zero-average methods, for determining sap velocity and sap flow at depths beyond those penetrated by the sap flow gauges. Parameter V(h) varied significantly with time of year (DOY), tree size (S), and radial wood depth (RD), and there were significant DOY x S and DOY x RD interactions. Use of a mean whole-tree V(h) value resulted in differences ranging from -6 to +47% for both sap velocity and sap flow for individual sapwood annuli compared with use of the V(h) value determined at the specific depth where a probe was placed. Whole-tree sap flow was 7% higher when calculated on the basis of the individual V(h) value compared with the mean whole-tree V(h) value. Calculated total sap flow for a tree with a DBH of 48.8 cm was 13 and 19% less using the zero-step and the zero-average velocity techniques, respectively, than the value obtained with Hatton's weighted average technique. Smaller differences among the three methods were observed for a tree with a DBH of 24.4 cm. We conclude that, for Acer saccharum: (1) mean V(h) changes significantly during the year and can range from nearly 50% during winter and early spring, to 20% during the growing season;(2) large trees have a significantly greater V(h) than small trees; (3) overall, V(h) decreases and then increases significantly with radial wood depth, suggesting that radial water movement and storage are highly dynamic; and (4) V(h) estimates can vary greatly and influence subsequent water use calculations depending on whether an average or an individual V(h) value for a wood core is used. For large diameter trees in which sapwood comprises a large fraction of total stem cross-sectional area (where sap flow gauges cannot be inserted across the entire cross-sectional area), the zero-average modification of Hatton's weighted average method reduces the potential for large errors in whole-tree and landscape water balance estimates based on the HPV method.     

Ein Markstein im deutschen Pflanzenschutz

Zusammenfassung Mit dem neuen deutschen Pflanzenschutzgesetz wird eine neue Epoche des Pflanzenschutzdenkens eingeleitet, das den Schutz der pflanzlichen Produktion und ihrer Erträge vor Schadorganismen (Schädlingen) und Krankheiten zwar in den Mittelpunkt stellt, das aber die Pflanzenschutztechnik, insbesondere die Anwendung von chemischen Pflanzenschutz- und Vorratsschutzmitteln, von der Beachtung wirksamer Schutzvorschriften für die Gesundheit von Mensch, Tier und Natur (Ökosystem) abhängig macht. Dabei werden auf gesetzlichem Wege erstmalig auch biologisch-ökologische bzw. biologisch-chemisch kombinierte (integrierte) Verfahren den Maßnahmen des Pflanzen- und Vorratsschutzes zugeordnet. Es wird erläutert, wie dadurch auch die wissenschaftliche Forschung (biologische Schädlingsbekämpfung) gefördert wird. Die im Gesetz der Landwirtschaft, der Mittel-industrie, dem Pflanzenschutz-Lohnunternehmen, der Forschung und dem praktischen Pflanzenschutzdienst gestellten Aufgaben lassen das Zusammenwirken von Biologie, Ökologie, Phytomedizin, Chemie, Toxikologie und Medizin (Hygiene) erkennen. Die angestrebte Synthese zwischen den Belangen des Pflanzen- und Vorratsschutzes, des Gesundheits-, Tier- und Naturschutzes erscheint im gesetzlichen Rahmen ohne unzumutbare Belastung der Landwirtschaft praktikabel gelungen. Nutznießer der strengen Vorschriften in Verbindung mit der geltenden Höchstmengen-Verordnung (Begrenzung der Pflanzenschutz-Vorratsschutz-Mittelrückstände) soll in erster Linie der Konsument sein. Die Gewähr für seinen Schutz wird vor allem durch die obligatorische Prüfung, Zulassung und Kennzeichnung aller Pflanzenschutz- und Vorratsschutzmittel gegeben. Die Erfüllung der Bedingungen für ihre Zulassung schließt bei sachgerechter Mittelanwendung Gefahren, Risiken und Schäden praktisch aus. Das Gesetz läßt Wilikür nicht mehr zu und setzt ausreichendes Fachwissen und Verantwortungsbewuß tsein des Praktikers voraus. Die wichtigsten Vorschriften des Gesetzes, u. a. auch die Arbeitsteilung zwischen Forschung, Prüfung, Kontrolle und Pflanzenschutzexekutive, werden erläutert, die Bedeutung des Gesetzes für die künftige Entwicklung gewürdigt.

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Summary The latest German Plant Protection Act initiates a new epoch in plant protection thinking in so far as it puts a momentum on the protection of plant production and its crop yields against pests and diseases but makes plant protection techniques, in particular the use of pesticides, dependent on the observance of effective provisions for the safeguard of human health, animal health and nature (eco-system). Thus, for the first time, combinations (integration) of biological-ecological and/or biological-chemical methods are by law included in plant and stock protection procedures. An explanation is given of how this contributes to promoting scientific research (biological pest control). The tasks set by this Act to agriculture, industries, wage-paying plant protection enterprises, research and plant protection field services show that there is an interaction of biology, ecology, phyto-medicine, chemistry, toxicology and medicine (hygenics). This Act seems to have established a practical synthesis of the issues of plant and stock protection, public health, animal health and conservation of nature without imposing intolerable duties into agriculture. The consumer is first and foremost to be the beneficiary from the rigid regulations on maximum tolerances (fixed tolerances for pesticide residues). The main safeguards of consumer protection are compulsory inspectation, licensing and labelling of any type of pesticide. Fulfilling the requirements for licensing practically excludes any hazard, risk or damage provided that the substances are properly used. The Act makes no allowance for arbitraryness and demands technical knowledge and responsibility on the part of the executive. The important provisions of the Act, e. g. division of labour between research, testing, control and executive are elucidated and an outlook is given on the significance of the Act for the development in the future.

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Résumé La récente loi relative à la protection des plantes est à l'origine d'une nouvelle époque en ce qui concerne la conception de la «protection des plantess», représentant une concentration sur la protection de la production végétale et le rendement des cultures contre les organismes nuisibles («parasites») et les maladies des plantes, instituant, cependant, pour la technique de la protection des plantes et particulièrement pour l'application des pesticides une dépendance de l'observation de rè glements efficaces pour la protection de la santé de l'homme, de l'animal et de la conservation de la nature (éco-système). Ainsi, pour la premierè fois, une combination (intégration) de méthodes biologiques-écologiques ou biologiques-chimiques avec les mesures de la protection des plantes et des aliments stockés est réalisé par la législation. Une explication est donnée, comment cela représente une contribution à l'encouragement de la recherche scientifique (lutte biologique contre les parasites). Les tâches attribuées par la loi à l'agriculture, à l'industrie, aux entrepreneurs dans le domaine de la protection des plantes, à la recherche et au Service de Protection de Végétaux montrent l'interaction de la biologie, de l'écologie, de la phyto-médecine, de la chimie, de la toxicologie et de la médecine (hygiène). La loi semble avoir réussi en é tablissant une synthèse praticable entre les intérêts de la protection des plantes et des aliments stockés et ceux de la protection de la santé de l'homme, de l'animal et de la conservation de la nature, sans imposer à l'agriculture une charge excessive. Le consommateur sera, en premier lieu, le béné ficiaire des règlements rigides du décret en force sur les tolérances maximales (fixation de tolérances pour les résidus des pesticides). La garantie pour sa protection consistera surtout dans l'inspection obligatoire, dans l'admission et dans le marquage de tous les pesticides. Si les conditions pour l'admission sont remplies et le pesticide est employé dans une manière appropriée, il n'y aura pratiquement pas de dangers, risques et dommages. La loi supprime l'arbitraire et exige un degré suffisant de connaissances techniques et de responsabilité chez les organes dans la pratique. Les règlements importants de la loi, p. ex. la division du travail entre la recherche, le contrôle et l'exécutive de la protection des plantes sont expliqués et le rôle de la loi est reconnu en vue du développement futur.

     

The Gastroduodenal Effects of Buffered Aspirin, Carprofen, and Etodolac in Healthy Dogs

Twenty-four healthy mixed-breed dogs were divided into 4 groups. Group 1 received a placebo p.o. q12h, group 2 received an average of 16.5 (15.1-17.8) mg/kg buffered aspirin p.o. q12h, group 3 received an average of 2.2 (2.0-2.4) mg/kg carprofen p.o. q12h, and group 4 received an average of 12.8 (11.7-13.8) mg/kg etodolac p.o. q24h (with a placebo in the PM). All treatments continued for 28 consecutive days. Gastroduodenal endoscopy was performed on days -9, 0, 5, 14, and 28. Multiple gastric biopsies were obtained endoscopically on day -9 to determine each dog's Helicobacter infection status. Four regions in the stomach and 1 region in the proximal duodenum were evaluated endoscopically, and each was assigned a score from 1 to 11. Scores for each region then were summed to give a total score for each endoscopic evaluation. Erosions and submucosal hemorrhages were seen in all dogs receiving aspirin. Only minor gastric lesions were observed in the carprofen, etodolac, and control groups. No adverse clinical signs were noted in any dog given any treatment. Median total score on days 0, 5, 14, and 28, respectively, were as follows: group 1: 5.0, 5.0, 5.0, 5.0; group 2: 5.0, 27.0, 26.0, 27.5; group 3: 5.0, 5.0, 6.0, 5.0, group 4: 5.0, 7.0, 5.0, 5.0. There was no significant difference among dogs receiving carprofen, etodolac, or placebo. The administration of carprofen, etodolac, or placebo to healthy dogs resulted in significantly less gastroduodenal lesion development than in dogs receiving buffered aspirin.     

Die norwegische Krähen-Massenfalle

Ohne Zusammenfassung     

Carbon dioxide and gaseous nitrogen emissions from biochar‐amended soils under wastewater irrigated urban vegetable production of Burkina Faso and Ghana

To quantify carbon (C) and nitrogen (N) losses in soils of West African urban and peri‐urban agriculture (UPA) we measured fluxes of CO₂‐C, N₂O‐N, and NH₃‐N from irrigated fields in Ouagadougou, Burkina Faso, and Tamale, Ghana, under different fertilization and (waste‐)water regimes. Compared with the unamended control, application of fertilizers increased average cumulative CO₂‐C emissions during eight cropping cycles in Ouagadougou by 103% and during seven cropping cycles in Tamale by 42%. Calculated total emissions measured across all cropping cycles reached 14 t C ha^?1 in Ouagadougou, accounting for 73% of the C applied as organic fertilizer over a period of two years at this site, and 9 t C ha^?1 in Tamale. Compared with unamended control plots, fertilizer application increased N₂O‐N emissions in Ouagadougou during different cropping cycles, ranging from 37 to 360%, while average NH₃‐N losses increased by 670%. Fertilizer application had no significant effects on N₂O‐N losses in Tamale. While wastewater irrigation did not significantly enhance CO₂‐C emissions in Ouagadougou, average CO₂‐C emissions in Tamale were 71% (1.6 t C ha^?1) higher on wastewater plots compared with those of the control (0.9 t C ha^?1). However, no significant effects of wastewater on N₂O‐N and NH₃‐N emissions were observed at either location. Although biochar did not affect N₂O‐N and NH₃‐N losses, the addition of biochar could contribute to reducing CO₂‐C emissions from urban garden soils. When related to crop production, CO₂‐C emissions were higher on control than on fertilized plots, but this was not the case for absolute CO₂‐C emissions.