Reduzierung des Phytophthora-Primärbefalls durch eine Kupferbeizung unter den besonderen Bedingungen des Ökologischen Kartoffelanbaus

Im ökologischen Kartoffelanbau stellt der Primärbefall ein großes Problem dar, weil er mit Kupferspritzungen nur schwer zu kontrollieren ist und schnell zum vorzeitigen Ausbruch von Sekundärbefall führen kann. Nach ergiebigen Niederschlägen und hoher Bodenfeuchte kann der Erreger Phytophthora infestans entweder von der latent infizierten Pflanzknolle im Stängel nach oben wachsen oder auf der Oberfläche der Pflanzknolle sporulieren. Unter für den Erreger optimalen Witterungsbedingungen können beide Infektionswege einen Primärbefall am Stängel auslösen

Strategien zur Minimierung des Einsatzes kupferhaltiger Fungizide bei der Krautfäulebekämpfung im Ökologischen Kartoffelanbau – ein vom Bundesprogramm Ökologischer Landbau gefördertes Forschungsprojekt

Ziel des Projektes ist es, auf Basis der witterungsbedingten Epidemiebewertung, die Kupferaufwandmengen auf das absolut notwendige Maß zu begrenzen. Dazu werden verschiedene Strategien verfolgt. Zum einen soll durch eine Pflanzgutbeizung mit Kupferpräparaten das Auftreten von Primärbefall reduziert werden, um den Epidemiebeginn und somit auch den Spritzstart nach hinten verlagern zu können. Zum andern werden zur Kontrolle des Sekundärbefalls Applikationsstrategien erarbeitet, bei denen die Kupferaufwandmengen und die Spritzabstände variabel an den Infektionsdruck angepasst werden, um mit möglichst niedrigeren Mengen auszukommen

Möglichkeiten zur Optimierung der Kupferwirkung gegen Krautfäule im Ökologischen Kartoffelanbau

Die Regulierung der Kraut- und Knollenfäule, verursacht durch Phytophthora infestans, stellt im ökologischen Landbau nach wie vor ein nur schwer zu lösendes Problem dar. Bislang ist eine befriedigende Befallsreduktion nur durch den Einsatz kupferhaltiger Pflanzenschutzmittel möglich, deren Einsatz durch die Anbauverbände, sofern überhaupt gestattet, auf 3kg pro Jahr begrenzt ist. Im Rahmen des Projekts „ÖKO-SIMPHYT“ wurden daher verschiedene Kupferapplikationsverfahren zur Bekämpfung der Phytophthora infestans-Sekundärinfektionen untersucht, um die zur Verfügung stehenden Kupfermengen optimal einzusetzen

Strategien zur Reduzierung der Kupferaufwandmengen im ökologischen Kartoffelanbau – Projekt “ÖKO-SIMPHYT“

Potato late blight (Phytophthora infestans) is still an unsolved problem in organic farming. Up to now the disease can only be controlled by copper fungicides. Our project is aiming to reduce the application of copper-containing fungicides by introduc-tion of the new blight forecasting system “ÖKO-SIMPHYT” based on meteorological parameters. Primary stem infections should be reduced by seed treatment with copper fungicides thus to postpone the beginning of the blight epidemic as well as the start of spraying. To control secondary infections on the foliage, fungicide strategies should be elaborated to achieve best efficacy with reduced amounts of copper. Therefore copper amounts and spraying intervals should be adjusted to the infection pressure. Based on the biological and epidemiological conditions for primary and secondary infections the new developed potato blight forecast system ÖKO-SIMPHYT should be optimized

INVESTIGATION OF THE MECHANISMS OF HEAT EXCHANGER CORROSION IN A MUNICIPAL WASTE INCINERATION PLANT BY ANALYSIS OF THE RAW GAS AND VARIATION OF OPERATING PARAMETERS

The detailed mechanism of high temperature chlorine corrosion, the dominant cause of corrosion in a municipal solid waste incinerator (MSI), has still to be clarified (Schroer, 2002). Upon its way through the boiler the raw gas is subject to various physical and chemical processes and interactions. Of these, sulphation of chlorides is supposed to have the major impact on chlorine corrosion (Neumann, 1997). The physical and chemical mechanisms of corrosion were investigated at a municipal solid waste incinerator. Both, the particulate and gas phase of the flue gas, were chemically and physically analyzed during their way through the boiler, at temperatures from close to 1000 °C down to 200 °C. The raw gas composition was analyzed during normal operation and soot blowing cleaning routine. Additionally, operating parameters of the plant were varied, and deposition processes were evaluated with the aim to find out primary measures to reduce corrosion rates. The particle mass concentration exhibits a bimodal size distribution with maxima at approximately 0.5 μm – growing by duration of travel – and 100 μm. First results show that sulphation of the particles can be observed upon travel through the boiler and on the fouling. Sulphur containing additives increased the sulphation of the particles during flight though not to completion

Kupferminimierungsstrategien im ökologischen Kartoffelanbau – Projekt “ÖKO-SIMPHYT“: Erste Erfahrungen aus dem norddeutschen Freiland

In the research project „ÖKO-SIMPHYT“ different strategies are tested to reduce the copper application for Phytophthora infestans in organic potato cultivation. Within the first two years of our research a reduction of the total amount of copper per hectare could be accomplished when applying the new developed forecast system ÖKO-SIMPHYT. With this decision support system a reduction of copper up to 46% was possible, when the infection pressure was relatively low. These first results have now to be proven under high infection pressure conditions. Experiments were carried out in the greenhouse to test the rain stability of copper and contacting agents. It could be proved that precipitation of 30 mm is able to reduce the degree of a copper treatment by up to 25%

Phytophthora-Sekundärbefall - Kupferminimierungsstrategien im ökologischen Kartoffelanbau

Auf Grund der negativen Auswirkungen von Kupfer auf Nicht-Ziel-Organismen, wie z.B. aquatische Organismen und Regenwürmern sowie der Anreicherungsproblematik im Boden, ist eine weitere Reduzierung des Kupfereinsatzes dringend erforderlich. Deshalb werden im Rahmen des Forschungsprojekts „ÖKO-SIMPHYT“ Kupferminimierungsstrategien für den ökologischen Kartoffelanbau zur Kontrolle des Sekundärbefalls von Phytophthora infestans entwickelt

Groundwater contamination by trichloroethene (TCE) in a residential area of Perth: Distribution, mobility, and implications for management

Substantial TCE and ammonia contamination was detected in groundwater beneath a residential area in Perth. Investigation has successfully determined broad aspects of the extent of the TCE plume and its impact. The plume extends approximately 900 m in groundwater downgradient of an industrial area. The contamination is about 300 m wide and 6 - 8 m thick. A peak concentration of 2000 ugL{-1} TCE was measured. The mobility of the plume and the residence time for the contamination in the sand aquifer are estimated based on the groundwater velocities and retardation factors. Biological or chemical transformation of TCE cannot be excluded, although no transformation products have been found in a small portion of the plume. Currently no remediation of the contaminated site is planned. An approach for managing the contamination is presented and important issues for future remediation options for TCE contaminated sites in Perth are discussed

Groundwater contamination by trichloroethene (TCE) in a residential area of Perth: Distribution, mobility, and implications for management

Substantial TCE and ammonia contamination was detected in groundwater beneath a residential area in Perth. Investigation has successfully determined broad aspects of the extent of the TCE plume and its impact. The plume extends approximately 900 m in groundwater downgradient of an industrial area. The contamination is about 300 m wide and 6 - 8 m thick. A peak concentration of 2000 ugL{-1} TCE was measured. The mobility of the plume and the residence time for the contamination in the sand aquifer are estimated based on the groundwater velocities and retardation factors. Biological or chemical transformation of TCE cannot be excluded, although no transformation products have been found in a small portion of the plume. Currently no remediation of the contaminated site is planned. An approach for managing the contamination is presented and important issues for future remediation options for TCE contaminated sites in Perth are discussed

The Influence of Chemical and Mineral Compositions on the Parameterization of Immersion Freezing by Volcanic Ash Particles

Volcanic ash (VA) from explosive eruptions contributes to aerosol loadings in the atmosphere. Aside from the negative impact of VA on air quality and aviation, these particles can alter the optical and microphysical properties of clouds by triggering ice formation, thereby influencing precipitation and climate. Depending on the volcano and eruption style, VA displays a wide range of different physical, chemical, and mineralogical properties. Here, we present a unique data set on the ice nucleation activity of 15 VA samples obtained from different volcanoes worldwide. The ice nucleation activities of these samples were studied in the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud simulation chamber as well as with the Ice Nucleation Spectrometer of the Karlsruhe Institute of Technology (INSEKT). All VA particles nucleated ice in the immersion freezing mode from 263 to 238K with ice nucleation active site (INAS) densities ranging from ∼10$^{5}$ to 10$^{11}$ m$^{-2}$, respectively. The variabilities observed among the VA samples, at any given temperature, range over 3.5 orders of magnitude. The ice-nucleating abilities of VA samples correlate to varying degrees with their bulk pyroxene and plagioclase contents as a function of temperature. We combined our new data set with existing literature data to develop an improved ice nucleation parameterization for natural VA in the immersion freezing mode. This should be useful for modeling the impact of VA on clouds