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

Hot-Fire Testing of 100 LB(sub F) LOX/LCH4 Reaction Control Engine at Altitude Conditions

Liquid oxygen/liquid methane (LO2/LCH4 ) has recently been viewed as a potential green propulsion system for both the Altair ascent main engine (AME) and reaction control system (RCS). The Propulsion and Cryogenic Advanced Development Project (PCAD) has been tasked by NASA to develop these green propellant systems to enable safe and cost effective exploration missions. However, experience with LO2/LCH4 as a propellant combination is limited, so testing of these systems is critical to demonstrating reliable ignition and performance. A test program of a 100 lb f reaction control engine (RCE) is underway at the Altitude Combustion Stand (ACS) of the NASA Glenn Research Center, with a focus on conducting tests at altitude conditions. These tests include a unique propellant conditioning feed system (PCFS) which allows for the inlet conditions of the propellant to be varied to test warm to subcooled liquid propellant temperatures. Engine performance, including thrust, c* and vacuum specific impulse (I(sub sp,vac)) will be presented as a function of propellant temperature conditions. In general, the engine performed as expected, with higher performance at warmer propellant temperatures but better efficiency at lower propellant temperatures. Mixture ratio effects were inconclusive within the uncertainty bands of data, but qualitatively showed higher performance at lower ratios

Summary of Altitude Pulse Testing of a 100-lbf L02/LCH4 Reaction Control Engine

Recently, liquid oxygen-liquid methane (LO2/LCH4) has been considered as a potential "green" propellant alternative for future exploration missions. The Propulsion and Cryogenic Advanced Development (PCAD) project has been tasked by NASA to develop this propulsion combination to enable safe and cost effective exploration missions. To date, limited experience with such combinations exist, and as a result a comprehensive test program is critical to demonstrating the viability of implementing such a system. The NASA Glenn Research Center has conducted a test program of a 100-lbf (445-N) reaction control engine (RCE) at the center s Altitude Combustion Stand (ACS), focusing on altitude testing over a wide variety of operational conditions. The ACS facility includes a unique propellant conditioning feed system (PCFS) which allows precise control of propellant inlet conditions to the engine. Engine performance as a result of these inlet conditions was examined extensively during the test program. This paper is a companion to the previous specific impulse testing paper, and discusses the pulsed mode operation portion of testing, with a focus on minimum impulse bit (I-bit) and repeatable pulse performance. The engine successfully demonstrated target minimum impulse bit performance at all conditions, as well as successful demonstration of repeatable pulse widths. Some anomalous conditions experienced during testing are also discussed, including a double pulse phenomenon which was not noted in previous test programs for this engine

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

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

Prognosegesteuerte Bekämpfungsstrategien im Ökologischen Kartoffelanbau- mögliche Kupfereinsparungspotentiale und Vergleich der Bekämpfungserfolge

Im Rahmen des Forschungsprojektes ÖKOSIMPHYT liegen mittlerweile dreijährige Versuchsergebnisse zur Bekämpfung der Kraut- und Knollenfäule (Phytophthora infestans) im Ökologischen Kartoffelanbau vor, in denen die Anwendung des neuen Prognosesystems ÖKOSIMPHYT im Freiland getestet wurde. Ziel des Projektes ist, durch eine zielgerichtete Applikation den Kupfereinsatz sowohl aus Bekämpfung- als auch aus ökologischer Sicht zu optimieren

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

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%

Testing of a Liquid Oxygen/Liquid Methane Reaction Control Thruster in a New Altitude Rocket Engine Test Facility

A relocated rocket engine test facility, the Altitude Combustion Stand (ACS), was activated in 2009 at the NASA Glenn Research Center. This facility has the capability to test with a variety of propellants and up to a thrust level of 2000 lbf (8.9 kN) with precise measurement of propellant conditions, propellant flow rates, thrust and altitude conditions. These measurements enable accurate determination of a thruster and/or nozzle s altitude performance for both technology development and flight qualification purposes. In addition the facility was designed to enable efficient test operations to control costs for technology and advanced development projects. A liquid oxygen-liquid methane technology development test program was conducted in the ACS from the fall of 2009 to the fall of 2010. Three test phases were conducted investigating different operational modes and in addition, the project required the complexity of controlling propellant inlet temperatures over an extremely wide range. Despite the challenges of a unique propellant (liquid methane) and wide operating conditions, the facility performed well and delivered up to 24 hot fire tests in a single test day. The resulting data validated the feasibility of utilizing this propellant combination for future deep space applications

Thermal Stability of RP-2 for Hydrocarbon Boost Regenerative Cooling

A series of tests were performed in the NASA Glenn Research Centers Heated Tube Facility to study the heat transfer and thermal stability behavior of RP-2 under conditions similar to those found in rocket engine cooling channels. It has long been known that hydrocarbon fuels, such as RP-2, can decompose at high temperature to form deposits (coke) which can adversely impact rocket engine cooling channel performance. The heated tube facility provides a simple means to study these effects. Using resistively heated copper tubes in a vacuum chamber, flowing RP-2 was heated to explore thermal effects at a range of test conditions. Wall temperature (850-1050F) and bulk fluid temperature (300-500F) were varied to define thermal decomposition and stability at each condition. Flow velocity and pressure were fixed at 75 fts and 1000 psia, respectively. Additionally, five different batches of RP-2 were tested at identical conditions to examine any thermal stability differences resulting from batch to batch compositional variation. Among these tests was one with a potential coke reducing additive known as 1,2,3,4-Tetrahydroquinoline (THQ). While copper tubes were used for the majority of tests, two exploratory tests were performed with a copper alloy known as GRCop-42. Each tube was instrumented with 15 thermocouples to examine the temperature profile, and carbon deposition at each thermocouple location was determined post-test in an oxidation furnace. In many tests, intermittent local temperature increases were observed visually and in the thermocouple data. These hot spots did not appear to correspond with a higher carbon deposition