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A series of experiments were conducted to determine the potential of a new method of steam treatment for the control of soil-borne diseases, insects and weeds in sustainable crop production.  The new method involved rapidly heating a bed of prepared soil on a porous base by passing an upward flow of steam through it.  The aim was to determine whether the new method would be suitable for use in a field machine, making large-scale field steaming practically and economically viable. In the first experiments, the feasibility of the new method was tested.  It was shown that it was an effective and rapid way in which a soil bed could be steamed.  However, for some soils at, or near, permanent wilting point, the entrainment of aggregates in the steam flow was shown to be a problem.  The second series of experiments showed that the key factor determining the flow rate at which aggregate entrainment occurred was the mean aggregate diameter of the soil being treated.  The third series of experiments examined the rate at which heated soil would cool when placed in the field.  It was shown that where there was contact with unheated field soil, cooling was very rapid.  The final series of experiments investigated the effects of the new steaming method on the soil.  A three minute steaming time was used to account for the short time it had been shown some of the heated soil would remain at steam temperature when replaced in the field.  The effects of the new method, including the effectiveness of disinfection, were shown to be similar to those of a conventional steam treatment. It was concluded that the new steaming method was an effective way to steam treat soil and should be suitable for use in a field machine.

Methyl bromide is a widely used soil disinfectant that, because of its ozone depleting properties, is being phased out in the EC by 2005.  Soil steaming is a well-established system of soil disinfestation and is increasingly seen as a viable option to methyl bromide replacement.  Traditional glasshouse steaming techniques create a number of problems because it involves treatment of soil with high-temperature (100-140°C) steam for up to eight hours or more.  This not only eliminates unwanted soil-borne pests and diseases, but also creates a ‘biological vacuum’, in which target pests and pathogens may quickly re-enter and luxuriate, perpetuating the need for regular disinfestation.   Soil steaming at lower temperatures, e.g. at 70°C, does not normally result in these unwanted side effects, because of the partial survival of the saprophytic microflora population. In this study agricultural soil samples, containing a range of important soil-borne pests and pathogens, were treated with steam in a specially designed laboratory steam-rig.  It was found that treatment at 60°C, for a duration of only 3 minutes plus eight minutes ‘resting’ (“low-temperature/short duration soil steaming”) was enough to 100% kill soil-borne fungal pathogens <i>Sclerotinia sclerotiorum, Sclerotium cepivorum, Verticillium dahlia</i>e and <i>Pythium ultimum;  </i>potato cyst nematodes <i>Globodera rostochiensis </i>and <i>Globodera pallida,</i> and weeds <i>Chenopodium album </i>and <i>Agropyron repens.</i> When low temperature/short duration soil steaming was compared with a chemical soil disinfectant, using the fumigant dazomet (Basamid) at a rate of 760 kg/ha, both disinfestation methods resulted in 100% elimination of the above pathogens, nematodes and weeds and caused IGR (Increased Growth Response) of lettuce plants. In a further study, using four different soil types at three different matric potentials, it was found that efficacy of low-temperature/short duration steaming is dependent on soil type and soil moisture content, and that treatment of soil in a moist state is more effective than treatment in a dry state, especially when treating fine-textured sand and loam soils. Soil samples containing survival structures of soil pests were also treated with ozone gas in a specially designed ozone treatment chamber, but this did not result in elimination of target organisms.

Der Maiszünsler zählt zu den wichtigsten tierischen Schaderregern im Mais. Zur Befallsminderung sind örtlich gezielte Bekämpfungsmaßnahmen notwendig. Für eine exakte Terminbestimmung kommen Lichtfallen zum Einsatz. In einer zweijährigen Studie wurde als alternative Lösung überprüft, ob verschiedene Pheromone Lockwirkung zeigen. Der Fang der Maiszünslerfalter erfolgte über Z- und E-Pheromone. Die Fängigkeit der Pheromonfallen war sehr unterschiedlich. Keines der eingesetzten Pheromone lieferte zuverlässige Daten für die Terminbestimmung. Die Untersuchung ergab, dass die derzeitig angebotenen Pheromone für einen großflächigen Einsatz nicht geeignet sind. Die Pheromonfallen stellen keine Alternative zur Lichtfalle dar.

Die Broschüre fasst die Ergebnisse einer Untersuchung zur wirksamen Bekämpfung von Maiszünslerlarven auf dauerhaft konservierend bestellten Ackerflächen zusammen. Der alleinige Einsatz von Pflug und Grubber zeigte keine ausreichende Wirkung, weil der Anteil intakter und für die Überwinterung der Larven geeigneter Maisstoppeln zu groß ist. Der Einsatz des Pfluges erhöhte die Erosionsgefährdung des Bodens. Lediglich die Scheibenegge zeigte als Sologerät eine hinreichende Zerkleinerungswirkung bei der flachen Einarbeitung der Erntereste. In Kombination mit dem Mulcher werden bei allen untersuchten Bodenbearbeitungsvarianten ausreichend Maisstoppeln beschädigt. Es kann empfohlen werden, Maisstoppeln mit einer Kombination aus Mulcher und Scheibenegge bzw. Grubber zu bearbeiten. So kann bei hinreichendem Erosionsschutz der Maiszünslervermehrung vorgebeugt werden. Gleichzeitig wird damit die Gefahr einer Fusarieninfektion im nachgebauten Getreide reduziert.

In den Jahren 2011 und 2012 wurden umfangreiche Untersuchungen zur aktuellen Situation der Pflanzenschutzmittelresistenz in Sachsen durchgeführt. Einbezogen waren wirtschaftlich bedeutsame Schadorganismen in Sachsen sowie verschiedene insektizide, fungizide und herbizide Wirkstoffe. Die Erhebungen zeigen, dass in Sachsen ein Anstieg von Pflanzenschutzmittelresistenzen gegenüber den untersuchten Schadorganismen zu verzeichnen ist. Aus den Projektergebnissen wurden entsprechend angepasste bzw. neue Behandlungsstrategien zum Antiresistenzmanagement für die sächsischen Anbauregionen abgeleitet. Ziel ist es, der Resistenzausbreitung und der damit verbundenen Zunahme von chemischen Pflanzenschutzmaßnahmen entgegenzuwirken.