Dieter von Hörsten

Effect of Exposure to Radio-Frequency Electric Fields on Fusarium graminearum in Wheat Seed

Fusarium graminearum is a pathogenic fungi that causes various diseases in field crops. Especially the Fusarium Head Blight causes reduced yield and grade. The control measures consist mainly on preservative measures. A seed treatment that lead to disease free seed can help to control the fungi. The effect of RF treatment on germination and infection rate of wheat seed, which had been inoculated artificially with Fusarium graminearum has been examined. The results show that RF treatment lead to a complete eradication of Fusarium graminearum in wheat seed while maintaining germination.

Assistenzsystem zur teilflächenspezifischen Applikation von Pflanzenschutzmitteln

Recent studies on endophytic Kosakonia radicincitans DSM 16656T demonstrated a wide plant growth-promoting activity. The application of this Gram-negative bacterium as a biofertilizer is limited due to the lack of adequate formulation that protects the cells during drying and storage and supports plant colonization. Here we set out to elucidate the compatible solutes accumulation influence of K. radicincitans triggered by osmotic stress on its capacity as an endophyte in radish plants. We found that physiological modifications by osmotic stress treatments and accumulation of compatible solutes during cultivation, improve the capability of K. radicincitans formulated in dry beads to colonize and to promote radish growth. Thus, pre-conditioning of cells with NaCl 4% and by adding compatible solutes such as hydroxyectoine during cultivation induced a positive effect on relative gene expression response, enhancing significantly the ability to colonize plant tissue up to 10 fold. Additionally, when this osmolyte was added, either dry matter of tuber or leaves increased by 3 % and 13.59 %, respectively in comparison to beads without the bacterium. These first results indicate that a systematic approach to cultivation and formulation may increase the endophytic capacity of this bacterium.

Neue Pflanzenbausysteme entwickeln – welche innovativen Techniken werden benötigt?

The agricultural sector is faced with sweeping changes arising from various challenges of economic, ecological and social nature. With a persistent prolongation of the recent technical development path, these challenges cannot be mastered in future. Therefore, it is necessary to put the plant cultivation system as well as the for operational design necessary processes under close scrutiny to achieve the demanded sustainable intensification of agricultural production. Against this backdrop, this requirement profile for a plant production in the future is defined, the resultant challenges formulated and individual aspects of an alternative production system are considered how, with the help of modern techniques, new alternatives in plant production can be explored. The focus therefore is first of all to satisfy the basic necessities of cultivated plants together with superordinate requirements and restriction particularly with regard to structures. This will provide the basis for the required process technologies for a site-specific farm management. This is in contrast with previous practice, by which i. a. the technique development in uniform farm-management leads to the increasing size of fields.

Möglichkeiten der Pflanzenschutzmitteleinsparung durch Nichtbehandlung der Fahrgassen

Die Daten der Vergleichsbetriebe stellen den Status quo im Pflanzenschutz in Deutschland dar. Der Behandlungsindex in Mohre und Frischkohl betrug im Durchschnitt der Jahre (2007-2014) bei 6,2 bzw. 9,2. Mohren wurden vorrangig mit Herbiziden und Frischkohl mit Insektiziden behandelt. Unter dem Aspekt des Pflanzenschutzes und zur Reduktion der Behandlungsintensitat mit Insektiziden kann Abbildung 1: Behandlungsindex der Herbizide (Herbizid-BI) in Abhangigkeit der Vorfrucht in den Vergleichsbetrieben fur Mohre, 2007-2014, in Deutschland, ungleiche Buchstaben symbolisieren signifikante Unterschiede (p<0,05), nBlattfrucht=58, nGemuse=28, nHalmfruchte=115 208 72. ALVA-Tagung, Seminarhotel Wesenufer, 2017 der Fruhkohlanbau empfohlen werden. Im Kohl- und Mohrenanbau konnen Halmvorfruchte Schadlingsbefall vorbeugen. Die Mittelaufwandmengen wurden vorrangig bei Herbizidanwendungen reduziert In beiden Kulturen wurden Abweichungen vom notwendigen Mas verzeichnet. Die Pflanzenschutzberatung sowie die regelmasige Durchfuhrung von Bonituren konnen Pflanzenschutzmittelanwendungen dem notwendigen Mas naher bringen und die Umsetzung des IPS in der Praxis verbessern. Fur die Ausschopfung nichtchemischer Masnahmen sind Praxisdemonstrationen und der intensive Austausch zwischen Wissenschaft und Praxis notig, genauso wie Forschungsforderung zur Entwicklung neuer und Optimierung bestehender integrierter Verfahren und neuer Wirkstoffe. Vorbildhaft wird der IPS von den Demonstrationsbetrieben u. a. in den Kulturen Mohre und Weiskohl, seit 2014 umgesetzt. Die Betriebe werden individuell und intensiv betraten, um Pflanzenschutzmittelanwendungen auf das notwendige Mas zu beschranken. Hierfur werden Bonituren unter Nutzung von Schadschwellen, Warndiensthinweisen und Monitoringverfahren durchgefuhrt.

Neuentwicklung eines Mähdrescherhäckslers - Versuchsergebnisse zu Wurfweiten und Häcksellängen

Der Verbleib von Stroh auf dem Feld ist heutzutage fast die einzige Moglichkeit der Strohverwertung. Durch den Ubergang zu Anbauverfahren mit reduzierter Bodenbearbeitung bis hin zur Direktsaat sind die Anspruche an die Aufbereitung und Verteilung des Strohs erheblich gewachsen. Hacksler sind nach dem derzeitigen Stand der Technik nicht in der Lage, die Strohzerkleinerung und insbesondere die Verteilung zufriedenstellend zu erfullen. Aus diesem Grunde wurde ein vollig neues Hackselkonzept entwickelt, welches die Anforderungen erfullen konnte. In ersten Versuchen wurde deutlich, dass der Prototyp Wurfweiten bis zu 14 m erzielen kann, kleine Partikelgrosen erzeugt und Voraussetzungen fur eine gleichmasige Verteilung erfullt.

Substitution of Slash-And-Burn techniques in the tropics by application of a newly developed bushchopper

In northeastern Brazil, Para State, shifting cultivation is still one of the most important small farmer’s land-use-systems. Traditionally, the system consists of a 2-year cropping period followed by a fallow period of several years. Land preparation prior to the cropping is done by burning the slashed fallow vegetation. Intensifying the land-use, but keeping the traditional agricultural practices leads to a decrease of the system’s productivity. A key factor of this degradation is the nutrient loss due to slash burning. If, however, it was not burned, the biomass could contribute substantially to the management of the soil organic matter in order to improve the physical, chemical and biological properties of the soil. Accordingly, the Institute of Agricultural Engineering of the University of Gottingen developed a tractor-powered bush chopper to substitute the slash and burn practice by a fire-free land preparation system.The first prototype was tested in 1997 and proved the feasibility of the mechanized non-burning land preparation. In the first half of 2002 the second prototype was introduced and tested. For the application of the mulching technology having a positive income effect for the smallholders, it is broadly accepted throughout the research region. The research studies and the developing were carried out within the SHIFT- project, a German-Brazilian research program. The machine was particularly developed for the Brazilian field conditions. However, during the developing period a series of new fields of application for this type of machinery have arised such as landscape conservation or biomass harvesting for energy purposes.