Research

Grape powdery mildew, caused by Erysiphe necator Schwein., is one of the major diseases in viticulture. Currently, the pathogen is mostly controlled with 6-10 fungicide applications. Due to the negative effects of pesticides on the ecosystem, the EU Commission aims to reduce the pesticide use by 50 percent by 2030. This project contributes to this goal and aims to reduce the number of fungicide applications needed to control powdery mildew without sacrificing crop quality. There is evidence that especially at the beginning of the vegetation there is a possibility to reduce the number of fungicide treatments. Mathematical models can make an important contribution here; however, in order to fully exploit this potential, numerous gaps in knowledge about the epidemiology of the pathogen still need to be filled. Targeted and thus pesticide-reducing management requires consideration of local disease development. The project addresses key factors here: The time of primary infection, the spread of ascospores and the incubation period will be investigated in combination with weather factors under natural and controlled conditions. Based on these results, mathematical models and regionally adapted fungicide strategies for winegrowers will be developed. These knowledge-based strategies will enable sustainable concepts for plant protection in viticulture and contribute to the achievement of a 50% pesticide reduction.

As a result of increasingly strict legislation on the use of pesticides, especially glyphosate, and pressure from society, alternative methods of weed control in permanent crops such as orchards and vineyards are gaining in importance. In a transnational cooperation, alternatives in weed management are therefore to be developed. In Bavaria, the project "Alternative weed management in fruit and wine growing with ecologically harmless substances and an alternative mulching method based on renewable raw materials - ABOW", submitted by the Technology and Promotion Centre in the Competence Centre for Renewable Resources (TFZ) Straubing together with the State Institute for Viticulture and Horticulture Veitshöchheim, was launched in January 2019. An Austrian project focusing on the development of an autonomous device and alternative substances in weed management was launched in summer 2019. In this project, the Institute of Plant Protection is investigating whether alternative natural substances and the sprayable mulch films developed in Bavaria have sufficient weed suppression.

In the years 2017 to 2019 an outbreak of the sugar beet weevil Bothynoderes punctiventris Germar (Coleoptera: Curculionidae) caused enormous damage to sugar beet crops in eastern Austria. The search for efficient pest control strategies raised question on the ecology of the sugar beet weevil that need to be researched under controlled conditions in the laboratory. Knowledge on the host plant selection behaviour of this pest is of particular importance for the development of novel control measures. To date the olfactory cues – or any other stimuli - used by the beetles to localize young sugar beet plants have not been investigated. The attractiveness of the odour bouquets of potential host plants other than the sugar beet to the weevil has not been researched either, and odour components present in the plant odours of secondary hosts have not been analysed, although olfactory attractive odour compounds could enhance the efficiency of the currently used attractant Grandlure III-V. Moreover, the potential of secondary host plants – crops, weeds or miscellaneous plants – to sustain the B. punctiventris population needs to be clarified. Finally, feeding deterrent plant extracts and minerals applied to young sugar beet plants may disrupt the host selection process of this pest. Research on the behaviour of the sugar beet weevil is a sine qua non for the development of future environmentally friendly and sustainable control strategies.