Evaluation of novel biological seed technologies for the defense against insect pests in rape seed.

Rapeseeds are grown on approximately 10% of the German arable land. Thus rape is the most successful oil plant in Germany and at the same time an important supplier of plant protein for animal nutrition and potentially also for human nutrition. A risk to rape cultivation is the regular occurrence of insect pests which attack the plants and consequently lead to high yield losses. In the first 4 to 6 weeks after the sowing of rapeseed in autumn, the young plants are exposed to massive damage to the roots, shoots and leaves caused by infestation with the cabbage-stem flea beetle (Psylliodes chrysocephala L.) and the cabbage root fly (Delia radicum L.). In view of this problem, NPZ Innovation GmbH (Hohenlieth, Schleswig-Holstein), a service and research company for rape cultivation, together with the University of Göttingen and the seed breeding company W. von Borries-Eckendorf GmbH & Co. KG (Leopoldshöhe, Lower Saxony) initiated the research project InRaps, in which biological control options are investigated without the use of synthetic plant protection products against these pests. The main focus here is the treatment of rapeseed with useful microorganisms or natural preparations (e.g. plant extracts) to provide a defense against the pests. This can be a direct effect of the seed treatment on the pest or indirectly via the activation of the plant defense.



The assessment of different seed treatments for the damage of cabbage-stem flea beetle and cabbage root fly is carried out in a laboratory experiment by the Department of Agricultural Entomology of Prof. Vidal. Variations that reduce the pest infestation are then carried out in several field trials of NPZ Innovation GmbH and W. von Borries-Eckendorf GmbH to test the effectiveness of the seed treatment under practical conditions. At the same time, in the research group of Prof. Feussner of the Department Plant Biochemistry, chemical analyzes of plants are carried out in order to identify substances which are responsible for the positive effect on plant health. In this way biochemical mechanisms can be deciphered and scientific knowledge about the plant-insect relationship can be obtained.
The results of the InRaps project are intended to enable the establishment of a biological seed treatment against insects and thus make an important contribution to the reduction of plant protection products in the context of sustainable rape cultivation.