Development, in-house validation and practical testing of a biotest with garden cress to record plant reactions after treatments with the biodynamic horn manure preparation (2015 - 2017)

The question of the effectiveness of low amounts of substances on life is highly topical. In medicine, allergic phenomena are an increasing problem and in environmental science the toxicity of highly diluted pollutants is well known. In plant physiology, the sensitivity of plants to bioactive compounds such as plant hormones and signaling compounds has been described down to very low concentrations. This knowledge sheds new light on the application of biodynamic preparations in agriculture. A characteristic of biodynamic preparations is that they are applied at very low concentrations. They are approved for organic farming in EU Regulation 834 (28/06/2007) and are mainly used on Demeter Association farms. However, in principle, they are interesting for all farms. This is shown by the use of the preparations to improve quality on many winegrowing farms that are not Demeter member farms. Effects of low amounts of substances are not easy to investigate, especially in natural conditions such as in field trials, because the reproducibility of results is problematic due to the many factors involved. Therefore, standardized bioassays under laboratory conditions have been developed. Their greatest advantages lie in their repeatability. In biodynamic preparation research, however, such laboratory bioassays have hardly been used so far. In our own preliminary experiments, the potential of a laboratory test to determine the efficacy of the horn manure preparation at practical concentrations was investigated. This germination test with garden cress (Lepidium sativum L.) was originally developed for the testing of small amounts of substances in medicine. The results of these preliminary tests showed statistically significant influences of the horn manure preparation in the bioassay over a period of months, and its sensitivity was thus demonstrated. However, the repeatability of the efficacy of the HMP in other time periods was not guaranteed. The objective of the project is the further development of the test especially in view of the reproducibility, to test its suitability as a laboratory test for the horn manure preparation according to the guidelines USP 1033 for the validation of a bioassay and finally to test the test in a practice-oriented question.