Bioskiva – A carrier for cyanobacteria and cabbage fly repellents

BIOSKIVA® - is a flat shadow-disk consisting of the fiber part of fermented animal manure, which is used by being placed around the stem of culture plants. The disk has at least two functions: as a nutrient supplier and as a carrier for natural substances or living biosystems producing repellents against e.g. insects and plant pathogenic microorganisms. BIOSKIVA is produced from ecological farm manure following a flow-scheme in a bioreactor with three major steps: hygienisation, fermentation and separation. This procedure gives two components: A. a fiber part (the disk) and B. a fluent part. In general, the use of BIOSKIVA is agricultural and focused on use for ecological farmers since no synthetic chemicals are linked to the disk as pesticides. Field tests have been performed with BIOSKIVA for years testing its effectiveness as a fertilizer and as a mechanical protectant against weeds. In the last 2-3 years secondary metabolites, e.g. essential oils isolated from plants, and a slow release system and cyanobacteria as a living biodegrading system for cabbage flies have been implemented in the disk. In the period 2003-2005, the fiber part and the use of the disk in the production of vegetables, e.g. cabbage and its repellent function against cabbage fly has been studied. Etheric oils isolated from thyme and karve (I have forgotten what this is in English, please use the English or Latin term) by water steam distillation and incorporated into bee wax (as a slow release system) are applied to the disk. In addition salicylaldehyde was used and added in variable concentrations to the disk. When attacking the plants the fly lays egg at the lower part of the stem. In 2005, field tests were also performed using cyanobacteria to function as a natural repellent producing system. Two species of cyanobacteria (Phormidium sp. and Pseudanabaena sp.) were used as a reproducing living biofilm. The recent results obtained will be presented. In Norway, cabbage fly will lay eggs twice during the summer period (June and July) at approximately a 5 week interval. Intensive work was put into test studies in the laboratory, in greenhouse and in field tests using BIOSKIVA as a carrier for: a slow release system, secondary metabolites as repellents and cyanobacteria as a biofilm. Using salicylaldehyde embedded in bee wax, kiselgel and soya it was found that the two first embedding media were the most effective slow release systems with best results obtained using bee wax. Based on the results obtained, testing the different embedding media embedded in bee wax show that the number of eggs per plant was lowest when using thyme and cyanobacteria. It is believed that cyanobacteria represent the potential for future use as natural repellents sources. Applied on BIOSKIVA as a biofilm it is hoped that these organisms will have the capacity to produce repellents against insects, bind nitrogen to increase the nutrient supply, be easy to produce, be able to withstand storage as a component on BIOSKIVA and show optimal growth as a biofilm when the disk is used in plant production.