It is widely accepted that a lowered input of pesticides on a farm level will also reduce leaching and outflow of pesticides to marine environments. In order to minimize input of pesticides on a farm level, several challenges exist as: a) weeds, pests and diseases are not homogeneously distributed in time and space, b) different weeds, pests and diseases have different negative impact in different periods of different production lines and c) different pesticides have different efficacy on different weeds, pests and diseases depending on conditions on a field level. Application of pesticides according to the motto: ‘as little as possible, as much as required’ is therefore a complex and a great challenge. Consequently, pesticides are often applied more or less by routine, which inevitably will lead to a more intensive use of pesticides than required on a field level. An existing Danish Decision Support System (DSS), which is an ICT-tool, which can suggest herbicides treatment options that match needs on a field level, which has proven robust for conditions in Denmark and Norway, and which has demonstrated potential for substantial reductions of herbicide use, will be generally improved, adapted, tested and disseminated in Baltic Regions of Poland and Germany. The DSS will be adjusted to agronomical, biological and lingual conditions for winter wheat in Baltic regions of Denmark, Poland and Germany. Existing, scientific data in Denmark, Poland and Germany on interactions between crop, weeds and herbicides will be exchanged in order to support adaptation of the DSS to conditions in each of the 3 countries. Farm advisors will test the robustness and the potential of the DSS against existing 'best practices', and advisors and farmers will also evaluate the added value of the DSS. Professional communicators will be involved to disseminate project results to main target groups. Achievements: Four annual workshops have been held in the DSSHerbicide project. On the workshops project participants and relevant invited people have discussed DSS and related issues. Field trials have been discussed and participants have had hands-on test of the DSS.Activities have also been initiated to investigate whether weeds growing in Denmark, Poland and Germany are equally susceptible to herbicides. As the experiments have shown that there is a good correlation between the efficacies, the Danish data has been used when no data was available for certain combinations of herbicides and weed species in Germany and Poland.A feasibility study of the possibilities of integrating a yield loss function based on weed density (the ‘Cousens-function’) has been completed. A prototype was developed based on the study, but the actual implementation in the core program of the DSS has led to severe difficulties. It has, however, been possible to test the prototype in field trials. Further development of this protoypes has been abandoned due to low increased value in the DSS.The prototypes, which are maintained after the project main period, is decided upon and will be kept updated the next 5 years. Project homepages have been constructed: In Denmark www.dssherbicide.dk. In Germany: www.dssherbicide.de. In Poland: www.dssherbicide.pl. Link to project homepages are active on relevant national webpages.Field trials were established in autumn 2011 + 2012, and sprayed according to recommendations from the DSS prototypes in autumn and spring. The last sampling occurred at harvest in Aug. 2013. Spraying recommendations had low input compared to commonly used doses, especially in Germany and Poland. Many farmers and advisors in Mecklenburg-Vorpommern have now heard about DSS and some of them have seen the weed control from the DSS in field trials. Overall the efficacy evaluations have shown that DSS is really a new and appreciated tool to lower herbicide doses science-based. In Germany the interest in DSSHerbicide is increasing. After SAF had reported on DSS the plant protection authorities of the other german federal states were very interested in testing the system. In March 2013 information were given, suggestions for experimental designs were mailed around. In this way 'DSSHerbicide' could become the decision supporting system of herbicide use in Germany.Legal restrictions, in Poland, on use of reduced dosages and herbicide mixtures have been changed in 2012 and therefore there are great interest in a system, which can assist farmers and advisors in their choices. The farmers and advisors are not use to make these differentiated decisions and have not got the experience to support these decisions properly. DSSHerbicide is potentially just the tool they need.