The 6 applicants from HU and SK eligible regions develop a 24 month R+D project with the scope to apply combined innovative procedures to improve the health status and quality of regional Prunus species fruit production. Hungary and Slovakia is considered as endemic centres for the Prunus species viruses. Against the viruses no chemical or biological curative treatments are available, at the moment a short-term solution is the eradication of infected trees, the plantation of virus-free material and protection against the virus vector insects. Developing the CBC project is necessary as the group of Prunus spp. viruses (PPV, PDF, PNRSV) involved in the proposal has a severe negative effect on the economic, ecologic and social situation in the involved regions, affecting cca. 25% of HU and SK cca.25-30% of farms and SMEs, traders, processors the quantitative losses can be up to 100% and up to 40% qualitative losses. There is a need for reducing the production and processing costs, to increase the competiveness of the SMEs, SME associations and farmers, to assure high quality products for the processing industry and fresh market. The root of the problems can be solved by the application of the planned RTD activities (activity 2,3,4,5). The climatic conditions of the HU and SK regions allow the production of the targeted Prunus species as 50 % from the national production is realised in the eligible regions.