For a couple of years european farmers in some main cereal growing regions have to cope with a previously undescribed disease on cereal crops, particularly on barley. A complex of leaf spots, usually appearing within a few days after anthesis can cause an extensive and rapid loss of green leaf area. Yield penalties up to 20 % were reported.The apparent diversity of symptoms between different geographic regions led to some confusion about the causal agents. Biotic (pathogenic fungi) and abiotic (environmental) factors were made responsible. The fungus Ramularia collo-cygni has been identified as one pathogenic factor. Environmental conditions discussed, include high solar irradiation, insufficient nutrition (B, K, Zn) surface near ozone and even quick temperature changes. There is still considerable debate about the relative importance of each of these factors.

The objectives of this project are the development of techniques for the identification, isolation, storage and propagation of Ramularia collo-cygni, the development of a common quick visual assessment system for field symptoms, the identification of resistant barley genotypes and the start of a breeding program for the development of new resistant breeding lines.

A clear defined project aim is the release of resistant cultivars in post project years.