Abstract Ramularia collo-cygni is the biotic factor responsible for the disease Ramularia leaf spot (RLS) of barley (Hordeum vulgare). Despite having been described over 100 years ago and being considered a minor disease in some countries, the fungus is attracting interest in the scientific community as a result of the increasing number of recorded economically damaging disease epidemics. New reports of disease spread and fungal identification using molecular diagnostics have helped redefine RLS as a global disease.

Abstract:The annual average area sown with barley (Hordeum vulgare) in South America during 1999–2003 was 795 000 ha. In Argentina, Brazil, Chile and Uruguay, two-rowed spring cultivars are used mostly for malt production. Research has been developed in private malting companies and official institutions supported by the industry. In Argentina, tolerance to drought and heat stress during grain filling are important in drier areas. Yield and malt extract had been improved in cultivars released from 1940 to 1998.