Complex of barley leaf spots in Ukraine

Barley is one of the most important cereal crops globally. In Ukraine it is grown on an area of 2.4-2.8 million hectares annually and is the second largest grain crop in Ukraine after wheat. Barley grain export is about 4.3 million tons p.a.. At the same time, one of the limiting factors for obtaining a high-quality yield are diseases, in particular, leaf spots. In recent decades, there have been significant changes in the technology of cultivation, the composition of varieties and the pathogenic complex. Net blotch (Pyrenophora teres Drechsler) in net and spot forms and spot blotch (Bipolaris sorokiniana Shoem.) remain the most common among the diseases of barley leaves. They occur in all regions where barley is grown. Barley scald (Rhynchosporium secalis (Oudem.) Davis) is distributed mainly in Forest and Western part of Forest-Steppe zones and has become more widespread in years with rainy summers. Outbreaks of stripe spot (Pyrenophora graminea S. Ito & Kurib.) occur sporadically. Ascochyta leaf spot (Ascochyta spp.) was found in Lviv and Dnipropetrovsk regions in 2020, and in Lviv, Donetsk and Zaporizhia regions in 2021. In the field, spots can be misdiagnosed as barley scald, so its prevalence can be much higher. In 2021 during seed ripening period, ramularia leaf spot was found in Kherson and Vinnytsia regions. The disease was diagnosed in the laboratory by obtaining a typical conidial sporulation of the fungus Ramularia collo-cygni B. Sutton & J.M. Waller on affected tissues (wet chamber). So, last years the composition of the barley leaf spot pathogens has became wider and needs further investigation.