Incidence of eyespot in winter wheat and quantification of the fungi Oculimacula acuformis and O. yallundae in Lithuania

Eyespot, caused by Oculimacula acuformis and O. yallundae, is one of the most damaging diseases in areas, including Lithuania, where mild and damp autumn and winter conditions favour the development and spread of the pathogens. The aim of this study was to estimate the incidence of eyespot in Lithuania and to use real-time polymerase chain reaction to determine the structure of Oculimacula fungi in winter wheat crops, which has not been previously established. From 2008 to 2012, 122 winter wheat fields in three different agro-ecological zones of Lithuania were reviewed for incidences of eyespot. Eyespot was identified in 95.9 % of the tested fields. Eyespot incidence in winter wheat varied depending on the experimental year and location, and the disease was spread over almost all of the tested fields. Depending on the year, the incidence of eyespot in different agro-ecological zones varied from 26.7 to 60.8 %. Both O. acuformis and O. yallundae were found to coexist on winter wheat stems. The amounts of Oculimacula spp. DNA varied between experimental years and sites. The highest amounts of both O. acuformis and O. yallundae were found in mid-lowland zones. For all years, higher averaged amounts of O. acuformis DNA were found in Middle Lithuania; however, for 2 years out of 3, averaged amounts of O. yallundae DNA were higher in eyespot-diseased winter wheat stems from western zones.