Diagnostic of white mold and their occurrence in winter oilseed rape fields in southwestern Slovakia in 2012-2013

During 2012 and 2013 petals of rape flowers were collected and placed onto agar (PDA). Agar plates were assessed for Sclerotinia occurrence. Further assessments of health status of plants were made during maturation at the same oilseed crop and number of plants attacked by Sclerotinia sclerotiorum was recorded. There was found relationship between the % of flower parts testing positive for Sclerotinia by agar plating and final levels of Sclerotinia rot. The method can be used to obtain information on the level of infection pressure and the risk of white rot occurrence in the field. Base on the forecast the level of white rot infection during flowering can be determine the time of fungicide application. If the level of Sclerotinia infection pressure is low there is no need for oilseed crop control.