S4-2: Overview of the joint research project "SkleroPro" – Evaluation of environmental factors affecting Sclerotinia sclerotiorum

Abstract: Sclerotinia stem rot (SSR) is an economically damaging disease of winter oilseed
rape in all areas of intensive oilseed rape cultivation. SkleroPro, a forecasting model, was
designed to support the process of decision-making for fungicide application against SSR
during the flowering growth stage. This work aims to update and evaluate the environmental
data affecting the SkleroPro model. Climate chamber experiments were designed to evaluate
the effect of temperature, light intensity, and relative soil humidity on carpogenic germination of sclerotia under controlled conditions. Results showed that a temperature of 15 °C at a relative soil moisture content up to 75 % was optimal for sclerotial germination. Additionally, a day/night regime of 12/12 h with a UV light component was necessary for formation of apothecia. At lower temperatures, the formation of stems and apothecia took significantly longer. At higher temperatures, stems were thinner and longer. Lower soil moisture content resulted in slower germination. No germination could be observed at relative soil moisture content of less than 50 %.