Development of a rapid quantitative detection method for sclerotinia stem rot inoculum to aid disease risk assessments and fungicide spray decisions

The Challenge

Sclerotinia sclerotiorum is one of the most important biotic stresses influencing long-term production and economic stability for canola producers. Without a reliable stem rot forecasting system, growers estimate risk associated with the pathogen which typically increases environment and economic effects.

The Project

Continue the Growing Forward Canola Cluster project through the development and refinement of a rapid quantitative method for pathogen detection on flower petals, as well as understanding the relationship between the amount of pathogen present on the petals and final stem rot levels. Pathogen detection, weather-based forecasts and final disease severity will be assessed for correlation, and the deployment of an available test to the canola industry for stem rot forecasting.

The Results

The qPCR-based assay is the first method to be developed in Canada for detection and measurement of S. sclerotiorum. The relationship between inoculum level and disease incidence was found to be complex as factors such as weather, crop density, and seeding date influenced the disease pressure. With further research, it has the potential to serve as the basis for a Sclerotinia stem rot risk assessment tool.

Grower Benefits

Although the rapid quantitative method can’t tell growers to spray their canola with a fungicide or not, it does provide a general indication of stem rot risk. Considering pathogen incidence and distribution along with environmental factors can aid in furthering the decision.