Q. What conditions favor white mold?
- Adequate rainfall before flowering that keeps the soil wet.
- Cool to moderate temperatures during bloom.
- Long wet periods (rain/heavy dew/fog) during flowering.
- Dense canola canopies that create a wet microclimate.
Q. How do the risk map and risk calculator help me?
Both tools help you understand your risk for white mold, which can help you decide whether or not to apply a fungicide. We always encourage growers to make the most informed decisions they can using as much information as possible; these tools can help you make those decisions.
Q. When should I start using the risk map and risk calculator?
The risk map and risk calculator are only applicable when your canola is in bloom. Canola petals are necessary for infection by Sclerotinia ascospores to occur. Thus, canola is only susceptible when it is blooming. From colonized petals, the fungus spreads to healthy green tissues and eventually, large yield-robbing lesions will develop on the stem and branches.
Q. How does the risk map work?
The Sclerotinia risk map is created from weather data collected from NDAWN weather stations to determine if conditions are favorable for ascospore dispersal and disease development. Green, yellow and red areas signify areas of low, medium and high risk.
Q. How does the risk calculator work?
The Sclerotinia risk calculator uses the same data collected from NDAWN, but also takes into account additional data that grower can enter into the site. The additional data adds personalization and precision to Sclerotinia risk forecasts and is especially helpful when fields are in areas of intermediate risk.
What limitations do the risk map and risk calculator have?
- Canola is only at risk during flowering and consequently the Risk Map and Calculator are only applicable during flowering.
- The maps are only as good as the data received from NDAWN, and rainfall is notoriously variable. If you know that your fields have had more (or less) rain that the nearby station your risk may be higher (or lower).
Q. Who developed the risk map and risk calculator?
The tools were developed by NDSU canola pathologist Luis del Rio with funding from the Northern Canola Growers Association.
Extension Plant Pathologist, Broad-leaf Crops
Luis del Rio