Sclerotinia Risk Map and Risk Caluculator Will Begin June 18th 2017

The first Sclerotinia risk map for the 2017 season will be available on June 18th, at three different websites, the NDSU Canola Pathology program, the Northern Canola Growers Association, and the Minnesota Canola Council. The Sclerotinia risk calculator will be available only at the NDSU canola pathology website.

The color coded Risk Map is designed to estimate risk of white mold development; low (green), moderate (yellow) and high (red). Maps will be refreshed on a daily basis beginning next week and can be observed by clicking on the “Risk Map” button. Clicking on any NDAWN station in the map will show the estimated percentage of risk of disease development for that station. This information will help growers make a more informed spraying decision.The Risk Calculator is an interactive tool that gives more precise risk for a specific field by allowing growers to enter important information about their field (such as crop rotation and disease history) into the forecasting model.

Q. What conditions favor white mold?

1. Adequate rainfall before flowering that keeps the soil wet.
2. Cool to moderate temperatures during bloom.
3. Long wet periods (rain/heavy dew/fog) during flowering.
4. Dense canola canopies that create a wet microclimate.

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?

1. Canola is only at risk during flowering and consequently the Risk Map and Calculator are only applicable during flowering.
2. 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.

Sam Markell
Extension Plant Pathologist, Broad-leaf Crops
 

Luis del Rio
Canola Pathologist