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Sclerotinia Risk Map for the 2016 Growing Season to Start on June 20th (06/09/16)

The first Sclerotinia risk map for the 2016 season will be available on June 20th, 2016 at three different websites.

Sclerotinia Risk Map for the 2016 Growing Season to Start on June 20th

The first Sclerotinia risk map for the 2016 season will be


available on June 20th, 2016 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. Both, the risk map and the risk calculator were designed to help growers determine if environmental conditions are favorable enough for white mold that a fungicide application is warranted.  The risk map and risk calculator are only applicable when canola is in bloom. The user-friendly tools were developed by canola pathologist Luis del Rio at NDSU with funding from the Northern Canola Growers Association.

How they work. Canola petals are necessary for infection by Sclerotinia ascospores to occur. From colonized petals, the fungus spreads to healthy green tissues and eventually, large yield-robbing lesions will

develop on the stem and branches (Figure 1). However, infection only occurs if conditions are favorable; adequate rainfall before flowering and cool to moderate temperatures with long wet periods during flowering will promote infection.  

The Sclerotinia risk map is created from weather data collected from NDAWN weath

er stations to determine if conditions are favorable for white mold. Green, yellow and red areas signify areas of low, medium and high risk.

The Sclerotinia risk calculator uses the same data collected from NDAWN, but also takes into account additional data that growers 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.

Two words of caution. First, canola is only at risk during flowering and consequently the Risk

Map and Calculator are only applicable during flowering. Secondly, the maps are only as good as the data received from NDAWN. If you know that your fields have had more (or less) rain that the nearby station your risk may be higher (or lower).

Sam Markell

Extension Plant Pathologist, Broad-leaf Crops


Luis del Rio

Canola Pathologist


This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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