Sclerotinia + Fungicides
If we have moisture, we will have sclerotinia.
Sclerotinia stem rot is the most economically significant canola disease in Canada and is hard to predict based on its influence from environmental conditions leading up to and during canola flowering. With a build-up of sclerotinia in the area and the potential for a wet/humid spring and summer in many parts of Saskatchewan, ensuring prevention of sclerotinia could be crucial for the success of your canola crop this season.
Canola plants are infected with sclerotinia during flowering when spores are present and conditions include rainfall and humidity causing leaf wetness and soil moisture. Other factors can include crop density, crop canopy/plant architecture, and crop height, which can aid in moisture retention. When there is moisture in our area, there is sclerotinia.
The sclerotinia fungus spends most of its life cycle in the soil as a hard-walled resting structure called a sclerotium, waiting for the next canola crop to be planted and then for the right amount of moisture to germinate and produce apothecia, releasing spores in high numbers. The Prairies have a history of large canola crops with regular incidence of sclerotinia, leaving the pathogen everywhere. Which is why environmental conditions are key in predicting sclerotinia.
Early signs of sclerotinia in your canola will include the appearance of soft white to grey lesions on the leaves and stems. As lesions advance, the tissue will rot and form rings that may appear in a “bull’s eye” pattern. When sclerotinia is present in your canola, there will be yield loss.
According to the Canola Council of Canada, “fungicides are the most effective management tool to control sclerotinia stem rot in canola when the risk of infection is high.”
It can be helpful to look at your fungicide investment as an insurance policy as well as a prescription. Considering the spray window for sclerotinia is 20-50% of flowering, and after flowering is too late, the risk has to be assessed and acted on.
Contact your Sharpe’s Crop Services team to help you decide on a fungicide solution for this season.