Glossary
Sclerotinia (Sclerotinia sclerotiorum)
A fungal disease of canola caused by Sclerotinia sclerotiorum that thrives in dense, humid canopies and is managed with a well-timed fungicide pass at 20–30% flower.
Definition
Sclerotinia stem rot is caused by the soil-borne fungus Sclerotinia sclerotiorum. Apothecia release ascospores into the canola canopy during flowering. Spores land on senescing petals, the petals stick to leaves or stems, and the fungus then colonizes the plant. Severe infections collapse the stem, white mycelium fruits inside, and yield is lost.
In an Alberta Context
In Central Alberta, the disease pressure window typically falls between 20% and 30% flower, when enough petals are present to be infected but the canopy is not yet too dense to spray. Fungicide product choice is straightforward; the harder problem is hitting the timing window in a year where rain blocks ground sprayers for several days at a stretch.
Why It Matters
A missed sclerotinia spray on infected canola can cost 10–50% of yield. Drone application keeps the spray window open in wet years and avoids tramping a flowering canopy that ground equipment would crush — which is why a drone pass on canola at 20–30% flower is one of the highest-ROI uses of an aerial applicator on an Alberta grain farm.