The symptoms include premature ripening and pale-grey or white lesions on stems, branches and pods. Sclerotia form within the stems, branches and pods. Severely infected crops frequently lodge, shatter at swathing, and make swathing more time consuming. If the field has a previous history of sclerotinia and weather conditions have been wet several weeks prior to canola flowering, scout the field for small mushrooms at the early blossom stage. After flowering look for prematurely- ripened plants.
Infections begin as a soft rot that girdles the stem.
The lesions turn white, become brittle, and tend to shred. Economic Thresholds Petal test kits and in-field diagnostic kits are commercially available. These enable a grower to determine the cost effectiveness of sclerotinia control. A sclerotinia stem rot checklist can also assist in predicting stem rot disease levels. The checklist considers yield potential, previous disease presence and current weather conditions.