Harvest is a great time to assess the incidence and severity of canola diseases, an important step in management for next year.
Post-swathing disease scouting is possible but results are not as accurate as pre-swath scouting. As plants die down after cutting, the plant’s immune system no longer works and saprophytic organisms start growing rapidly. These organisms can darken tissue surfaces and inside stems, making it more difficult to identify blackleg, sclerotinia stem rot and other diseases. Clubroot galls also break down quite quickly after swathing. Within a few days, the opportunity to identify diseases and assess disease severity after swathing is lost.