Canola Watch quiz – Sclerotinia spray decision

June 27, 2018 – Issue 13

Five questions that could help you think through the sclerotinia stem rot spray decision.

1. Assuming continued soil moisture, how long does it take for sclerotia in the soil to germinate, produce apothecia (shown in the photo) and then release spores?
2. When does this spore release occur?
3. Most sclerotinia infection in canola begins at which one of these crop stages?
4. If a fungicide is required, the recommended window for application generally falls somewhere between 20% and 50% flower, with optimum timing typically around 30% flower. What is the flowering stage of the crop in this photo?

5. Risk of economic loss from sclerotinia stem rot is considered high enough to warrant a spray if the canopy is thick and moist, soil moisture is enough for sclerotia germination and canola yield potential is at least _____ bu./ac.

 

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