Canola Watch quiz – clubroot

Check pre-mature ripening areas for diseases, digging up roots to look for galls. Credit: Dan Orchard
Check pre-mature ripening areas for diseases, digging up roots to look for galls. Credit: Dan Orchard

1. At what concentration of clubroot spores per gram of soil are you likely to start seeing field symptoms?
2. Fill in the blank: Heavily-infested fields in Alberta can have _________ or more clubroot spores per gram of soil.
3. Tillage is the fastest way to spread clubroot within a field. If distributed evenly, just one gram of heavily infested soil (the volume of a Smartie) contains enough spores to seriously infest how much canola?