Canola seed size can be quite variable. A sample of thousand seed weights (TSW) this spring is ranging from 2.8 to 6.0 grams per 1000 seeds. Essentially the number of seeds (and ultimately plants) in one pound of seed can vary significantly. Take note of the seed size (TSW should be marked on seed tags or seed bags) and adjust seeding rates accordingly. A seeding rate calculator can help with the planning:http://www.agric.gov.ab.ca/app19/calc/crop/otherseedcalculator.jsp
Keep a seed sample and the blue seed tag from each variety and seed lot sown, and store in a paper or cloth bag in a cool, dry place.