Nectar collection and honey yield is most dependent on the age demographics of the bees in the hive at the time of the flow of the target bloom(s). Timing of the peak of population, and right age of population, is the difference between boxes packed full of honey and a mediocre crop. The boxes can be full of bees, and get no crop. Or the boxes can have much fewer bees and get a huge crop. Colonies that are in build-up mode, as in pre / post pollinating, will never collect as much nor impress.
With respect to canola, all I can say is that when a hive is primed, 2 boxes completely packed full of fat 9 frame deeps half capped in 4 days is the norm. 3 to 4 boxes (160-200lbs) crop per hive in one week. Canola here is a very fast, very short crop window (7-10 days). If the bees peak at the same time as the bloom, it is overwhelming, bumper crop. If the bees peak before or after the bloom, it is underwhelming - and everyone goes to the coffee shop complaining about the weather. It is rarely ever the weather. It is nearly always if the beekeeper hit or missed on the timing of his/her hives. How else would you explain different beekeepers operating in the same area, with hives visible from from each others bee yards, where one is complaining over a cup of java while the other is working so hard at capturing the bumper crop that he has no time for java or such nonsensical talk?
I have never been set in a canola field that didn't completely overwhelm us with the rapidity and the volume of the flow. I have been to other's neighbouring bee yards that the hives were very underwhelming in their preparedness and performance - in pretty much the same field.