Canola seed size has climbed in recent years from a once-common 4 grams per 1,000 kernel weight to north of 7 grams per 1,000 seeds. What does that mean to you, the farmer? It means that if you’ve stuck with your typical four pounds per acre seeding rate (and there are good reasons to do so) you’re actually putting down nearly half as many seeds as before.
Are big, fat seeds more vigourous? At the recent CanoLAB event held in Brandon, Murray Hartman, oilseed specialist with Alberta Agriculture, tackled that exact topic. Turns out that, yes, larger seed is ever so slightly more vigourous, however, the slight increase is more than cancelled out by the far fewer seeds per foot of row you’d end up with if you stick with seeding at your historical rate.
Hartman recognizes though that doubling your seeding rate to make up for the seed size difference isn’t reasonable either. Instead, he encourages farmers to dial up the pounds per acre slightly but take the extra time to ensure more of those seeds become actual producing plants.
(Source – http://www.farms.com/news/making-adjustments-for-canola-seed-size-74620.aspx)