Canola can reach its yield potential with a stand of 7 to 14 plants per square foot. To hit that target, growers may need a different pound-per-acre seeding rate for each seed lot. That’s because canola seed can range in size from 3 grams or less per 1,000 seeds all the way to 6 grams or more per 1,000. To seed the same number of seeds per acre, growers need to adjust their seeding rate accordingly. Drills should be calibrated when switching between crops, or between canola varieties or seed lots with substantially different thousand seed weights (TSW). This will help growers deliver an appropriate seeding rate to achieve the targeted plant population, and may avoid costly errors due to improper settings.
The table below shows how seed size (shown in the left column) influences plant stand. For example, for seed that weighs 5 grams per 1,000, growers need to seed at 7 pounds per acre to achieve 7.3 plants per square foot — based on typical 50% emergence. With 3.5-gram seed, growers can achieve the same plant stand with only 5 pounds per acre. If growers want to stick with their 5-pound seeding rate for the seed lot with a 5-gram TSW, they will need to take steps to improve their rate of emergence.