Update: The Canola Council of Canada has developed online calculators to determine your target plant density based on your individual field conditions, abilities and appetite for risk, as well as optimum seeding rate. You can find them at CanolaCalculator.ca.
While the official industry recommendation for an optimal canola plant stand remains 7 to 10 plants per square foot, farmers have cut back on seeding rates to save on seed costs.
Not everyone in the canola agronomy world agrees, but some extension agronomists and researchers are suggesting the industry recommendation should also be lowered to acknowledge the economic reality of higher seed prices.
Murray Hartman, oilseed specialist with Alberta Agriculture & Forestry, made the case for lower seeding rate recommendations at the 2016 Canola Discovery Forum recently held at Winnipeg.
“I don’t think 7 to 10 is an economic range for producers to target. It should be lower than that,” he explains in this Canola School episode.
Hartman would like to see a calculation or app developed that takes multiple variables into account to provide growers with the personalized optimal economic seed rate.
In some cases (the seeding rate) is too low and growers are sacrificing yield and economics — Murray Hartman
As he explains, there’s a long list of variables and risks that need to be considered, including seed costs, canola prices, seed placement and emergence rates, target yield, weed pressure and resistance concerns (since a thinner stand might require an extra application), seed-placed fertilizer toxicity, frost risk, flea beetle pressure, and fungicide timing.
“There are a lot of factors to consider, and not all of them are easy to quantify,” he notes.
While the optimal rates for individual fields might differ, Hartman favours lowering the industry standard to four to six, or even five to seven plants per square foot.
“It’s a significant change, but it’s something that’s already occuring in the country,” he says. “And in some cases it is too low and growers are sacrificing yield and economics, so it’s ‘what is the optimum to go down to?’ And that’s going to vary between producers on some of these factors.”
As noted in this article, the Canola Council of Canada is sticking with its recommendation of 7 to 10 plants per square foot.