7 to 10 plants per square foot is still the target plant population when seeding canola. That hasn’t changed, but some of the practices used and the way we think about achieving an ideal plant stand might need to be re-evaluated.
For example, research has shown that stand establishment is generally higher with a lower seeding speed, so there’s been an emphasis on not driving too fast when seeding.
Driving slower, by itself, may not result in any stand benefit, notes Neil Harker of Agriculture and Agri-Food Canada – Lacombe in this Canola School episode.
“Depth is the biggest factor. The complicating factor is if you go really fast, the depth will change,” he explains.
Harker also suggests growers are increasing their risk of poor stand establishment by cutting back on seeding rates, going as low as 1.5 pounds per acre.
“Going down to 1.5 pounds per acre is not going to give you 7 plants,” he says. “In fact, it can’t unless your seed size is well below 2 grams per thousand, which is about half the normal seed size.”
He notes excellent soil moisture conditions during or right after seeding in recent years have allowed growers to get away with lower rates.
“Over the last 2 or 3 years, especially in ’13 and ’14, we had really excellent soil moisture conditions. They did all those studies under really excellent soil moisture. Then you come to a normal year and all the great results turn to dust. I’m worried that once we come under more normal conditions, these really low seeding rates are going to hurt us.”
Not only does a good plant stand have a higher chance of producing a bigger yield, growers should also consider the extra costs — less room for insect damage and likely additional herbicide applications — that come with helping a poor stand limp to harvest, notes Harker. More uniform maturity and a tighter flowering period are also benefits to getting that 7 to 10 plants per square foot.
Neil Harker shared some reminders about achieving good canola stand establishment at the Canola Discovery Forum in Canmore, AB:
- Canola School: Plant Stand Counts
- Canola School: Assessing Seed Survival and Seeder Performance
- Canola School: Ignoring the Outlier Growing Season