Canola School: The plant emergence assessment toolbox


You’ve finished seeding, and now you’re getting curious as to how the crop’s looking and what kind of plant stand you’ve got. Getting an idea of how many plants per square foot or square meter is a really good idea, but more importantly, an early emergence evaluation helps diagnose any plant stand issues and what may have caused them.

“On the Prairies we see between 45 and 65 per cent average emergence on a given year,” says Autumn Barnes, agronomy specialist with Canola Council of Canada. Although, she says, so far the sample size is small.

Not sure how to tally up survival? Using the plant density (plants per square foot or square meter) in combination with thousand seed weight and seeding rate and plugging them into the canola calculator can help you figure out your emergence percentage.

Barnes says that record keeping is the “unsung hero” of agronomy and looking back at previous emergence records can be a useful exercise. Plus, you don’t just have pen and paper at your disposal, the digital record-keeping tools out there now are abundant, which can record precipitation, seeding speed, and GPS locations of abnormal patches.

Where should the plant population end up? Farmers should target five to eight canola plants per square foot, or around 75 plants per square meter.

“Some growers might want to be in the low end of that range — five to six plants — and some of them, if they have less of an appetite for risk, might want to be in the higher end,” says Barnes.

Here are Barnes’ tips for assessing emergence:

  • Use a plant count hoop or foot square with a known area. Barnes suggests using a hula hoop that’s a quarter of a square meter, because throwing the hoop provides more randomness, and removes some of that bias when scouting. When you do the count, you can multiply the number by four and that will give you plants per square meter.
  • Get out of the headlands and corners of fields, those areas won’t give you an accurate representation of your field, also make sure the crop is at two to four leaf stage.
  • Throw the hoop as many times as you can — the larger your sample size, the more accurate your end result is. Ideally aim for five different spots in the field, but don’t just settle on one area for your count.
  • Try to get to multiple areas of the field, walk a W pattern, get back in the truck and drive to another area, or use a quad to get around if you have one.
  • When you get back to the office, or wherever you keep your records, use the canola calculator tool to get your emergence percentage.

While you are scouting, take note of anything that’s stressing the plant — understand what the damage threshold for an insect is and what that looks like, look for strips in the field that may be due to mechanical issues from the seeder or sprayer, check soil moisture, consider how heavy residue is, and also consider weed pressure. These are additional things that can affect your emergence percentage.

Catch the full conversation between Autumn Barnes and Kara Oosterhuis below:

Other Episodes

Canola School (view all)Season 12 (2020) Episode 17

Please register to read and comment.


Register for a RealAgriculture account to manage your Shortcut menu instead of the default.