Control weeds early to eliminate the competition for this year’s canola crop, says Arvel Lawson, crop production program manager with the Canola Council of Canada.

“Young canola plants are not very competitive,” explains Lawson. “Weeds just out-compete young canola plants for soil moisture and nutrients. The yield loss can be high.”

Research shows that weeds that emerge before or with the canola crop cause greater yield loss than weeds that emerge after the crop is established – approximately the 4- to 6-leaf stage. But a pre-seed burnoff with glyphosate can allow canola to develop with minimal weed competition, she says.

Scouting for weeds before applying a pre-seed burnoff is critical this season since the cold, dry spring has limited weed emergence in many areas. If few weeds are visible in the field and the ideal seeding date has arrived, consider using a post-seed, pre-emergent treatment BEFORE seeded canola comes out of the ground, says Lawson. First, make sure weeds are actually present.

Remember glyphosate is a systemic herbicide that needs time to work for maximum control, Lawson adds. Consider formulation and target weeds when determining the time required between application and soil disturbance from tillage or seeding.

”With temperatures getting close to or dipping below zero at night, we recommend spraying glyphosate only after temperatures have warmed the following day,” she says. “After a hard frost, check for new growth before applying herbicide because weeds must be actively growing to ensure herbicide uptake and maximum kill.”

If volunteer canola control is your target, the only option before canola is a pre-seed application of glyphosate and carfentrazone. This will control all types of volunteer canola if used at the proper stage. Applying even light rates of 2-4,D or MCPA to control volunteer canola or other hard to control winter annuals is a bad idea because this is not a registered use prior to canola and may result in herbicide injury to the crop, says Lawson.

For more information, contact:

Arvel Lawson, Program Manager, Crop Production, 204-982-2124 or

Kelly Funke, Communications Officer, 204-982-2111

For more information in your area, contact:

Derwyn Hammond, Manitoba, 204-729-9011

Jim Bessel, North Central & North Eastern Saskatchewan, 306-373-6771

David Vanthuyne, Eastern Saskatchewan, 306-946-3588

Doug Moisey, East-Central Alberta and Northwestern Saskatchewan, 780-645-3624

Matthew Stanford, Southern Alberta and Southwestern Saskatchewan, 403-327-4832

John Mayko, West-Central Alberta, 780-764-2593

Erin Brock, Peace Region, 780-586-3326

This media release is supported regionally by:

Alberta Canola Producers Commission; Saskatchewan Canola Development Commission;

Manitoba Canola Growers Association; Canola Council of Canada; Peace River Agriculture Development Fund; B.C. Ministry of Agriculture and Lands.