Promoting Canadian Oats


Broadleaf management strategies that should be considered include increasing seeding rates, using weed control (tillage or herbicide) prior to seeding and varying seeding dates. There are also a number of herbicides available for weed control in oats.

Herbicides containing 2,4-D should be avoided on oats as it has been shown to cause considerable yield reduction. Products containing dicamba should be used according to the stage restrictions on the label. Application of dicamba products under stress conditions should be avoided.


Grassy weed management strategies are much more difficult in an oat crop. Growers should be considering increasing seeding rates, using weed control (tillage or herbicide) prior to seeding and varying seeding dates. There are a limited number of herbicides registered to control grassy weeds. Lorox/linuron are registered for controlling barnyard grass and suppression of green foxtail.

There are a number of strategies used to deal with wild oats. They include:

  • Growing on fields with low wild oat populations.
  • Delaying seeding until wild oats have emerged and are controlled.
  • Using tillage or herbicides just before emergence of the oats to control emerged wild oats.
  • Increasing the oat seeding rate in order to have a more competitive crop.
  • Applying fertilizer in precision bands adjacent to the seedrow in order to make the crop as competitive as possible.
  • Using delayed release seed placed N to keep nutrients for later crop stages.
  • Growing most competitive variety of oats.
  • Consider seeding oats with a larger seed size. [See research article below]
  • In rotational crops before and after an oat crop, wild oat populations can be depleted with the use of herbicides or growing a perennial forage crop for a number of years.

2017 Alberta guide to crop protection:$Department/deptdocs.nsf/all/agdex32/$FILE/606-1.pdf
2017 Saskatchewan guide to crop protection:
2017 Manitoba guide to crop protection

RESEARCH PAPER (2005): Crop Science 45: 1410-1416 (2005)

“Oat Caryopsis Size and Genotype Effects on Wild Oat-Oat Competition”

Christian J. Willenborg1, Brian G. Rossnagel2, and Steven J. Shirtliffe3*.

  1. Dep. of Plant Sciences, Univ. of Saskatchewan
  2. Crop Development Center, Univ. of Saskatchewan
  3. Dep. of Plant Sciences, Univ. of Saskatchewan, *Corresponding author

“Wild oat competition causes extensive yield and quality losses in… oat”
“Traditionally, wild oat was controlled by delaying planting so that emerged wild oat could be controlled by tillage. However, delayed planting of oat causes substantial declines in grain yield, test weight, plump seed and groat percentage with a corresponding increase in thin seed percentage.”
“A key component of integrated weed management systems is to grow competitive varieties.”
“Our main objective was to assess the relative importance of oat caryopsis [grain] size and genotype in affecting wild oat-oat competition in the greenhouse….We conducted this study in a greenhouse because it provided us with a high degree of experimental control, repeatability, and precision, allowing us to isolate the effects of seed size on oat competitive ability.”

This greenhouse study was conducted during 2002 and 2003 at the University of Saskatchewan at Saskatoon. AC Assiniboia, CDC Boyer and CDC Orrin were the varieties used. All seed was sourced from the same location. The seed groupings LARGE, MEDIUM and SMALL were determined on the basis of the groat size to eliminate the effects of the size of the hull.

“Oat derived from large caryopses [grain] produced 17% more biomass and 15% more panicles per m2 than plants derived from small caryopses, irrespective of genotype or wild oat competition. Similarly, plants established from medium-seeded caryopses produced 11% more biomass and 9% more panicles than from plants established from small caryopses.” It was noted that statistically, the large and medium effects were not significantly different from each other.

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