Early weed removal is best

May 6, 2015 - Issue 8

Lamb's-quarters

Lamb’s-quarters

Early weeds have large impact on canola yield potential. Past research has demonstrated an advantage of 3 bu./ac. for controlling weeds at the 1-2 leaf stage of canola versus the 3-4 leaf stage, and a 7 bu./ac. advantage for the 1-2 leaf stage versus the 6-7 leaf stage.

Weed control timing has a huge influence on overall crop profit with no added cost.

These numbers will be even higher if a preseed burnoff was not completed. If the crop is seeded without a pre-seed burnoff, in-crop weed control should occur as early as possible. Canola is much more vulnerable to weed competition prior to reaching complete ground cover. Smaller weeds are also much easier to kill than weeds at their 4-leaf stage or later.

Scout fields to determine the number, size and species present in each field before choosing a rate and tank mix.

Related links:

Winter annual cleavers need pre-seed control
We had a frost last night. When can I resume weed control?
Canola Encyclopedia chapter on post-emergence weed control
Pre-seed burnoff: 8 top weeds and how to control them

Canola Watch