Not too late for pre-seed burnoff

2010 - Issue 4

We have conditions for fast and effective herbicide results: sunny, warm and humid. Good performance also depends on evening temperatures remaining well above freezing.

If growers haven’t seeded yet,  they should consider pre-seed burnoff — even at this  date. If they just seeded, consider a post-seed, pre-emergent spray. Large weeds left standing to compete with the emerging crop, which won’t be up for 10 days if you seed today, will take a huge bite out of yields — and will be that much harder to control.

What about a second pre-seed burnoff? If growers did an early pre-seed burn two weeks ago but haven’t seeded the crop, they may want to consider a second pre-seed application. “That application can be the equivalent of an in-crop spray if it happens late enough in the spring,” says Clark Brenzil, weed management specialist with Saskatchewan Ministry of Agriculture. “Canola growers make three herbicide applications now with their double shots, so how does this differ from making two burn-offs and one in-crop app? The diesel to run the sprayer is the same but the cost of herbicide will definitely be less.”

Work by Neil Harker et al at the AAFC Lacombe Research Centre also shows that a second in-crop glyphosate application rarely pays off in terms of higher returns from the crop. The second in-crop glyphosate application, according to study results, did reduce weed biomass, but canola yield was not significantly different.


Canola Watch