As part of our Growing Series 2016-17 season, we’re bringing you timely agronomic advice to help you achieve your yield goals. Cutworms are a serious pest in canola, and this year they seem to be fairly widespread in growing regions throughout Alberta, Saskatchewan and Manitoba. So how do you prevent cutworms from showing up in your canola fields next spring?
My lesson in cutworm prevention
I know first-hand just how painful cutworm damage can be. Earlier this year, my husband and I left our farm for a weekend away. I really pride myself on doing a good job scouting my fields, so I felt confident that my canola crop would be fine on its own for a couple days. But when we returned home, I was horrified to find cutworms feasting on most of our fields!
I’d never had cutworms in my fields before, and I used to think that I could control a threat with an insecticide application. Now I know better. Here’s why I’ve changed my view and will now be adding a product like Lumiderm® or Fortenza® to our canola seed treatment package.
1. Cutworm damage can be devastating
Cutworms are a very tricky pest to control because they’re so difficult to predict. It’s hard to know when they’ll show up, and when they do arrive in a field, cutworms can do an enormous amount of damage in a very little time if the conditions are right. They are voracious eaters and can strip a field of canola in just a few days. By the time this happens, it’s often too late to reseed canola and many other crops.
2. Cutworms are now damaging crops under a wider range of conditions
Another important consideration is that it’s getting much more difficult to control cutworms these days. In the last half-dozen years or so, different species of cutworms have emerged that feed under a wider range of environmental conditions. It used to be when it was rainy outside you didn’t have to worry about cutworms in your canola, but that’s simply not the case anymore.
3. You must scout 1-2 times per day during early crop stages
Because cutworms can be so aggressive, we need to scout fields very carefully and deliberately if we hope to spot the pests before they cause too much damage. Ideally, this means scouting your canola fields every day – and sometimes twice a day – during the spring when leaf development is from the cotyledon to the six-leaf stage.
For most growers or agronomists though, it’s hard to imagine having this much time to spend scouting for cutworms. And even if you are a dedicated crop scouter, you could still run into a similar scenario to mine.
4. Foliar insecticides can be tricky to apply
Once cutworms are established in a canola field, a foliar insecticide can give you control. However, trying to kill insects that live just under the soil surface and having to spray for them at night is not an ideal situation.
After I discovered the cutworms on my farm, we applied foliar insecticide on about 1,200 acres. Fierce, relentless winds required us to leave large no-spray buffer zones around the edges of the affected fields. Unfortunately, these buffer zones became refuges for cutworms, which then quickly continued to spread.
Consider cutworm seed treatment as insurance against crop failure
Adding a cutworm control to your canola seed treatment package is not cheap. It’s also not an investment that’s guaranteed to return, since there’s no guarantee that cutworms will show up in your canola in any given year. For these reasons, I used to skip the cutworm treatment myself.
Now I know that the value of cutworm seed treatment goes beyond ROI.
Growers in areas with a history of cutworm infestation understand this point. They regularly invest in seed treatments with cutworm control because they know it’s the best way to safeguard against devastating yield loss. But if you feel as I did at the start of the season, and you’re on fence about cutworm seed treatment, I encourage you to ask yourself, “What is my peace of mind worth?” For me, it’s worth the extra dollars per acre.
When you’re booking your canola seed for next season, I encourage you to talk to your Cargill rep about adding cutworm protection to your seed treatment. For more information on this pest and strategies to control it, give your local Cargill agronomist a call.
Lumiderm® is a registered trademark of E. I. du Pont de Nemours and Company. Fortenza® is a trademark of a Syngenta Group Company.