Canola Watch – August 5 ,2021

August 5, 2021
Verticillium stripe is a new disease which thrives in dry conditions. It is starting to show up as prematurely ripened patches across fields in Manitoba.

Canola Quiz – This Week in Insects

Four questions on insect observations in canola fields this week in Western Canada.

Take the Quiz

In This Issue

Know the facts before spraying for late-season insects

Depending on location, late-season insect pests such as lygus bugs and grasshoppers may be causing concerns for producers already experiencing a hot, dry growing season. The question most farmers have is whether it’s worthwhile to spray. For lygus bugs, this updated article  features tips on lygus scouting and thresholds. This article offers advice for managing late-season flea beetles, which generally don’t impact canola yield this late in the season. Interested in learning more about grasshoppers in canola? Check out this story. One of the most important things you need to know before spraying is whether doing so at this stage will affect the marketability of your canola. This depends greatly on the pre-harvest interval (PHI) of the pesticide you’re using; in some cases it may be too late to spray. The  Spray to Swath Interval Calculator can help producers determine the PHIs of various pesticides on canola.

Swath or straight-cut: a common question that comes up every year

Do you swath or straight-combine canola when the stand is uneven? When the crop is lodged? When you want to combine sooner? Advice on all these scenarios and more is available here. Straight-cutting thin stands comes with both upsides and risks. Some tips are available here. If you’re straight-cutting, desiccation timing and tools are crucial knowledge to have pre-harvest — see this article. And with such hot, dry conditions throughout most of the Prairies, desiccation may not be necessary. See this story for more information. Again, check the  Spray to Swath Interval Calculator before using any product – including desiccant — on canola. This is a must with harvest rapidly approaching.

Late season essential time for disease scouting

Diseases are usually easiest to see and diagnose in the couple of weeks around swath timing. This article is a near-comprehensive guide to pre-harvest scouting for a large number of diseases including blackleg, clubroot and sclerotinia. Verticillium stripe is a new disease to keep an eye out for which thrives in dry conditions. It is starting to show up as prematurely ripened patches across fields in Manitoba. Premature ripening can be caused by a number of factors, so it’s best to check plants and fully assess from pod to root. Scouting tips for the disease can be found in the preceding link and the above video. As well, the CCC Canola Disease Scouting Guide can be brought along to the field and the Pre-Swath Disease Scouting video can be used as a reminder and visual reference for all major canola diseases.

Tools you can use

Canola Council of Canada features a range of tools that can help you get the most from this year’s canola harvest or adjust future management decisions. Learn more:

Scout Checklist


Herbicide history (and carryover risk)

Lygus bugs

Root Rots



Verticillium Stripe

Community Connect

Helpful links for delivery contracts. Many growers have expressed concerns about not being able to deliver on forward-priced delivery contracts. Our national producer group, the Canadian Canola Growers Association (CCGA), has developed resources that can help farmers navigate their contracts: CCGA: What to Consider if Production Comes Up Short on a Deferred Delivery ContractCCGA: A Practical Guide to Navigate Grain ContractsCCGA: website

Thanks from Manitoba Canola Growers. Manitoba Canola Growers would like to thank everyone that joined us for our Make Every Seed Count: Practical Tips to Minimize Canola Harvest Loss webinar. We really appreciated everyone who took part in the event and asked questions. We are happy to share this webinar recording with everyone that registered.

Leave check strips in fields sprayed for lygus. Help us harvest valuable information from this challenging year by leaving a check strip in fields that get sprayed for lygus. After sweeping the field, record lygus numbers (threshold is 2-3 mature or late instar nymphs per sweep). The impact of lygus is different in wet and dry conditions, and if we collect enough data from check strips this year, we will have better information the next time a hot, dry, lygus summer occurs. The check strip should be 200-300 m long (or the length of the field) and be situated away from the field margins. Think you can do this or already have? Reach out to Keith Gabert ([email protected]) or Autumn Barnes ([email protected]) with the Canola Council of Canada.

Canola flower midge. Tiny midge larvae have been collected within pods in a few fields in south central Saskatchewan and Alberta. DNA analysis from 2020 identified one of these samples as Contarinia brassicola (canola flower midge). If you find larvae in canola or any other unexpected pest in your canola, collect and preserve them. Then contact your local Canola Council agronomy specialist to assess. Canola flower midge is not considered an economic threat to canola production in western Canada, but since it is closely related to swede midge, a serious pest elsewhere in brassica vegetables, canola and oilseed rape production globally, research is underway to learn more about this relatively new pest.

SURVEY: Agroclimate Impact Reporter: Growing Season 2021. Agriculture and Agri-Food Canada is currently collecting information from producers to detail the impacts they are facing due to weather and climate. Please complete this five-minute survey to provide information on the situation in your local area and distribute to others in your network who may have information to share.



Canola Watch is a free, unbiased, timely and research focused weekly newsletter from the Canola Council of Canada Crop Production Team

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