What is all the Buzz About?

Mercedes Canola is Blooming!

Picturesque fields of winter canola are starting to be observed across the province. Winter Canola has been gaining popularity in Ontario over the last few years. Mercedes is proving to be well adapted for the Ontario climate with strong winter survival and exceptional yield potential. Last fall there were approximately 5,000 acres of Mercedes planted across the province.    

Much of the winter canola is at the early bloom stage and for the most part looks excellent. The frost/snow event we had on April 22 does not seem to have damaged the canola very much. The day following that weather event, the canola was significantly laying over but it has since stood back up and looks strong.

When assessing canola following a frost event, look for cracked stems, frost damaged leaves, damaged crowns, and aborted buds. Just because the stems might be cracked does not mean it is dead.

Mercedes one day following frost event on April 22
Same field five days later standing back up and looks strong

For more information on assessing frost damage, refer to Meghan Moran’s Field Crop News story from last year.


A majority of the winter canola is currently in the early bloom stage which is prime time for fungicide applications for white mould. Fungicides are targeted between 20-50% bloom.

5 – 10% Bloom

Cabbage Seedpod Weevil

It is important to be on the lookout for Cabbage Seedpod Weevil. In the spring, adults emerge from their overwintering sites (shelterbelts, leaf litter, fencerows, and ditch banks) when air temperatures reach 18°C. These newly emerged adults move into winter canola and areas containing other host plants such as wild mustard. After feeding briefly and mating, the female then lays her eggs, typically one per pod, directly into the seedpod itself. The larvae hatch within approximately one week and cause the most damage as they feed on the seeds.

Adult weevils can be seen feeding on the upper flower bud clusters. Pods, flower petals, and buds may also have small visible holes. Punctures become more noticeable with time as the tissue around the hole deteriorates or becomes infected with other pathogens. Pods may also appear bent or distorted from the larva developing within.

Begin sweeping when the crop enters the bud stage through until after flowering. Take 10 sweeps in 10 locations of the field and determine the average number of adult weevils per sweep. Thresholds are 2-4 adults/sweep. Spraying should be timed to when the crop is in the 10 to 20% bloom stage (2-4 days after flowering starts) to control adult weevils before they can lay eggs.

For more information of White Mould Control and Scouting for Cabbage Seedpod Weevil please refer to the following Field Crop News Story form Meghan Moran. https://fieldcropnews.com/2021/04/white-mould-and-cabbage-seedpod-weevil-mangement-in-canola/

Looking ahead to 2022

When looking to plant winter canola this summer be sure to go over this checklist before you plant:

  • Have your seed spoken for well ahead of time. If you have not already done so, please contact your C&M Seeds dealer and book your seed today!
  • Refer to herbicide labels used on previous crops and their re-cropping restrictions as canola is extremely sensitive to certain active ingredients.   Refer to Publication 75 Pages 67-72 http://www.omafra.gov.on.ca/english/crops/pub75/pub75A/pub75A.pdf
  • Ensure your equipment get accurately meter a low seeding rate. Seeding rates on Mercedes can range from 3-5lbs/ac depending on seed size.
  • Start with clean fields as there are very little options for broadleaf weed control in crop. Remember, Eragon and 2,4-D are a no-go ahead of planting. Some tillage may be necessary to help incorporate some residue, perform some weed control and mitigate slug damage. However, no-till has been successful but it is certainly riskier.
  • If you are planting on clay plan to plant on the earlier side in order to have a strong healthy plant going into winter.

Refer to the below C&M Seeds Winter Canola production guide where you will find more management strategies, fertility recommendations, establishment guidelines and other scouting tips! https://redwheat.com/agronomy/wheat-news/winter-canola-production/

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