The Prairie Giants Crop Report

Field observations at your fingertips

November 27, 2021

Taylor Kurtenbach

2021 Season in Review
Wow – what a year! The 2021 season brought many challenges, but among it successes as well. The season started off cool and dry, but a mid-May rain got crops off to a good start. Flea beetle pressure was high, with many growers applying insecticide to fields multiple times. Canola treated with Buteo Start and Lumiderm fared better but were not immune. We also noticed other abiotic stresses in crops such as colour banding in cereals and heat canker in canola due to the extreme temperature fluctuations at the soil surface. 
Colour banding

Colour banding

Heat canker

Heat canker

Herbicide application timing brought hot temperatures, making spraying a challenge. Crops continued to prosper, despite the tough conditions they faced. Extreme heat continued into flowering resulting in heat blasting. Fungicide applications in wheat showed value this year, while sclerotinia applications in canola did not.

We were lucky enough to be able to host an in-person crop tour this year – it was a great day getting together with growers and industry reps! We were able to see and hear about lots of new and exciting innovations coming down the pipeline in the next couple years, including new wheat and canola varieties as well as a new fungicide from BASF (Shaerex).  

August brought rain, and although it was too late for many crops, it helped to replenish moisture deficits and help breakdown herbicide residues (more on this later). Crops matured earlier than normal, due to lack of moisture. For the most part, yields were better than expected and correlated with rainfall. On September 14th, the canola trial was successfully harvested with the big winner being L340PC! We were able to watch this trial throughout the season and got a good feel for the varieties, including two experimental varieties* that are available for the 2022 growing season. A huge thank you to our grower co-operator, Reece Keay, for all his hard work with the trial!
*Experimental Dekalb = DKLL 83 SC; Experimental Brevant pending registration

Thank you to all who supported us this past year, we look forward to working with you all for years to come! – Doug, Shelly, Braden, Taylor, Andrea and Kaleb
2022 Herbicide Carryover Risk
Herbicides are broken down by two main pathways – microbial activity and chemical hydrolysis, but microbial activity is the most important. These are influenced by several factors including:
  1. Soil PH
  2. Organic matter content – organic matter binds to herbicide molecules making them less available to be taken up by crop roots[1][2].
  3. Soil texture – clay acts similar to organic matter binding to herbicide molecules. Therefore, sandy soils are at a greater risk for carryover[2].
  4. Soil temperature – microbes are most active between 10-30°C[1].
  5. Soil moisture – in-season (June 1st - August 30th) rainfall is the most important component for herbicide breakdown[2]. 
Every product has different requirements for re-cropping; you should always refer to the product label for details. The following is a summary:
Product2021 Rainfall RequiredOther Requirements2022 Re-cropping
(Clopyralid) based products*
140 mm June 1 -August 31
175 mm over entire growing season
N/APeas, soybeans
N/AN/AWheat, barley, oats, rye, corn, flax, canola, forage grasses, mustard
Sierra 3.0, Everest 3.0**100 mm within 60 days of applicationPrecipitation equal or above
10-year average during growing season . Organic matter > 4% pH < 7.5

N/AN/ASpring/durum wheat, barley, canola, flax, field bean, soybeans
Viper ADV125 mm June 1 -September 1N/ACanola, durum wheat, canary seed
N/AN/AWinter wheat (3 months after app.), barley, chickpea, field corn, peas, flax, lentil, oats, sunflower, spring wheat
Odyssey Ultra NXT125 mm June 1 -September 1N/ADurum wheat, canary seed
N/AN/APea, lentil, CLEARFIELD canola, oats, barley, corn, chickpea, spring wheat
Ares125 mm June 1 - August 31N/AWheat, barley, canary seed, corn
N/AN/AChickpea, CLEARFIELD canola, CLEARFIELD wheat, pea, lentil
*Akito, Cirpreme XC, Eclipse III/XC, Lontrel 360/XC, Prestige XC/XL, Prominex, Spectrum, Salute. Please note there are other products that contain Clopyralid, but these are the products we deal with.
**Black soil zone requirements

Infinity based products (Infinity, Infinity FX, Velocity, Axial Xtreme iPak) has no re-cropping restrictions for the black soil zone, but may see carryover on peas especially on light land/sandy knolls.

For the most part, rainfall received this year should meet the minimum requirements for re-cropping for our trading area, thanks to the late rains we got in August. Growers should assess their fields on a case-by-case basis, as the following are average numbers from Environment Canada/Government of Manitoba weather stations.

May 1 - August 31 = 253 mm
June 1 - August 31 = 211 mm

May 1 - August 31 = 275 mm
June 1 - August 31 = 230 mm

May 1 - August 31 = 232 mm
June 1 - August 31 = 182 mm

St. Lazare
May 1 - August 31 = 338 mm
June 1 - August 31 = 301 mm

According to the Government of Saskatchewan, the central-east region of Saskatchewan is under normal (>160 mm June 1st-August 30th) risk for herbicide carryover. Click here to check out the published map. 

Waiting to seed until soils are warm may help mitigate risk – not only do you avoid the stress on seedlings from cold soils, but it may also increase microbial activity due to warming soils and moisture from snow melt[1].

Check out the following resources for more information:

Manitoba Managing Dry Conditions and Drought

Saskatchewan Herbicide Residues

Saskatchewan Herbicide Carryover Risks and Considerations

BASF IMI Announcement
[1] Sask Canola, Saskatchewan Pulse Growers and Sask Wheat. 2021. Herbicide Carryover Risk and Considerations. [Online] Available:
[2] Government of Saskatchewan. 2021. Herbicide Residues. [Online] Available:

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