A well-executed pre-harvest herbicide application can mean the difference between a smooth, efficient harvest and one plagued by green weeds, uneven maturity, and grain quality issues. 

Here are practical, agronomist-backed tips to help you get the most out of your fall pre-harvest herbicide application in wheat and canola. 

 1. Know Your Goal 

Are you targeting: 

• Weed control (especially perennials like Canada thistle)? 

• Crop dry-down for uniform maturity? 

• Both? 

Your goal determines your product choice and timing.

 2. Time It Right 

Wheat: 

• Apply when grain moisture is below 30% (hard dough stage). 

• Use the thumbnail test—if the kernel resists denting, it’s too early. 

Canola: 

• Apply when 60% of seeds on the main stem are brown or black. 

• Seeds in the top third should be firm, not mushy. 

 3. Choose the Right Product 

Here’s a quick reference: 

Always check the label and consult your grain buyer to ensure compliance with Maximum Residue Limits (MRLs). 

We recommend adding Crimson NG to all pre-harvest tank mixes.  Most farms work with hard water which can negatively affect product performance.  Crimson NG neutralizes the minerals in hard water that reduce effectiveness. 

 4. Watch the Weather 

• Avoid spraying before heavy rain or frost. 

• Apply during warm, dry conditions for best uptake. 

• Early morning or late evening applications may reduce efficacy due to dew or cooler temps. 

 5. Use the Right Equipment 

• Ensure even coverage with properly calibrated sprayers. 

• Use clean water and follow mixing instructions carefully. 

• Maintain label-recommended water volumes for effective coverage, especially with contact herbicides. 

 6. Use Trusted Resources 

• SaskWheat Pre-Harvest Guide 

• Canola Council Fall Weed Control 

• Keep It Clean Glyphosate Guide 

• Grainews: Pre-Harvest Tips 

 7. Document Everything 

Keep records of: 

• Product used 

• Application date and time 

• Weather conditions 

• Field staging notes 

This helps with traceability, crop marketing, and future planning. 

 Final Thoughts 

A successful fall pre-harvest herbicide application is all about timing, product choice, and precision – it’s not a decision to make quickly. Done right, it can streamline your harvest, protect grain quality, and reduce weed pressure for next season. harvest approaches across the Prairies, grain farmers are considering whether to apply a pre-harvest herbicide – a critical decision that impacts crop quality, harvest efficiency, and marketability. When timed and executed correctly, this practice offers significant agronomic and logistical benefits—especially in wheat and canola production. 

Why Consider a Pre-Harvest Application? 

Pre-harvest herbicide applications serve two main purposes: 

1. Weed Control: Targeting late-season perennial and annual weeds that can interfere with harvest and contribute to the seed bank. 

2. Harvest Management: Aiding in crop dry-down and improving uniformity, which can reduce harvest delays and improve grain storage conditions. 

Wheat 

According to SaskWheat’s 2024 guide, glyphosate and other registered products can be used to manage green weed material and improve harvest efficiency. However, timing is critical.  

Canola 

In canola, pre-harvest herbicides like glyphosate or saflufenacil (Heat LQ) are used to manage late-emerging weeds and assist with dry-down. Accurate application timing ensures effective weed control without compromising seed quality or violating Maximum Residue Limits (MRLs) in the seed. 

Pre-harvest herbicide applications are a valuable tool in the Western Canadian grower’s toolbox. When used responsibly and in accordance with staging and label guidelines, they can improve harvest efficiency, reduce weed pressure, and protect grain quality for both domestic and export markets.