As 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.