Strategies to Manage Stubborn Weeds

Fifteen weed species in North America are confirmed glyphosate resistant, including waterhemp.

Herbicide resistance continues to become an ever more challenging aspect of crop production. Currently, fifteen weed species in North America are confirmed glyphosate resistant. Some of the most persistent and prolific weeds challenging growers include waterhemp, Palmer amaranth, and common and giant ragweed. 

Consider mapping out your strategy to fight resistant weeds. Consider these guidelines:

  • Use multiple herbicide modes of action – Consider use of a soil-applied herbicide. Where resistance is already a problem, evaluate other herbicides, your tank mixes, and other actions you can take.
  • Be planned, diligent, aggressive – Treat weeds at the right size. Few herbicides are as forgiving as glyphosate.
  • Anticipate potential problems – Resistant weeds can rapidly change from barely noticeable to heavily infested fields within a few seasons. Vigilantly monitor fields.
  • Clean machinery - Where resistance is established, it's especially important to clean machinery between fields.