Importance of Pre- Herbicides

Source: Bayer Chemical Company

With the number of herbicide resistant weeds growing in the United States, and slowly creeping up to our neck of the woods; scientists believe that the best option we have is using a no tolerance rule, or using pre-herbicides with residuals and multiple modes of action.  This will give the fields a clean start and reduce the spread of resistance.


When fields start off weedy, it robs the crop seedling of their critical nutrients, sunlight, soil, and water.  So right off the bat the seedling is off to a slow start.  One way to keep a field clean during the year is start with a pre-emergence application while the field is still clean, or with a nonselective burndown. Scout your own fields or have your agronomist out scouting for seedlings of weeds for it is becoming more important as the resistant weed population continues to grow.


Here are some things to consider while talking about, picking pre-herbicides with your agronomist:

  • Residual time
  • Timing of application vs how soon planting is
  • How many weeds are controlled
  • How many weeds are resistant to the mode of actions in your pre-herbicide
  • Rotate crops

Weed management is a very important part of agronomy and should be thought of as a  preventative management tool rather than extra money being spent.