Can you rely on post-emergence weed control?

Published on: 14:31PM May 11, 2010
Chuck Foresman

ALS-inhibiting herbicides became very popular in the ‘90s when they successfully controlled tough weeds post-emergence. But then resistance developed.
Glyphosate-tolerant seed quickly became popular, and glyphosate also controlled tough weeds post-emergence. But now resistance has developed.
Many growers rely on post-emergence weed control for tough weeds. But with weed resistance spreading, do you know what effective options are still available post-emergence? A little research shows that some problem weeds are very good at developing resistance to herbicides. After investigating a bit further, I learned that based on the types of herbicide resistance already showing up in weeds, if glyphosate resistance were to develop, there may not be many post options left to control these weeds.

That’s why I recommend pre-emergence herbicides and herbicides with multiple modes of action to manage against weed resistance.