Herbicide-resistant weeds are one of the biggest threats to crop production—and the problem is accelerating.

Weeds are evolving, developing resistance to herbicide groups that once worked, and even showing higher levels of resistance in groups already failing.

Adding to the challenge, aggressive newcomers like waterhemp and Palmer amaranth are arriving pre-loaded with multiple-herbicide resistance.

Understanding how and when to test for resistance is critical to staying ahead.