Due to the extensive use of herbicides to control weeds, populations of weeds with resistance to one or more herbicides continue to increase within the USA. Pesticide applicators using herbicides must make an effort to understand herbicide resistance, learn to identify it early, and implement management tactics to reduce the evolution of herbicide-resistant weeds. This lesson presents several practical concepts related to herbicide resistance in the field.

Students completing this lesson will:

• Understand the importance of scouting for herbicide-resistant weeds.
• Know the factors that can contribute to weeds being present after a herbicide application.
• Know how to identify herbicide resistance in the field.
• Understand when to suspect and test for herbicide resistance in the field.
• Know procedures for confirming herbicide resistance.

Successful completion of this module will earn you 1 recertification credit for New York State DEC certified pesticide applicators in categories 1a, 2, 3a, 3b, 5a, 6a, 9, 10, 21, 22, 23, 24, and 25.

*If you are certified in Maryland, Pennsylvania, Rhode Island, or West Virginia, check the appropriate state-specific credit information page under the "Store Menu" to confirm approval and recertification credit values.

*Connecticut, Maine, Massachusetts, New Hampshire, and Vermont have approved all DLC courses and awards the same credits as New York.