Knowing your enemy is the best place to start developing an appropriate action plan. This holds true also when it comes to managing pesky herbicide-resistant weeds. This session will highlight the options available to farmers and agronomists for herbicide resistance diagnostics, including sampling, testing, and how to interpret results. It will also focus on new tools, such as genetic testing for resistance diagnostics, that are currently under development and will be available for resistance diagnostics in the near future. The unique differences between traditional bioassays (offered currently by most diagnostic labs) and genetic testing will be discussed to outline the utility of each approach to understanding the resistance issues in your fields