Investing Checkoff Dollars

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emergence of weeds that germinate later in the season. However, remember it is still important to start out with good early weed control. Late summer or fall-seeded cover crops have also been shown to be beneficial to reduce early-season weed growth. In MSU research, planting green into a cereal rye cover crop suppressed horseweed similar to a soil-applied herbicide until the time of a postemergence herbicide (4 to 6 weeks after planting). Implementing one or more of these cultural practices can reduce the selection pressure of certain herbicides.

Scout for Weed Escapes

One of the most important things that can be done to help preserve the effectiveness of our current herbicides is to scout for weeds that have escaped herbicide applications. When weed escapes are found, it is important to consider all the possible reasons why these weeds were not controlled. Was there too little or too much rain for the soil-applied herbicide to work? Was there good spray coverage? Did the weeds emerge after the postemergence herbicide was applied? Were the weeds too large? If none of these questions explain the weed escape, consider if this could be a herbicide-resistant weed. If possible, try to manage this escape or put strategies in place not to spread seed to other fields. Also, consider getting the weed screened for resistance. MSU Plant & Pest Diagnostics has a screening program that can test for herbicide resistance. For more information on herbicide resistant weed screening visit www.canr.msu.edu/psetid/submit-samples/ herbicid-resistant-weeds-in-Michigan .