Lisa Behnken, Extension Educator, Fritz Breitenbach, IPM Specialist SE Minnesota, Jeff Gunsolus, Extension Agronomist, Weed Science, and Phyllis Bongard, Content Development and Communications Specialist, University of Minnesota Photo 1. Giant ragweed in corn herbicide trial at Rochester, MN, May 20,2016. Plot was planted April 25, 2016. The recent frost across southeast Minnesota may have slowed down corn and soybean development, but it did not slow down the rate of weed growth. There are plenty of 1-4 inch giant ragweed and 1-2 inch common lambsquarters in corn and soybean fields. Waterhemp is also beginning to emerge (1/4 – 3/4 inch). The current dilemma that needs to be addressed is most evident in fields where a preemergence herbicide was not used or it provided poor giant ragweed control. In addition, our recent 1-2 inch rainfall may limit the ability to get into the field in a timely manner to control the weeds when they are most susceptible to control and before they