Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension

Extension > Agriculture > Crops > Weed management > Resistance management

Print Icon Email Icon Share Icon

Resistance management

Herbicide resistance management

Herbicide resistance management series

Herbicide resistance and mode of action basics

Dr. Jeff Gunsolus describes what herbicide resistance is and how it can occur. Herbicide mode of action and mechanisms for developing resistance are also introduced.

Herbicide mode of action breakdown

This second video in the Herbicide Resistance Management series focuses on how herbicides work. For each group of herbicides, the affected biochemical reaction, translocation, time of herbicide application and symptoms are described.

Herbicide resistance development by site of action

This third video describes how resistance develops with continued use of the same herbicides, the importance of developing a robust resistance management program and the need to diversify herbicide sites of action.

History of herbicide resistance throughout Minnesota

Dr. Beverly Durgan describes the history of herbicide resistance development in Minnesota, beginning with triazines in the 1980's to glyphosate resistance today.

Herbicide resistant waterhemp

Herbicide resistant waterhemp: A layered approach

Waterhemp has an extended emergence pattern, making it difficult to control. In addition, some populations are resistant to glyphosate (SOA-9) and ALS (SOA-2) herbicides, limiting control options. A 2015 trial demonstrated the effectiveness of layering residual herbicides for waterhemp control and results are shown in this video.

Herbicide resistant giant ragweed biology and management series

Research project overview

Due to its large seed and early emergence, giant ragweed can be difficult to control. In addition, biotypes in Minnesota have developed herbicide resistance. Jared Goplen describes a study looking at alternative management practices to control this weed.

Giant ragweed emergence patterns

This second video in this series focuses on emergence patterns of giant ragweed and how crop rotation and planting date may be used to help control this weed.

Weed seed production

This video describes seed production and shattering patterns of giant ragweed. Controlling this weed in fencerows before its seed is viable and avoiding spread of its seed through the combine are important control strategies.

Seed bank depletion and zero weed threshold

This research project showed that the giant ragweed seed bank could be 97 percent depleted within two years if a zero weed threshold could be maintained. Jared Goplen concludes the video series with strategies for achieving a zero weed threshold.

  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy