Overview and Objectives of Herbicide Resistance: Mechanisms, Inheritance and Molecular Genetics


This lesson will detail the biochemical mechanisms and genetics of herbicide-resistance in weeds. Herbicide resistance is a major issue in weed science today; therefore, it is important to have a basic understanding of the process by which it occurs. The management and spread of herbicide-resistant weeds in relationship to the biochemical mechanisms and inheritance of resistance will be explained. Resistance based on changes in the target-site, herbicide metabolism and other types of resistance will be described.


After completing this lesson, students will be able to:

  1. Understand the development of herbicide-resistance.
  2. Describe how and why herbicide resistance occurs based on the genetics and biochemistry involved.
  3. Explain the difference between target-site based resistance, metabolism-based resistance, and other types of resistance.
  4. Understand the difference between cross- and multiple-resistance.

Copyright 2000

Development of this lesson was supported in part by the Cooperative State Research, Education, & Extension Service, U.S. Dept of Agriculture under Agreement Number 00-34416-10368 administered by Cornell University and the American Distance Education Consortium (ADEC). Any opinions, findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.