Introduction for Herbicide Classification


This lesson focuses on herbicide classification as a basis for understanding herbicide-plant interactions including herbicide resistance management. Plant and weed response to herbicides are characterized in the context of classification. The herbicide classification system will be examined and an overview of the eight herbicide mode of action groupings provided.


1. Understand how herbicides are classified and why it is important for managing herbicide resistance.

2. Classify herbicides by mode of action rather than chemical family.

3. Know the difference between mode of action and site of action.

4. Differentiate between herbicide families, modes of action, and sites of action.

5. Understand common name, trade names and sites of absorption.

Copyright 2004

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.