How Herbicides Work

 
 
Subscribe to our free E-Newsletter, "Agri-News" (formerly RTW This Week)Agri-News
This Week
 
 
 
 

How Herbicides Work

How Herbicides Work is targeted at professionals who work with herbicides. The book may also prove valuable to producers who have an interest in the technical aspects of herbicides.

This 134 page book provides a comprehensive look at:

  • how herbicides enter and move in the plant
  • how herbicides break down in the plant and soil
  • how plants develop resistance to herbicides
  • how herbicides can best be transferred from the sprayer to the target

Agdex 606-2
$35.00


Copies of this book may be purchased by:

  • Calling 780-427-0391.
  • Cheque or money order, please complete the order form and send it to our Publications Office.
  • On-line credit card purchase by accessing the on-line sales website.
Free Digital Version (6.75 MB)
This low resolution PDF version of How Herbicides Work is available at no charge and can be used as outlined in the terms of the Open Government Licence Alberta.

Policy available at: http://data.alberta.ca/content/government-alberta-open-information-and-open-data-policy
Licence available at: http://data.alberta.ca/licence

Contents

Acknowledgments

Foreword

How Herbicides Work
  • Target sites
  • Why herbicides kill plants
  • Physical/Chemical properties
  • Uptake
  • Translocation
  • Selectivity and metabolism
  • Toxicity
Soil-Applied Herbicides

Inhibitors of Cell Division
  • Physical/Chemical properties
  • Inhibition of cell division and cell enlargement
  • Uptake and translocation
  • Metabolism and selectivity
  • Symptoms
  • Toxicity
  • Implications for application
Inhibitors of Very Long Chain Fatty Acid Biosynthesis
  • Physical/Chemical properties
  • Inhibition of very long chain fatty acids
  • Uptake and translocation
  • Metabolism and selectivity
  • Toxicity
  • Symptoms
  • Implications for application
Amino Acid Biosynthesis Inhibitors

Inhibitors of Acetolactate Synthase (ALS)
  • Physical/Chemical properties
  • Inhibition of acetolactate synthase (ALS)
  • Uptake and translocation
  • Metabolism and selectivity
  • Toxicity
  • Symptoms
  • Implications for application
Inhibitor of EPSPS
  • Physical/Chemical properties
  • Inhibition of EPSPS
  • Uptake and translocation
  • Metabolism and selectivity
  • Symptoms
  • Toxicity
  • Implications for application
Inhibitors of Glutamine Synthase
  • Physical/Chemical properties
  • Inhibition of gluatamine synthase
  • Uptake and translocation
  • Metabolism and selectivity
  • Toxicity
  • Symptoms
  • Implications for application
Inhibitors of ACCase

ACCase Inhibitors
  • Physical/Chemical properties
  • Inhibition of ACCase
  • Uptake and translocation
  • Metabolism and selectivity
  • Toxicity
  • Symptoms
  • Implications for application
Auxinic Herbicides
  • Physical/chemical properties
  • De-regulation of growth
  • Quinclorac
  • Uptake and translocation
  • Metabolism and selectivity
  • Symptoms
  • Toxicity
  • Implications for application
Photosynthetic Inhibitors

Photosynthesis
  • PS II function
  • PS I function
Inhibitors of PS II
  • Physical/chemical properties
  • Inhibition of PS II electron transport
  • Uptake and translocation
  • Metabolism and selectivity
  • Symptoms
  • Toxicity
  • Implications for application
Inhibitors of PS I
  • Physical/chemical properties
  • Uptake and translocation
  • Inhibition of PS I electron transport
  • Metabolism and selectivity
  • Toxicity
  • Symptoms
  • Implications for application
Herbicide Resistance

Herbicide Resistance - A Challenge to Conventional Agriculture
  • What is herbicide resistance?
Resistant Weeds in Western Canada
  • Severity of the resistance problem
  • Herbicide Resistance Development
  • Selection for herbicide resistance
  • Mechanisms for surviving herbicides
  • Target site resistance
  • Herbicide metabolism
  • Rapid growth
  • Other mechanisms
  • Multiple herbicide resistance
Identification of Herbicide Resistant Weeds
  • Diagnosing herbicide resistance in the field2
  • Patches
  • Field tests
  • Testing facilities on the prairies
Prevention or Delay
  • Vary weed control measures
  • Determine weeds at risk
  • Determine herbicides at risk
  • Vary herbicide used by group
  • Reduce weeds selected
  • Include herbicide mixtures
  • Avoid residual herbicides
  • Use certified seed and clean management practices
  • Monitor for suspicious weed patches
Management Strategies
  • Seed-bank management
  • Site-by-site
  • Patch control
  • Non-selective herbicide options
  • Other weed control options
  • Stop spread of resistant weeds
Looking Ahead

Dose Transfer

Overview
  • Atomization
  • Transport to target
  • Impaction and retention
  • Deposit formation
  • Movement in/on plant
  • Biological effect
  • Why is this important?
Atomization
  • Basic processes
  • Nozzle nomenclature
  • Nozzle wear
  • Measurement of droplet size spectra
  • Other nozzles
  • Calibration and patternation
Transport to Target
  • Droplet dynamics
Impaction and Retention
  • Impaction
  • Retention
  • Canopy penetration
Deposit Formation
  • What kind of spray deposit?
Movement In/on Plant

Adjuvants

Adjuvants: Definitions and Function
  • An introduction to adjuvants
Surfactants
  • Other groups of adjuvants
How Surfactants Work
  • Surface tension
  • Atomization
  • Spray retention
  • Evaporation and persistence
  • Deposit formation
  • Cuticle penetration
  • Water quality and ammonium sulfate fertilizer
  • Environment
Summary

Spray Drift

Factors Influencing Spray Drift
  • Weather conditions
Sprayer Settings
  • Coarser sprays
  • Pressure
  • Carrier volume
  • Low-drift nozzles
  • Drift-reducing spray adjuvants
  • Protecting sprays from wind
Droplet Size and Efficacy

Importance of Active Ingredient

Appendix I - Weed Science and Herbicide Information Sources
  • Journals
  • Books on herbicide mechanism of action5
  • Other references
  • Web sites
Appendix II - Source List

Appendix III - Glossary
 
 
 
 
Share via AddThis.com
For more information about the content of this document, contact Ag Info Centre.
This information published to the web on April 24, 2001.
Last Reviewed/Revised on February 24, 2015.