Editing Herbicide (section)

===WSSA and HRAC classification===
Using the Weed Science Society of America (WSSA) and [[HRAC classification|herbicide Resistance and World Grains (HRAC) system]]s, herbicides are classified by mode of action.<ref name=Shaner>{{cite book|last1=Shaner|first1=D. L.|last2=Leonard|first2=P.|editor1-last=Powles|editor1-first=S. B.|editor2-last=Shaner|editor2-first=D. L.|title=Herbicide Resistance and World Grains|date=2001|publisher=CRC Press, Boca Raton, FL.|pages=279–294|isbn=9781420039085|chapter=Regulatory aspects of resistance management for herbicides and other crop protection products}}</ref> Eventually the Herbicide Resistance Action Committee (HRAC)<ref>{{Cite web|url=https://hracglobal.com/|title=PROTECTING CROP YIELDS AND QUALITY WORLDWIDE|website=Herbicide Resistance Action Committee}}</ref> and the [[Weed Science Society of America]] (WSSA)<ref>{{Cite web|url=https://wssa.net/|title=Weed Science Society of America|accessdate=4 April 2023}}</ref> developed a classification system.<ref name=Retzinger>{{cite journal|last1=Retzinger|first1=E. J. Jr.|last2=Mallory-Smith|first2=C.|title=Classification of herbicides by site of action for weed resistance management strategies|journal=Weed Technology|date=1997|volume=11|issue=2|pages=384–393|doi=10.1017/S0890037X00043116|s2cid=251572710 }}</ref><ref name=Schmidt>{{cite book|last1=Schmidt|first1=R. R.|title=1997 Brighton crop protection conference: weeds|date=1997|publisher=Proceedings of an international conference, Brighton, UK, 17–20 November 1997, British Crop Protection Council|pages=1133–1140|chapter=HRAC classification of herbicides according to mode of action}}</ref> Groups in the WSSA and the HRAC systems are designated by numbers and letters, inform users awareness of herbicide mode of action and provide more accurate recommendations for resistance management.<ref name=Mallory-Smith>{{cite journal|last1=Mallory-Smith|first1=C.|title=Impact of labeling herbicides by site of action: A University view|journal=Weed Technology|date=1999|volume=13|issue=3|page=662|doi=10.1017/S0890037X00046376|s2cid=89106416 }}</ref>