Classification of electric transmission right-of-way herbicides by primary mechanism of action.^{^a}

Growth Regulators:
Phenoxy acetic acids
2,4-D	2,4,5-T
Phenoxy propionic acids
dichlorprop	silvex
Picolinic acid and related compounds
picloram	triclopyr
Benzoic acids
dicamba
Inhibitors of Amino Acid Synthesis:
fosamine^{^b}	glyphosate
ulfonylureas
metsulfuron methyl
midazolinones
imazapyr
Dessication and Plasmolysis:
ammonium sulfamate^{^c}

↵^a Adapted from Warren (1975) and Ashton and Crafts (1981).
^b Categorized as an amino acid synthesis inhibitor by Newton and Knight (1981).
↵^c As defined by Gangstad (1989).