Table 2.1-8

Table 2.1-8. Some herbicide classes, products, and resistant weeds identified in the United States.
WSSA herbicide group¹ Site of action Herbicide trade name Resistant weeds

WSSA herbicide group is a system of classifying herbicides developed by the Weed Science Society of America based on mode and site of action to help understand and plan for resistance management. Herbicide manufacturers are voluntarily, including the WSSA herbicide groups on their labels.
1 ACCase Achieve barnyardgrass
Assure/Targa crabgrass spp.
Fusilade foxtail spp.
Fusion (part) italian ryegrass
Hoelon johnsongrass
Poast/Poast Plus perennial ryegrass
Select  
2 ALS-enzyme Accent common cocklebur
Ally, Cimarron common lambsquarters
Amber downy brome
Arsenal eastern black nightshade
Assert foxtail spp.
Autumn horseweed
Beacon italian and perennial ryegrass
Classic johnsongrass
Everest kochia
Express mayweed chamomile
Glean, Telar pigweed spp.
Harmony SG prickly lettuce
Matrix, Resolve prickly sida
Maverick ragweed spp.
Olympus shattercane
Option wild mustard
Osprey  
Peak  
Permit/Sandea  
Pursuit  
Raptor, Beyond  
Scepter  
9 EPSP-enzyme glyphosate common and giant ragweed
goosegrass
horseweed
italian ryegrass
johnsongrass
pigweed spp.
3 Microtubule inhibitors Balan annual bluegrass
Barricade goosegrass
Curbit  
Pendulum  
Prowl  
Sonalan  
Treflan  
4 IAA-like 2,4-D field bindweed
kochia
prickly lettuce
wild carrot
5 Photosystem II Atrazine  
Milo Pro  
Pramitol  
Princep annual bluegrass
Sencor common groundsel
Sinbar common lambsquarters
Velpar common ragweed
  downy brome
  foxtail
  kochia
  pigweed spp.
  velvetleaf
  witchgrass
22 Photosystem I paraquat horseweed
14 PPO (protoporphyringogen oxidase Action common ragweed, pigweed spp.
Aim  
Authority  
Blazer  
Cobra  
Goal  
Reflex, Flexstar  
Resource  
Ronstar  
Valor, Payload