From labels and weed guides
Best herbicides for canada thistle in barley
For canada thistle in barley, the weed guides list 7 active-ingredient groups rated good or excellent, after checking that the products are labeled for barley.
Canada Thistle control in barley
Every listed product is labeled for barley. Ratings are shown when each weed guide that rates this weed stays at good or excellent for the active-ingredient group. If a guide gives a range, the weaker end of the range has to be good or excellent.
Based on 2 weed guides, 7 active-ingredient groups are rated good or excellent for canada thistle in barley.
| Example product | Active ingredients | MOA group | Ratings checked |
|---|---|---|---|
| Bite EPA 83529-74; same active ingredients on 8 other branded products | clopyralid | 4 | ND Weed Guide 2026: E (PDF) |
| COLT AS EPA 34704-1019; same active ingredients on 5 other branded products | clopyralid and fluroxypyr 1-methylheptyl ester | 4 | ND Weed Guide 2026: G-E (PDF) |
| Imitator + 2,4-D EPA 19713-635; same active ingredients on 2 other branded products | 2,4-d and glyphosate | 4, 9 | ND Weed Guide 2026: G-E (PDF) |
| Commando EPA 42750-92; same active ingredients on 1 other branded product | 2,4-d and clopyralid | 4 | ND Weed Guide 2026: G-E (PDF); WinField Crop Protection 2026, small grains: E (PDF) |
| Agility SG EPA 352-751 | dicamba, metsulfuron-methyl, thifensulfuron, and tribenuron-methyl | 2, 4 | WinField Crop Protection 2026, small grains: G (PDF) |
| Curtail M EPA 62719-86 | clopyralid and mcpa | 4 | ND Weed Guide 2026: G-E (PDF); WinField Crop Protection 2026, small grains: E (PDF) |
| Supremacy EPA 66330-406 | fluroxypyr 1-methylheptyl ester, thifensulfuron, and tribenuron-methyl | 2, 4 | ND Weed Guide 2026: G (PDF) |
Rating legend: E=excellent, G=good, F=fair, P=poor, N=no control. A range such as G-E means the guide gives a range; 'a' after a rating (e.g., Ga) means the guide assumes its recommended additive.
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Sources
Data from current labels and weed guides. Last source update: 2026-07-14.