From labels and weed guides
Group 4 herbicides for canada thistle in oats
There are 5 Group 4 active-ingredient groups rated good or excellent for canada thistle in oats, with products labeled for oats.
Group 4 mode of action (MOA) options
Group 4 is a herbicide mode of action (MOA) group. Treat it as one resistance-management check, not as the whole program.
Every listed product is labeled for oats. 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, 5 active-ingredient groups are rated good or excellent for canada thistle in oats.
| 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) |
| 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.
Build the full program
Check crop, timing, state, resistance, and rotation in one plan before you make a recommendation.
Sources
Data from current labels and weed guides. Last source update: 2026-07-14.