From labels and weed guides
Best herbicides for canada thistle in field corn
For canada thistle in field corn, the weed guides list 8 active-ingredient groups with every rating at least 80% control, after checking that the products are labeled for field corn.
Canada Thistle control in field corn
Every listed product is labeled for field corn. Ratings are shown when each weed guide that rates this weed has a lower interval bound of at least 80% control for the active-ingredient group. If a guide gives a range, its lower bound must be at least 80%.
Based on 3 weed guides, 8 active-ingredient groups are rated at least 80% control for canada thistle in field corn.
| Example product | Active ingredients | MOA group | Ratings checked |
|---|---|---|---|
| Bite EPA 83529-74; same active ingredients on 8 other branded products | clopyralid | 4 | Mi Weed Guide 2026 Corn, mi corn post: E → 90–100% control (FieldMarshal policy interval) (PDF); ND Weed Guide 2026: E → 90–99% control (PDF) |
| Definite EPA 83529-105; same active ingredients on 7 other branded products | acetochlor, clopyralid, and flumetsulam | 2, 4, 15 | ND Weed Guide 2026: G-E → 80–99% control (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 → 80–99% control (PDF) |
| Enlist Duo EPA 62719-649; same active ingredients on 3 other branded products | 2,4-d and glyphosate | 4, 9 | Mi Weed Guide 2026 Corn, mi corn post trait enlist: G → 80–90% control (FieldMarshal policy interval) (PDF); ND Weed Guide 2026: G-E → 80–99% control (PDF) |
| Commando EPA 42750-92 | 2,4-d and clopyralid | 4 | ND Weed Guide 2026: G-E → 80–99% control (PDF) |
| Halex GT EPA 100-1282 | glyphosate, mesotrione, and metolachlor | 9, 15, 27 | Mi Weed Guide 2026 Corn, mi corn post trait glyphosate: G → 80–90% control (FieldMarshal policy interval) (PDF); ND Weed Guide 2026: G-E → 80–99% control (PDF) |
| Kyro EPA 62719-766 | acetochlor, clopyralid, and topramezone | 4, 15, 27 | Ky Weed Guide 2025, ky corn perennial postemergence: **9** → 80–90% control (FieldMarshal policy interval) (PDF); Mi Weed Guide 2026 Corn, mi corn post premix: E → 90–100% control (FieldMarshal policy interval) (PDF) |
| Sequence EPA 100-1185 | glyphosate and metolachlor | 9, 15 | Mi Weed Guide 2026 Corn, mi corn post trait glyphosate: G → 80–90% control (FieldMarshal policy interval) (PDF) |
Rating bands: E 90-100%, G 80-89%, F 70-79%, P under 70%, N none. Policy intervals are marked in the source ratings. 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. Read the rating method.
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Sources
Data from current labels and weed guides. Last source update: 2026-09-30.