From labels and weed guides
Best herbicides for canada thistle in sweet corn
For canada thistle in sweet corn, the weed guides list 4 active-ingredient groups rated good or excellent, after checking that the products are labeled for sweet corn.
Canada Thistle control in sweet corn
Every listed product is labeled for sweet corn. 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 1 weed guide, 4 active-ingredient groups are rated good or excellent for canada thistle in sweet corn.
| 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 3 other branded products | clopyralid and fluroxypyr 1-methylheptyl ester | 4 | ND Weed Guide 2026: G-E (PDF) |
| Enlist Duo EPA 62719-649 | 2,4-d and glyphosate | 4, 9 | ND Weed Guide 2026: G-E (PDF) |
| IMPACTZ EPA 5481-612 | atrazine and topramezone | 5, 27 | 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.