From labels and weed guides

Best herbicides for knotweed in field corn

For knotweed in field corn, the weed guides list 14 active-ingredient groups with every rating at least 80% control, after checking that the products are labeled for field corn.

Knotweed 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 1 weed guide, 14 active-ingredient groups are rated at least 80% control for knotweed in field corn, showing the top 12 below.

Example productActive ingredientsMOA groupRatings checked
AAtrex 4L
EPA 100-497; same active ingredients on 31 other branded products
atrazine5WinField Crop Protection 2026, corn post: G → 81–90% control (PDF)
Actylis Metribuzin
EPA 2749-660; same active ingredients on 31 other branded products
metribuzin5WinField Crop Protection 2026, corn post: E → 91–100% control (PDF)
Comet
EPA 71368-87; same active ingredients on 8 other branded products
fluroxypyr 1-methylheptyl ester4WinField Crop Protection 2026, corn post: G → 81–90% control (PDF)
Broclean
EPA 34704-891; same active ingredients on 5 other branded products
bromoxynil6WinField Crop Protection 2026, corn post: G → 81–90% control (PDF)
COLT AS
EPA 34704-1019; same active ingredients on 5 other branded products
clopyralid and fluroxypyr 1-methylheptyl ester4WinField Crop Protection 2026, corn post: G → 81–90% control (PDF)
Distinct
EPA 7969-150; same active ingredients on 2 other branded products
dicamba and diflufenzopyr4, 19WinField Crop Protection 2026, corn post: E → 91–100% control (PDF)
Double Header
EPA 34704-1099; same active ingredients on 2 other branded products
acetochlor and mesotrione15, 27WinField Crop Protection 2026, corn post: G → 81–90% control (PDF)
Daikon
EPA 91234-217; same active ingredients on 1 other branded product
dicamba and halosulfuron-methyl2, 4WinField Crop Protection 2026, corn post: G → 81–90% control (PDF)
Peak
EPA 100-763; same active ingredients on 1 other branded product
prosulfuron2WinField Crop Protection 2026, corn post: G/E → 81–100% control (PDF)
Acuron
EPA 100-1466
atrazine, bicyclopyrone, mesotrione, and metolachlor5, 15, 27WinField Crop Protection 2026, corn post: G → 81–90% control (PDF)
Acuron Flexi
EPA 100-1568
bicyclopyrone, mesotrione, and metolachlor15, 27WinField Crop Protection 2026, corn post: G → 81–90% control (PDF)
DiFlexx DUO
EPA 264-1184
dicamba and tembotrione4, 27WinField Crop Protection 2026, corn post: E → 91–100% control (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.