From labels and weed guides
Group 5 herbicides for seedling johnsongrass in field corn
There are 2 Group 5 active-ingredient groups rated good or excellent for seedling johnsongrass in field corn, with products labeled for field corn.
Group 5 mode of action (MOA) options
Group 5 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 field 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, 2 active-ingredient groups are rated good or excellent for seedling johnsongrass in field corn.
| Example product | Active ingredients | MOA group | Ratings checked |
|---|---|---|---|
| Bicep II Magnum EPA 100-817; same active ingredients on 15 other branded products | atrazine and metolachlor | 5, 15 | WinField Crop Protection 2026, corn pp pre: E (PDF) |
| Acuron EPA 100-1466 | atrazine, bicyclopyrone, mesotrione, and metolachlor | 5, 15, 27 | WinField Crop Protection 2026, corn pp pre: E (PDF); WinField Crop Protection 2026, corn post: 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.