Mark VanGessel, Extension Weed Specialist; mjv@udel.edu
A few questions have come in about controlling some perennial species in field corn; with pokeweed being the most common species. We had a trial 2 years ago with tall pokeweed (sprayed in late June) and had results similar to a study conducted at Southern Illinois University. Dicamba [Banvel, Clarity, Sterling]; also available in Distinct or Status; NorthStar or Callisto were the best treatments for conventional corn hybrids (over 90% control). Glyphosate was also effective if Roundup Ready corn was planted. Our trial did not include Lightning, but the SIU trial reported good control with Lightning with Clearfield corn. For soybeans, glyphosate is the best option. In non-Roundup Ready soybeans, Synchrony was fair (but requires STS-soybeans) or FirstRate which was only fair in the SIU trial.
Canada thistle control in corn is best with Stinger; Hornet contains Stinger and is much less expensive. In addition, the herbicides listed above will provide good control. Dewberry (wild blackberry) is difficult to control and Accent appears to provide the highest level of control.
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Single active ingredient products
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Canada thistle | Dandelion | Dewberry species | Dock species | Field bindweed | Groundcherry | Hemp dogbane | Honeyvine milkweed | Horsenettle | Common milkweed | Mugwort | Pokeweed | Trumpetcreeper |
| 2,4-D |
P-F |
G |
P |
F-G |
F-G |
F-G |
P-F |
P-F |
P |
P |
P |
P-F |
P-F |
| Accent |
P-F |
P |
F-G |
P |
P-F1 |
- |
P1 |
P1,2 |
P1 |
- |
P1 |
P |
- |
| Banvel / Clarity |
P-F |
F-G |
P |
G |
F-G |
F-G |
P-F |
P-F |
P-F |
F |
F-G |
F-G |
P-F |
| Beacon |
F 1 |
P |
N |
- |
P-F 1,2 |
- |
F1,2 |
P 1,2 |
F 1,2 |
F 1 |
P 1 |
F 1 |
- |
| Callisto |
G |
F-G |
- |
- |
- |
- |
- |
- |
G |
- |
- |
F-G |
- |
| Glyphosate products |
G |
F |
F-G |
G |
F-G |
F-G |
F-G |
F |
F |
F-G |
F |
F |
F |
| Liberty |
F |
F-G |
- |
F-G |
- |
- |
- |
- |
P-F |
- |
- |
- |
- |
| Stinger |
E |
G-E |
N |
- |
- |
- |
- |
- |
|
- |
G |
- |
- |
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Premixes |
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|
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|
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|
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| Celebrity Plus |
F |
F-G |
F-G |
G |
F-G |
F-G |
F |
P-F |
P-F |
- |
F-G |
P-F |
- |
| Distinct / Status |
G |
F-G |
P |
G |
G |
F-G |
P-F |
P-F |
P-F |
F |
F-G |
F-G |
- |
| Hornet WDG |
G-E |
G |
N |
G |
- |
- |
- |
- |
- |
- |
G |
- |
- |
| Lightning |
- |
- |
- |
- |
F-G 1 |
- |
- |
F-G |
|
- |
- |
- |
- |
| Marksman |
F |
F-G |
P |
G |
F-G |
F-G |
P-F |
P-F |
P-F |
F |
F-G |
P |
P-F |
| NorthStar |
F-G |
F-G |
P |
F-G |
F-G |
F-G |
F-G |
P-F |
F-G |
F-G |
F-G |
F-G |
P-F |
1Control ratings will be higher if either Banvel or Clarity is included as a tank-mix.
2Control ratings will be higher if 2,4-D is included as a tank-mix.
G=good; F=fair; P=poor; N=no control; – = insufficient data or experience available
Tags: 16:12, field corn, field corn weed control