Mark VanGessel, Extension Weed Specialist; mjv@udel.edu
Some corn fields need to be sprayed for weeds, but the corn is only 3 to 4 collars. In many ways this is good because the corn leaves will not interfere with herbicide spray pattern and will allow for maximum control. However, that means it may be two to three weeks until the corn canopies over. So relying on glyphosate or Liberty for postemergence weed control, could run into situations of weeds emerging between the postemergence sprays and the time corn canopies over. You should consider a residual herbicide in this scenario. Be sure to read individual labels for information on maximum corn size and recommended adjuvants. The following table of products will help with your selection:
Table of Corn Herbicides
|
Control of: |
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| Herbicide1 | POST activity2 | Broadleaf | Morningglory | Grasses |
| Atrazine | Yes | Yes | Yes3 | No |
| Callisto | Yes | Yes | No | No |
| Capreno | Yes | Yes | No | Limited |
| Halex | Yes | Yes | No | Yes |
| Impact** | Yes | Yes | No | ## |
| Laudis** | Yes | Yes | No | ## |
| NorthStar | Yes | Yes | No | No |
| Permit Plus | Yes | Yes | No | No |
| Resolve | Yes | Yes | No | Yes |
| Dual | No | Some | No | Yes |
| Prowl H2O | No | Some | No | Limited |
| Warrant | No | Some | No | Yes |
1Other herbicides maybe be available, but the list includes those UD Weed Extension has evaluated.
2Refers to control of emerged weeds, provided those species are susceptible to the herbicide
3Level of control depends on rate. For residual control of morningglory, rates should be at least 1.25 lbs ai/A
##No local data
Tags: 20:9, field corn weed control