General Information


Medal II AT is a selective herbicide recommended before planting, before or after emergence (see directions) for control of most annual grasses and broadleaf weeds in corn. Medal II AT can also be used before crop emergence for control of most annual grasses and broadleaf weeds in grain or forage sorghum, provided the sorghum seed has been properly treated by the seed company with Concep. This product may be tank mixed with other herbicides specified on the label for weed control in conventional, minimum-till, and no-till corn, grain sorghum, or forage sorghum.

Note: Tank mixtures are permitted only in those states where the tank mix partner is registered. Refer to and follow the label of each tank mix product used for precautionary statements, directions for use, geographic and other restrictions.

Following many years of continuous use of atrazine (one of the ingredients in Medal II AT), and products chemically related to atrazine, biotypes of some of the weeds listed on the label which are controlled by the atrazine component have been reported to develop resistance to this and chemically related herbicides. Where this is known or suspected, and weeds controlled by this product are expected to be present along with resistant biotypes, we recommend the use of Medal II AT in combination or in sequence with registered herbicides which do not contain triazines. Consult with your State Agricultural Extension Service for specific recommendations.

Precautions: (1) If sorghum seed is not properly pretreated with Concep, Medal II AT will severely injure the crop. (2) Injury may occur to sorghum following the use of Medal II AT under abnormally high soil moisture conditions during early development of the crop.

Medal II AT alone or in tank mixture with AAtrex, Balance, Dual Magnum, Dual II Magnum, or Princep may be applied early preplant, preplant surface, preplant incorporated, or preemergence on corn, in water or fluid fertilizer. Apply postemergence treatments of Medal II AT to corn, alone or in combination, using water only as the carrier. Medal II AT may be applied in tank mix combination with Gramoxone Inteon, Landmaster BW, Touchdown, or Roundup with or without the above herbicides preplant surface or preemergence to corn. Medal II AT alone may also be applied on sorghum early preplant, preplant incorporated, preplant surface, or preemergence in water or in fluid fertilizer.

When tank mixing or sequentially applying atrazine or products containing atrazine to corn or sorghum, the total pounds of atrazine applied (lb. a.i./A) must not exceed 2.5 pounds active ingredient per acre per year.

Medal II AT may be applied in water by aircraft. Applications in fluid fertilizer should be only by ground equipment.

To avoid spray drift, do not apply under windy conditions. Avoid spray overlap, as crop injury may result.

Do not apply this product through any type of irrigation system.

Do not apply under conditions which favor runoff or wind erosion of soil containing this product to nontarget areas.

To prevent off-site movement due to runoff or wind erosion:

1. Avoid treating powdery dry or light sand soils when conditions are favorable for wind erosion. Under these conditions, the soil surface should first be settled by rainfall or irrigation.

2. Do not apply to impervious substrates, such as paved or highly compacted surfaces.

3. Do not use tailwater from the first flood or furrow irrigation of treated fields to treat nontarget crops, unless at least 1/2 inch of rainfall has occurred between application and the first irrigation.

Where reference is made to weeds partially controlled, partial control can either mean erratic control from good to poor or consistent control at a level below that generally considered acceptable for commercial weed control.

Dry weather following preemergence application of Medal II AT or a tank mixture may reduce effectiveness.

Cultivate if weeds develop in conventional tillage corn or sorghum.

Observe all precautions and limitations on the label of each product used in tank mixtures.

Thoroughly clean sprayer or other application device before using. Dispose of cleaning solution in a responsible manner. Do not use a sprayer or applicator contaminated with other materials, or crop damage or sprayer clogging of the application device may occur.


Within rate ranges in all tables on the label, use the lower rate on soil relatively coarse-textured or low in organic matter; use the higher rate on soil relatively fine-textured or high in organic matter.

Please refer to “SPRAY EQUIPMENT” and “MIXING PROCEDURE” section on the label for recommended spray equipment and for proper mixing application instructions when applied in combination with other herbicides.


- On Highly Erodible Land (as defined by the Natural Resource Conservation Service)

If conservation tillage is practiced, leaving at least 30% of the soil covered with plant residues at planting, apply a maximum of 2.58 qts./A of Medal II AT (2.0 lbs. a.i./A) as a broadcast spray.

If the soil coverage with plant residue is less than 30% at planting, a maximum of 2.1 qts./A of Medal II AT (1.6 lbs a.i./A) may be applied.

- On Land Not Highly Erodible

Apply a maximum of 2.58 qts./A of Medal II AT (2.0 lbs. a.i./A) as a broadcast spray.


If no atrazine was applied prior to corn emergence, apply a maximum of 2.58 qts./A of Medal II AT (2.0 lbs. a.i./A) broadcast. If a postemergence treatment is required following an earlier atrazine application, the total atrazine applied may not exceed 2.5 lbs. active ingredient (3.2 qts. of Medal II AT) per acre per calendar year.

Limitations, Restrictions, and Exceptions


Early Preplant (Corn): Use on medium- and fine-textured soils with minimum-tillage or no-tillage systems in CO, IA, IL, IN, KS, KY, MN, MO, MT, ND, NE, SD, TN, WI, and WY. Apply 2/3 the recommended rate of Medal II AT as a split treatment 30-45 days before planting and the remainder at planting. Applications made less than 30 days prior to planting may be as either a split or single treatment. Use the lower rate for light expected weed infestations and the higher rate for heavy expected weed infestations.

On medium- and fine-textured soils with minimum- or no-tillage systems in DE, MD, MI, NY, OH, PA, VA, and WV, early preplant applications may be applied following the directions for use above. If the amount of rainfall results in unsatisfactory length of weed control following the earlier treatment, a postemergence application of an appropriately labeled broadleaf and/or grass weed herbicide may be used, i.e., AAtrex, Beacon, Basagran, 2,4-D, Banvel, bromoxynil (Brominal or Buctril), Exceed, or Marksman. If the postemergence treatment includes the herbicide used early preplant, do not exceed the labeled rate for corn on a given soil texture. Observe all directions for use, precautions, and limitations on the label of the postemergent herbicide. Medal II AT may be used according to the above directions to control winter wheat planted as a cover crop in IN, KY, and OH, in addition to providing residual weed control. The wheat must be less than 6 inches tall (preferably still in a dormant or semi-dormant state coming out of winter) at the time of application. Depending on rainfall, 10-20 days may be required to completely kill the wheat. In the event that adequate rainfall does not occur, control of the winter wheat may be unsatisfactory and the application of a contact herbicide (i.e., Gramoxone Inteon, Touchdown, or Roundup) may be required before planting the crop. Medal II AT may be applied in the fall, as a single application, for control of the winter weeds listed on the label within the ecofallow (no-till) production areas of NE and KS where wheat (or other small grain cereals) will be rotated to corn. The application must be made to untilled wheat stubble in the fall following wheat harvest, but before soil freeze-up. The ground must remain untilled through the establishment of the corn crop.

On medium- and fine-textured soils following final seedbed preparation in the Blacklands and Gulf Coast areas of TX, an early preplant application of Medal II AT at 1.6-1.9 qts./A may be made 30-45 days before planting. Grass suppression of 2-3 weeks after planting can be expected as a result of this application. Do not incorporate or disturb the soil before planting, and avoid moving the soil during the planting operation. A follow-up application of Dual Magnum, or Dual II Magnum may be needed in fields with a history of heavy grass pressure. Apply after planting, but before corn and grass weeds emerge.


(1) If a follow-up application of Dual Magnum, or Dual II Magnum is needed, do not exceed a total of 1.6 lbs. a.i. of S-metolachlor per acre, including the preplant Medal II AT application on medium- or fine-textured soils. On fine-textured soils with more than 3% organic matter, do not exceed 1.9 lbs. a.i. of S-metolachlor.

[To determine the total lbs. a.i. of S-metolachlor per acre, use the following 2-step method:

A. Determine the lbs. a.i. of S-metolachlor applied as Medal II AT (1.0 qt. = 0.6 lb. a.i. of S-metolachlor); then,

B.If Dual Magnum or Dual II Magnum is to be used, add the lbs. a.i. to be applied in these products to the lbs. in Step A above.]

(2) To the extent possible, do not move treated soil out of the row or move untreated soil to the surface during planting, or weed control will be diminished.


- Split applications can be made less than 30 days before planting if desired.

- Do not exceed this rate on highly erodible land with less than 30% plant residue cover. Control of certain weeds may be reduced and a tank mix partner or an application of a postemergence herbicide may be needed.

Control may be improved by following these suggested procedures:

1. In corn, apply up to the maximum single application rate in Table 1 for your given soil texture and rate limitation based on your soil conservation practices.

2. Thoroughly till moist soil to destroy germinating and emerged weeds. If Medal II AT is to be applied preplant incorporated, this tillage may be used to incorporate Medal II AT if uniform 2-inch incorporation is achieved as recommended under Application Procedures.

3. Plant crop into moist soil immediately after tillage. If Medal II AT is to be used preemergence, apply at planting or immediately after planting.

4. If available, sprinkler irrigate within 2 days after application. Apply 1/2-1 inch of water. Use lower water volume (1/2 inch) on coarse-textured soils and higher volume (1 inch) on fine-textured soils.

5. If irrigation is not possible and rain does not occur within 2 days after planting and application, weed control may be decreased. Under these conditions, a uniform, shallow cultivation is recommended as soon as weeds emerge.

Restricted Entry Interval

24 hours

Exception: If the product is soil-injected or soil-incorporated, the Worker Protection Standard, under certain circumstances, allows workers to enter the treated area if there will be no contact with anything that has been treated.