General Information


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

Dual II Magnum is a selective herbicide recommended as a preplant surface-applied, preplant incorporated, or preemergence treatment in water or fluid fertilizer for control of most annual grasses and certain broadleaf weeds in beans, peas, and lentils; corn (all types); cotton; grasses grown for seed; peanuts; potatoes; safflowers; sweet, grain, or forage sorghum; soybeans; soybean, immature seed; sugar beets; sunflowers; and tomatoes.

Restrictions: Do not use in nurseries, turf, or landscape plantings.

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 directions specify a Dual II Magnum tank mixture with AAtrex formulations, other brands of atrazine may be used. Follow the rates, recommendations, and limitations on the AAtrex or respective atrazine product label, if other brands of atrazine are used.

Restrictions: Certain states may have established rate limitations for atrazine within specific geographical areas. Consult your state lead pesticide control agency for additional information. It is a violation of the label to deviate from state use regulations.

If Dual II Magnum is incorporated, any supplemental tillage before planting must not exceed the depth of incorporation.

Dry weather following preemergence application of Dual II Magnum or a tank mixture may reduce effectiveness.

Cultivate if weeds develop.

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.

Precaution: Injury may occur following the use of Dual II Magnum under abnormally high soil moisture conditions during early development of the crop.


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

Restrictions: Dual II Magnum may be applied preemergence alone, or in combination with tank mix partners specified on the label, following preplant incorporated herbicides when used according to their label recommendations, provided that such use is not prohibited on the respective labels.

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 any other materials, or crop damage or clogging of the application device may result.

Weeds Controlled

Dual II Magnum is taken up by the shoots and/or roots of emerging weeds. This uptake results in the inhibition of shoot and root tissue growth soon after weed germination. Because of this, Dual II Magnum will not control emerged weeds and should be applied prior to weed emergence.

If Dual II Magnum is incorporated, do not exceed a 2- to 3-inch depth. Any tillage after the Dual II Magnum incorporation and before planting should not exceed 2-3 inches.

Dry weather following application of Dual II Magnum may reduce weed control. Cultivate if weeds develop.

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. Control of these weeds can be erratic, due partially to variable weather conditions. The following procedures may improve the control of weeds listed as partially controlled in Table 1:

1. Thoroughly till soil to destroy germinating and emerged weeds.

2. Plant crop into moist soil immediately after tillage. If Dual II Magnum is to be used preemergence, apply at planting or immediately after planting.

3. 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. Also, refer to the section on Center Pivot Irrigation Application for this method of applying Dual II Magnum.

4. 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.



Dual II Magnum alone or in some tank mixtures with other labeled herbicides may be applied for weed control in certain crops at various times. Refer to the given crop section of the label to determine if application timings listed below are recommended.

Preplant Surface-Applied: For minimum-tillage or no-tillage systems only, Dual II Magnum alone and some Dual II Magnum tank mixtures may be applied up to 45 days before planting certain crops. Use only split applications for treatments made 30-45 days before planting, with 2/3 the recommended broadcast rate for the crop and soil texture applied initially and the remaining 1/3 at planting. Treatments less than 30 days before planting may be made either as a split or a single application. Refer to individual crop section on the label to determine if early preplant surface application is recommended.

If weeds are present at the time of treatment, apply in a tank mixture combination with a contact herbicide (for example, Gramoxone Inteon, Touchdown brands, or Roundup brands). Observe directions for use, precautions, and restrictions on the label of the contact herbicide. 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.

Preplant Incorporated: Apply Dual II Magnum to the soil and incorporate into the top 2 inches of soil within 14 days before planting, using a finishing disk, harrow, rolling cultivator, or similar implement capable of providing uniform 2-inch incorporation. Use a preplant incorporated application if furrow irrigation is used or when a period of dry weather after application is expected. If crop will be planted on beds, apply and incorporate Dual II Magnum after bed formation, unless specified otherwise.

Preemergence: Apply Dual II Magnum during planting (behind the planter) or after planting, but before weeds or crops emerge.

Postemergence: Dual II Magnum will not control emerged weeds so it must be applied to a weed-free soil surface or in tank mixture with products that provide postemergence control of weeds present at the time of application. Refer to the individual crop section of the label if a postemergence application is recommended.


CA Only (Beans, Peas, and Lentils; Corn; Safflowers): Preplant Incorporated: Broadcast Dual II Magnum alone or with tank mix partners listed on the label to the soil and thoroughly incorporate with a disk or similar implement set to till 4-6 inches deep. For more thorough incorporation, till the soil in 2 different directions (cross-till). Crops may be planted on flat surface or on beds. Use caution when forming the beds that only soil from the Dual II Magnum treated zone is used (i.e., untreated soil should not be brought to soil surface). If the application is made to preformed beds, incorporate Dual II Magnum with a tillage implement set to till 2-4 inches deep. Care should be taken during tilling to keep the tilled (Dual II Magnum-treated) soil on the beds. Preemergence: Apply Dual II Magnum after planting. Water with sprinkler or flood irrigation within 7-10 days.

Fall Application for Spring Weed Control (Only in IA, MN, ND, SD, WI, and portions of NE and IL - See specific instructions in the Beans, Peas, and Lentils; Corn; and Soybeans sections of the label for timing of application and other information):

Do not apply to frozen ground. Use on medium and fine soils with greater than 2.5% organic matter that will be planted to corn or soybeans the next spring. Ground may be tilled before or after application. Do not exceed a 2 to 3-inch incorporation depth if tilled after treatment. Restrictions: If a spring application is made, the total rate of the fall plus spring applications must not exceed the maximum total rate for the specific crop, or illegal residues may result.

Fall Application for Italian Ryegrass Control (Corn, Cotton, Grain and Forage Sorghum, and Soybean Only – See specific instructions in the Corn, Cotton, Grain and Forage Sorghum, and Soybean sections of the label for timing of application and other information): Dual II Magnum may be applied in the fall (September 1-December 1) for residual control of glyphosate-resistant Italian ryegrass (Lolium multiflorum). A tillage operation may precede the application. Do not incorporate to a depth greater than 2-3 inches if tillage follows the application of Dual II Magnum. Restrictions: 1) Do not apply Dual II Magnum to frozen ground. 2) All crops on the Dual II Magnum label may be planted the following spring after application. 3) If a spring application is made, the combined total amount of Dual II Magnum applied in the fall plus the spring must not exceed the maximum seasonal S-metolachlor rate for the specific crop planted, or illegal residues may result. 4) Refer to the crop sections on the label for specific directions.

Ground Application: Apply Dual II Magnum alone or in tank mixtures by ground equipment in a minimum of 10 gals. Of spray mixture per acre, unless otherwise specified.

Use sprayers that provide accurate and uniform application. For Dual II Magnum tank mixtures with wettable powder or dry flowable formulations, screens and strainers should be no finer than 50-mesh. Rinse sprayer thoroughly with clean water immediately after use.


For Broadcast Ground Application Only

Use sprayers, such as Ag-Chem RoGator, Hagie, John Deere Hi-Cycle, Melroe Spra-Coupe, Tyler Patriot, or Willmar Air Ride, that provide accurate and uniform application. Only water may be used as a carrier. Screens in suction and in-line strainers should be 50-mesh. Manufacturers may require that tip screens as fine as 100-mesh be used with some nozzles. Use a pump with capacity to: (1) maintain up to 35-40 psi at the nozzles, and (2) provide sufficient agitation in tank to keep mixture in suspension. Use a minimum of 5.0 gals. of spray mixture per acre. Maximum recommended sprayer speed is 15 mph. Rinse sprayer thoroughly with clean water immediately after each use.

Restrictions: Low pressure nozzles are recommended to reduce drift and increase application accuracy. Care should be taken when using automatic rate controlling devices to spray the material within the rated working pressure and flow ranges of the nozzles selected. Nozzle screens should be used when recommended by the manufacturer. All nozzles should be placed on 20-inch centers, except flooding types which should be placed on 40-inch centers. When Flat Fantype nozzles are used, angles of 80° or 110° are recommended. Always read and follow the manufacturer’s directions for optimum setup and performance of their nozzles or tips.


Apply Dual II Magnum in water alone or in tank mixtures with AAtrex, Lorox, or Sencor in a minimum total volume of 2.0 gals./A by aircraft. Dual II Magnum may also be applied by air in combination with Balan, Prowl, or Treflan. Avoid application under conditions where uniform coverage cannot be obtained or where excessive spray drift may occur. In order to assure that spray will be controllable within the target area when used according to label directions, make applications at a maximum height of 10 ft., using low-drift nozzles at a maximum pressure of 40 psi, and restrict application to periods when wind speed does not exceed 10 mph. To assure that spray will not adversely affect adjacent sensitive nontarget plants, apply Dual II Magnum alone or Dual II Magnum + AAtrex by aircraft at a minimum upwind distance of 400 ft. from sensitive plants, or apply Dual II Magnum + Lorox or Sencor at a minimum upwind distance of 300 ft. from sensitive plants.

Refer in the label regarding tank mix information.

Refer in the Supplemental label for Recommendation to Tank Mix BALANCE PRO with Dual II MAGNUM for use in Field Corn for the state of Iowa (specific counties only).

Limitations, Restrictions, and Exceptions


Preplant Incorporated or Preemergence

Use the higher rate of Dual II Magnum if heavy weed infestations are expected.

Restrictions: To avoid possible illegal residues: (1) Do not allow livestock to graze or feed in treated area. (2) Do not exceed the maximum label rates for sunflowers for the soil type.

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.