SORGHUM

General Information

General Information

Marksman herbicide is a water-dispersible formulation for use in corn, sorghum, or fallow to control annual broadleaf weeds and to suppress perennial broadleaf weeds.

Mode of Action

Marksman contains two active ingredients: dicamba and atrazine. Dicamba is readily absorbed by plants through shoot and root uptake, translocates throughout the plant’s system, and accumulates in areas of active growth. Dicamba interferes with the plant’s growth hormones (auxins) resulting in death of many broadleaf weeds. Atrazine is absorbed by roots and shoots and controls weeds by inhibiting photosynthesis.

Resistance Management

Dicamba has a low probability of selecting for resistant biotypes. With repeated use, atrazine has selected for resistant biotypes of some weed species. Combining the two herbicides, which are each active in a similar broadleaf weed spectrum, reduces the risk of selecting for resistant biotypes.

Marksman herbicide can be applied pre-emergence or postemergence to actively growing weeds as aerial, broadcast, band, or spot spray applications using water or sprayable fertilizer as a carrier. Sprayable fluid fertilizer as a carrier is not recommended for use after crop emergence. For crop-specific application timing and other details, refer to section VI. Crop-Specific Information.

To avoid uneven spray coverage, Marksmanshould not be applied during periods of gusty wind or when wind is in excess of 15 mph.

Avoid off-target movement. Use extreme care when applying Marksman to prevent injury to desirable plants and shrubs.

Sensitive Crop Precautions

Marksman may cause injury to desirable trees and plants, particularly beans, cotton, flowers, fruit trees, grapes, ornamentals, peas, potatoes, soybeans, sunflowers, tobacco, tomatoes, and other broadleaf plants when contacting their roots, stems, or foliage. These plants are most sensitive to Marksman during their development or growing stage.

Aerial Application

Water Volume: Use 2-10 gallons of water per acre. Use the higher spray volume when treating dense or tall vegetation.

Application Equipment: Select nozzles designed to produce minimal amounts of fine spray particles. Make applications at the lowest safe height to reduce the exposure of spray droplets to evaporation and wind.

Ground Application (Banding)

When applying Marksman herbicide by banding, determine the amount of herbicide and water volume needed.

Ground Application (Broadcast)

Water Volume: Use 10-50 gallons of spray solution per broadcast acre for optimal performance. Use the higher spray volume when treating dense or tall vegetation.

Application Equipment: Select nozzles designed to produce minimal amounts of fine spray particles. Spray with nozzles as close to the weeds as is practical for good weed coverage.

Limitations, Restrictions, and Exceptions

Sorghum

Marksman may be applied preplant or postemergence in sorghum to control many annual broadleaf weeds and to reduce competition from established perennial broadleaf weeds as well as control their seedlings.

Do not apply to furrow planted sorghum until level (plowed in).

Do not apply Marksman to sorghum grown for seed production.

Do not graze or feed forage from treated areas for 21 days or more following application.

Do not graze livestock in treated areas for 21 days or more following application.

Do not add crop oil if application is made after sorghum emergence. Do not add surfactant unless possible crop injury is acceptable.

For preemergent sorghum forage uses, a 60-day PHI is required.

For postemergent sorghum forage uses, a 45-day PHI is required.

Postemergence applications to sorghum must be made before crop reaches 12 inches in height.

Maximum broadcast application rates for sorghum must be as follows:

- If no atrazine was applied prior to corn emergence, apply a maximum of 2.0 lbs. of atrazine a.i./A broadcast. If postemergence treatment is required following an earlier herbicide application, the total atrazine applied may not exceed 2.5 lbs. a.i./A per calender year.

- Apply a maximum of 2.0 lbs. of atrazine a.i./A as a single preemergence application on soils that are not highly erodible or on highly erodible soils (as defined by the Natural Resource Conservation Service) if at least 30% of the surface is covered with plant residues; or

- Apply a maximum of 1.6 lbs. of atrazine a.i./A as a single preemergence application on highly erodible soils (as defined by the Natural Resource Conservation Service) if <30% of the surface is covered with plant residues; or 2.0 lbs. of atrazine a.i./A if only applied postemergence.

PREPLANT APPLICATION:

Up to 2 pints of Marksman herbicide may be used and must be applied at least 15 days before sorghum planting.

POSTEMERGENCE APPLICATION:

Apply Marksman in sorghum between the 2-5 leaf stage (about 2-8\" tall) of the sorghum. For best performance, apply when sorghum is in the 2-3 leaf stage. Applying Marksman to sorghum during periods of rapid growth may result in temporary leaning of plants or rolling of leaves. These effects are usually outgrown within 10-14 days. On coarse soils, injury to sorghum may occur if heavy rain immediately follows application.

Apply 1.5 pints of Marksman per acre to control actively growing redroot pigweed less than 3\" tall. Apply 2 pints of Marksman per acre for all other listed broadleaf weeds.

SPLIT APPLICATIONS:

Marksman may be applied in split applications: preplant followed by postemergence applications.

Crop may be grazed or fed to livestock at mature grain stage.

1.5 pints / acre - Postemergence application

Up to 2 pints / acre - Preplant application

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.