Rangeland Weed and Brush Control

Common Herbicides
Herbicide common name Product name Active ingredient
or acid equivalent
Clopyralid Reclaim 3 lbs./gal.
2, 4-D several Variable
Dicamba Banvel 3 lbs./gal.
Dicamba:2, 4-D (1:4) Weedmaster 4 lbs./gal.
Hexazinone Velpar L 2 lbs./gal.
Metsulfuron Ally or Escort 60%
Picloram Grazon PC 2 lbs./gal.
Picloram:2, 4-D (1:2.87) Grazon P+D 2.5 lbs./gal.
Tebuthiuron Spike 20P 20%
Triclopyr Remedy 4 lbs./gal.
Triclopyr:2, 4-D (1:2) Crossbow 3 lbs./gal.

Calibration of Boomless/Clusterjet Nozzle Sprayers:

  • Fill spray tank with water to a marked level
  • Drive in a straight line for 660 feet, operating the sprayer at a constant pressure and speed.
  • Refill the tank to the original level to determine the numer of gallons used.
  • Measure the width (ft.) of the area sprayed.
  • Calculate as follows:
    (gallons used x 66) / width of sprayed area (feet) = gallons sprayed per acre
    tank capacity(gallons)/gallons sprayed per acre = acres sprayed per tank
  • Add the appropriate amount of herbicide to the tank and fill.

Calibration of Boom Sprayers:

  • Record the time required to travel 100 feet under spraying conditions.
  • Record the number of ounces sprayed from one nozzle for the length of time required to drive 100 feet.
  • Calculate as follows:
    (40 x ounces sprayed) = nozzle spacing (inches)
    tank capacity(gallons)/gallons sprayed per acre = acres sprayed per tank
  • Add the appropriate amount of herbicide to the tank and fill.

Basal Bark Application Techniques

  • Conventional basal:
    Apply diesel fuel oil, kerosene or a herbicide/diesel fuel oil mixture (2 to 4 percent herbicide) to the lower 12 to 18 inches of the trunk of a brush plant. The solution is applied completely around the trunk with sufficient volume to allow runoff and puddling a the soil surface.
  • Low-volume basal:
    Apply a mixture containing diesel fuel oil plus 15 to 25 percent herbicide, or diesel fuel oil plus 15 to 25 percent herbicide to wet the lower 12 to 18 inches of the trunk completely around, but not to the point of runoff.
  • Streamline basal:
    Apply a mixture containing diesel fuel oil plus 15 to 25 percent herbicide, or diesel fuel oil plus 15 to 25 percent herbicide and 10 percent penetrant, in a band (3 to 4 inches wide) completely around the trunk near ground level.

Addition of Surfactants to Foliar Sprays:

  • 1 to 2 qts. per 100 gals. water
  • 2 to 4 tsps. per gal. water

Broadcast vs. Individual Plant Treatment:

  • Fewer than 200 stems/acre, use individual plant treatments
  • More than 200 stems/acre, use broadcast treatments

Weed Control

  • Spray when weed density is three or more per square foot.

Determining Stems per Acre:

  • Mark off area 22 yards x 22 yards.
  • Count stems within this area.
  • Multiply the number of stems by 10.
Recommended Tractor Size(s)
for Various Rangeland Brush Control Implements
Implement Recommended tractor size
Roller choppers (heavy duty)
- less than 10 ft. wide
- more than 10 ft. wide
D7 crawler tractor
D8 crawler tractor
Chains (minimum 180 ft.) D6 – D8 crawler tractor
Rootplows D7 – D8 crawler tractor
Heavy offset disks D8 crawler tractor
Front mounted grubbers
- high energy
- low engery
D6 – D7 crawler tractor
D3 – D5 crawler tractor; 35 – 120-hp farm tractor or wheeled loader
Rear mounted grubbers 35 – 120-hp farm tractor
Quantity of Herbicide Needed to Obtain Various Concentrations
To mix Concentration desired
1/2% 1% 1 1/2 % 2%
1 gal. 6/10 oz. or 18cc. 1 1/4 oz. or 38cc. 1 9/10 oz. or 58cc. 2 1/2 oz. or 77cc.
25 gals. 1 pt. 1 qt. 3 pts. 2 qts.
100 gals. 1/2 gal. 1 gal. 1 1/2 gals. 2 gals.

Prescribed Burning
Red Flag Conditions for Winter Burns:

  • Wind speed greater than 20 mph.
  • Relative humidity less than 20 percent.
  • Air temperature greater than 80 degrees F

Fine Fuel Loads for Effective Burns:

  • Minimum of 1,500 to 2,000 pounds/acre.
  • Optimum of 3,000 pounds/acre or more.

Diesel: Gasoline Mixture for Drip Torches:

  • 60 to 75 percent diesel plus 25 to 40 percent gasoline.

Optimum Weather Conditions for Winter Backfires:

  • Relative humidity between 40 and 60 percent
  • Air temperature between 40 and 60 degrees F
  • Wind speed between 5 and 8 mph

Optimum Weather Conditions for Winter Headfires:

  • Relative humidity between 25 and 40 percent
  • Air temperature between 70 and 80 degrees F
  • Wind speed between 8 and 15 mph

Texas Air Control Board Regulations for Prescribed Burns:

  • Wind speed must be between 6 and 23 mph.
  • Burn must be started after 9 a.m.
  • Burn must be completed by 5 p.m.
  • Burn must be at least 300 feet from adjacent residential, recreational, commercial or industrial properties.
  • Burn cannot be conducted when atmospheric temperature inversions are predicted.
  • Burn must be outside corporate limits of a city or town.

Minimum Downwind Protection (Backfire + Mineral Fireline Width):

  • Slighly volatile fuels = 50 to 100 feet
  • Moderately volatile fuels = 100 to 200 feet
  • Highly volatile fuels = 300 to 500 feet

Minimum Mineral Fireline Width:

  • 8 feet + 1 foot per mph of wind expected.