J. F. CADENHEAD, III. Texas Agricultural Extension Service. Vernon, TX
Spraying the stem bases of individual plants can be a very effective and economical way to acquire selective control of various brush species. This method permits treatment throughout the year and is not as “weather-dependent” nor as “growth stage-dependent” as is foliar application. Fair to good results have been obtained from applications throughout the year, however, best and most consistent results have come from spring/summer growing season applications. Best results are also realized when applications are limited to younger plants possessing basal stems with smooth, thinner bark that has not yet matured into a thicker rougher corky layer.
The most efficient way to apply the herbicides is with a backpack sprayer, although a garden pump-up sprayer or any type of hand sprayer may be used. Using a sprayer nozzle with a small orifice (such as the Conejet* 5500-X1) can reduce total quantity of spray applied by as much as 80 percent over standard nozzles (McGinty and Ueckert 1995). Adjust the nozzle tip to deliver a narrow, cone-shaped mist, and apply the mixture lightly and evenly to each basal stem from the ground line up to about one foot high. Make sure that the spray mixture completely wraps around each stem for the entire 12 inches up before moving on. Just spray to cover all around the stem, as spraying to the point of puddling is wasteful and unnecessary.
The most commonly recommended herbicide mixture for basal stem applications is a Remedy** and diesel fuel oil combination. The diesel serves as a carrier and penetrating agent to assist with herbicide absorption through the bark. The amount of Remedy to use in the mixture depends on the size and age of the brush – whether or not it has rough bark. See the following table for the recommended percentages of herbicide and volumes of both to make one gallon of mixture:
This table (McGinty and Ueckert 1995) indicates the amounts of herbicide to use if, for example, you are only mixing one gallon (128 fluid ounces = one gallon) of total mixture with diesel. Pour the required amount of herbicide into a mixing container and then bring it to total volume with the diesel to give the proper percentage concentration of herbicide desired.
Points to Remember for Basal Spraying:
- Follow herbicide label directions.
- Treatment costs escalate rapidly as plant densities or stem numbers per plant increase.
- Multiple-stemmed plants or rough-barked plants are more difficult to control.
- Do not spray when stems are wet.
- Agitate the spray solution until well mixed before spraying.
- Dense grass around the stem bases reduces application and control efficiencies.
Recommended Concentration of Remedy as a Percentage of the Total Mixture with Diesel
|Smooth Bark Stems||% Remedy||Volume of Remedy||Volume of Diesel|
|– 1.5 inch Diameter or less||15 %||19 ounces||109 ounces|
|– 1.5 in. to 4 in. Diameter||25 %||1 quart||3 quarts|
|Rough Bark Stems||25 %||1 quart||3 quarts|
McGinty, Allan and Darrell Ueckert. 1995. Brush Busters: How to Beat Mesquite. L-5144. Texas Agri. Ext. Ser. College Station, TX
*Trademark of Spraying Systems Co.
**Trademark of DowElanco.
Comments: Dale Rollins, Professor and Extension Wildlife Specialist
Updated: Mar. 18, 1997