Controlling vegetation in utility rights of way is essential for meeting Federal Energy Regulatory Commission (FERC) guidelines and ensuring an uninterrupted power supply to protect public safety. One challenging brush species in the Southwest is mesquite. The plant’s hardiness and easy seed distribution by wildlife make it exceptionally hard to control.

Formidable Opponent

Mesquite is extremely invasive, quickly overtaking land and crowding out desirable vegetation. It can be identified by its narrow, compound leaves, which are 2 to 3 inches long and sharply pointed.

Mesquite is also drought-tolerant and can switch water sources easily. It pulls water through a taproot that can stretch nearly 200 feet or from supplies closer to the soil surface.

Overgrown mesquite rapidly creates hazards and interferes with utility infrastructure. Most mesquite plants are shrub-sized, but older individual plants with hardwood trunks can reach heights of 20 feet or more. Adding to the difficulty, new growth has tough, needle-sharp thorns up to 3 inches long and mesquite can regenerate from a piece of root left in the soil, making thorough control even more critical.

Precision Control
Utility managers must find ways to control mesquite quickly and effectively, while preserving a healthy grass understory. This adds to crew demands and to costs, since it may require potentially dangerous hand-cutting.

Fortunately, newer herbicide options provide better answers for mesquite control and offer both improved control and selectivity. DuPont™ Streamline® herbicide delivers reliable control of mesquite in a single product while preserving desirable native grasses. Streamline® also controls other difficult weed and brush species, including boxelder, hackberry, huisache and cottonwood.

In a recent trial near Childress, Texas, Streamline® was used on land with heavy mesquite coverage. Plants were 4 to 6 feet tall and had not been treated or mowed. The trial tested Streamline® at 11.3 ounces per acre. All treatments were applied in late July as a broadcast spray in water at 15 gallons per acre and included methylated seed oil (MSO) at 1 percent v/v.

The results demonstrated that, when applied at the 11.3 ounces per acre rate, Streamline® provided exceptional control – providing 92 percent mesquite control more than two years after treatment.

Spraying Tips for Successful Control

  • To successfully control mesquite, apply Streamline® in late spring to late summer and only in non-crop areas.
  • Ideal spraying dates vary by region and depend on proper soil temperature (about 75 degrees or higher) and height and maturity of mesquite. Apply to plants that are 12 to 18 inches with dark green leaf color and healthy foliage.
  • Apply when mesquite is producing carbohydrates and sending them to the roots for storing over the winter so the spray will be carried to the roots.
  • Since mesquite leaves produce the food source and send it to the root zone, it is important to eliminate basal buds. Mechanical control will only activate basal buds, triggering more plant growth.

For more information on maintaining clear rights of way and increasing site safety through effective mesquite control, visit landmanagement.dupont.com.