Grazing North Texas — To Kill A Mesquite

The very small green growing points on this mesquite twig indicate that bud break is taking place in the tree, and it will be ready to spray later in the summer. (Photo by Tony Dean)

By Tony Dean 

Ranchers interested in using aerial spray for mesquite control usually pick one of two options. Some elect to use a less expensive chemical in an attempt to simply defoliate the trees and increase grass production for a couple of years. Others use herbicide designed for a total root kill on the trees but at a higher cost per acre.

Research conducted by Texas Tech University and others in the ‘70s and ‘80s isolated a handful of conditions that, when present during the spraying process, could significantly increase percent root kill when that is the goal.

The key to killing mesquite with herbicide application to the leaves is to first get good absorption into the leaf and then get the herbicide translocated to the root system. The following conditions are important indicators that translocation to the roots is taking place and the mesquites are on track for a successful spraying:

1. Soil temperature at the 12” to 18” depth needs to be consistently 75 degrees Fahrenheit or warmer. If rainfall causes the soil temperature to decrease below 75 degrees, spraying should be delayed.

2. Trees need to have all turned from light green leaves to dark green leaves.

3. Leaves must be healthy and not seriously damaged by frost or insects.

4. If trees are still in the flower stage, flowers must be yellow. If beans are present, they must have extended to their total expected length and still be green in color.

To read more pick up a copy of the May 2018 NTFR issue. To subscribe call 940-872-5922.