“Mesquite is able to do things in the environment that other plants aren’t able to do,” Hart says. “It can survive on little water. It can send its roots down as far as needed in order to get water. It’s a very prolific seeder, so it’s going to reproduce itself through seed. It’s just well adapted the area it lives in.

“It’s ready for anything we can throw at it; freezes, droughts, floods, you name it. It’s resilient to all of those. But Sendero helps range managers overcome that resilience.”

Best control results are normally seen when the soil temperature is 75 degree or warmer at least 12 inches deep. “If temperatures are below that 75 degrees, the plant is not metabolizing,” Hart says. “The herbicide will have difficulty entering the root system.”

In pastures farther south, treatments can be made as early as mid-May. In order to obtain the best control in North Texas, southern Oklahoma and some northern New Mexico regions, it may be as as late as mid-July before soil temperature is warm enough for treatment.

“We have about the same window of mesquite herbicide application as we’ve always had,” Hart says. “Ranchers will see best results when a plant is healthy and there’s a lot of leaf growth. You might think it’s easier to kill a weak tree than an unhealthy tree. It’s just the opposite with mesquite. The mode of entry of this herbicide is through the leaf. The more leaf you have on the plant, the more chemical you get into the plant.”

Hart says a typical Sendero application rate is 28 oz./per acre mixed with 5 gal. of water and a labeled rate of a surfactant. With that prescription, broadcast aerial application of small droplets should provide ideal penetration into leaves. A spot spray program may be needed in a maintenance control system.

Application should be made between 42 and 63 days after bud break. No applications should be made during bean elongation, which is normally 63 to 72 days after bud break. Treatment can resume after that up to 90 days after bud break.

Hart says soil moisture should be sufficient for good growth. Treatment should not be made just after a heavy rainfall of a-half inch or more. Relative humidity should also be 25% or higher.

“Mesquite management is a long-term relationship,” Hart says. “You must have a follow-up plan. There is no silver-bullet for mesquite control. It’s more of mesquite management. You’re going to have new seedlings come in.  Mesquite is going to re-invade.

‘It’s cheaper treat mesquite when it is young. Once you get rid of a mature population, the objective is to go back in and retreat periodically to control new plants when they are young.”