For more than 30 years, ranchers and applicators have tried to align a puzzle of environmental factors to pick the best time to spray mesquite. Now that timing decision can be a whole lot easier.
Until recently, those environmental factors — soil temperature, soil moisture, leaf color, foliage condition and days after bud break — were the only way researchers had found to determine when mesquite might be most susceptible to herbicide.
Now, new digital and imagery technology — in the form of LandVisor™ advanced brush management — can help make that call easier, quicker and more accurate. And it’s customized to the target pasture. A human consultant still confirms it with an on-the-ground inspection.
“Before LandVisor, we were totally dependent on visual indicators to guess what was going on in the plant,” says rangeland ecologist Charles Hart, Ph.D. Hart is a market development specialist with Corteva Agriscience.
“It was the only way we had to judge the plant’s ability to absorb and translocate the herbicide. We got pretty good at it, but it didn’t always work as expected,” he says. “There were things going on within the plant that we couldn’t see.
“But with LandVisor, we can see things we can’t see with the naked eye. We can’t see photosynthetic capacity with our eyes. It’s difficult to compare leaf volumes across years. We can do that with LandVisor.”
The ability of the foliage to absorb and translocate the herbicide is a key element in successful control of mesquite. Where experts once had only color and condition of foliage as an indicator, LandVisor accurately measures those factors, photosynthetic capacity, biomass (quantity of leaves) and other factors to determine a value for “plant vigor.”
The technology combines the plant vigor value with readings of soil temperature, soil moisture and other indicators to identify a window of time to spray mesquite for the best results. That spray window begins when all the factors are near peak condition.
LandVisor determines that peak by comparing current conditions with those of the last four years on the property to be sprayed.
“So, the prescription is customized for the particular target site,” Hart says. “We can set a minimum percentage of peak condition and offer a warranty of performance. At the minimum we set, we can warranty 70% control.” 1
If conditions aren’t at the minimum level, the consultant will not release the job for spraying. He asks the customer to wait another year.
“In some years, we may not get there,” Hart says, “but some years will be exceptional. LandVisor can tell us that, and we can take advantage of it.”
Historically, rains have often interfered with spray timing. Rainfall, especially after a dry period, can cause new leaf growth on twig tips, indicating upward translocation. That’s not good for getting herbicide to the roots to the kill the plant.
“Before LandVisor, we’d get a rain and have to wait two weeks to see if new growth appeared,” Hart says. “If we didn’t get new growth, we could spray. But by then we may have missed the window.
“With LandVisor, we know when we have a significant rainfall event. Then we can wait three to five days and evaluate vegetative readiness again. It gives us more time to spray.”
Sophisticated LandVisor technology monitors the mesquite remotely. Before spraying, however, a human consultant still visits the target site to substantiate what the technology sees and check out any anomalies.
“LandVisor gives us a scouting map showing real-time variability in mesquite conditions across the pasture,” Hart says. “For example, there may be bug damage in one area and the consultant verifies that.”
If conditions are within the target parameters, the consultant confirms with the rancher-customer and releases the job to be sprayed by an applicator certified by Corteva Agriscience.
“There has always been more to mesquite control than just the herbicide,” Hart says. “Mesquite control is like a three-legged stool.”
For successful mesquite control, Hart says, those legs are: 1. herbicide and rate; 2. plant condition and stage of growth at the time of application; and 3. proper application.
“If any one of those falls short, the stool falls over — it doesn’t work. LandVisor addresses all three of those areas for success,” he says.
170% control is calculated according to the LandVisor Service Policy.
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