Keeping power flowing at utility sites and maintaining infrastructure around oil and natural gas sites is always a challenge for vegetation management crews, but the upsurge in herbicide-resistant weeds has amped up their task. To adhere to maintenance and safety standards required at these sites, applicators have had to adapt their strategies to match evolving weed-control challenges.

The team at Chemical Weed Control, a Texas-based vegetation management company covering 11 states, is constantly searching for the best way to maintain a weed-free, safe environment at utility sites to help ensure a steady stream of energy, says Layne Fields, operations manager for the company’s northern region.

“Our customers recognize that they’re part of the communities in which they’re located and want to be good neighbors and environmental stewards by maintaining clean, safe sites,” says Fields. “Whether we’re working on an oil, natural gas or electric utility site, we need to keep out encroaching weeds so crews do not run over our operators' equipment. We also need to keep small weeds from turning into trees that can get into transformers and other instrumentation, thus interrupting service.”

Resistant Weeds Add Pressure

Complicating vegetation management for Fields and his crew is development of difficult-to-control herbicide-resistant weeds.

“We’ve been trying to stay ahead of tough weeds such as Russian thistle, kochia, pigweed and ragweed for the last decade,” Fields notes. “Recently, we’ve found that a two-pass-per-year herbicide program with spring and fall applications provides very good control for our customers.”

Fields uses DuPont™ Perspective® herbicide in one application of the two-pass program, adding a tank-mix partner for a broader spectrum of control.

“We’ve used Perspective® for more than two years and have had really good success controlling resistant species that previously gave us trouble,” he says. “Without Perspective®, we were looking at making more than two applications a year to keep tough species under control.”

Long-Lasting Residual Control

To arrive at a successful two-pass program, Fields tested several combinations of products and application timings at different sites. One of his most successful treatments has been a Perspective® + ProClipse tank-mix application during the fall-to-winter time frame.

“We’ve found that a Perspective® + ProClipse winter application followed by adequate moisture helped keep sites with resistant weeds clean longer into the spring,” Fields says. “We had some sites in the northern Texas Panhandle that were still clean more than a year after a winter application. That really surprised us.”

The second part of Fields’ two-pass program features a late spring or early summer application with herbicides that include an alternate mode of action for effective weed resistance management and consistent bareground weed control.

“We have been very pleased that Perspective® has helped us cut our retreatments, especially on resistant Russian thistle, kochia and pigweed, to nearly zero,” Fields adds. “And if we can avoid some retreatments, we’re not just saving the cost of the extra application, we’re also able to move that applicator on to other jobs and increase our revenue. That’s a big advantage for us.”