Researchers gaining on bindweed

Mark Renz, a weed specialist with New Mexico State University’s Cooperative Extension Service, holds flowering field bindweed. New Mexico State Extension Service photo

Staff and wire reports

ALBUQUERQUE — Researchers at New Mexico State University are using chemicals and parasites to successfully control field bindweed, a pesky plant that invades crops, pastures and gardens in eastern New Mexico and throughout the state.

Bindweed found its way into New Mexico more than a century ago and has now spread to all 33 counties.

Curry County agriculture extension agent Stan Jones said the weed has heavily infiltrated the area and can be found in yards, farms, road ditches and just about anywhere else.

“Bindweeds are the hardest weed to kill because they put down a root system that can be as deep as several feet,” Jones said. “In a farm if you plow through it you will just spread it around your farm.”

The key to the hardy weed’s survival — even during times of extreme drought — is a massive root system that can penetrate 30 feet into the soil, said Leonard Lauriault, forage agronomist at NMSU’s Agricultural Science Center in Tucumcari.

“This is a very difficult weed to control, and it’s very hard to kill,” he said. “It choked out the Bermuda grass in my back yard, just to give you an idea of how tough this weed is.”

The viney plant is a cousin of the morning glory, with thin, arrowhead-shaped leaves and small white flowers. It can be dug up or mowed but such efforts only further spread the plant’s seeds, which can last up to 50 years in the soil, Lauriault said.

“All crop types are affected — annually cropped fields, well-managed hay fields and including any kind of pasture, even home lawns and cemeteries,” Lauriault said.

“Herbicides do not go far enough to kill the plant.”

Experts are now combining herbicides with a parasite — the bindweed gall mite — to control the weed.

Lauriault said herbicides, such as glyphosate and phenoxy, destroy the plant’s foliage. The mites will then work their way down to the roots, eventually weakening and killing the plant.

Though the mites only move about a foot a year down the roots, Lauriault said it can still help control the weed with aggressive treatment.

“You have to give the mites a chance to get established, about two weeks, and then mow or spray the plants with herbicide. It has to be a combination to be effective,” he said.

After a full year of treatment, Lauriault killed off the bindweed in his yard. But he also starved off the mites, and the weed came back the next year thanks to those long-lasting seed.

The key to bindweed control, he said, is to keep the mites alive.

“All herbicides are not equal,” he said, explaining that some can kill the mites.

In September, Curry County began a three year study on controlling bindweed at a site near Broadview, Jones said. A second stage will begin late September or early October.

Though the treatment system can’t completely control bindweed, it’s another tool researches can use to help find an ultimate solution.

“Each person has to decide how aggressively they want to work to get rid of the weed,” Lauriault said. “People will be very upset if they think they can put the mites out there and expect them to do all the work.”