Pete Stidman

Target: Japanese knotweed

JAMAICA PLAIN GAZETTE

The third in a series chronicling Jamaica Plain’s invasive species.

Philip Burgess of JK International did not need to describe Japanese knotweed to the audience. The crowd of greenspace-oriented professionals, students and volunteers sitting in the front room of the Hunnewell building at the Arnold Arboretum had already been frustrated by its bamboo-like, reddish hollow stems and oval leaves for years.

“This little guy is tenacious when it comes to life,” said Burgess, pointing to a photo of the plant projected at the front of the room. “It is one of the most durable plants I’ve ever come into contact with.”

The photo showed a baby Japanese knotweed plant growing next to a steel-belted radial. The painted yellow line next to the weedling was the second clue that the knotweed does not need black loamy soil to grow. It was pushing up through a crack in road’s asphalt.

Mowing doesn’t kill it, and the clippings will take root even without soil, said Burgess. Spraying it only kills the top growth, and new shoots quickly replace those. Even the combination of mowing, then spraying into the stems doesn’t work, because the poison won’t travel far enough through its root system. As if that weren’t enough, the plant is also a rhizome. Dozens of plants can be connected by rootstalks underground.(Read more)

“It has a root structure that you wouldn’t expect,” he continued. “It will go down up to 3 meters and travel out 10 to 13 meters in any direction.”

It’s been over 40 years since Japanese knotweed was first noted as a nuisance in the US, and even two months ago local park experts were saying “You can’t get rid of it, you just have to manage it.” But now, a small but growing family business from the Northwest, where knotweed has taken over whole rivers, is saying it has the ultimate weed weapon: the glyphosate gun The holster is optional.

The gun fits the persona of Burgess, who could easily be imagined as a county sheriff or a rancher with his Wrangler twill jeans and sauntering gait.

His son Brian came up with the idea for the gun in collaboration with his father using the syringes his mother used to treat her baby goats.

“We knew that if we could get herbicide into the plant, it would be more effective,” said Brian Burgess before introducing his dad and a chemist to speak. “One of our problems was herbicide blowback.”

Knotweed’s hollow stems are sealed cells. Each time a cell was injected, he said, some of the herbicide inevitably blew back out of the hole made by the syringe.

The Burgesses made a breakthrough when they manufactured a needle that deploys the pesticide glyphosate from a point halfway up its stem, as opposed to the traditional syringe needle, which squirts out near its point. With this needle, the stem can be punctured twice, once going in and once going out the other side. This eliminates “herbicide blowback” and subsequent tests showed it to be very effective.

“How often do you have to go back and reapply to kill a plant?” asked a member of the audience.

“This is a one-time application,” said Philip Burgess, and a ripple of surprise worked its way through the crowd.

Where he works in Clark County, Wash., he explained, Japanese knotweed had covered the banks of entire rivers. The plants have no natural predators in North America and can survive almost anywhere.

“It was almost one of those nightmares where you close your eyes and say to yourself, ‘I never saw that at all,’ he said. “It decimated a river system in just under nine years. Boaters had to take a machete with them just so they could get down to the bank and launch their boats.” And those cut stems traveled downriver and took root somewhere else.

With a grant from Congress over a couple of summers, Philip Burgess and 22 part-time workers with Clark County Weed Management were able to remove over 95 percent of the plants from one river, working from the watershed down.

“And did we hurt the environment? Hell, no.” said Philip Burgess.

Dr. Ron P. Crockett, a member of Monsanto’s technical marketing development team, put it differently to the crowd: “I can’t say ‘safe,’ but I can say ‘benign in its environmental properties.’”

Glyphosate’s chemical formula includes recognizable components such as carbon dioxide, nitrogen and phosphate. According to Crockett, soil microbes attack and consume the formula’s nitrogen and phosphate components, thus rendering the product harmless.

The herbicide, known more commonly as Roundup, was formulatedby John Franz in 1970 and was selling for $60 a gallon by 1974. Glyphosate is by far the most commonly used herbicide in the farming industry, including its use on a few of Monsanto’s highly controversial genetically modified organisms, such as Roundup-resistant soybeans and corn.

Glyphosate blocks growth and kills plants by inhibiting the production of certain proteins–specifically, the essential amino acids phenylalanine, tyrosine and tryptophan. None of these proteins are produced in the human body, thus glyphosate’s consumption by humans is theoretically safe, although not recommended, said Crockett.

Studies that prove Roundup has a negative effect on the ecosystem are few, but they do raise questions for agricultural use and cautions for spraying in wetlands. A study of amphibians completed by Rick Relyea concluded that tadpole populations were adversely affected by heavy doses of Roundup in April, 2005. The study rippled through environmentalist circles and focused attention on the herbicide.

But Relyea readily admits that his study showed the danger of a certain surfactant (a substance that helps penetrate plant cells), not glyphosate itself. Certain mixtures that include glyphosate, such as Aquamaster Pro, do not contain the surfactant. A similar product was used by Philip Burgess on Japanese knotweed near rivers in the northwest to protect freshwater habitats.

The health effects of glyphosate, should it be consumed, are a matter of debate. At least two studies have identified glyphosate as an endocrine disruptor that may interfere with reproduction, and one Swedish study has linked it to non-Hodgkins lymphoma, a cancer of the lymphatic system. But the latter study was based on a questionnaire that asked people to remember what herbicides they had used over a period of many years. A comprehensive review of the product’s harmful effects was performed by the European Union in 2001 and concluded that it was not a carcinogen.

Glyphosate has also been found in drinking water in different parts of the world, including reports of contamination in the St. Joseph’s River in Indiana and groundwater in Denmark. In defense of its product, Monsanto reportedly blamed the latter on heavy rains.

Under certain conditions, many people concerned with Jamaica Plain’s parks are open to the idea of herbicide use if it could solve the expensive and time consuming invasive problem without endangering people or other species.

“The invasive species question is overwhelming the world, whether it is the human, or other species invading,” said Gerry Wright, president of the Jamaica Pond Project, who stopped by to comment while walking down Centre Street. “It has become such a complicated question… I am not against [all] kinds of herbicide use. At times we should experiment to see what can contain the species that are detrimental to natural habi-tats.”

“I do worry that three or four years from now, cutting down knotweed is going to get old,” said Christine Poff of the Franklin Park Coalition in another impromptu interview.

Don Eunson of the Emerald Necklace Conservancy attended the talk at the Arboretum and expressed hope that anti-herbicide groups would see an occasional need for their limited use.

“When people try to simplify down to ‘no herbicide ever,’ they’re really missing the complexity of the ecosystem and how we, as human beings, interact with green spaces,” he said.

Margaret Connors of JP’s leading anti-pesticide group, Neighborhood Pesticide Action Committee, refrained from supporting or opposing the gun’s use until she can get more information on its effects.

“It’s better than spraying,” she said. “But knowing that it can be persistent and mobile in the soil, what happens to the product when the plant dies? I can’t say that we’d support it.”

The Arnold Arboretum already owns two of the guns, and is set to order four more for this summer, said Steve Schneider, assistant superintendent of the grounds. His crew eliminated a patch of knotweed that was creeping onto the grounds via the Bussey Brook last summer.

“It was so thick we couldn’t get in there to inject all the canes,” he said, adding that most of the plants are gone and workers will return to finish the job this season. With the help of volunteers he also plans to attack a large knotweed patch near the Hebrew Rehabilitation Center on Weld Hill. Schneider was also responsible for inviting JK International and Crocket to speak at the Arboretum.

“I researched them,” he said. “They’re a family business. Phil has a conservation background. It wasn’t just DuPont trying to push a product. They didn’t pick some hack chemist to deal with either,. They really did their homework. Hopefully the Arboretum will become the hub of Japanese knotweed eradication.”