SHUTESBURY — Invasive and destructive, the growth of Japanese knotweed along town roads and municipal rights of way is an increasing concern for some residents, due to its potential for reducing animal and insect biodoversity, lowering water quality and potentially preventing native trees from growing.

While there is general agreement about how knotweed can impact the community, the possibility that chemical sprays, including Roundup weed control, may be used to fight it is spurring a petition calling for the Select Board to impose a five-year moratorium on using glyphosate and similar toxic herbicides for vegetation control on land under the town’s jurisdiction.

Organized by Miriam DeFant, who formerly chaired the Conservation Commission, and MaryJo Johnson, the change.org petition has more than 100 signatures so far, asking that the town establish a committee to organize, train and implement an evidence-based knotweed management plan and study this program’s effects.

There is also a call to create a waiver policy, that, should non-glyphosate control methods not work over a period of three years, stem injection of chemicals be used, rather than spraying to reduce glyphosate spread in the environment. This waiver policy, however, should not allow any glyphosate use in any wetland or its buffer zone.

The petition is being promoted by Shutesbury Rights of Wetlands Initiative, which calls itself a grassroots organization of environmental advocates who seek to protect the town’s fragile ecosystem

A group known as the Subduing Knotweed Coalition has been at the forefront of efforts to control knotweed and is encouraging the Select Board and Highway Department on ways to control the invasive.

Mary Jo Maffei, who is part of the coalition, said it is a community initiative focused on awareness, education, and solutions in New England.

“We are concerned about the spread and negative effects of this invasive plant. Our focus is on early detection and removal. We are also working to stop mowing of knotweed on our roadsides which is the biggest cause of knotweed spread,” Maffei said.

The coalition has a website with advisories, including that knotweed shouldn’t be mowed, that dirt with knotweed shouldn’t be moved and care should be taken when composting it. The coalition also has an early response team for digging out the invasive, with an iNaturalist app for people to input data about where they are seeing knotweed that needs to be removed.

“Small populations can be dug up in their entirety, and when accompanied by systematic monitoring afterwards, can prevent a knotweed incursion entirely,” the website states.

But the coalition’s website doesn’t mention possible chemical control.

Shutesbury has been wrestling with the topic for many years. In 2013, a Japanese Knotweed Group came up with a management plan, with pesticide application proposed and a $2,000 cost for two days of treatment, though the treatment would have to be done over a three-year period, meaning the total cost was to be $6,000. That was never acted on.

Town Administrator Becky Torres said the town, though, has done some mitigation over the years, using a method of removing it, drying it and then bagging it for disposal. In informal conversations with the coalition, she said members were referred to the Conservation Commission for a response about actions that could be taken and whether its proposals would need to be done by filing a request for determination of applicability or a notice of intent.

Critics of using chemicals call it “short-sighted and ill-advised,” that knotweed is only in isolated areas of town and there is risk glyphosate can pose to wetlands in a town that depends on private well water. They point to previous concerns with contamination, including PFAS in some wells, a gasoline leak below the fire station and road salt.

In a letter to the Board of Health, DeFant and Johnson wrote “Given that knotweed infestations in Shutesbury are still sporadic, we believe the town should forego the use of glyphosate until these other methods have been attempted and properly deemed ineffective. A prudent policy involving highly restrained use of herbicides on town-owned properties benefits the town and its residents.”

To the Conservation Commission, their letter urges “a broad, holistic look at upgradient runoff risks and practicable alternatives to foliar spraying” and “a cost-benefit analysis to arrive at the best outcome.”

Scott Merzbach can be reached at smerzbach@gazettenet.com.