A growing number of scientists are calling for an end to weed spraying in provincial forests.
Rodney Savidge, a biologist at UNB Fredericton, said using chemicals to control undergrowth for the benefit of the forestry industry is ludicrous.
The spraying is designed to protect desirable softwood stands from encroaching hardwood saplings, allowing the softwood trees to grow faster.
The problem is that young hardwoods are an important food supply for deer.
Despite the concerns, New Brunswick taxpayers continue to foot the bill for the annual spring spraying of 15,000 hectares of Crown land.
Savidge has been studying tree growth at the molecular level for more than 40 years.
He said a recent study suggests that herbicide can stay in the ground for up to a year.
"We are really trying to fight nature, and it’s ludicrous," he said.
He said forest managers should be taking advantage of what nature provides instead of constantly trying to alter it.
"Whether it's the Crown managing for an unnatural forest, in terms of climate change, and what's right for this area, or by putting synthetic chemicals on to have a healthy forest — it is flawed logic."
DNR declined an interview with CBC News but in an email said: "The herbicide program is essential to the future of New Brunswick's forestry industry and involves the use of federally-approved herbicides on Crown land."
The Conservation Council of New Brunswick has been trying to get the chemicals banned for years.
Tracy Glynn, with the council, said she is still hopeful public pressure will force the government to change its practices.
"When we look around at our neighbours, Quebec banned herbicide spraying of its public forests in 2001, and it's well overdue that the government get into 21st century forest management that is ecologically and socially responsible," she said.
Health Canada is now reviewing over 400 pesticides that were registered before 1994 — that review is expected to be completed by next year.