And Greensboro is going to be the lab rat:
Duke Energy chose Greensboro to be among three North Carolina cities where it will test a chemical product that slows tree growth, according to company leaders.
Rainbow Treecare will inject the “growth regulator” Cambistat into the ground near trees within Duke Energy’s rights of way, where branches can interfere with power lines. About 20 species of trees will be treated, including maples, elms, sweet gums and oaks, said Shawn Bernick, Rainbow’s vice president for research and development and technical support.
It's not surprising they would choose Greensboro as one of the test cities, as the Gate City has a very healthy canopy, at least in some of the older neighborhoods. It may be a first for Duke, but other utilities have used this approach to curb tree growth:
Several residents of the Homeland Neighborhood Association along Greenleaf Boulevard are resisting Indiana Michigan Power's effort to apply a herbicide to the trees to retard growth. Although the substance being used, Cambistat, is said to be safe, the neighbors are worried it will contaminate their well water.
Looking at a printout of Cambistat's label, Verna Brinson, who lives on Greenleaf, pointed to the ingredient listing. The active ingredient, paclobutrazol, comprises 22.3 percent of the product while the remaining 77.7 percent is identified only as "other ingredients." If it was just water, Brinson surmised, the makers would have put water on the label.
"I would rather they top the trees like that than put something into the ground," said Joanne Klopfenstein on Sundale Place. "The trees will grow out. They look funny for a year or so then they grow out."
Cambistat has been on the market since 2003 and is used by utilities and landscapers across the country, said Jim Neeser, national utility sales specialist at Rainbow Treecare Scientific Advancements, the company that makes Cambistat. The substance is ingested by the tree through its fine root system and then binds to the wood cell to stop the production of the growth hormone, gibberellic.
Neeser declined to disclose the additional chemicals. That is what makes Cambistat unique, he said, and publicizing those ingredients would be releasing proprietary information. However, he said, the U.S. Environmental Protection Agency knows the complete recipe and has tested and approved the product.
That "proprietary information" thing seems to be a common refrain from chemical companies. And as long as government lets them use it to conceal critical information from the public, they'll keep using it.