PORTLAND — Members of the Maine timber industry are pushing back at a proposal to prohibit aerial spraying of herbicides in the state’s forests. 

Herbicides are substances that destroy unwanted vegetation. They are used widely in agriculture, forestry and other industries. A bill proposed by Democratic Senate President Troy Jackson stated that it would ban the use of “aerial herbicide spraying for the purpose of deforestation.” 

Jackson’s proposal was scheduled Thursday to come before a legislative committee on agriculture, conservation and forestry. Several members of the timber industry have said the bill’s definition is far too broad, and enacting the proposal would take a valuable tool away from companies that harvest trees from Maine’s vast forests. 

Anthony Hourihan, director of land development for major timber player Irving Woodlands, said in testimony that the company uses aerial herbicide spraying to halt the growth of vegetation that competes with valuable trees. Taking that ability away would jeopardize the state’s forest products industry and mills, which are major employers in rural parts of the state, Hourihan said. 

“The planting of trees and the use of aerial herbicide allows us to produce more wood on the land base, which in turn allows us to protect more land area in conservation forest,” he said. 

State pesticide regulators also have concerns about the proposal. Megan Patterson, director of the Maine Board of Pesticides Control, testified that appropriately managed aerial spraying of herbicides are “a clearly regulated, carefully considered, essential tool for the Maine forestry products industry” and Jackson’s proposal would eliminate it. 

The Maine Farm Bureau and other timber interests, including Seven Islands Land Company that manages more than 800,000 acres (323,755 hectares) of timberland in Maine, also have said they oppose the proposal. 

The proposal received support from one person, Allagash resident Hilton Hafford, at a public hearing on May 9. Hafford characterized aerial spraying as a threat to wildlife in northern Maine.