>>>Are you sure?
Yes. In February 2008 (during the Bush Administration), faced with declining sales, members of the National Christmas Tree Association created a task force to consider the merits of a checkoff program, which would allow the USDA to collect a fee from growers in order to fund research into marketing Christmas trees.
They created a task force. OK.
Was this voted on by the National Christmas Tree Association?
It appears you may be right. But nothing was stated about the vote or the approval by USDA.
http://averyjournal.com/Community/story/Choose-and-Cut-season-2011-arrives-id-009009
As reported in a series of articles last spring by The AJT, Christmas tree growers and their associations nationwide are trying to stem the tide of mostly imported fake Christmas trees. To do so, a national task force comprised of growers from across the country began work in 2008 designing a plan petitioning USDA to create a Christmas Tree Promotion, Research and Information Order, known as a “check-off.”
“We are almost there, I am confident the check-off program will go through,” said Church. “USDA informed us to begin the selection process for the 12-member board of directors that will oversee the national program.
“Some very good people have been nominated and we hope to have at least two members selected from North Carolina; the East Coast is allotted four members in all.”
According to your previous link, there have been 3 previous lawsuits concerning check-off arrangements.
This one might be number 4.