Commentary: Mainers benefit most from medical cannabis – time to leave it alone Broad, mandatory product testing and other extreme state regulations would undermine the Maine Medical Marijuana Program’s success. By Arleigh Kraus and Paul T. McCarrierSpecial to the Press Herald Share Cannabis is now Maine’s most valuable cash crop. The industry is thriving, providing tremendous revenue to the state without assistance from the federal government such as Paycheck Protection Program relief, earned income credit or FDIC banking privileges. A state-licensed grower holds a handful of buds from a medical marijuana plant in 2011. Maine’s medical cannabis industry is on track to bring in $266 million this year – more than potatoes and more than twice as much as milk.