"No one yet knows the cost of production," he said. "No one seems to know the market and what the demand is, or what the price is. A lot of information is going to have to be gathered before it can be a viable crop."
The biggest obstacle for now is hemp's outlaw status. The crop hasn't been grown in the U.S. since the 1950s as the federal government moved to classify hemp as a controlled substance because it's related to marijuana.
Hemp and marijuana are the same species, cannabis sativa, but are genetically distinct. Hemp has a negligible content of THC, the psychoactive compound that gives marijuana users a high.
Hemp advocates hope the crop gets a pardon, but Comer said Kentucky will get back into hemp production only if the federal government approves.
"If you don't have that, then we're just fighting a losing battle," Whitaker said.
Supporters say there's a ready-made market for hemp. U.S. retail sales of hemp products exceeded $400 million last year, according to industry estimates. The versatile crop can be turned into paper, clothing, food, biofuels, lotions and many other products.
Brian Furnish, who runs a company that seeks export and import markets for tobacco, said hemp has the potential to stake out a role in Kentucky agriculture. One advantage is it could be grown on marginal land unsuitable for grain production, he said.
Furnish, who raises tobacco, corn, wheat, hay and cattle in Harrison County, said he'd plant hemp if given the chance.
"If there's a profit in it, farmers will do it," said Furnish, a member of the state hemp commission. "If there's not a profit in it, they won't grow it. But if the Canadian farmers are growing it, we have the same ability, technologies and equipment they do."
Comer's efforts to take hemp mainstream include trying to persuade the Kentucky Chamber of Commerce to back his legislation.
Kentucky Chamber President David Adkisson said the organization is studying the issue.
Adkisson said his own family has ties to the crop — his mother's family grew hemp during World War II to aid the war effort. At the time, the U.S. government encouraged farmers to grow hemp because other industrial fibers were in short supply.
"It's not a foreign concept to an older generation of Kentuckians," Adkisson said. "I don't have a feel for its economic potential as an agricultural product. I know that there's a compelling case being made, and we're going to take a look at that."