An alliance of California marijuana growers is trying to block state rules that they fear could open the way for vast farms that would drive smaller cultivators out of business.

A lawsuit filed Tuesday in Sacramento by the California Growers Association comes just weeks after the nation's most populous state began allowing legal pot sales.

It argues that state regulations would allow businesses to acquire an unlimited number of certain growing licenses, creating large operations that would have a "devastating effect" on smaller operations.

It says those rules conflict with state law that intended the new pot market to be built around small- and medium-sized growers.

The California Department of Food and Agriculture didn't immediately respond to a request for comment.