Copied from the Missouri Department of conservation site.
Deer and turkeys may not be taken with the use of dogs, bait, electronic calls, electronically activated calls or live decoys. Scents and minerals, including salt, are not considered bait, however, mineral blocks with food additives are prohibited. An area is considered baited for 10 days even after complete removal of the bait. It is illegal to place bait in a way that causes others to be in violation of the baiting rule.
http://mdc.mo.gov/hunt/deer/genregs.htm