(Some small potatoes from the garden pulled up in early March 2015)
Here is another article by Gracy Olmstead arguing the case for allowing sales from farmer-to-consider to be free of licencing and regulation; think of it as the 'lemonade-stand principle', that the lemonade stand shouldnt be regulated, and caveat emptor.
Im not sure I agree - I dont see why stable businesses shouldnt put up with some regulation of their products. (It would also produce inconsistent treatments - a small farmer gets no regulation, but an ad hoc dining arrangement gets treated like a restaurant). The problem is whether you regulate all giving and taking, financial exchanges, or only for profit exchanges, or exchanges that are by businesses of a certain size.
Its a good starter article to think about risk - risks of charlatans and occasional unintentional malpractice on the one hand, and the larger and more significant risk of homogenised industrial food slowly stuffing up the population by obesity, nutritional deficits, hormonal disruption etc. I am not sure it makes the case, but it does raise the issue.
I think its also worth distinguishing between sold unprepared vegetables, and food that has any kind of preparation. The touch of regulation should be far lighter for the former than the latter. (Although for vegetables, there is probably a need to regulate to stop excessive preponderances of pesticides and GM etc.).