It has been used by Socal saltwater guys on the Local Sportboats since the early 90's and it was more closely associated with the term Farmer in the past. If one of the regulars on a boat kept loosing fish, the others on board would start calling him/ her a Farmer implying they have no place on boat and should have never left the Farm. As the term and meaning evolved Anglers started using the word farmed to describe lost fish it just kind of took off and stuck. I can't say for certain that it all started on the Socal Sportboats but if I had to guess I would say that's where it took root.

Thanks,
JerryG