I know the feat says “farm implements”, but is there a full list of what can count as one, really?
For example, a Bill weapon got its start as a derivitave of the agricultural billhook. It’s possible that it could count with a bit of finagling with the GM. I’m certain sickles could fit in as well.
You linked to a YouTube video. Imperial Conscript (d20pfsrd's name) or rather Taldan Conscript (real name) is here.
I do not believe Paizo has published (or will publish) a list of what items count as farm implements.
Personally I would go with "if you look it up in the dictionary/encyclopedia, is it described as a farm implement, a tool for dealing with crops, etc?" So sickles would certainly count ("an edge tool for cutting grass or crops"). The bill would not, because the dictionary has separate entries for "a cutting instrument... used in pruning etc" and "a weapon of infantry."
But that's me. A more lenient GM could reasonably include the bill. If so, they should include a bunch of other polearms too---at least, my understanding is that many of them started as farm implements.
Whoops. Should have double checked that link.
Still, I appreciate the advice.