The Pitchfork Part is a item you get from a chrono quest in which you must make 100 bread in the desert without coming back. The only use of this item is to make the Golden Pitchfork. The golden pitchfork itself is just a improvement of the normal pitchfork. It's very hard just geting to the desert by itself- having to get a plant plot and a wheat seeds to make bread is another hard thing about it.
You can only get one of this item during a pacifist gameplay (by savagery you can take one from others), and having no alternative way to get it, it's one of the rarest items in the game.
It was added in the "Desert" update.