Don't know if that was a contemporary epithet or something that historians came up with later.
They actually did grow wheat there, something Florida isn't known for.
Floridians may have had similar traditions, something about their state as the "breadbasket of the Confederacy" -- as do Georgians and Texans -- but it's silly to see this as "dog-whistle" politics.
(the lefts meltdown has brought me no end of amusement!)