I know originally the developers intended the game to have solely European/Old World crops, but (so I've heard) this has changed, so if we already have Cassava (native to South America) and Sunflowers, I don't see why Corn, Squash, Avocado, Beans, Cacao Trees (Cocoa), Tomatoes, Peanuts, Peppers, Tobacco or Potatoes couldn't be added in the game, since it's set in a sort of post-history. Even if it's a European setting a post-history would be well long after we brought new world crops over and they would still be found growing in the former Europe.
I'm not entirely familiar of the lore so please correct me if I'm wrong! I've only had the game for a week or so.
A non New World addition could be Coffee! Coffee is native to Ethiopia and could commonly be found growing in parts of Europe. Coffee beans could be combined with water and give the drinker a caffeine buff.
These don't all need to be added but these are just some really cool crop ideas that I think would fit if it's set in a post-civilization Europe long after human cultivation of them.
Tobacco, while not a food crop, could be used for medicinal purposes, as it can be used as an antiseptic, sort of like Flax has use as a utilitarian crop. Alternatively, while unhealthy, tobacco could also be smoked to provide a temporary buff of some kind. I'm not promoting drugs at all but tobacco was a popular historical use.
Cocoa could be used to make chocolate, chocolate cake, chocolate pies, hot cocoa, and so much more!
Let me know of your thoughts! I would love to see these crops in the game. The amount of crops is already incredible and the addition of some of these would make the game even more unbelievable!