We also have an ingame key toggle to increase game performance. First toggle removes half the crops and thins the forests. Second toggle removes rest of the crops, but leaves the plowed furrows to let you know where fields are. Third removes all vegitation.
At least thats how I have it so far. This can easily be changed around in the map csv's to whatever you prefer btw.
So there's no real need to go to the Options screen for veggie issues if you don't want.