Hi David,
I think that modern "banana knife" is a kama.
Perhaps we're getting to the point where Fernando needs to go bananas?
Actually, I didn't phrase that quite right--perhaps Fernando should find a banana to harvest with it? Banana plants are soft enough that it shouldn't harm the piece. Then, if we can't say that it was designed to cut bananas, at least we can say that it can harvest bananas.
F