that came out after i wrote the dissertation and i don't know anything about grain. probably you do need plantations and exploitation to make it possible for a banana to be 20p in tesco in crawley. and it is by all accounts an industry with shit working conditions when you're talking about like ecuadorian banana plantations. i've driven through the bit of ecuador between machala and guayaquil and what i remember is just relentless monoculture endless banana plantations, and that is where (well it least it used to be, no idea now) bananas for europe and america came from, ecuador peru and colombia.
bananas grow in loads of places though, like it's not like people in south asia are eating ecuadorian bananas, i think they come from like smallholder farmers. it's not like a plantation has to be inherantly exploititative either. there's other ways to organize agricultural production. that would depend on eg ecuadorian politics. i don't know anything about ecuadorian politics but when i was there i visited a union HQ and they told me that one of their guys was shot outside the week before. presumably they face the same issues of state and mafia etc violence that a lot of union organizing face in places like that.