Your original statement was that this work would not happen at all, not that Monsanto specifically would not do the work. I was saying that your copyright analogy doesn't work for you, because plenty of writing still happens.
You were saying that the work would not get done, not that Monsanto specifically would not do the work.
There's plenty of other entities that would be interested even without patents. Large agribusiness would be interested in increasing yields (your 'bigger banana'). Health organisations would be interested in dietary components (your 'vitamin A deficiency'), and it's not like research universities are forbidden from doing agricultural research.
