Apparently, anyone can read things (some things, at least) by the National Academy Press. Such as
Lost Crops of Africa: Volume II: Vegetables.
When that study was announced (a follow-up to the 1996 study on grains) it was intended to cover Fruits & Vegetables. The book was published last year, and fruits are notably lacking. I hope they're still working on a third one to finish the topic. And I hope they finish it soon... like, in the next week or so.