Another claim about what Alexander 'brought back' ... from Saanich News:

The plum has been cultivated longer than any other fruit with the exception of the apple. It’s believed Alexander the Great introduced plums to Greek society after his triumphs in Persia and Syria.


... can't really find much on this one. So we'll set that aside and look at this, from Euro Weekly:

Another, and by far the longest, is about the Indian sub-continent where Stivers draws on his historical knowledge to enlighten the reader. In Afghanistan, he prompts us to recall the time when it was the gateway between Persia (today’s Iran) and China. He climbs on to the shoulder of a giant sandstone Buddha in Bamian that was built by Alexander the Great, a magnificent statue later destroyed by the Taliban.


... pehaps he should prompt us to recall our sense of anachronism (we're at least 600 years off here, no?). And speaking of anachronism, I don't think the editor of the Times read down to the last paragraph of this book review:

Imperial correspondence goes back to Roman times. Augustus kept up a lively correspondence with the younger Pliny, then a governor in Asia Minor, advising him to turn a blind eye to the activities of the Christians.