I'm reading through 'The Gates of Europe: A History of Ukraine' by Serhii Plokhy, and found it odd that he cites Herodotus as describing Scythian plowmen on the Right Bank of the Dnieper as 'produc[ing] corn for sale'.
Similarly, when I read 'When China Ruled the Seas' by Louise Levathes I found mention of 'corn' being a common staple in parts of China in the early 1400s.
This begs a series of questions: Am I wrong in assuming that it was impossible for anyone to grow corn in Eurasia prior to 1492? Is there a grain that gets commonly mistranslated to English as 'corn'? What were those Scythian plowmen growing, anyway?
This is more a dictionary question than a historical one but...
In British English "corn" can refer to any grain, usually whatever the most common grain in the region is. See definition 3 below
https://www.merriam-webster.com/dictionary/corn
"Maize" is the British term for what Americans call "corn". So in books written in British English you will often see references to corn long before the Columbian exchange.