redleg: you stated “n Yiddish (and German), KORN is the word for rye”. That may be true. But the Mishna Berurah (in at least 2 places) uses the term “Tirkishe Veitz” for corn.
208:2
http://www.hebrewbooks.org/pdfpager.aspx?sits=1&req=49624&st=%u05D5%u05D5%u05D9%u05D9%u05D9%u05E5
453:4
http://www.hebrewbooks.org/pdfpager.aspx?req=49627&st=&pgnum=95