1) Wheat and rye, considered to be hardier than barley and oats.
1549 one acar of hardcorne sawne price 6s 8d, Marrick
1557 to my sonne Thomas my farmeholde at Wytt wood ... and my wife to sawe the hardcorne ther, Kippax
1622 Item 8 day-worke of hard corne 26li 13s 4d, Pudsey
1664 make theire fences joyneinge on hardcorne, Hepworth
1798 Aug. 17 We began to shear hard corn in the Lodge Feld ... nine sickles, Sessay. The word evidently has a much longer history: 1295-6 Grangie decim de Ayredale respond de duro blado hoc anno, Bolton Priory.