In a 2011 lecture at Iowa State University, Prof. Thomas Sinclair (North Carolina State) concluded from models and projections of yields of maize that maximum US corn yields would be in the neighborhood of 254 bushels per acre, that is, 16 metric tons per hectare.
Between 2009 and 2012 the national average corn yield has been 123 to 165 bushels per acre, about half Sinclair’s maximum of 254. Because Sinclair was speaking of maximum and the US Department of Agriculture reported actual yields for the vast US crop, the excess of Sinclair’s maximum over an actual average is not surprising and shows the opportunity for agronomist scientists is considerable.
Fortunately other reports, these of actual experience, show an even greater opportunity than that between Sinclair’s projected maximum and averages over the entire USA.
For 50 years the National Corn Growers Association has conducted a national contest, and in 2014 the NCGA reported seven participants beat 400 bushels per acre. One participant, Randy Dowdy of Valdosta, Georgia produced 503.
Thus, actual yields of corn show that farmers and suppliers have plenty of room to raise the US average yield from about 150 bushels per acre toward a maximum of 503.
And that performance that professors conclude impossible in theory can happen in practice.