If U.S. corn growers continue to increase yields at the rate they’ve been doing for the last 55 years, they should be able to reach the fabled national average yield goal of 300 bushels per acre by around, oh, 2086.

With food experts predicting the 300-bushel-per-acre average will be needed long before then and possibly as early as 2030, the average rate of increase of 1.9 bushels per acre over the last half century may not be good enough, a Purdue University agronomist says.

Individual growers — some of them in the South — have reached that goal of 300 bushels per acre and more in the National Corn Growers’ yield contests, says Bob Nielson, Extension corn specialist at Purdue, who spoke at this year’s Integrated Crop Management Conference at Iowa State University.

“Furthermore, the physiological yield components necessary to produce a 300-plus-bushel crop are not terribly out of reach today,” he noted. “Potential ear size is easily 1,000 kernels with today’s hybrids, which would be equal to an ear with 18 kernel rows and 56 kernels per row.”

If that ear size could be maintained at a harvest population of 30,000 plants per acre and if kernel weight could be maintained at about 85,000 kernels per 56-pound bushel, those yield components would multiply to equal a yield of 356 bushels per acre.

Speaking at the ICM Conference in Ames, Iowa, which is attended by about 900 crop advisors annually, Nielsen said steadily rising yields are a relatively recent phenomenon for U.S. corn producers.

“For 70 years, beginning in 1886, national corn grain yields in the U.S. were essentially flat and averaged only 26 bushels per acre during that entire time,” he said. “The absence of noticeable yield improvement throughout all those years is remarkable given the farmers of the day were essentially also plant breeders, selecting the best ears from one crop for planting in the next.”

After the Great Depression and the Dust Bowl years in the 1930s, growers began to plant hybrid seed corn that launched a slow, but steady rise in production. With the advent of mechanization, herbicides, inorganic fertilizers, farmers began to see even greater increases that averaged about 2 bushels per acre from 1955 to the present.

“To reach that lofty goal of 300 bushels per acre by 2030, another quantum leap shift in the rate of annual yield gain would have to occur beginning next year that would take us to an annual increase of about 7.5 bushels per acre per year for the next 19 years,” says Nielsen.

“Such a quantum leap shift in yield improvement would be unprecedented in the history of corn production. Contrary to the hype and hoopla over transgenic corn traits by the farm press and seed corn industry, there is little evidence such a leap has begun.”

If some farmers are already producing 300 bushels per acre and more today, what can other growers do to push their yields into that range?