Pasquotank County farmer Michael Gray vividly remembers the first time he thought about planting his corn crop in narrower rows and at higher densities. It was during a farm tour in a nearby county, where N.C. State University crop science specialist Ron Heiniger had established a row width and plant population test.
“Dr. Heiniger had three different ears of corn,” recalls Gray, who farms 1,700 acres of corn, soybeans, wheat and cabbage outside of Elizabeth City with his father, Charles, and brother, Scott.
“He had one ear of corn that was 6- or 7-inches long. He held up another one that was 5.5-inches long. And the other was probably 4. He said, ‘How many farmers want ears of corn like this?’ and held up a 7-inch ear of corn. Of course, everybody always thought the bigger, the longer, the better – more kernels on the cob. He said that was a pretty good choice: I forget exactly, but it was like 190 bushels per acre.
“And then he said, ‘How many of you want this?’ and held up a 4-inch ear. And nobody wanted the little teeny nubbin,” Gray says. “But he said this would’ve been 238 or 240 bushels per acre – the difference being in the number of plants per acre.
“And that kind of got me to thinking, it really didn’t matter how big the corn ear is, it’s how many you have out there.”
Understanding this, when it came time for Gray to buy new equipment, he made the switch to 20-inch rows. And he’s glad he did, because he believes the change has brought him higher yields.
Indeed, Heiniger’s research showed that growers could increase yield by 15 percent if they simply planted rows of corn closer together. And today, more than 40 percent of North Carolina’s corn acres are planted in these narrow rows, with more narrow-row acres added each year. Growers have reported yield increases of 25 to 30 bushels per acre or more and report less stress and more consistent yields during dry seasons. Heiniger estimates that the research has increased the value of North Carolina corn by more than $50 million.
Heiniger’s research also demonstrated that growers could plant more corn plants per acre and increase yield – a 3-bushels-per-acre yield increase for every additional 1,000 plants per acre. Growers have taken this information, provided through Cooperative Extension programs, to heart. The average corn plant population in North Carolina increased from 28,000 plants per acre in 2000 to 34,000 plants per acre in 2010.
Gray says he can’t estimate the value of the help that local extension agents and specialists have provided, but he knows their recommendations makes a difference.
“Without the Extension service,” he says, “there would be a lot of trial and error. When we have a problem, they always come up with the right answer as far as what we need to do.”