How do you grow 500-bushel-per-acre corn without breaking the bank?
Obviously, you have to begin with a stand that will produce enough grain to total 500 bushels per acre, says Randy Dowdy, the Pavo, Ga., grower who set the world corn record with a yield of 503.79 bushels per acre in 2014.
But you also have to be “proactive” in protecting that stand (52,000 plants per acre in Dowdy’s case) to make sure the corn reaches as close to the yield potential that’s in the bag of corn seed before it’s ever opened.
“The breeders tell us there is 700 bushels of yield potential in a bag of seed,” says Dowdy, speaking on a windy day at a BASF Grow Smart media event at the Memphis, Tenn., Agricenter International. “Everything we do is aimed at capturing and protecting as much of that yield potential as we can.”
Growing corn behind corn can present special challenges, especially in fields where growers are trying to produce high yields and thus create high volumes of residue at harvest.
“We understand that we’re planting corn on corn, and we have to be more proactive with some of our diseases up front,” says Dowdy. “Northern corn leaf blight is a big problem in Georgia, especially where you’re growing corn on corn.
“We do a good job of trying to minimize litter, we do a good job of trying to provide nutrients so we provide energy to micro-organisms to break down that fodder, but we still have the potential for northern corn leaf blight to fire up from the bottom up.”
Dowdy says he uses fungicides in a proactive rather than reactive approach. “If that plant tells you something visually whether it’s nitrogen deprivation or drought, that yield loss is irrevocable. You don’t get it back.”
He uses tissue sampling throughout the year with an understanding of his crop rotation and what his disease pressures are in the field. Fungicides, he believes, help his corn withstand the higher daytime and nighttime temperatures that occur in Georgia.
“Everybody always says ‘how did he do it in Georgia?’” said Dowdy, referring to the impact high temperatures can have on corn pollination. “We have irrigation. We’re able to cool the plants down at night. We also use the fungicides to help us do that, as well to mitigate the stress the plant may express because of northern corn leaf blight.”
Grain fill, obviously, is another challenge, especially so in light of Southern corn rust, which can be a debilitating disease in Georgia. “For us, it’s not a matter of whether we’ll get Southern rust,” says Dowdy. “It’s a matter of when, how bad is it going to be and how many times we have to spray it.”
Understanding the fungicides
It’s also a matter of understanding the fungicides. “If they have a shelf life of 21 days of efficacy, then we need to be in the field, making sure that we’re overlapping the treatments or we’re seeing if the pressure is there to merit the treatments. We spray Southern rust one or two times or more per season, if necessary.”
At the same time, Dowdy is looking at return on investment and disease management. “Sometimes we get better than three weeks of control; sometimes we get 10 to 14 days,” he notes. “It depends on what the pressure is.
“We’re looking at a full-system approach. Not all yield is about ‘I planted X number of plants, and we hope for the best.’ I’m a guy that likes to know what’s doing and not just hope for the best. To be successful, I want to do all I can to make sure all those boxes are checked.”
For more on Randy Dowdy's farming operation and philosphy, visit www.growbigcorn.com.