What really makes yield per acre? It’s not plant population — that’s merely one component.

“It’s actually the number of ears, and how much corn each ear produces (through length, girth and depth of kernel) — ultimately, bushels per ear,“ says Farm Journal Field Agronomist Ken Ferrie.

Ferrie’s studies show a hybrid’s yield can vary by 6 bu. to 12 bu. per acre per thousand ears, depending on how it is managed.

Think of bushels per ear as hybrid efficiency, like miles per gallon for a vehicle.

“Just as you can maximize miles per gallon by the way you drive and maintain a vehicle, you can maximize a hybrid’s efficiency — bushels per ear — by the way you manage it,” Ferrie says. “Even small adjustments, like tire pressure on a vehicle, impact efficiency.”

Here are five important principles to help you maximize bushels per ear:

1. Start with a picket-fence stand with photocopied plants.

“The yield potential contained in a bag of seed can’t be increased,” Ferrie says. “But everything that happens after the seed is in the ground can reduce it. We can’t guarantee a good stand will stay that way, but a non-uniform stand will stay that way. Late-emerging plants more than one leaf collar behind the rest of the field are like one foul spark plug in an engine — it still works but miles per gallon falls off. Late emergers drastically reduce yield.”

2. Plan for maximum bushels per ear long before you hitch up the planter.

 First, set realistic yield goals, Ferrie coaches. Start with each farm or field’s average production history, the documented yield used for multi-peril crop insurance.

Then go one step farther. If a field averages 250 bu. per acre, there probably are areas yielding 300 bu. and others 180 bu. Isolate the zones in each field and set a yield goal for each one. This will help as you move into variable-rate and variable-input management, which you will need to maximize bushels per ear.

3. Choose a cropping system that supports each zone’s yield goal.

In some zones, you will need to conserve every drop of moisture, while in others you might have excess water at planting time. No-till would be a good choice on sandy areas. Strip-till might let you plant wetter soils in a timely fashion, while maintaining soil health and structure, which would suffer under conventional tillage.

4. Determine what population each management zone can support.

“Base population on the soil’s water-supplying capability,” Ferrie explains. “Consider seasonal rainfall and irrigation if you have it. It takes about 3,000 gal. of water to produce 1 bu. of corn. If you push population too high and run out of water, you will get fewer bushels per ear.”

5. Choose the best hybrid for each zone, based on ear type and leaf orientation.

“For example, on a droughty soil, you might want to avoid determinate-ear hybrids because they require high plant populations to maximize yield,” Ferrie says.

Leaf orientation (pendulum, semi-pendulum, semi-upright and upright) determines how much sunlight will be used for photosynthesis. “By the time the plants reach the reproductive stage, you need to be intercepting at least 95% of the light,” he says.

A perfect stand of the right hybrid in each zone lets ears compete equally for water, nutrients and sunlight, laying the foundation for more bushels per ear.

To learn more about ear type and leaf orientation, visit AgWeb.com/ears-flex

3 Ingredients for Perfect Stands

A perfect stand lets every ear receive equal amounts of what Farm Journal Field Agronomist Ken Ferrie calls the big three: sunlight, water and nutrients.

“Check the quality of your seed,” Ferrie says. “Knowing the cold germination score can help you decide what hybrid to plant in tough growing conditions. Checking the condition of the pericarp can help you avoid fertilizer burn from in-furrow applications, which can sabotage a good stand.

“Make sure you have the equipment and manpower to plant in the optimum window,” he adds. “With changing weather conditions, that window seems to be getting tighter every year.”

Bushels Per Ear

Want to learn more about managing your crop to maximize bushels per ear?

AgWeb.com/bushels-per-ear