Learn about the conditions that cause it, and the corn head that harvests it.

Any corn grower will tell you, there is no greater concern when it comes to potential yield loss than harvesting down corn.

If corn plants have lodged and aren’t standing upright, grain may not make it into the bin, leaving the farmer with a field full of untapped crop revenue at harvest’s end. Minimizing the amount of yield lost from down or lodged corn often depends on having the right equipment during harvest, says Fenton, Iowa, farmer and Dragotec President Denny Bollig.

“It’s one of those frustrating things about farming; everything you worked for all season can be laid flat by Mother Nature in a matter of minutes,” he says. “It’s not uncommon to see 10 to 20 bushels/acre of yield loss in down corn, and in severe cases, losses can accelerate up to 50 bushels/acre.”

“When corn plants lodge and go down, the yield is still there. You just have to go down and get it.”

Mother Nature’s influence

Although severe storms and high winds contribute to stalk lodging and down corn, crop conditions throughout the planting and growing season can also impact the likelihood a down corn event will occur.

“Saturated soils early in the season can have long-term effects on root development,” Bollig says. “When excessive rainfall results in areas of very shallow rooted corn, wet conditions and compaction from heavy equipment weaken plant standability and increase susceptibility to wind damage.”

Deterioration of stalk material from plant diseases, like root and stalk rots, or infestation from insects, such as stalk borers, can also cause premature plant break-off or lodging.

Because these conditions can change so rapidly across the field, it’s a good idea to scout fields for problem areas and check the condition of stalks and ears when beginning harvest.

Even in short bursts, high winds can lay down a plant, and while corn is resilient, its ability to bounce back depends on the time of year and severity of the conditions that caused it to go down.

“You can have perfect corn plants, and in 10 or 15 minutes of a super cell with a downdraft, even the best corn out there will be knocked flat or broken off. It can happen so quickly,” Bollig says.

Take any down corn into account when beginning harvest.

Harvesting down corn first

It’s best to start with any down areas to minimize ear loss because as plant material starts to dry out and break down, yield loss potential mounts quickly, says Iowa State University Extension ag engineer Mark Hanna.

“Scout fields to determine where problem areas are and the condition of stalks and ears. Harvest the problem areas first when field conditions are better and before ears in close proximity to the ground have an opportunity for potential further deterioration,” Hanna says. “An exception might be made to harvest an area with particularly weak stalk strength that is still standing if the odds of lodging from weather seem high.”

The role of crop management

Crop management can have a big influence on whether corn will lodge or go down. Today’s production practices are pushing yield thresholds higher, with 300-bushel/acre corn much closer to reality for farmers than it was a few years ago. Seed genetics have advanced to improve both standability and yield potential, and farmers are increasing plant populations in an effort to get more bushels out of every acre.

The latter can be a big contributing factor to yield loss. Because of the concentration of organic matter that can attract pests and disease, higher plant populations can lead to root or crown rot, even if you have average conditions.

To prevent these types of issues from causing rot, lodging and down corn that ultimately lead to yield loss, it’s important to plant populations that your soils can sustain.

Make the right adjustments

Reducing corn yield loss at harvest in down or lodged corn takes both the right machinery and specific attention to how it must be adjusted to pick up and process corn plants hugging the ground. Hanna recommends the following steps to ensure any corn head and combine is ready for a field with downed corn:

• Set deck plates carefully: If you are running a corn head with hydraulic deck plates, make sure they are “only slightly wider than cornstalks” in order to cut down on stalks breaking off before ears can be removed. If running a Drago corn head with automatic self-adjusting deck plates, variable stalk sizes are accounted for in each individual row.
• Get low, but not too low: Operate the head as low as practical without picking up rocks or significant amounts of soil.
• Adjust how you drive: Moving against the grain of the stalks of down corn can reduce harvest losses.

“Evaluate losses, though, before spending large amounts of time dead-heading through the field,” he adds.

Slow everything down: Harvesting slower than normal if harvesting down corn is typical. Make sure everything is adjusted to account for the necessary slowdown.

“If harvest speeds are significantly reduced, the amount of material going through the combine is reduced. Fan speed may need to be reduced to avoid blowing kernels out of the combine, and rotor speed may also need to slow to maintain grain quality. Check kernel losses behind the combine and grain quality to fine tune cleaning and threshing adjustments,” Hanna says.

Once the machinery has been adjusted, Hanna adds that it’s important to remember that harvesting down or lodged corn takes longer than standing corn.

“It’s all about going out there and getting that down corn. Drago is unmatched in picking it up,” Bollig says. “Our aggressive overlapping gathering chains reach down, pick it up, get it in the row unit and get it going through the combine.”

Check out our video on down corn and the benefits of Drago corn heads in down corn.