Odd ears offer a teaching tool

The PowerPoint presentation has become a farm meeting favorite, but when it comes to showing farmers what can go wrong, it’s better to have something they can hold, says Peter Thomison, OSU Extension corn agronomist. So he brings along examples of abnormal ears.

“Working with Extension agents, I try to present examples of the most common problems so growers can see what might be going on during the growing season,” he says.

Most of the trouble spots are not very big, Thomison notes. “For example, beer can ears may show up in only small pockets — sometimes less than an acre within a field. But the impact within these localized areas can be dramatic.”

In most years, poor tip fill and kernel abortion due to drought stress are among the most common problems Thomison sees. Poor kernel fill may be the result of adverse climatic conditions during pollination that disrupt the reproductive timing. Ears that have tip dieback may be stressed by a lack of water as a result of dry conditions or perhaps water shortfall combined with high plant populations.

“Year in, year out, poor kernel fill at the tips is probably the biggest concern,” he says. “But it may be better to have some dieback at the tip. A completely filled ear may indicate that plant population is not high enough, and farmers want to be sure they have taken full advantage of the hybrid’s yield potential.”

More is at agcrops.osu.edu/specialists/corn/specialist-announcements/AbnormalCornEarsPoster_000.pdf/view.

Peter Thomison’s poster of abnormal corn ears has been translated into Spanish versions and is headed for Turkey, as well.

Beer can ears may result from a cold shock during early ear formation (V8 to V12) or may be caused by applications of various products. Different hybrids respond differently.

DAMAGE: Uneven rows, jumbled kernels and pinched ears may be signs of injury from applications done near tasseling.

BANANAS AND ZIPPERS: Tip dieback and missing rows are indications of stress or defoliation injury following pollination.

FAMILY TREE: Corn has changed over time. Open pollinated varieties at left were popular until the early 1940s. The pod corn on the right is a more primitive form. Examples were grown at the 2009 Farm Science Review heirloom plot.

KERNEL KILLERS: Poor kernel set means only a few ovules were pollinated. Poor pollination may be caused by any of several factors, including severe drought and high temperatures, uneven crop development, herbicide damage, insect feeding, or phosphorous shortages.

The arrange-ment of this blue corn, planted next to yellow corn, shows how pollen from GMO hybrids can drift, causing varying degrees of contamination in non-GMO fields.

This article published in the March, 2010 edition of OHIO FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.