An example: Why corn genetics matter

Oct. 7, 2022

This hybrid’s DNA lets ears begin falling near maturity. Coupled with looser husks, these ears are less prone to ear mold.

Dave Nanda, Ph.D., director of genetics for Seed Genetics Direct, has walked cornfields for more than 60 years. A former plant breeder, he has a certain type of ear structure and design in mind when he compares one hybrid to another.

“All other things being equal, including yield potential, I prefer hybrids that allow ears to begin to droop over as corn reaches maturity versus hybrids that hold ears upright and tight,” said Nanda. “I also prefer ears with adequate husks that extend to the tip of the ear, but aren’t so thick that the ear is sealed tight. in In seasons when ear molds are a threat, these traits really come into play. If ears remain upright and husks are tight, ears tend to hold more moisture, and it provides a more favorable environment for ear molds to develop.”

The 2022 season was the perfect storm for ear molds in some locations. Plants were predisposed to infections due to early dry, hot, stressful conditions followed by plentiful rains during grain fill. These infections can appear either as ear molds and rots or as stalk rots, or both. Various ear molds, including gibberella and fusarium, appeared in the Corn Watch ‘22 field this year, even before black layer occurred.

To understand why some hybrids hold ears tighter to the stalk, Nanda refers to basic biology. He explains that the “peduncle” is the short stemmy structure connecting a fruiting body to the plant. In corn, it connects the base of the ear to the corn plant.

“The peduncle on hybrids in the Corn Watch field this year were short, due to their genetics, explaining why ears were held upright and close to the stalk. When plants were stressed early and then there is lots of moisture and warm weather later, ears with short peduncles held upright are easier targets for infection.”