Pam Smith, Farm Journal Crops & Issues Editor
One of the pleasures of fall is peeling back the husks on an ear of corn to reveal rows of golden kernels. A few weeks ago, I was checking a crop in central Illinois and was dismayed to find many kernels had begun to sprout.
There was a pattern to the sprouting. Several late fall downpours are no doubt to blame, but upright ears with tight husks were sprouting in the fields I visited. Ears hanging down with loosened husks seemed to have weathered the storm.
University of Illinois extension agronomist Emerson Nafziger says he has also seen the problem this year. "It's much worse in ears that remain upright because they accumulated water in the husks at the base of the ear,” says Nafziger. "It's mostly the husks that hold water, so it is more of problem where husks hold tight to the ear, but we've also seen sprouting when kernels have started to mold.”
Nafziger says kernels normally have the biochemical ability to remain dormant while they dry down, but if they stay wet long enough and start to mold, they seem to lose this ability and begin to sprout. Later-maturing hybrids tend to experience it less often because they don't dry down as early, he adds.
That doesn't necessarily mean hybrids with droopy, sloppy husked ears are better when you're choosing your next hybrid lineup. "There are probably some differences among commercial hybrids, but its [sprouting] is rare enough that it's probably not worth trying to select against,” Nafziger says.
"If you look at a variety trial at harvest time, you'll likely find most ears pointing down. But when they start to turn down will differ among hybrids, based on maturity and attributes like shank length and strength. Some of these things might be genetic and some due to conditions as far back in the season as pollination when the shank was forming,” he adds.
"Whether plant death was ‘natural' or related to stress or disease also has an effect. For example, when you see early death of plants in lighter soils under stress, those ears often drop very early, probably due in part to poor lignification (woody strengthening) of the shank.”
In fact, Nafziger says it could be counterproductive to select hybrids based on early ear bend-down. Good plant growth often results in high yield and strong shanks that tend to remain upright longer. Husks that stay green longer tend to be related to delays in the drop of ears and they are also photosynthetic and able to contribute to some grain filling.
Husk cover—number and thickness—is dictated by both genetics and growing conditions. "Breeders typically reject hybrids with very heavy or inadequate husk cover and I don't think there are large differences in genetic husk cover traits among commercial hybrids. There are differences in how husk cover responds to growing conditions—often related to maturity and how hybrids respond to stress,” he says.
Sprout damaged corn can still be harvested. In fact, it often has the same nutritional value as regular No. 2 yellow corn. The problem is damage discounts are likely when selling sprouted corn. Sprouted corn is also more susceptible to mycotoxin development.
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You can email Pam Smith at firstname.lastname@example.org.
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