Mother Nature wraps every kernel of seed corn in a thin protective coat, called the pericarp. It covers the seed like skin, providing a first line of defense against soil pathogens, pests and microorganisms. The seed pericarp also regulates water absorption for germination.
As Ken Ferrie has evaluated seed corn sample test results coming into his office this spring, he’s noticed there is a significant amount of severe pericarp damage, meaning damage has occurred to the embryo axis (the indented part of seed corn).
“Granted, we’ve only got the first 50 samples back, but we’ve seen 5.8% of them with severe pericarp damage, with 25% of the samples having what we consider a failing grade,” says Ferrie, Farm Journal Field Agronomist, based in central Illinois.
By comparison, 3% of the 150 seed samples he had tested in 2024 came back with severe pericarp damage and few were in the failing category.
Risks And Rewards
Severe pericarp damage doesn’t mean the seed is not viable to plant – if other results of warm and cold germ tests are positive. It does mean you need to give consideration to fertilizer management.
Ferrie explains that seed corn with tears in the embryo axis is susceptible to salt burn from in-furrow fertilizer applications. Cracks in the embryo axis allow the salt to get into the seed germ, the embryo, which can stop germination.
“If severe pericarp damage gets above 6% we recommend not applying starter in-furrow, especially if you’re planting into dry conditions,” Ferrie advises.
“While you’ll get the visual starter response, the odds of losing the severe pericarp-damaged plants to salt burn are high, which will lower your ear count beyond what the starter response can make up,” he adds.
Ferrie says applying fertilizer off the seed is not a problem.
“I’m not concerned, for instance, with a 2x2 system or the 360 Wave. With the FurrowJet, I would shut off the in-furrow fertilizer line and send it all to the wings,” he advises.
Hold Onto Some Samples
A practice called the “fast green test” is used in seed corn to detect potential damage to the pericarp. If you’re concerned about damage being an issue this spring, the Michigan Crop Improvement Association advises checking with your local laboratories as some offer a one-day turnaround for tests.
If you don’t have time to test seed corn prior to planting, Ferrie suggests keeping a small sample of seed – about 2 pounds from each lot – in a cool, dry place until the corn crop is emerged and stand counts can be made.
“If everything is OK, then we can discard it,” he says. “But if we have trouble with stand establishment, then we can send it off for testing to rule out seed quality issues.
“Testing (after the fact) won’t fix the problem, but it might answer some questions when we’re out there evaluating fertilizer burn issues,” he adds.
Another consideration: If you are concerned you have some questionable seed corn lots, hold off on planting those particular lots until soil temperatures are warmer (above 55°F) and the forecast is for mild conditions, usually around May 1 in central Illinois.
In the meantime, Ferrie is hoping the percentage of pericarp damage he has seen so far drops lower in tests he currently has underway.
“We have over 70 samples at the lab being tested now and more going in, so maybe these numbers will turn around,” he says.
Be sure to check out this week’s Boots In The Field podcast. Ferrie addresses soybean planting and how to “hoe before you know” if you think soil crusting could be an issue. Here’s the link: https://www.croptechinc.com/bifr-4-8-2025/
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