The Journey of Seed Corn

The Journey of Seed Corn

Follow the steps from planting through conditioning and packaging

Tractors can drive themselves, irrigation systems can be controlled from miles away and seed can be stacked with traits to protect yield. Modern-day farming requires high-tech and high-touch management from all facets of the industry, including seed production.

Since inbreds are often different maturities, farmers plant fields up to three times.

“Good ground, good environment produce good seed,” explains Jason Morehouse, production manager for Beck’s Hybrids.

Growing corn for seed production often requires higher quality soil and drainage than commercial production to ensure proper grain fill and germination when planted the following year. Seed production involves more management—more trips across the field, more people to lend a hand and more stringent quality standards.

For Wyffels Hybrids, planting in Illinois starts at the end of April or early May and lasts up to one month. 

Companies send out machines to cut tassels before deploying a detasselling crew.

“In many fields, we plant the males at a different time than the females to make sure they pollinate at the right time, says Jacob Wyffels, field operations supervisor at Wyffels Hybrids. That means they could run a planter across the field up to three times.

To maximize pollination in the interplant production system, the male is never more than 19" from the female, says Tom Burrus, owner of Burrus Seed. Since seed production uses sexual reproduction, instead of asexual, it can be a challenge to make sure the male adequately pollinates the female inbred. Removing the female tassel guarantees the plant doesn’t pollinate itself.

Prior to harvest, stomping machines destroy male plants so their seeds are not harvested.

Throughout the season, agronomists and field specialists monitor the corn for issues that could jeopardize seed quality. If treatment is needed, the field becomes the farmer’s top priority until the issue is under control.

“Inbreds tend to be more sensitive to chemicals than hybrids, so producers are limited on chemistry choices,” Morehouse explains. “Thresholds triggering a treatment for disease or insect pressure are lower than in hybrid crops. I can calculate about 30 different trips in the field during corn production.”

Harvesting equipment leaves the husks on the ears to maintain the best seed quality possible during the process.

Thresholds are lower for two reasons: Crop value is higher and certain inbreds can be more susceptible to disease, he adds.

Harvest starts in early September and is done by early October to avoid frost damage.

“We harvest at 32% to 35% moisture on the ear to protect the kernel,” Morehouse says. “Only 20% of the kernel is exposed when on the ear.”

After leaving the field, the ears travel to the corn processing facility. The husk is removed, and the ears are sent to sorting tables. 

Each year, we hire 300 to 350 seasonal employees for harvest, says Jeff Bomleny, plant operations manager for Wyffels Hybrids.

During the first quality check, the sorters look for ears that are discolored, moldy or don’t meet the look of the hybrid they are processing.

When corn arrives at the facility, it is belted to a machine that removes the husks for further processing.

From there, the corn is moved to the dryer systems. The dryers at processing facilities, which use low heat and high airflow, are different than on-farm or co-op dryers. Heat stays below 100°F, and up and down air movement maximizes drying efficiency.

“We dry corn to 12.5% in 72 hours. That’s between 0.25 to 0.33 points of moisture per hour,” Bomleny notes.

The goal is to preserve the living germ in the seed, explains Jim Herr, processing, inventory and wholesale manager at Beck’s Hybrids. Drying seed corn to approximately 13% ensures it can be safely shelled.  

After the corn is dry and shelled, all debris is cleaned off to minimize foreign material during testing and storage. Representative samples are taken for quality testing before the corn moves to storage.

Once corn is husked, it is added to sorting tables for employees to pick out damaged or abnormal ears.

Quality testing is one of the most important aspects of the process. The seed must pass several steps before it is deemed satisfactory for sale.

“Most companies tag corn at 95% germination, so legally, at least 95% must germinate in testing to support the claims on the tag,” Herr says. 

Many companies perform both cool and warm germination tests. Cool simulates April planting, and warm shows what it can do in ideal conditions.

The sample is removed and planted into a combination of sand and silt. Any seed that doesn’t produce a “normal” seedling is considered dead and not included in the successful germination count.

In addition to germination, the plant must be pure, and the hybrid has to hold up to its claims. 

“At Beck’s, we make sure the DNA is truly the target product of DNA from parent seed,” Herr explains.

To make certain this happens, seed companies complete purity tests. Several companies use third-party labs to protect themselves and farmers if an issue arises.

Purity tests check to see if genetics stem from the expected parents as well as verify trait efficacy and trait presence. In the lab, they grow the seed and apply herbicides to check for resistance, use Elisa strips to test for Bt proteins and, if the product is supposed to be non-GMO, test for adventitious traits. At this point, the corn is pollinated from another field and creates a GMO offspring.

Wyffels Hybrids performs quality tests quarterly for each hybrid to ensure no damage occurs during storage, Bomleny says.

In the final leg of the journey, conditioning, the corn seed goes through its most rigorous cleaning yet to remove any impurities. 

“It takes about one hour to travel all the way through the conditioning step,” Burrus explains.

The seed then runs through a color sorter to look for insect damage, disease or any other quality issues that would hurt germination. Seeds that don’t meet standards are rejected. 

After the culling process, the seed is placed on separator screens to divide kernels by size. This is a multi-level configuration that allows small seeds to drop through and larger seeds to remain on the higher screens.

Next, the seed is moved, by size, to a gravity table for another seed quality check. The table uses shakers to move light seed to the top to get rid of any damaged product, Herr says.

Finally, the seed is moved to the treatment facility. Refuge corn is treated and then mixed with untreated seed corn as necessary to comply with refuge in a bag products, says Wyffels’ Bomleny. 

After treatment and refuge integration, the seed is packaged in bulk, in black boxes or in bags. 

“About 42% of our packaging is in black boxes. This goes up 2% every year,” Bomleny says.

When seed is packaged, it goes into storage until it’s ready to be shipped to the seed dealer or farmer. 

“We store seed at 50°F and 50% humidity for preservation,” Burrus says.

Regardless of how your seed order is packaged, it’s safe to say it’s gone through a long journey from the field through conditioning and finally to your planter. 

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Spell Check

Jake H.
Geneva, NE
12/3/2016 12:16 PM

  We just started using the tomra sorting solution tables with 2 LED cameras that read the corn and use and air shear to sort the corn, we have managed to go from upwards of 100+ human sorters, to simply 1 person at the end of the belts, incredible success with these machines.


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