Testing key to production

Andrew D. Brosig
Posted 7/24/20

Computer modeling and genetic testing have revolutionized crop seed development in recent years.

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Testing key to production

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ALLIANCE, Neb. – Computer modeling and genetic testing have revolutionized crop seed development in recent years.

Gathering the data about the genetics of parent plants, researchers can get a good idea of what a particular cross will do, what traits will be passed along in the offspring and how that offspring will fare against specific pests. But computer modeling can’t tell seed developers everything. 

At some point, they have to grow the plants to see if the predictions are true. And that’s where the ages-old practice of seed testing in plots specifically planted for that purpose comes in.

“We’ll always have to put seeds in the ground,” said Mark Lubbers, an agronomist with Bayer Crop Science responsible for growing regions in Nebraska, Wyoming, Kansas and Colorado.

“Computers help us understand what’s the result if we cross plants,” he said. “But we’ll always have to use test plots.”

And that’s what brought a team from Bayer and Prairie Sky Seed in Hemingford, Neb., together last week in a mostly-harvested wheat field north of Alliance. Using a combine specifically designed to harvest the 5-foot by 15-foot test areas, they garnered information, ranging from standability to yield to disease resistance on dozens of different varieties of new wheat seed.

These weren’t seed available today, Lubbers said. The earliest some of these varieties could see the market – provided they pass these and a battery of future testing – is probably six years.

“Mostly, this is germ plasm testing,” he said. “We’re looking at multiple stages of testing in these plots – germ plasm differences with new male/female crosses.”

The beauty of the new combine is it allows two plots to be harvest at one, side-by-side. As it moves through the field, it’s essentially two combines in one – doing the job of a regular combine by separating the wheat from the chaff.

The grain from each plot is directed through a separate channel and into a weigh-bin, where test weight, plot weight and moisture content are analyzed. An onboard computer then crunches those numbers and calculates projected yield for each 75-square-foot test plot.

The results are logged by the combine operator and simultaneously uploaded to remote servers, where Lubbers and other company agronomists can access the data in almost real time.

“Somebody at our headquarters in St. Louis, Mo., can see that data within about two minutes of its being collected,” he said. “We have these combines deployed around the world. I can go online and look at a combine in South Africa – I can look at a yield map as it’s going through the field.”

Bayer Crop Systems has about 26 wheat test plots operating around the region Lubbers is responsible for this year. In addition to the standability and yield tests, the field near Alliance – and a similar field south of Sidney – are specifically testing varieties for resistance to the pest wheat stem sawfly.

“Plant breeders make several thousand crosses per year, trying to find the right male/female combinations,” Lubbers said. “Diseases like stripe rust and leaf rust are always changing. Over time they may have slight changes, to where a variety that was once resistant is now susceptible.

“We’re always trying to stay ahead of nature.”

While the field-testing phase of the process can help Bayer Crop Science and Lubbars develop better varieties, Brett Sorensen, manager at the Prairie Sky Seed plant in Hemingford, is more interested in the long-term viability of different varieties. 

Prairie Sky doesn’t raise any public seed varieties, growing instead for different companies through Husker Genetics from the University of Nebraska. They’ll take parent seed and produce the pure-stock foundation seed that could later advance to the market as a registered variety. They also take the foundation varieties and propagate to produce registered seed, Sorensen said.

The also sell some of the seed they produce – which is where the test plots come in. Sorensen and his crew need to be able to ensure growers they seed they’re buying will produce. They repeatedly test varieties anywhere from three to five growing seasons or more to get a good average of the results, Sorensen said.

“There’s some varieties in [the test plots] we won’t be able to sell for 5 or 10 years,” he said. “We have spread those varieties out in different wheat-growing regions to see what variety works well consistently.

“We don’t want to sell on just one year of testing – wheat can shine one year then fall off in other years,” Sorensen said. “The test plots give us confidence when we go out and sell to our customers that we know, year after year [a specific variety] is one of the best out there.”