More options for SCN control

JOHNSTON, Iowa — Of the two predominant sources of resistance for soybean cyst nematode, PI 88788 is used in over 90% of the commercial soybean varieties today.

However, as with most products used to control insects or diseases over time, those same pests develop resistance.

To combat SCN resistance, Pioneer launched the largest class of soybeans with Peking resistance ever in a single year. The varieties are also stacked with Phytophthora resistance.

“Results of sampling two years ago found over 70% of the fields sampled in Illinois, Iowa, South Dakota, Nebraska, Minnesota and Wisconsin had SCN levels that could cause yield loss,” Matt Essick, Pioneer commercial unit agronomy innovation leader in the western United States, said during Corteva Pioneer’s Media Day.

Peking has been in Pioneer’s SCN-resistant lineup for a few years, but last year’s rollout expanded opportunities across multiple maturities to cover more of the geographies that are impacted by the pest.

“That expansion of maturity was a big thing for us, and for growers, to be able to manage this pest,” Essick said.

Yield Drag Eliminated

The old “dig” years ago on the Peking source was its yield drag compared to PI 88788.

“We used to plant Peking the variety itself just as a demonstration. Peking had not only some yield drag challenges, but it was also very lazy; it would fall over. The pods would shatter. It takes a while in breeding to eliminate the bad and just keep the good. So, it took a little while to bring some of those varieties forward,” Essick said.

“With years and years of research, we’ve been able to bring in the good traits and not some of the other characteristics that you bring in when you incorporate that Peking gene into the system.

“If you looked at yield comparisons now of a PI 88788 versus the Peking soybeans, you’re often going to see the Peking soybean yield even more, especially if we’re in a soybean field that has a history of high SCN levels because we control more of that SCN.

But also in fields where with low pressure, there’s parity.”

Beyond switching SCN-resistant traits, agronomists also recommend other management strategies, including testing the field to know the SCN numbers, rotate to non-host crops, consider using a nematode protectant seed treatment, and consulting university Extension specialists for specific management recommendations for a specific state.

Pipeline

Essick was asked if there are any other SCN-resistant tools coming down the research pipeline.

“The fun part is that the research teams have access to several different sources of cyst resistance, and they’ve learned how they can take certain genes and they don’t have to bring all of them. What I mean by that is we can bring some of the resistance genes, but maybe not some of those yield drag effects that we’ve had in the past,” he said.

“They’re constantly working on different sources of SCN resistance because we know that no matter what we do, if we over-manage with one particular thing, we create resistance to that one particular management tactic. Really whether it’s SCN, corn rootworms, northern corn leaf light, anything in general, if we manage it too much with the same thing, we end up leading ourselves down a path where we need additional management tactics.”