Pioneer Hi-Bred International, Inc., is introducing an expanded lineup of soybean varieties for the Midwest this season with a novel source of soybean cyst nematode (SCN) resistance as an added tool of protection against the pest. Available in two Pioneer brand soybean varieties in 2006, the Peking source of SCN resistance will be offered in a growing number of Pioneer soybean products in future growing seasons.

The Peking source has not been widely deployed in the Midwest. Pioneer researchers are now integrating this source into high-performance soybean varieties

“Race 3 has long been the predominate SCN race in the Midwest and SCN resistance from the PI 88788 source has been the primary choice of resistance deployed in Midwestern varieties,” says Jeff Thompson, research scientist for Pioneer in Mascoutah, IL. “In the past three or four years, we have been receiving more and more reports that PI 88788 has not been providing adequate SCN protection in some fields. While these reports have been isolated, it compels us to consider future SCN resistance strategies.”

Just as alternating herbicides with different modes of action helps prevent weed resistance from developing, agronomists also recommend planting soybeans with different sources of SCN resistance. The Peking source, which controls SCN races 1, 3 and 5, was introduced in the U.S. from China nearly a century ago.

“The Peking source of resistance was first incorporated in soybean varieties in the South more than 30 years ago,” Thompson says. “Over time, repeated use of the same source caused changes in SCN populations in the field, and SCN resistance from Peking was no longer very useful in that region. In the Midwest, however, it is an excellent source of SCN resistance.”

The new varieties in 2006 with the Peking source of SCN resistance, Pioneer brands 92M52 and 92M75, are Group II varieties with the Roundup Ready trait.

Both 92M52 and 92M75 have performed well in field trial testing. Pioneer will offer more Peking source varieties in the future, Thompson adds. In addition to Pioneer products already available in Groups I and II, Pioneer will expand product offerings into maturity Groups 0, III and IV.

“More Midwest growers now have access to Peking as well as PI 88788,” he says. “Growers have the choice to rotate SCN sources in their fields, which provides a complete and sustainable SCN management system. This gives soybean growers another tool in their battle against SCN.”