New SCN Resistant Soybeans Manufactured

DES MOINES - Jul 20/06 - SNS -- Pioneer Hi-Bred International, Inc. has manufactured two new varieties of soybeans which contain a new source of soybean cyst nematode (SCN) resistance.

Called the Peking source, it has not been widely used in the U.S. Midwest. Pioneer researchers, using sophisticated molecular marker technology, 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, Ill.

"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 United States 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(R) trait.