The number of available SCN-resistant soybean varieties increases every year.

It is important to know the level of SCN infestation in a field and adjust crop rotation, crops grown, and soybean varieties planted to match the level of infestation.

Several sources of resistance are used by soybean industry:

• PI 88788 (95% of varieties)
• Peking
• Cyst-X

Rotate SCN-resistant varieties
The current SCN resistance in soybean varieties suppresses the reproduction of the soybean cyst nematode. There is now known to be races of SCN—genetic forms of SCN found that can reproduce on soybean varieties with the PI88788 source of resistance. These SCN populations will affect the performance of specific SCN-resistant varieties. Therefore, it's important to rotate SCN-resistant varieties with different sources of resistance. If other sources of resistance are not available, rotate varieties with PI88788 resistance.

For a good discussion on how to use SCN-resistant varieties see:
So Many Choices, So Much Potential: Soybean Cyst Nematode-Resistant Soybean Varieties by Greg Tylka, Iowa State University (pdf)

Performance of commercially available SCN-resistant varieties
The latest information on SCN-resistant varieties can be found in the variety trials of the University of Wisconsin and neighboring states:

UW Soybean Variety Test Results 1997-2007 - see Table 9 (link to UW Agronomy)
SCN-Resistant Soybean Variety Trials 2007 (link to Iowa State University)
Varietal Information Program for Illinois - go to "Compare Varieties" (link to IU)
Minnesota State Variety Trials - scroll to "performance in SCN-infested sites"