Soybean cyst nematode (SCN), or Heterodera glycines, is the most destructive pathogen of soybean in North America. Soybean producers in the United States lost more than 300 million bushels to the soybean cyst nematode from 2003 to 2005. More yield is lost to SCN than any other soybean pathogen. At present, soybeans are planted on more than 70 million acres in North America. SCN is widely distributed in all major soybean production areas of the United States (see map, right). SCN was first found in the Western Hemisphere in North Carolina in 1954. Before then, SCN was known.
