Credit: Christopher Marett and Gregory Tylka The soybean cyst nematode (SCN) is the most damaging pathogen of soybean in the United States and Canada and it is spreading rapidly, according to information compiled by Gregory Tylka and Christopher Marett, nematologists at Iowa State University. SCN was first found in the United States in 1954 and most recent estimates show that SCN results in $1.5 billion in annual yield losses. "The continuing spread of SCN is alarming, but not surprising," said Tylka. "Anything that moves soil can move the nematode, including wind, water, and farm machinery....