The amount of damage caused by the soybean cyst nematode (SCN) is determined, in large part, by the population densities or numbers of the nematode present in the field. More severe yield losses generally occur in fields with high SCN population densities compared to damage in fields with low or moderate numbers of SCN. Long-term, profitable soybean production in fields infested with SCN requires growing SCN-resistant soybeans and nonhost crops, such as corn, to keep nematode population densities in check.