Integrated Crop Management News

Document Type


Publication Date



Many different species of plant-parasitic nematodes occur in cornfields throughout the Midwest. Most of these microscopic, parasitic worms must reach a damage threshold number before they cause yield loss in corn. The damage threshold numbers for most nematodes that feed on corn in Iowa (see Common Corn Nematode Characteristics, ICM News, Aug. 3, 2009) are 100 or more worms per 100 cm3 , which is a little less than a half-cup of soil. The exceptions are the needle and sting nematodes, which damage corn even if only one or two worms per 100 cm3 soil are present. Fortunately, needle and sting nematodes only occur in soil with at least 70 percent sand and, therefore, do not occur in most Iowa fields.

Copyright Owner

Iowa State University



File Format





The Iowa State University Digital Repository provides access to Integrated Crop Management News for historical purposes only. Users are hereby notified that the content may be inaccurate, out of date, incomplete and/or may not meet the needs and requirements of the user. Users should make their own assessment of the information and whether it is suitable for their intended purpose. For current information on integrated crop management from Iowa State University Extension and Outreach, please visit