Soybean cyst nematode confirmed in Ida County in 2008

December 10, 2008
ICM News

By Greg Tylka, Department of Plant Pathology

The soybean cyst nematode has been known to exist in Iowa since 1978.  The first Iowa finding was in Winnebago County.  In the 1980s and 1990s, SCN was found for the first time in many different Iowa counties.  By 2000, SCN had not yet been found in only nine Iowa counties. By the end of 2007, it had not yet been found or officially confirmed in only three Iowa counties – Allamakee, Ida, and Lyon County.  Earlier in 2008, SCN was confirmed to be present in Lyon County.

Recent results reveal that SCN also is present in Ida County. Soybeans were grown in the greenhouse for one month in soil from an Ida County field and numerous SCN females were observed on the roots of the plants.

So there now is only one Iowa county, Allamakee County, in which there is no official record of SCN.

Counties in which SCN has been found in Iowa – December 2008. (SCN-infested counties in red)

Although SCN has been found in all but one Iowa county, not every field in the state is infested with the nematode. A comprehensive, random survey of Iowa currently is being conducted by ISU personnel in collaboration with the USDA National Agricultural Statistics Service (NASS) personnel and supported by soybean checkoff funding from the Iowa Soybean Association.  In 2007, soil samples were collected from 205 randomly selected fields, and the nematode was found in 71 percent of the fields. A summary of the 2007 survey findings is available. The survey continued in 2008 and will be conducted again in 2009.  Results of the 2008 survey will be made available in the near future.

If anyone knows of SCN in Allamakee County fields, they are encouraged to send soil samples from the fields to the Iowa State University Plant and Insect Diagnostic Clinic, 327 Bessey Hall, Ames, Iowa 50011, so that soybeans can be grown in the soil to verify that SCN is present.


Years of discovery of SCN infestation in Iowa counties – June 2008.

Counties in which SCN has been found in the United States and Canada – December 2008 (SCN-infested counties in red).


Greg Tylka is a professor of plant pathology with extension and research responsibilities in management of plant-parasitic nematodes.

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on December 10, 2008. The information contained within may not be the most current and accurate depending on when it is accessed.


Greg Tylka Morrill Professor

Dr. Greg Tylka is a Morrill Professor in the Department of Plant Pathology and Microbiology at Iowa State University with extension and research responsibilities for management of plant-parasitic nematodes. The focus of Dr. Tylka's research program at Iowa State University is primarily the soybea...