Search results

How high should the SCN population density (egg count) be before growing a SCN-resistant soybean variety?

Here at ISU, we have two management recommendation for SCN-infested fields. The recommendation given is based on the SCN egg population density (egg count) of the sample submitted.

Recommendation #1 - for fields with egg densities up to 5,000 eggs per 100 cc soil

We recommend that growers follow a six-year crop rotation scheme as illustrated below:



Cyst Tech logo

Cyst Tech® products are mixtures or blends of seed from two or more soybean varieties.

According to the company, Cyst Tech® level A (CTA) is a blend of seed of both SCN-susceptible and SCN-resistant varieties and Cyst Tech® level B (CTB) is a blend of seed from two or more SCN-resistant soybean varieties.



CystX Logo


CystX® varieties are soybean varieties with single sources of SCN resistance.

CystX® SCN-resistant soybean varieties were developed by Purdue University scientists from the University of Missouri SCN-resistant soybean variety ‘Hartwig,’ which possessed SCN resistance from the soybean breeding line ‘PI 437654’ (“PI” stands for “plant introduction”).


Field evaluation of SCN-resistant soybean varieties

Investigators: Gregory L. Tylka, Gregory D. Gebhart, Christopher C. Marett
Funding: Iowa Soybean Association, seed company fees

An effective and affordable way to manage SCN is to grow resistant soybean varieties. SCN-resistant soybean varieties suppress SCN reproduction, reducing the yield loss caused by damage from nematode feeding. SCN resistance preserves the yield of soybean varieties growing in SCN-infested fields.

More Choices of SCN-resistant Soybean Varieties for Iowa for 2015 - 10/21/14

An effective way to manage the soybean cyst nematode (SCN) is to grow SCN-resistant soybean varieties. Resistant varieties can yield well in fields infested with the nematode and can keep SCN population densities (numbers) from greatly increasing.

SCN-resistant varieties for 2014 - 10/31/2013

The soybean cyst nematode (SCN) is a serious yield-reducing pathogen of soybeans. It is present in many fields throughout the Midwest, wherever soybeans are grown. To produce profitable soybean yields in fields infested with SCN, farmers should grow SCN-resistant soybean varieties. SCN-resistant soybeans can produce high yields while keeping SCN population densities from increasing.

SCN-Resistant Soybean Varieties - 10/17/2012

Profitable soybean yields can be produced in fields infested with the soybean cyst nematode (SCN) by growing SCN-resistant soybean varieties. SCN-resistant soybeans can keep SCN population densities from increasing and produce high yields. Each year, Iowa State University compiles a list of SCN-resistant soybean varieties that are available to Iowa soybean farmers for the upcoming growing season. The list is published with support from the Iowa Soybean Association.

2012 Season and SCN - 2/20/2012

The soybean cyst nematode (SCN) is one of Iowa’s most serious and persistent soybean pests. The nematode has the potential to cause devastating yield losses, population densities can increase very rapidly within a single growing season, and dormant eggs can survive for more than a decade in infested soils in the absence of soybeans. Random surveys funded by the soybean checkoff in 1995-1996 and again in 2006-2007 revealed that 70 to 75 percent of fields in Iowa are infested with the nematode.

SCN Control Among Varieties - 1/21/2012

The soybean cyst nematode (SCN) is one of the most damaging pests of soybean in Iowa and throughout the Midwest. The amount of yield loss that occurs is directly related to the SCN egg population densities (numbers) in the soil. Keeping SCN egg population densities from increasing to high levels is needed to maintain profitable soybean production in SCN-infested fields. An effective way to produce high soybean yields and keep SCN egg population densities in check is to grow SCN-resistant soybean varieties.