The soybean cyst nematode (SCN) (Heterodera glycinesIchinohe) is the major plant-parasitic nematode in US soybean production. SCN causes losses of up to 60% in susceptible cultivars,
and often losses of up to 30% occur without showing noticeable aboveground symptoms. SCN has been consistently listed as the number one pathogen causing yield losses to Illinois farmers over the past decades.

In Illinois, SCN is present in more than 80% of the fields and every county. SCN demonstrates the ability to survive in fields for years without growing soybean. Therefore, once SCN is identified in an area, management practices that maintain populations under the damage threshold will help farmers maximize yield and profitability.

A large fraction of the genetic resistance available in commercial varieties is currently derived from the same source (PI-88788), which has already led to the selection of SCN populations able to reproduce on these varieties. Management practices such as crop rotation and cover crops may help manage these resistant populations and all the benefits to soil health and erosion control.

Growers integrate cover crops in soybean production systems to reduce soil degradation and enhance the sustainability of crop production systems, enhancing soil chemical, physical and biological properties. As cover crops become more adopted through Illinois soybean fields, it is essential to investigate how SCN populations respond to cover crop species and varieties across different Illinois locations. Looking into SCN populations in the long-term research field will also better simulate growing conditions experienced by Illinois growers.

The objectives of this project are i) investigate the impact of cover crop species and varieties on SCN populations under field conditions; ii) Use metagenomics to study further how cover crops may potentially affect SCN populations; iii) Provide information regarding SCN management to Illinois soybean growers.

One outcome is a summary of most (if not all) cover crop research projects that are being managed via universities and funding agencies in the state of IL. This will be a resource that will be continuously updated and will benefit researchers and ISA. A second outcome will be the determination of how various cover crops and their production strategies will impact SCN and the microbial communities in these fields.

This approach will allow us to identify if specific cover crops affect SCN and the potential mechanisms of SCN suppression involved.