Soybean cyst nematode (SCN) is significantly reducing soybean yield in the U.S. by attacking soybean roots and inhibiting nutrient uptake.  It was introduced in Illinois in the 1970s and is here to stay. This pest is very well established, and its wrath affects around 80 percent of soybean farmers today.   

 A notable success in pest management occurred when university breeders developed resistant varieties to effectively combat SCN. Most of the soybean varieties sold today consist of the same (PI 88788) resistance. However, this story does not have a happy ending as a SCN HG type was able to adapt to this resistance; therefore, reproducing on resistant varieties, which allows the pest to continually build in numbers across many fields. Consequently, the most important management tool against SCN has been weakened.   

 The second most important management strategy against SCN is a rotation with a non-host crop such as corn to help to deplete SCN populations.  Seed treatments are a third management tool but only affects the first wave of juveniles that attack the roots and do not provide season long protection. We currently need a multifaceted approach to combat SCN but also want to look at other management tools such as cover crops.   

 Further research funded by the Illinois Soybean Association is helping us gain a deeper understanding of cover crops and their potential to mitigate damage caused by SCN.  It is going to take several years to gain adequate data to learn more about cover crops’ influence on SCN management. At the same time, researchers can also continue assessing cover crops’ environmental importance as well as overall profitability for the farmer. For further research updates, go to ILSoyAdvisor.com/learn.