b"Fighting an Invisible ThreatThe SCN Coalition is a resource for soybean growers fighting a yield-stealing nematode.By Aimee Nielson, Seed World U.S. EditorSOYBEAN CYST NEMATODE(SCN) is a microscopic parasite that attacks soybean roots, siphoning off nutrients and stunting plant growth. Though small, SCN's impact is mas-sive, causing approximately $1.5 billion in crop losses each year in the United States alone. This nematode not only reduces yields but also predisposes plants to other diseases, making it a multifaceted threat to soybean production.SCN has become particularly challenging due to its ability to adapt and overcome traditional management practices. Many growers rely on SCN-resistant soybean varieties as their pri-mary defense. However, SCN is constantly evolving, and some populations can now bypass these genetic defenses, rendering previously resistant varieties vulnerable once again. This adap-tive capacity of SCN is why organizations like the SCN Coalition are so vitalthey serve as a continuous force in the fight to stay ahead of the nematode's evolving threat.Enter the SCN Coalition, led by Horacio Lopez-Nicora, Ohio State University nematology professor. The coalitions primary mission is to educate growers about SCN and sustainable meas-ure of control. They advocate for routine soil testing, research and innovation that focuses on equipping farmers with the tools and knowledge they need to effectively combat SCN. Lopez-Nicora shares his insights into SCNs biology, its impact on soy-bean crops and the Coalitions proactive strategies for keepingHoracio Lopez-Nicora is and assistant professor of Soybean this formidable pest in check. Pathology and Nematology at The Ohio State University.Understanding the Costly Impact of SCN your crops and plant corn for several years, SCN will still be SCN has consistently ranked as the most damaging patho- there, waiting, he emphasized, highlighting the pests resilience. gen to soybean crops in the United States. Responsible for anIts like an unwelcome houseguest that never leaves.estimated $1.5 billion in annual losses, this tiny nematode is aLopez-Nicora explains how SCNs biological mechanisms stealthy adversary, often causing significant yield reductionsallow it to thrive within the soybean plants roots. without showing any visible symptoms.This animal is penetrating the root system, modifying cells No matter where you go and look for that in the literature,that are not supposed to be modified in a way that now the plant you will see that soybean cyst nematode consistently rankedbelieves that the whole project is down there in the root system, the number one, Lopez-Nicora says. Its robbing yield poten- he says. The nematode essentially hijacks the plants root tial from the crop, quietly taking away as much as 30% of yieldsystem, reprogramming the cells to feed itself. potential, even when the crop looks perfectly healthy. Once it penetrates the root, Lopez-Nicora says SCN uses a The SCN lifecycle is particularly problematic for farmers. Thespecialized stylet to inject effectors into the plant cells, manipu-nematode can persist in the soil for years, producing eggs thatlating them in ways that suppress the plants immune response lie dormant until the right host is present.and redirect nutrients to the nematode.Once you have it in your field, it is highly unlikely that you will get rid of it, you will have to manage it, and it can persist in theThe SCN Profit Checkerfield for many years, Lopez-Nicora explains. Even if you rotateThe SCN Coalition developed a suite of tools designed to help 48/ SEEDWORLD.COMDECEMBER 2024"