b'farmers better understand the SCN threat. Their SCN Profitsays. Some SCN types have adapted to specific resistance Checker provides an estimate of potential yield losses based ongenes, so its crucial for farmers to know which SCN types are SCN population levels and soil composition, such as sand per- present in their fields.cent and potential of hydrogen (pH).The coalition encourages growers to test their fields to deter-The tool works by calculating economic losses associatedmine the virulence profile of their SCN populations, which can with SCN, providing farmers with insights into the financialhelp guide decisions on soybean variety selection and manage-stakes.ment practices. You may have a nematode robbing your yield, and in a way,If you know your virulence profile, you can choose the right that is not visible, he said. The Profit Checker is really aboutvariety for your field, Lopez-Nicora says. Its about knowing giving farmers a clearer picture of how SCN is affecting theiryour enemy. The more you know about the SCN in your field, the bottom line and helping them make more informed manage- better equipped you are to manage it.ment decisions.Lopez-Nicora emphasizes that SCN often goes undetected inAdding Seed Treatments and Cover Crops to the Mixfields that appear healthy, which can lead to substantial financialBeyond crop rotation and genetic resistance, the SCN Coalition losses. advocates for the use of seed treatments and cover crops as A farmer might not see the impact, but that doesnt meanpart of a comprehensive SCN management plan. its not there, he said. SCN could be robbing them of yield yearSeed treatments offer an additional layer of protection, after year. With tools like the profit checker, were helping toLopez-Nicora says. They can enhance soybean root health and bring that hidden cost to light. help protect young soybean plants against several soilborne pathogens as they establish themselves. Managing the SCN Threat with Integrated Approaches He added that seed treatments are especially valuable when The SCN Coalition advocates for an integrated pest manage- combined with resistant varieties, providing a one-two punch ment strategy, which includes rotating crops, soybean varietiesagainst SCN.and sources of genetic resistance to limit SCNs ability to adapt.Cover crops, which are grown during the off-season, can also The SCN Coalition recommends a very proactive way ofplay a significant role in managing SCN populations. starting with rotating crops and varieties. Rotate, rotate, rotate!Cover crops improve soil health, which indirectly benefits he explained. Using the same resistant variety year after year issoybean plants by creating a more robust environment thats like issuing a selection pressure on SCN to evolve and overcomeless hospitable to SCN, he says. that resistance. Some cover crops, like cereal rye, act as non-hosts, reducing One of the major challenges in SCN management is theSCN populations by depriving the nematodes of a food source. nematodes growing ability to overcome the commonly used PICover crops are a great way to support soil health and help 88788 source of resistance. Lopez-Nicora pointed out that overkeep SCN in check, Lopez-Nicora says. Its about using every 90% of resistant soybean varieties rely on PI 88788, which hastool in the toolbox to fight this pest.been widely used for decades. Unfortunately, SCN has caught up, he says. Were nowA Continuing Battle Against a Relentless Pestseeing SCN populations that can reproduce on PI 88788, whichDespite these advances, Lopez-Nicora acknowledged that is a huge concern because it leaves farmers with fewer effectivemanaging SCN remains an uphill battle. He likened the fight options. against SCN to the Red Queens race in Through the Looking-The coalition is urging soybean growers to consider rotatingGlass, where characters must run as fast as they can just to stay different sources of resistance, including varieties with resistancein place. from Peking, which remains effective against many SCN popula- Were running as fast as we can just to keep up with SCN, tions. However, Lopez-Nicora acknowledged that varieties withhe says. Its a constant arms race, and we cant afford to let our alternative resistance sources are not always easy to find.guard down.More than 90% of the commercially available resistant varie- He encourages soybean growers to stay proactive and ties have that PI 88788 as a source of resistance, he notes. Wevigilant. need more diversity in our soybean genetics. Thats a big partSCN isnt going away, but with the right strategies, we can of what the Coalition is advocating fora broader toolbox forminimize its impact, he says. Know your numbers, under-farmers to draw from. stand your SCN type, and be strategic about your manage-ment choices. Thats the only way were going to stay ahead of Understanding SCN Virulence Profiles this pest.Lopez-Nicora also highlights the importance of understandingThe SCN Coalitions work shows the power of collaboration, virulence profilesa term that describes SCNs ability to infectinnovation and resilience in agriculture. different resistant varieties.Were fighting not just for todays crops but for the future of Not all SCN populations are the same, unfortunately, hesustainable soybean farming, he adds. SWDECEMBER 2024SEEDWORLD.COM /49'