Nematode Know-How

Manage the billion-dollar pest in soybeans with technologies that promote root health.
Roger Elmore, grower (left), and Brett Goecke, Syngenta Seed Advisor (right), examine soybean plants in Gladbrook, Iowa.
Roger Elmore, grower (left), and Brett Goecke, Syngenta Seed Advisor (right), examine soybean plants in Gladbrook, Iowa.
Like many soybean growers, Roger Elmore of Gladbrook, Iowa, has battled soybean cyst nematode (SCN) on his 1,230-acre farm for years. But the story of his struggle against this below-ground pest took a dramatic turn for the better in 2014, when a revolutionary seed treatment from Syngenta became commercially available.

Clariva™ Complete Beans seed treatment, a combination of separately registered products, provides direct, lethal, season-long protection against SCN, a pest that costs U.S. growers $1.5 billion annually. It also includes the market-leading insect and disease protection of CruiserMaxx® Beans with Vibrance® seed treatment, separately registered products that help shield soybeans against damage from all major early-season insects, as well as diseases, such as Rhizoctonia, Fusarium, Pythium and Phytophthora.

"Clariva gives my soybeans the protection they need when and where they need it," Elmore says. "It's an investment I can't afford not to make."

Because the treatment is on the seed, Clariva Complete Beans starts working beneath the soil surface, where crop emergence begins. That's important, notes Greg Tylka, Ph.D., because SCN live and multiply underground. "SCN is a hidden culprit that can cause significant damage to the roots," says Tylka, professor and nematologist at Iowa State University. "By the time above-ground symptoms are visible, SCN numbers often have increased to very high levels."

Root of the Problem

Without healthy, vigorous root systems, soybean plants lack the foundation to fully grow and develop. "Roots anchor the plant to support the pods and seeds," Tylka says. "Essentially, they are the lifeline of the plant, providing minerals, nutrients and water from the soil."

While it's easy to recognize and identify the importance of healthy leaves for photosynthesis, Tylka has found that the role of the root system is often overlooked, probably because of its limited visibility. "Roots are of equal importance to the health of the plant above ground," he says. "Without strong roots, the foliage will suffer, leading to potential yield loss."

Not only do vigorous root systems make for better nutrient and water uptake from the soil, but they also increase the resiliency of the plant. Enhanced crop development triggered by strong root systems helps soybean plants better withstand environmental stresses, including drought, wind and heat. It's simple: the stronger the roots, the stronger the plant, the higher the yields.

"Roots are of equal importance to the health of the plant above ground. Without strong roots, the foliage will suffer, leading to potential yield loss."

Greg Tylka
Root systems are compromised when SCN enters the picture. SCN-infected roots are smaller, and as the passageway for nutrition shrinks, the probability of yield loss increases. In the soil, SCN juveniles hatch from eggs, find a point of entry to the root and begin feeding on it. Adult females continue feeding on the root. As their bodies swell, they burst through the root's outer layer. Injury caused by this SCN invasion stunts growth and increases the soybean plant's susceptibility to other soilborne pathogens.

Game Changer

Unfortunately, Elmore has witnessed the telltale signs of SCN on his farm more times than he'd like to remember. Over the years, the withdrawal of older chemical solutions has left a huge gap in his SCN management plan, until 2014 when Clariva Complete Beans became a game-changer on his farm. "I planted 100 percent of my soybean acres with Clariva Complete Beans," he says. "Hands down, it was the best management decision I made all season."

Like any grower, Elmore wanted proof that his investment was reaping positive results. To check on the seed treatment's performance, he pulled a few soybean plants out of the ground. "The root system appeared more robust, more vigorous, with more nodulation," he says. "The results I saw confirmed what my Syngenta sales representative said about Clariva: unmatched root protection."

Thanks to the triple pest protection of Clariva Complete Beans, Elmore could see an obvious difference between his acres and the surrounding fields. "I noticed yellowing in my neighbor's soybeans, while my plants remained healthy and green," he says. "It proves to me that Clariva is doing its job, even above ground. I have observed overall faster emergence and better stand in my fields with Clariva."

Following the recommendations of Tylka and other soybean experts, Elmore practices an integrated pest management strategy to combat SCN pressure in his fields. He rotates his corn and soybean acres and plants SCN-resistant varieties, but it's Clariva Complete Beans that has made the most noticeable difference.

"I don't know why anyone wouldn't treat their seed," he says. "SCN populations are a problem for the majority of soybean growers, and Clariva is an easy way to enhance the performance of the plants and reduce the stress from the nematode. I'm happy with the seed treatment's performance and am most certainly treating all of my soybeans with Clariva again in 2015."

Dale Ireland, Ph.D., soybean and corn Seedcare technical product lead for Syngenta, echoes Elmore's confidence in the performance of Clariva Complete Beans. "2014 has been a fantastic growing season and continues what we have seen since field testing began in 2010," he says. "Root size, root mass and above-ground biomass of the soybeans treated with Clariva show improvement compared to nontreated soybeans."

Yield Booster

As a result, yields are increasing as well. "When using Clariva under SCN pressure, we've seen more than a 4 percent yield increase compared to the check treatment over the last several years of field testing," explains Ireland. "And well over 75 percent of our customers have experienced a yield increase compared to a check."

Pushing past the yield ceiling is the goal of any grower in any field. "I incorporate the Syngenta product portfolio in all of my corn and soybean acres," says Elmore. "Its products are a good fit for my fields, regardless of pest pressure. That's certainly true for Clariva Complete Beans. With this advanced seed treatment, I have an increased level of SCN protection in my fields and anticipate bumps in yield season after season."

Clariva Complete Beans: Managing the Billion-Dollar Bug