What began as an isolated and relatively unknown disease in Arkansas is now a major cause of crop loss across much of soybean acreage in the United States. As part of an annual monitoring program started nearly 20 years ago, university researchers have tracked the rise of sudden death syndrome (SDS) from relative obscurity to its current status as the second-leading cause of soybean crop losses due to disease in 2014. The increased severity of SDS in recent years has raised concerns among soybean growers, as they seek new solutions to help manage this yield-robbing disease.
In 2014, the damage caused by SDS cost soybean growers more than 60 million bushels in lost yield, second only to the damage caused by the soybean cyst nematode (SCN) and nearly equal to the losses associated with general seedling diseases. When all three of these top-soybean diseases are considered collectively, researchers found that they represented a yield loss of nearly 250 million bushels. Although it is too early to know for sure, some scientists suggest that the severity of SDS this year could be as bad, or even worse, than 2014.
Fortunately, new tools are emerging for SDS management. In 2015 Bayer CropScience launched its new seed treatment, ILeVO, the first product of its kind to provide breakthrough protection for soybean seedlings against the fungus that causes SDS. Daren Mueller, extension plant pathologist and SDS expert at Iowa State University, has evaluated ILeVO and finds it can be a much-needed tool in an integrated approach to disease management, noting "In our tests ILeVO has been a very effective treatment in preventing damage from SDS and you can visually see the difference.
Most soybeans seeds are treated with a base fungicide package, but addressing SDS with a seed treatment is relatively new to most growers. Nonetheless, the growing importance of this disease is changing the way growers view SDS management. According to Jennifer Riggs, product development manager for Bayer, "Soybean growers are looking for additional protection that can reduce infection of seedling roots and help minimize potential foliar symptoms later in the season. Doug Jardine, plant pathologist at Kansas State University summarizes his experience with ILeVO, saying "the product worked awesomely at our field site in Topeka last year. ILeVO is available as part of a seed treatment package with Bayer's Poncho/VOTiVO, and when paired with seedling disease base fungicide seed treatments, provides powerful protection against the top three soybean diseases – soybean cyst nematode, sudden death syndrome and seedling disease.
Like many soil pathogens, the severity of SDS is triggered by high moisture levels. A combination of cool wet conditions in early spring will increase the likelihood of disease outbreak, especially since SDS is well-established throughout the U.S. soybean growing area. The past 5 seasons have seen two major outbreaks of SDS (in 2010 and 2014), evidence that the disease has become an ever-present threat to soybean production.
Farmers may not be able to predict the weather, but they can prepare for it by using innovative products like Poncho/VOTiVO + ILeVO, to help protect their soybeans against the growing threat of SDS.