Sudden Death Syndrome or SDS is a sometime disease in soybeans that can significantly reduce yields under adverse environmental conditions.
After being discovered by Dr. John Rupe, professor of plant pathology at the University of Arkansas, the disease spread into the surrounding states and then into the Midwest in the 1980s. Since then, it has had an up and down impact on soybean yields.
“This SDS organism (Fusarium Solani) affects the plant early in the first two or three weeks after planting,” says Chip Graham, regional technical service seed representative for Bayer CropScience, who spoke at a BCS Showcase Trial event in Lonoke, Ark.
“It grows in the plant and then, under the right conditions such as a rainfall event or irrigation, the toxins are translocated up through the plant to the leaves and causes leaf drop. It seemed to decline for a few years after we began to grow tolerant varieties, but now it seems to be coming back.”
SDS has become very widespread in the Midwest – it was found all across Iowa in 2014 – and has been more of a problem the last two years in Arkansas, possibly because of increased rainfall and cooler temperatures.
Bayer CropScience is awaiting registration from EPA on a new product called IleVO, which has shown promise in reducing the severity of Sudden Death Syndrome. The announcement could come later this year.
ILeVO can be used in tandem with Bayer CropScience’s Poncho Votivo insecticide-nematicide seed treatment.
“These products offer the growers a couple of things,” says Graham. “One is the ability to plant more timely. One of the cultural methods for controlling SDS is moving your planting date back. That typically reduces your yield potential.
“What we think we can do with ILeVo-Poncho Votivo is to move that planting date back to where we should be to help the grower reach his full yield potential. Another aspect of ILeVO is nematode activity. Votivo is the part of Poncho Votivo that has nematode activity in that it colonizes the roots and provides protection beyond the 21 days of the typical seed treatment.”
ILeVO, on the other hand, is a true nematicide which has been shown to kill the underground pests in three years of trials in the Midwest and the Mid-South..
“I can hardly wait to get yields on these plots,” said Graham, refer to the trial that included several varieties with and without tolerance to SDS. “I think we will see some dramatic difference in these varieties. We have seen some nice yield increases even on varieties that were tolerant to SDS in the Midwest.
During the Showcase event, which started out indoors because of heavy rains in central Arkansas, University of Arkansas specialists discussed situations in which yields were reduced to five to 10 bushels per acre due to SDS.
“We haven’t seen those kinds of yield reductions in our field trials here in the Mid-South,” said Graham. “We have had some yield reductions down to 10 to 15 bushels in the untreated. In those cases, we’ve actually seen a 15- to 20-bushel yield increase with Poncho Votivo and ILeVO.
“That is very rare, and it was under very high disease pressure. Typically across the U.S. in about 158 trials, we’ve seen a four- to six-bushel increase on average, again depending on the disease pressure.”
In fields with the most dramatic reductions, he said, “the disease comes in at just the ideal time, and it affects pod set. It’s devastating to the plant early on. So it just depends on when the disease comes in and when you get those cool, wet conditions.”
For more information about SDS in other areas, visit https://www.extension.purdue.edu/extmedia/bp/bp-58-w.pdf