The challenge of raising soybeans is staying ahead of disease and other yield robbing factors that can dramatically lower yields in soybeans. One of these such diseases is Sudden Death Syndrome (SDS) in soybeans. There are a few main points you need to know in order to manage Sudden Death Syndrome on your farm.

Understanding the disease.
SDS is caused by a soil-borne fungus Fusarium virgulifome.  Overwintering is likely occurs in the soil residue.  Infection of SDS into soybeans happen shortly after germination and becomes a root disease which will cause defoliation late in the season.  Long wet and cold periods of weather are ideal for SDS to infect soybean seedlings.  This will be more prevalent in compacted areas.

Identifying the disease.
The foliar tissue will be yellow and look necrotic while the veins of the soybean leaf remain green.  This is a very recognizable leaf when SDS is present.  However, SDS looks exactly like Brown Stem Rot (BSR).  The only way to make sure that we do not have BSR is to split the stem and make sure the pith of the stem is a white color.  This will indicate that the stem is healthy and that SDS is the culprit.

Managing the disease.
The first step is to identify varieties that have a high level of SDS resistance. One of those soybeans that I recommend in the mid-north area is LGS1635RX. (check the LG Seeds Seed Guide, Web page, or with your LG Seeds Technical Team Agronomist for other products with high tolerance to SDS.)

Next, consider delaying your planting a week or two until soil temperatures and soil moisture improve.  This can make a huge difference in the infection rate of SDS.

There are effective seed treatments that can be used on soybeans.  One of those products is ILEVO^®This will help with SDS infection and aid in protection from the Soybean Cyst Nematode.  ILEVO^®will cost around $14.00/unit.  Thus assuming $8.50/bu. soybeans means that you need 1.64 bu. per acre to pay for the treatment.  Typically, we can see areas lose 20-30% of the yield if the severity is high.

Download a copy of this technical bulletin here: Sudden Death Syndrome in Soybeans

References and additional information:

https://soybeanresearchinfo.com/diseases/suddendeathsyndrome.html

https://extension.umn.edu/pest-management/sudden-death-syndrome-soybean

https://cropprotectionnetwork.org/resources/articles/diseases/sudden-death-syndrome-of-soybean