Soybean Sudden Death Syndrome

Aug 23, 2021

As we approach the end of August we are starting to see areas in the soybean fields stunted and leaves quickly wither and die. We are all too familiar with this disease called Sudden Death Syndrome (SDS). SDS is a soil borne fungus that infects plant roots and sends toxins to plant foliage. The yellowing and browning of the soybean leaves is a result of the toxins, not the physical fungus in the plant. The actual fungus has a blueish cast and can be seen at the crown of the soybean plant. SDS can sometimes be mistaken for Brown Stem Rot, but to tell the difference you need to split the soybean stem and if the middle pith is still white and not brown, that means you have Sudden Death Syndrome. Other characteristics are a light brown hardened soybean crown. When SDS is widespread in a field it is not uncommon to see 10+ bushel yield reductions. I have not seen enough SDS in fields yet to warrant a large yield reduction, but I want to make everyone aware that it is out there.

The best management practices are using a SDS Seed treatment and planting resistant varieties. It is well known that some soybeans handle SDS better than others and if you can place the variety that handles SDS better there are huge yield implications. The seed treatment controls the disease but in years that pressure is heavy you will still see some sudden death out in the fields. This year I have seen only moderate amount of Sudden Death Syndrome so far and am not too terribly concerned yet. As we know next week could change this story but consult your SFG agronomist about SDS in your field. We are there to help and provide solutions that will minimize the risk of Sudden Death Syndrome.