One of the most feared diseases of soybean is Sudden Death Syndrome(SDS). In quick fashion a previously perfect looking soybean field can deteriorate. The sight of yellow and brown soybean leaves with green veins is the first indication farmers have that they have a problem.

We sometimes forget that these foliar symptoms can also indicate a Brown stem rot problem. To determine the actual cause you need to split the stem open. Brown stem rot will cause the normally solid white pith in the center of the stem to look like a series of brown walled chambers, as seen in the the attached photo. If you split an SDS infected plant, the pith will probably look normal but the woody tissue of the crown and taproot will be have a brownish discoloration.

The University of Illinois Plant Clinic indicated that many of the suspected SDS samples submitted, this season, have actually been Brown stem rot.

Photo courtesy Dr. Suzanne Bissonnette, Assistant Dean, Agriculture and Natural Resources.