Plant Health Initiative

Sudden Death Syndrome - Scouting

Typical leaf symptoms of SDS are easy to see. Note green veins. Be aware, however, that some types of BSR fungi cause a similar foliar symptom. Photo credit: Craig Grau, University of Wisconsin

The same conditions which lead to high yields are also conducive to the development of SDS. Those are fields with high fertility and water availability,
suited for early planting. Because SDS causes foliar symptoms, it’s easier to see that there’s a problem compared to soybean cyst nematode (SCN), for instance. However, SDS looks similar to brown stem rot (BSR) and stem canker so farmers need to know the difference.

In identifying SDS, NCSRP researchers offer five suggestions:

• Watch for foliar symptoms. Foliar symptoms can appear early but most often are visible after flowering. The first symptoms to appear are interveinal chlorotic (yellow) blotches that progress to large irregular patches. The vein tissue remains green. .
• Split the stems to determine whether the problem is SDS or Brown Stem Rot (BSR). If the center of the stem is brown, it is BSR; if white, it is SDS.
• Dig roots, also, to determine between SDS or BSR. SDS causes root rot while root systems of plants affected by BSR remain healthy. Diseased plants are easily pulled out of the ground because the taproots and lateral rots have deteriorated. While not always present, if there is blue-colored sporulation, this indicates the presence of the pathogen that causes SDS.
• Note that SDS symptoms appear earlier than BSR.
• Be aware that stem canker is not as common as SDS. Stem canker can occur in the same year and fields as SDS. In addition to foliar symptoms, stem canker will often have cankers on the lower stem, and defoliation is not as pronounced as with SDS..
  

Comparison of the signs and symptoms of brown stem rot, sudden death syndrome, stem canker.