We are currently observing fields in Ohio affected by sudden death syndrome (SDS), caused by the fungal pathogen Fusarium virguliforme. While this is the most prevalent species in the region, other Fusarium species, as well as brown stem rot (BSR) or the yet-to-be-reported in Ohio, red crown rot (RCR), can exhibit similar symptoms.
With the support and funding from the Ohio Soybean Council, our goal is to:
1. Determine the species and genetic diversity of Fusarium associated with SDS in Ohio.
2. Assess the fungicide sensitivity of isolates in our culture collection.
3. Confirm whether the symptoms point to SDS, brown stem rot, or red crown rot.
To achieve these objectives, we need your assistance.
Symptoms to Watch For:
- Early leaf drop and stunted growth (Fig. 1A).
- Interveinal chlorosis (yellowing, Fig. 1B) and necrosis (browning, Fig. 1C) on leaves.
- Root rot and stem discoloration (see HERE).
Figure 1. Soybean field in south Ohio severely affected by sudden death syndrome (SDS) with premature defoliation in the R5/R6 growth stage (A); symptoms begin with interveinal yellowing (chlorosis) of leaf (B); eventually leaf tissue dies and becomes brown but veins remain green (C). The fungus infects the root and produces toxins that are responsible for the above-ground symptoms.
How You Can Help:
If you encounter symptoms indicative of SDS or suspect brown stem rot or red crown rot, we encourage you to submit a sample to our Soybean Pathology and Nematology Laboratory at The Ohio State University.
Submission Instructions:
1. Dig out three to five symptomatic plants, including roots.
2. Place the plants in a plastic bag.
3. Complete this SDS submission form.
4. Mail the samples to our lab.
For more information on SDS, click [HERE]. If you have any questions, please contact your extension educator or reach out to us directly.
Mail Your Samples To:
OSU Soybean Pathology and Nematology LabÂ
Attn: Horacio Lopez-Nicora, Ph.D.Â
c/o Jenna Moore
110 Kottman HallÂ
2021 Coffey Rd.Â
Columbus, Ohio 43210Â