We have received reports from the western part of Pennsylvania about fields showing symptoms of sudden death syndrome or brown stem rot (or potentially combinations of the two in the same field) (Figure 1).
While weather conditions have been variable during the 2022 growing season, these initial reports of stem diseases are an important reminder to be checking your fields for “stress” that may be due to important soybean stem diseases.
During scouting, you should look closely at the symptoms and ensure you correctly identify and differentiate the symptoms and signs causing the issue before making any recommendations. Long-term best management begins with the identification of the disease.
To help guide you in this process, we developed a guide called “Soybean stem diseases: What are the different symptoms and signs?“. This guide was adapted from the Crop Protection Network’s “Scouting for soybean stem diseases” and helps to identify the most likely cause of the soybean stem issue based on the location of symptoms and signs, including the outer stem, internal pith tissue, and leaf symptomology.
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We also have a learn-now video “How to identify sudden death syndrome in soybean” provides a quick description of the symptoms and signs that will help you identify the disease.
With any disease, it is also important to consider the soybean variety planted and if it has any genetic resistance to the suspected disease. Finally, note the relative distribution of the issue in the field. Does it appear aggregated in specific areas of the field (e.g., low areas or water-logged areas), or is it more random across the field? This information can help to improve the diagnosis.
If you see soybean stands that are variable and uneven, we recommend that you contact your local extension educator. Samples can also be submitted to the Plant Disease Clinic following instructions which are available online. Don’t forget to take a soil sample for nematodes, as we know there are interactions with several soybean stem diseases.