Skip to Main Content

Monitor Soybean Pod and Stem Blight


Pod and stem blight is found throughout most U.S. soybean-producing areas, and harvest is the time to check for pressure. Harvest is the time of year to check your soybean crop for signs of pod and stem blight. Check for signs of disease now because combining infected fields sooner rather than later helps reduce pod and stem blight pressure, especially when harvest is delayed due to wet weather.

Caused by the Diaporthe and Phomopsis fungal disease complex, grain damage of 2% or more reduces the grade of the harvested soybeans and thus profitability. This fungal complex infecting soybeans can cause liver damage in chickens and a reduction in the quality of oil, flour and other products.

  • The infection is only visible on dead plant tissue.
  • Stems develop linear rows of black specks, known as pycnidia, or fruiting structures.
  • Pods may be infected and show scattered pycnidia specks.
  • Infected seed appears shriveled, cracked and with a white, chalky mold.
Linear rows of pycnidia on the stem of an infected soybean plant. Source – Syngenta.

  • Fungal pathogen overwinters on infected soybean or other crop residue.
  • Infection usually occurs early in the summer from water splashing spores onto the plant.
  • Symptoms don’t develop until the plant begins to reach maturity.
  • Disease symptoms are favored by warm, humid conditions at plant maturity.
  • Moisture at maturity plays a major role in disease development given the plant can be covered with pycnidia in wet years at maturity, whereas in dry years, pycnidia are confined to areas of the plant closer to the soil.
  • Since the disease overwinters on infected crop residue, tillage and crop rotation will help reduce the infection. 
  • An R3 to R6 fungicide application, such as Trivapro®, can help mitigate disease and improve seed quality, but it is generally only recommended for soybean fields grown for seed. 
  • For the year ahead, plant high-quality, pathogen-free seed for affected acres by choosing varieties resistant to pod and stem blight.
Contact your Golden Harvest Seed Advisor with questions or for additional agronomic insights.

Photos are either the property of Syngenta or used under agreement.

Syngenta hereby disclaims liability for third-party websites.

You are viewing from

Thank you for visiting the Golden Harvest website. We understand how important it is for you to find agronomic and product information pertinent to your local area. Please enter your zip code or select your area below to ensure you are seeing the information that matters most to you.
Learn more about regions >


We’re sorry. Golden Harvest is not available in this area. Please try another zip code or contact a Golden Harvest Seed Advisor for more information.

Is this page helpful to you?

How can we improve
this page? (optional)

Can you tell us your
role in agriculture? (optional)

Thanks for the feedback.

We appreciate your participation