Pythium Of Soybeans

 

 

 

Soybeans are sensitive to multiple pathogens (see previous article), but I am concerned about Pythium infections in the earliest planted soybeans.  Pythium is favored by cool soils, generally less than 60o F and lots of water.  Soybeans that were planted three weeks ago had lots of both. 

 

The most common symptom of Pythium infection is rotting seeds, rotting roots and damping off.  High levels of disease can significantly reduce stands which can reduce yields.  Pythium species are in the group of pathogens that have swimming spores (zoospores) and need water to cause infection.  Consequently, Pythium causes the most damage in saturated or flooded fields and importantly, is often mistaken for water damage.

 

While you can’t manage Pythium damage once it occurs, seed treatments, rotation, selection of a defensive soybean, drainage improvements and lengthening a rotation may help reduce damage in the future.