Signs and Symptoms of White Mold

Apothecia of the white mold fungus. Click on image to view a larger version. Photo credit: Angie Peltier

 

 

The first signs of white mold are in the form of apothecia found on the soil surface about the time of canopy closure.

Apothecia are produced from sclerotia — the overwintering structure of the fungus — residing on the soil surface.

Spores produced from these mushroom-like structures initiate white mold infection when they are splashed or blown to senescing flowers of the young soybean plant.

 

 

 

 

Field symptoms of white mold infection. Click on image to view a larger version. Photo credit: Craig Grau

 

Later in the season, infected plants appear wilted, which might be mistaken for drought.

As the fungus invades the stem, all the plant tissue up from the infection point dies. This causes leaves and stems to turn brown and stand erect above the soybean canopy.

 

 

 

 

 

Signs of the white mold fungus on a soybean stem. Click on image to view a larger version. Photo credit: Craig Grau

 

A closer inspection of the stems may reveal lesions and a covering of thick white mold, which is diagnostic for white mold.