The sclerotia of whitemold Sclerotinia sclerotiorum in the laboratory.

Culture of Sclerotinia sclerotiorum on Potato Dextrose Agar (PDA). Isolated from pepper (Capsicum annuum).

Note the hard, black survival structures called “sclerotia” in culture plates.  Isolated from sweet coneflower (Rudbeckia subtomentosa Pursh)

A culture plate of the white mold fungus Sclerotinia sclerotiorum in the laboratory.

An ARDEC plot layout for a white mold (Sclerotinia sclerotiorum) experiment on drybeans.

A dry squash fruit containing the sclerotia of the white mold fungu (Sclerotinia sclerotiorum).

Apothecia of white mold (Sclerotinia sclerotiorum) in a petri dish.

White mold fungus (Sclerotinia sclerotiorum) inoculation on a zucchini squash field.

White mold fungus (Sclerotinia sclerotiorum) inoculation on a zucchini squash field.

White mold fungus (Sclerotinia sclerotiorum) inoculation on a zucchini squash field.

Inoculation of squash with the white mold fungus Sclerotinia sclerotiorum in the field.

Squash specimens inoculated with the white mold fungus Sclerotinia sclerotiorum on a field.

Straw technique used to inoculate experimental plants with white mold (Sclerotinia sclerotiorum) in the greenhouse.

Apothecia of white mold (Sclerotinia sclerotiorum) and fallen blossoms of dry bean that have been colonized by white mold.

Fallen blossoms of dry bean that have been colonized by white mold (Sclerotinia sclerotiorum).

Mycelium and sclerotia of white mold (Sclerotinia sclerotiorum) on the branch of a dry bean plant.

The colonization of a drybeans leaf by the white mold fungus Sclerotinia sclerotiorum in the field.

White mold (Sclerotinia sclerotiorum) apothecia.

White mold (Sclerotinia sclerotiorum) apothecia.

Signs of the fungus are found normally at the base of plants or on debris in float trays and include a white, cottony mycelium (fungal mass), present if humidity is high, and irregularly shaped, black sclerotia. Sclerotia resemble seeds or rodent droppi

A carrot field with white mold infection caused by the fungus Sclerotinia sclerotiorum at Lucerne. Please note the white mold sclerotia (black bodies) beneath the carrot canopy.

Some bean pods showing signs of the white mlod fungus Sclerotinia sclerotiorum in the field.

A sunflower plant with  white mold infection caused by Sclerotinia sclerotiorum in the field. The fungus mycellia are the white mass around the base of the stem.

cross-section of sclerotium

sclerotium

A sunflower stem with severe white mold infection caused by Sclerotinia sclerotiorum in the fiield.

Sunflower plants showing symptoms of  white mold infection caused by Sclerotinia sclerotiorum in the field.

White mold (Sclerotinia sclerotiorum) symptoms on some interspecifically crossed breeding lines of drybeans in the greenhouse.

White mold (Sclerotinia sclerotiorum) symptoms on some interspecifically crossed breeding lines of drybeans in the greenhouse.

Zucchini fruits infected with the white mold fungus Sclerotinia sclerotiorum in the field.

Zucchini fruits infected with the white mold fungus Sclerotinia sclerotiorum in the field.

Zucchini fruits infected with the white mold fungus Sclerotinia sclerotiorum in the field.

A zucchini fruit infected with the white mold fungus Sclerotinia sclerotiorum in the field.

A zucchini fruit infected with the white mold fungus Sclerotinia sclerotiorum in the field. Please note the fungal sclerotia on the fruit.

A zucchini fruit infected with the white mold fungus Sclerotinia sclerotiorum in the field. Please note the fungal sclerotia on the fruit.

Lower stem of an infected plants which severely rotted.

Close-up of margin between decayed and healthy stem.

A dry, lower stem rot usually with disintegrated pith tissue.

Sporangia produced at the backside of the leaf

Advanced symptoms of white mold (Sclerotinia sclerotiorum) on the branches and pods of bean plants.

Advanced symptoms of white mold (Sclerotinia sclerotiorum) in the canopy of bean plants in the field.

White mold symptoms on bean plants caused by Sclerotinia sclerotiorum (Lib.) de Bary in the field.

Wilting of a dry bean plant in the field, an initial symptom of infection with white mold (Sclerotinia sclerotiorum).

Wilting and death of the bean canopy, an advanced symptom of infection with white mold (Sclerotinia sclerotiorum).

A dry zucchini fruit infected with the white mold fungus Sclerotinia sclerotiorum. Please note the black sclerotia of the fungus.

Symptoms of white mold (Sclerotinia sclerotiorum) on the stem and branches of a dry bean plant.