EXTENSION PLANT PATHOLOGY

Disease: Sclerotinia Stem Rot (SSR) of Field Pea

Cause: Sclerotinia sclerotiorum (Lib) de Barry

Symptoms: The early symptoms of white mold are brown soft lesions, they usually start on the flowers then spread rapidly onto the developing pods.  The lesions can also develop from infected blossoms that fall onto other parts of the plant.  A fluffy white mycelium develops on infected parts and sclerotia form within a week.  These sclerotia are hard black bodies that are from 2-20mm long and are roughly spherical.  They form both in the stem and on the surface.  As the lesion dries the stem becomes bleached and break and shed easily.

Survival and Spread: The disease over winters in the soil and in crop residue in the form of sclerotia.  If the growing season is cool and wet these sclerotia produce fruiting bodies called apothecia.  These fruiting bodies then release ascospores that are blown into blossoms.  The ascospores can cause infection if wet conditions persist. The more common way of disease spread is by direct contact of lodged plants with the sclerotia on the soil surface.

Favorable Conditions: This disease requires extended periods of cool wet weather for the infection to get established.

Management: 

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