Soybean is generally more tolerant of C. parasiticum than is peanut. Differences in soybean varietal responses to this fungus have been noted, but are not adequately documented. The soil fungus, Sclerotium rolfsii causes southern blight and is present in nearly all North Carolina fields. Disease is most common in sandy soils, however. Plants suddenly wilt and die during hot, humid weather.
Leaves remain attached to the dead stem.
A white mat of fungal tissue may appear on soil and the base of the stem. Fungal structures called sclerotia frequently cover the fungal mat. Sclerotia are spherical, tan or brown in color, and about the size of a mustard seed. Soybean is generally tolerant to this disease and economic losses are rare in North Carolina. Charcoal Rot Macrophomina phaseolina is a fungus which is widely distributed in soils and may be either seedborne or soilborne.