The determination of which fungus is the causal organism must generally be done in the laboratory. Diagnostic kits are available and can accurately distinguish between these organisms but are fairly expensive. Pythium Root Rot at mid-season may affect scattered plants, but economic losses in North Carolina are rare. This disease is difficult to manage because of the wide host range of the pathogen and its persistence in soil. If the problem occurs on a yearly basis, changing varieties and improving drainage may be effective.
Symptoms usually appear late in the season, during or after pod set.
Foliar symptoms are generally noticed with the onset of cool weather in the fall. Upper leaves may turn yellow and leaves will later become brown between the veins. Plants will defoliate early and petioles will drop with the leaves. Affected plants may be scattered throughout the field or confined to one area of the field. Soybean is generally more tolerant of C. parasiticum than is peanut.