Charcoal Rot

Macrophomina phaseoli

Symptoms:
The charcoal rot fungus attacks roots, stems and fruits. Stems develop basal cankers that girdle the stem, resulting in yellowing of foliage and eventual wilting and collapse of the entire plant. Initially the lesions are brown and may have amber colored droplets on them (resembling gummy stem blight), but they later become light tan in color and are dotted with small, spherical dark colored fruiting bodies (sclerotia). Fruit develop large sunken areas that are dark grey to black in color.

Control:
Disease development is favored by high temperatures and wet conditions. Crop rotations are ineffective because of the wide host range of the fungus. Maintaining plants in good nutritional condition is the best preventative measure.

See also the Texas Plant Disease Handbook.

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