Rhizoctonia Rot of Citrus

a disease of the root system of citrus crops caused by the fungus Rhizoctonia violacea. A reddish-violet mycelial tomentum forms on the roots and penetrates the tissue. Affected roots wither, and the cortex separates and is converted into a semifluid, blackish, foul-smelling mass. The plants usually die. The disease occurs in citrus-growing regions. Control measures include digging up and burning diseased plants and disinfecting the soil after removal of the plants.