The fungus can survive in the soil for many years, and often it is found as deep in the soil as roots penetrate. Affected areas often appear as circular areas of dead plants in fields of infected crops. These areas gradually enlarge in subsequent years as the fungus grows through the soil from plant to plant. Infested areas as may increase 5 to 30 feet per year. Hyphae and strands.
Strands surround a root and grow toward the soil surface.
Immediately below the surface, the fungus proliferates around the hypocotyl, producing a cottony, mycelial growth. Below this mycelium, the bark is destroyed, and the fungus fills the vascular tissue of the plant. Following death of the plant, sclerotia form in the strands Sclerotia. Strand cells divide, grow and enlarge to form sclerotia. Sclerotia are first white, changing to buff, brown and black with age.