It may also occur in streaks that extend to the soil line. The red color may change to a dark brown and the lesions frequently crack longitudinally. The small lateral roots are usually killed, and clusters of roots may develop above the lesions and just below the soil line. Losses with this disease are usually more severe than the other root rots. Subsoiling to break up hardpans and bed shaping to improve drainage help to control the disease.
Shallow cultivation reduces injury to the root system.
Nematodes must be controlled. Rhizoctonia Root Rot Losses from Rhizoctonia root rot vary greatly from year to year with a loss of 5 to 10 percent are not unusual. The disease is caused by the cosmopolitan soil-inhabiting fungus, Rhizoctonia solani . On young bean plants, the fungus causes damping-off and attacks the stem below and above the soil surface. The young succulent plants die soon after infection.