Spots at first are distinctly zoned, later enlarging until entire cladodes turn a reddish-brown and finally die. The center of the disease area is grayish-brown and cracked. Other fungi may also be present in the diseased area. No practical control has been developed. Several members of the cactus family are susceptible to attack by the cotton root rot fungus.
Infected plants die.
When pulled from the soil the brown strands of the fungus can be found growing on the root surface. No control practice is available. For additional information, see the section on Cotton Root Rot. The bacterium enters tissue through natural openings and wounds. Under conditions of high humidity, the bacteria reproduce quickly, spreading to healthy parts of the plant.