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.
Diseased tissue is watery, soft, black and deteriorates rapidly.
If environmental conditions turn dry, the development of the disease may be checked. The best control is to avoid wounds, treat broken surfaces right away with a copper fungicide and avoid having plants in places where humidity is high. Most of the cacti and succulents are susceptible to infection by root knot nematodes. Infected roots show small galls which are typical of the disease and serve to identify it when clean, washed roots are observed. Fumigate or sterilize soil before potting.