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. Rusty colored, corky areas appear on the stems. Scab is thought to be a form of edema, resulting from overwatering and poor ventilation. Increase light and decrease humidity for control.
First symptoms are yellow spots.
It can completely rot a plant in four days. The fungicide Captan should give some control.