This disease first shows itself as small, light warts, which can later develop into large, cauliflower-like growths. Older growths turn brown. A similar appearance can sometimes be displayed by tubers attacked by powdery scab.
The disease is caused by the Synchytrium endobioticum fungus. The infection is transmitted by soil carried on seeds, machines, etc. The disease is extremely serious and can, if remedial actions is not taken, have catastrophic results.
It is therefore necessary to report the presence of the disease to the National Plant Protection Institute, which imposes a ban on growing or recommends the growing of resistant varieties.