The disease appeared in Europe around the turn of the century and spread to most regions of the world where potatoes are cultivated.
Most infested soils are in home gardens.
Wart disease presents biological, social, and legislative problems. This pamphlet attempts to put some of these problems in perspective. The major symptom of wart disease is a gall at the base of the potato stem, or the haulm, The gall, which is white when under ground, and black when decaying, may be as small as a pin or as large as a fist. Its surface is rough and corrugated-warty in appearance. Severe infestations destroy the potato crop by preventing tuber production.