Leafhoppers acquire the witches’ broom phytoplasma from infected legume hosts. Later, they migrate to potato fields and transmit the pathogen. Usually, infections occur too late in the season for symptoms to develop. Symptoms are usually visible on plants that emerged from infected seed tubers.
Plants are dwarfed. An excessive number of shoots proliferate at the base of the stems. Leaves are yellowish, round and simple. Tubers produced by infected plants lack dormancyNumerous small plants with simple leaves develop from infected seed tubers.
