Presence, absence, eradication and disappearance: potato diseases in Western Australia

Document Type

Conference Proceeding

Publication Date


Conference Title

Strong Foundations, Future Innovations: Australasian Plant Pathology Society Conference 2019

Place of Publication



biosecurity, potatoes




A critical re-evaluation of the pest status of potato pathogens in Western Australia was undertaken as part of a comprehensive policy review for the importation of ware potatoes. Historical records from 1133 potato samples submitted to the Department of Primary Industry and Regional Development for diagnosis between 1955 and 1992 were tabulated, and digital diagnostic records from 1993-2018, Western Australian Culture Collection lists, potato seed certification reports and survey data were examined for indications of disease presence. Annual reports of the Government Plant Pathologist from 1929 to 1974, historical correspondence and industry magazines were also checked. Five potato pathogens previously recorded in published lists as present in Western Australia are now considered absent. They are bacterial wilt (Ralstonia solanacearum), potato cyst nematode (Globodera rostochiensis), late blight of potato (Phytophthora infestans,), violet root rot (Helicobasidium purpureum) and stem nematode (Ditylenchus dipsaci). Successful eradication campaigns eliminated R. solanacearum in 1987 and G. rostochiensis in 1989. Intermittent outbreaks of P. infestans occurred in Western Australia from 1909 -1954, although the disease was of minor importance and P. infestans has not been reported since 1966. Two doubtful records of H. purpureum exist from 1919 and 1931, but no cultures were retained for verification and the fungus has not been reported again. It is likely that 1950s records of D. dipsaci associated with cereals and clovers resulted from the erroneous identification of native Ditylenchus species, and extensive surveillance over the past 30 years has not detected D. dipsaci. Furthermore, there have been no reports of D. dipsaci from horticultural crops in Perth since 1964. Based on criteria listed in ISPM 8 – Determination of pest status in an area, these five pathogens are classed as absent from WA. Changes in pathogen distribution, improvements in identification methods and ongoing taxonomic revisions all contribute to the need for continuing revision of pathogen lists