Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Potato bacterial wilt Race 3 biovar 2 (479)

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  • Worldwide distribution. In Australia, New Zealand, New Caledonia, Papua New Guinea.
  • A devasting disease of potato; also affecting tomatoes, eggplants, and others. Entry through roots: leaves rapidly turn yellowish and wilt; stems show browning and ooze from vascular areas; plants collapse and die. Ooze too from ‘eyes’ (buds) of tubers.
  • Spread: short distances by run-off water; longer distances by movement of infected tubers, soil on machinery, shoes. Possibly insects. Survival: in soil up to 2 years; on volunteers, weeds, roots of non-hosts.
  • Biosecurity: protocols needed to respond to a breach, and a plan should eradication fail.
  • Cultural control: use only certified seed; avoid cutting tubers; avoid land where diseases previously occurred, or have 2-3 year (preferably 4) rotation with unrelated crops (cereals, sweet potato, cabbages, onions); improve drainage using ridges or raised beds; rogue disease plants; clean machinery, tools, footwear after working in infested fields; collect debris after harvest and burn.
  • Chemical control: not appropriate for this disease.
Common Name

Brown rot of potato. It is also known as bacterial wilt of potato.

Scientific Name

Ralstonia solanacearum Race 3 biovar 2. Other names are: Bacillus solanacearum, Burkholderia solanacearum, and Pseudomonas solanacearum. There are five races of Ralstonia solanacearum: Race 1 has a host range of over 50 plant families (200 plant species), including chilli, capsicum, peanut, and Solanum species (but more rarely on potato); race 2 mostly affects banana and Heliconia, Race 4, ginger, and Race 5, mulberry.

Under a revised classification system (2005), and based on DNA sequencing, Ralstonia solanacearum has been divided into four groups, reflecting geography (phylotypes), and further by genetic sequence of an important gene (sequevars). By this method potato brown rot is Phylotype II, sequevars 1&2.

AUTHOR Grahame Jackson
Information from Charkowski A, et al. (2020) Bacterial Diseases of Potato. In: Campos H, Ortiz O (eds) The Potato Crop. Springer, Cham. (; and Lemay A, et al. (2003) Pest Data Sheet Ralstonia solanacearum race 3 biovar 2. USDA/APHIS/PPQ Center for Plant Health Science and Technology Plant Epidemiology and Risk Analysis Laboratory Raleigh, NC. USA. (; and from Sullivan M, et al., (2013) CPHST Pest Datasheet for Ralstonia solanacearum race 3 biovar 2. USDA-APHIS-PPQ-CPHST. ( Photo 1 Anare Caucau, Koronivia Research Station, MoA, Fiji. Photo 2 Clemson University - USDA Cooperative Extension Slide Series, Photo 4 Central Science Laboratory, Harpenden , British Crown, Photo 5 Ministry of Agriculture and Rural Affairs, ( Photo 6 National Plant Protection Organization, the Netherlands.

Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland and the Secretariat of the Pacific Community.

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