Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Potato soft rot (296)

Click/tap on images to enlarge
  • Worldwide distribution. On potato, brassicas, capsicum, carrot, aroids, ornamentals and more. Important bacterial diseases.
  • Three kinds: (i) soft rots in seed, brown with black margin, (ii) stem rots (uncommon); (iii) wet rots in storage. Spread in ground water, and trade in tubers.
  • Cultural control: certified seed; treat cutting tools (bleach); field drainage; avoid excessive N; avoid irrigation until emergence; avoid harvest when wet, and avoid wounds; harvest 7-10 days after vine are dead; avoid washing tubers before storage; store at 12-15°C for 1-2 weeks, and then at 10°C.
  •  Chemical control: none recommended.
Common Name

Bacterial soft rot

Scientific Name

Pectobacterium carotovorum subsp. carotovorum (previously, Erwinia carotovora subsp. carotovora). There are other, related, bacteria species causing stem and tuber rots in potato, most importantly 'black leg' caused by Pectobacterium atrisepticum, and Erwinia chrysanthemi (renamed Dickeya chrysanthemi) causing tuber rots, particularly in tropical countries (see Fact Sheet no. 179).

AUTHOR Grahame Jackson 
Information from Diseases of vegetable crops in Australia (2010). Editors, Denis Persley, et al. CSIRO Publishing; and DPI&RD (2017) Soft rot diseases of potatoes. Agriculture and Food. Government of Western Australia. (; and Reviewing best practices for potato soft rot and blackleg (2019) AUSVEG. (; and from Charkowski A et al. (2020) Bacterial diseases of potato. In: Campos H, Ortiz, O (eds.), The potato crop. ( Photo 1 Gerald Holmes, California Polytechnic State University at San Luis Obispo,

Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community. 

Copyright © 2022. All rights reserved.