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Bacterial Breakdown
Bacterial breakdown in washed potatoes
Bacterial breakdown is a significant problem in washed potatoes throughout Australia. This disease is caused by three species of Erwinia, which rots potatoes in the field and in storage.
Potato tubers have a higher potential risk of forming bacterial soft rot immediately after major handling steps such as harvest, washing and cutting seed pieces. Washing in particular has been associated with outbreaks of the disease and in South Australia rotting of washed tubers after packaging has caused major losses. Many potato washing sheds in South Australia use recycled water for the main washing and then apply either fresh bore water or bore water with chemicals added to sanitise the water in the final rinse.
As part of a project initiated to manage bacterial breakdown in washed potatoes, a survey of washing sheds in South Australia was undertaken to determine the levels of bacteria in the processing line. Erwinia was found at varying levels throughout the washing line and the numbers of infected tubers increased when washed with water. While all sanitising agents tested killed Erwinia, Oxine and Klorman were effective when added to washing plant water containing bacteria, soil and plant material. Maintaining tubers free of surface moisture after bagging reduced the risk of bacterial breakdown in washed potatoes.
This project was funded by the Potato Industry levy with matched funding from the Australian Government facilitated through Horticulture Australia Limited (HAL).
More information
- Project summary 1998 - 2003, HAL project PT98007
- A full report of the research can be obtained from Horticulture Australia Limited (HAL) (external site)
- Poster presentation, Control of Bacterial Soft Rot in Washed Potatoes in South Australia (.PDF 725KB), presented at the 8th International Plant Pathology Congress, New Zealand, February 2003.
- A report published in 2000 on investigations into the soruce of Erwinia in washing plants, Managing Bacterial Soft Rot in Washed Potatoes.
For more details contact Trevor Wicks.
- Managing Bacterial Soft Rot in Washed Potatoes in SA (html) = same copy as comes up under other entry below
More info on research into managing bacterial breakdown (soft rot) in potatoes in series of Newsletters 'Exposing Erwinia' - links to 6 issues, Feb 2000 through to Feb 2003
