VATIS UPDATE Article

Scientists from Plant & Food Research, New Zealand, have been trialing a specially engineered high-pressure washing machine for taro to help reduce the risk of pests entering the country. Taro is a particularly difficult vegetable to clean as it is covered in fibrous leaf and root matter and its pitted nature can mean soil residues. The high-pressure washing machine has been tested along with hot water treatments for its ability to eliminate this material and remove or kill microscopic organisms.

The machine, which was designed and built by engineers at Plant & Food Research’s Ruakura site, forms part of a larger biosecurity project by the Ministry for Primary Industries (MPI) to reduce the use of the fumigant methyl bromide, an ozone depleting gas which can damage the vegetable and affect storage quality and shelf life. “This has necessitated finding new applications in pest management which meet border control requirements while not compromising the quality of the product,” said Dr Allan Woolf, at Plant & Food Research.

Another key goal of the trial is to ensure that organic matter and unwanted organisms are removed without damaging the product itself. Although detailed post-trail data still need to be collected, initial results are said to be positive. The machine follows a similar design to those manufactured to clean apples and citrus fruit, but with a modified brush bed and high-pressure nozzles which target the taro corms at specific angles as they sit between the rollers.