Powdery scab can severely reduce the quality and marketability of seed, fresh market and processing potatoes. The powdery scab pathogen (Spongospora subterranea) also reduces tuber yields by disrupting root function, such as water and nutrient uptake, in actively-growing potato plants, and causes severe galling on roots.

A research initiative that began in March 2016 is aiming to identify soil factors that influence the development of powdery scab in potato crops, which is associated with multiple potato cropping.

This study, involving scientists at the New Zealand Institute for Plant & Food Research Limited, is funded by Hort Innovation and Potatoes New Zealand and builds on previous research from a long-term potato and onion trial in New Zealand that suggested the presence of ‘suppressive’ factors in the soil preventing severe outbreaks of powdery scab.

So far, the project has evaluated 12 field soils (including the soil from the original trial site from the previous research) using an extensive greenhouse pot trial, as well as assessing the soils’ physical and chemical characteristics. The project has also used the PreDicta Pt service offered by SARDI to undertake DNA testing of the soils and identify any potential soilborne pathogens.

As this project moves into its next stages, the team will collate the information they’ve collected through these tests to identify if any potential individual characteristics – or combinations of them – are associated with suppression of powdery scab, as well as look at the microbial populations in the soils and assess any disease-affecting soil factors that can be manipulated to reduce disease.

Project lead Professor Richard Falloon has written a detailed article on this research and its findings for the latest edition of Potatoes Australia, which you can find in the publications section of our website.

If you’re interested in receiving the latest potato industry research and development news for free, get in touch with us at communications@ausveg.com.au to subscribe to the hard-copy versions of Potatoes Australia, which we’ll deliver to your mailbox every two months.

Photo provided by Peter Wright.

This post appeared in the AUSVEG Weekly Update published 10 July 2018. Subscribe to the Update using our online form to receive the latest industry news in your inbox every week!

This project has been funded by Hort Innovation using the fresh potato and potato processing research and development levies and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.