What was it all about?

From 2016 to 2020, this project expanded the PREDICTA® PT testing system to help minimise the impact of soil and seed borne diseases on commercial Australian potato production.

Available through accredited providers in south-eastern Australia since 2013, PREDICTA Pt is a commercial DNA-based testing service that identifies pathogens and helps potato growers manage risks related to powdery scab, black dot and root knot nematode prior to planting.

The service expansion included adding other major production areas, new soil tests, and access to seed tuber testing. Disease risk categories were added for:

• Verticillium wilt caused by Verticillium dahlia, including quantifying specific root lesion nematode populations that increase dahliae infection when levels in soil are low
• Warm climate root knot nematodes species (Meloidogyne javanica, incognita, M. arenaria), enhancing value for growers in Queensland, Western Australia and New South Wales.

Tests developed outside this project, for pathogens that cause sclerotinia stem rot and leak rot, were evaluated in potato crops and are now reported by PREDICTA Pt, with population density categories against benchmarked industry results.

Inoculum on seed tubers can contribute to disease risk. For other pathogens, seed is an important source of infection.

In developing PREDICTA Pt Peel, the goal was to provide risk assessments for silver scurf, common scab and rhizoctonia. The service also includes tests for pathogens that cause black dot and pink rot, as seed inoculum contributes to disease risk.

Systems developed to test peel also enable quantitative testing of root and stem samples as a research tool to investigate observations in potato crops and trials.

Existing tests for Globodera rostochiensis (golden potato cyst nematode) and G. pallida (pale potato cyst nematode) have been calibrated and are now available to assist with surveillance.

The PREDICTA Pt resource manual and training course were upgraded to support the new testing services, now covering 11 diseases, plus protocols for sample collection and interpreting results.

Use of PREDICTA Pt continues to increase and is being used by:

• Seed growers to improve the percentage of crops meeting certification standards
• Fresh market growers to adjust management strategies for lower overall risk of black dot
• Processing growers to justify cost of implementing management options for root knot nematodes
• Agronomists evaluating crop rotation choices
• Agribusiness to compare and evaluate disease control treatments.

Further information on how PREDICTA testing can assist growers in managing disease risk is available in the Guide to Testing for Seedborne and Soilborne Pathogens of Potatoes.

ACT NOW

Visit the PREDICTA® Pt website for more information about the service.

Learn more about the PREDICTA Pt service and how it supports potato production decisions in this InfoVeg TV episode.