PREDICTA® Pt (Pt = potato) is a DNA-based soil testing service that helps potato growers identify which soil-borne pathogens pose a significant risk to their crops, so steps can be taken to minimise the risk of yield loss.

We provide a fast and cost-effective way for growers to:

  • determine the soil-borne disease risks
  • help inform variety choices
  • guide management to minimise losses.

Reporting results

PREDICTA® Pt determines the amount of pathogen DNA present in soil samples. Test results are reported under two categories:

  1. Disease Risk categories: the risk of yield loss associated with a particular level of pathogen DNA has been determined and displayed using a graphic to indicate a ‘low’, ‘medium’ or ‘high’ disease risk.
  2. Population Density: category for ‘tests under evaluation’ as the relationship between yield loss and pathogen level has not been determined. Population density categories enables new tests to be reported to growers faster, as developing disease risk categories can take several years. Results can be used to rank levels of inoculum in different paddocks, monitor changes in inoculum during different phases of the cropping sequence and confirm disease diagnosis.

Results are generally emailed to the accredited agronomist within two weeks of the lab receiving soil samples.

PREDICTA® Pt results report (PDF 523.2 KB)

Pathogens included in the PREDICTA® Pt testing

PREDICTA® Pt provides you with an indication of the disease risk from:

  • Powdery scab (Spongospora subterranea)
  • Black dot (Colletotrichum coccodes)
  • Root knot nematode (Meloidogyne fallax).

Population densities are reported for the following pathogens:

  • Streptomyces txtA gene
  • Rhizoctonia solani AG3
  • Rhizoctonia solani AG2.1
  • Meloidogyne hapla
  • Verticillium dahliae
  • Pratylenchus penetrans
  • Pratylenchus neglectus
  • Pratylenchus crenatus.

Benefits of PREDICTA® Pt testing

PREDICTA® Pt is an award winning, world-leading technology that is a proven, fast and cost-effective way for growers to determine the risks from soil-borne diseases. This information can be used to inform variety choices, in addition to optimising paddock management to minimise current and future yield losses from soil-borne diseases.

For further information:

Accessing PREDICTA® Pt testing service

If you are a potato grower, you can access PREDICTA® Pt services through an accredited consultant near you.

Accredited agronomists will interpret the test results and provide advice on management options to reduce the risk of yield loss.

Agronomist accreditation courses are held once a year. For further information contact Michael Rettke on 0401 122 124 or

Following the correct sampling procedure is essential. For advice on sampling, see: PREDICTA Pt sampling strategy (PDF 565.7 KB)

PREDICTA® Pt is not intended for in-crop diagnosis, instead see plant health diagnostic services.

Submitting PREDICTA® Pt samples

Samples must be submitted in PREDICTA® Pt soil bags, available for free from Russell Burns on (08) 8429 2238, 0401 122 115 or

Samples should be submitted to:

SARDI Molecular Diagnostics Group
Plant Research Centre
2B Hartley Grove
Urrbrae SA 5064


Soil samples from researchers can be submitted for PREDICTA® Pt testing. Contact Michael Rettke on 0401 122 124 or for details on test availability and cost.


For interpreting results, agronomist accreditation courses and research samples:

Michael Rettke
Phone: 0401 122 124

PREDICTA® Pt soil bags and sample tracking:

Russell Burns
Phone: 0401 122 115

Nigel Percy
Phone: 08 8429 2236

PREDICTA® is a registered trademark of Bayer Crop Science.

Page Last Reviewed: 05 Mar 2020
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