DUS protocols for testing plant varieties

Protocols and procedures for testing the distinctiveness, uniformity and stability (DUS) of certain agricultural and vegetable plants.

If you have a new plant variety, it must be tested to make sure it is distinct, sufficiently uniform and stable (DUS) as part of the application process to:

DUS criteria

DUS testing checks your new plant variety is distinct, uniform and stable.


A distinct plant variety has at least one important characteristic that is different from other varieties included in the national list.


A uniform plant variety has individual plants that share the same important characteristics.


A stable plant variety remains unchanged after ‘repeated propagation’, for example, reproduction from seeds, cuttings, bulbs or other plant parts.

Get your variety tested

APHA will ask you to send your seed or plant material for testing as part of your application to add your variety to the national lists or for PBR. They’ll tell you how much to send and when.

Do not send plant material until APHA requests it.

Testing takes:

  • 1 to 3 years for ornamentals depending on species
  • 3 years for trees
  • 4 years for herbage varieties
  • 2 years for other species

Your variety might need more tests on parental species if you’re registering hybrid varieties.

APHA will send you a copy of the test results.

DUS protocols

Read the DUS protocols for:

DUS reports in the EU and UK

The EU stopped accepting UK DUS reports from 1 January 2021.

The UK is reliant on EU testing for a large number of species where the UK does not have DUS testing capability. The UK will accept EU reports for these species, if the testing done for the report is of comparable quality to UK testing.

The UK will accept EU DUS test reports for the following species the UK does have testing capability for:

  • agricultural
  • amenity
  • vegetable
  • ornamental

EU testing must have started before 31 January 2020 for the UK to accept an EU DUS test report.

For all other species where the UK has testing capability, you need to get a UK DUS test as part of your national list or plant breeders’ rights applications.

DUS testing capability in the UK

DUS tests take place at approved centres over a 2-year period. You’ll get first year results and a final decision is generally made after the second year. Grasses can take up to 4 years to be tested.

There are 3 test centres for DUS testing of agricultural and vegetable varieties in the UK:

  • the Agri-Food and Biosciences Institute (AFBI)
  • the National Institute of Agricultural Botany (NIAB)
  • SASA

You can read the list of agricultural, vegetable and ornamental plant varieties that the UK tests for distinctiveness, uniformity and stability (DUS).

The UK does not have DUS testing capability for all the vegetable varieties listed. For the varieties that the UK does not have DUS testing capability for, the UK will do one of the following:

  • purchase the DUS report
  • entrust another examination office to carry out the DUS testing on behalf of the UK

Applications for vegetable varieties that the UK does not have DUS testing capability for can be received all year round. However the closing date for receipt of plant material is at the discretion of the examination office.

UK DUS report requests

If you apply for PBR or a national listing in another country, the country you apply to will need a copy of your UK DUS test report.

The national dedicated authority (NDA) of that country will request a copy of your test report from APHAAPHA will email a copy of your report to the NDA.

Published 16 June 2014
Last updated 15 February 2024 + show all updates
  1. Added 2022 DUS protocol for potato.

  2. Updated the DUS variety testing time to 1 to 3 years for ornamentals depending on species.

  3. The UK will accept EU DUS test reports for ornamental species that the UK has testing capability for.

  4. Removed DUS protocols for beetroot, broad bean, broccoli, brussels sprout, cabbage, carrot, celery, curly kale, leek, onion and echalion, parsnip, potato, radish, rose, runner bean, shallot, watercress.

  5. Removed the 2023 DUS protocol for sugar beet and replaced with previous version. The 2023 DUS protocol for Sugar Beet is under review.

  6. Added sugar beet DUS protocols for 2023.

  7. Added DUS protocols for barley, beetroot, broad bean, broccoli, Brussels sprout, cabbage, carrot, celery, curly kale, festulolium, field beans, field pea and pea, fodder kale, hybrid ryegrass, Italian ryegrass, leek, oats, oilseed rape and fodder rape, onion and echalion, parsnip, perennial ryegrass, potato, runner bean, radish, rose, shallot, sugar beet, swede, turnip, turnip rape, watercress, wheat, white clover.

  8. Added a new section on UK DUS report requests

  9. Removed information on the EU Directive as this is not directly applicable to DUS testing in the UK.

  10. Removed DUS forms and added option to email for a copy of the DUS protocol for some species.

  11. Updated DUS protocols - barley, field beans, ryegrass hybrid, ryegrass Italian, ryegrass perennial and wheat.

  12. Updated EU Directive section.

  13. Updated DUS protocols for potato

  14. Oilseed rape and fodder rape protocol updated

  15. Notice announcing the implementation updated

  16. DUS protocol for potatoes updated

  17. Broccoli, Brussels sprout, Cabbage and Field pea and pea DUS protocols updated.

  18. Sugar beet protocol updated

  19. Oats DUS protocol updated

  20. Notice announcing the implementation of 2016/1914/EU published

  21. Notice announcing the implementation of EU Directive 2016/1914/EU published

  22. DUS protocols for 'oats' and 'oilseed rape and fodder rape' updated

  23. Updated DUS protocol - field beans

  24. Field beans DUS protocol updated

  25. Notice announcing the implementation of EU Directive 2015/1168/EU published.

  26. Sugar beet protocol updated

  27. DUS protocols - peas, radish, rape and swede updated

  28. Notice announcing the implementation of EU Directive 2014/105/EU published.

  29. First published.