DUS protocols for testing plant varieties

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

The EU does not accept UK distinctiveness, uniformity and stability (DUS) protocols.

The UK will accept EU DUS reports during the transition period for the agricultural, amenity and vegetable species tested by any of the following organisations so long as the testing started before 31 January 2020:

  • AFBI (Agri-Food and Biosciences Institute)
  • NIAB (National Institute of Agricultural Botany)
  • SASA (Science and Advice for Scottish Agriculture)

For other species, the UK will continue to accept EU DUS provided it is of comparable quality to UK testing.

EU Directive

EU Commission Directive 2019/1985/EU was implemented in the UK on 29 May 2020. This specifies the minimum characteristics to be measured and conditions for examining certain varieties of agricultural and vegetable species for DUS.

See the notice announcing the implementation (PDF, 246KB, 5 pages).

DUS tests

As part of the application process to add a plant variety to the National List or for approval of plant breeders’ rights, the plant variety must be tested to ensure it is distinct, sufficiently uniform and stable (DUS).

DUS tests are carried out at approved centres over a 2-year period. They are done in line with protocols and procedures approved by the Plant Variety and Seeds Committee, which represents the national authorities on seeds issues.

The Community Plant Variety Rights Office develops the technical protocols which set the characteristics to be used in the DUS tests.

DUS criteria


A distinct plant variety has one or more important characteristics that are different from other varieties included in the National List, a list of another EU state, or the EU Common Catalogue.


A uniform plant variety has individual plants which have similar or genetically identical important characteristics, with very few aberrations.


A stable plant variety has important characteristics which remain true to their original description after successive propagations or multiplications.

DUS protocols

Published 16 June 2014
Last updated 28 May 2020 + show all updates
  1. Updated DUS protocols - barley, field beans, ryegrass hybrid, ryegrass Italian, ryegrass perennial and wheat.

  2. Updated EU Directive section.

  3. Updated DUS protocols for potato

  4. Oilseed rape and fodder rape protocol updated

  5. Notice announcing the implementation updated

  6. DUS protocol for potatoes updated

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

  8. Sugar beet protocol updated

  9. Oats DUS protocol updated

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

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

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

  13. Updated DUS protocol - field beans

  14. Field beans DUS protocol updated

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

  16. Sugar beet protocol updated

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

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

  19. First published.