DUS protocols for testing plant varieties
Source: gov.uk (2025-12-08)

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:
- add a plant variety to the GB and NI Variety Lists (https://www.gov.uk/guidance/national-lists-of-agricultural-and-vegetable-crops)
- get intellectual property rights (known as plant breeders’ rights (PBR) (https://www.gov.uk/guidance/plant-breeders-rights))
DUS criteria

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

Distinct

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

Uniform

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

Stable

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 variety 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:
- Barley (https://assets.publishing.service.gov.uk/media/69288c7c2a37784b16ecf69b/Barley_DUS_protocol.pdf) (PDF, 497 KB, 34 pages)
- Festulolium (https://assets.publishing.service.gov.uk/media/69288c909c1eda2cdf034242/Festulolium_DUS_protocol.pdf) (PDF, 472 KB, 34 pages)
- Field beans (https://assets.publishing.service.gov.uk/media/69288c709c1eda2cdf034241/Field_Beans_DUS_protocol.pdf) (PDF, 389 KB, 30 pages)
- Field pea and pea (https://assets.publishing.service.gov.uk/media/69288c5fa245b0985f034226/Field_Pea_and_Pea_DUS_protocol.pdf) (PDF, 604 KB, 51 pages)
- Fodder kale (https://assets.publishing.service.gov.uk/media/6914c930db01ecfcf96fc891/Fodder_Kale_DUS_Protocol.pdf) (PDF, 303 KB, 27 pages)
- Hybrid ryegrass (https://assets.publishing.service.gov.uk/media/63a1c1cfd3bf7f3763457f42/Hybrid_Ryegrass_DUS_Protocol_2022.pdf) (PDF, 428 KB, 27 pages)
- Italian ryegrass (https://assets.publishing.service.gov.uk/media/63a1c211d3bf7f375f7c437a/Italian_Ryegrass_DUS_Protocol_2022.pdf) (PDF, 328 KB, 29 pages)
- Oats (https://assets.publishing.service.gov.uk/media/680f5aa0521c5b6f2883ccdd/Oats_DUS_Protocol_2025.pdf) (PDF, 350 KB, 30 pages)
- Oilseed rape and fodder rape (https://assets.publishing.service.gov.uk/media/66d98bed561701fa1c214e64/Oilseed_Rape_and_Fodder_Rape_DUS_Protocol_2024.pdf) (PDF, 306 KB, 29 pages)
- Perennial ryegrass (https://assets.publishing.service.gov.uk/media/63a1c2c48fa8f5391a4ed4bc/Perennial_Ryegrass_DUS_Protocol_2022.pdf) (PDF, 749 KB, 38 pages)
- Potato (https://assets.publishing.service.gov.uk/media/67e1816d0114b0b86e59f50e/Potato_DUS_Protocol.pdf) (PDF, 1.51 MB, 49 pages)
- Sugar beet (https://assets.publishing.service.gov.uk/media/675c642998302e574b915390/Sugar_Beet_DUS_Protocol.pdf) (PDF, 311 KB, 28 pages)
- Swede (https://assets.publishing.service.gov.uk/media/672e10abcc61d0a714ffdab5/Swede_DUS_Protocol_2024.pdf) (PDF, 363 KB, 37 pages)
- Turnip (https://assets.publishing.service.gov.uk/media/672e10cd4f7608e424ffdaac/Turnip_DUS_Protocol_2024.pdf) (PDF, 459 KB, 40 pages)
- Turnip rape (https://assets.publishing.service.gov.uk/media/672e10bc4f7608e424ffdaab/Turnip_Rape_DUS_Protocol_2024.pdf) (PDF, 431 KB, 45 pages)
- Wheat (https://assets.publishing.service.gov.uk/media/680f6514172df773f0305ed1/Wheat_DUS_Protocol_2025.pdf) (PDF, 321 KB, 30 pages)
- White clover (https://assets.publishing.service.gov.uk/media/63a1c385d3bf7f3762ed5468/White_Clover_DUS_Protocol_2022.pdf) (PDF, 302 KB, 33 pages)
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 variety list or PBR applications.

DUS testing capability in the UK

The UK has DUS testing capability for a range of species, including over 800 ornamental plant species.

You need to get a UK DUS test as part of your variety list or PBR applications, for species where the UK has testing capability.

DUS tests take place at approved centres, usually over a 2-year period or 2 growing cycles. You’ll get the 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:
- Agri-Food and Biosciences Institute (AFBI)
- National Institute of Agricultural Botany (NIAB)
- Scottish Agricultural Science Agency (SASA)
The NIAB specialises in DUS ornamental plant species testing. You can read the list of agricultural, vegetable and ornamental plant varieties that the UK tests for distinctiveness, uniformity and stability (DUS) (https://www.gov.uk/government/publications/dus-testing-lists-for-agricultural-vegetable-and-ornamental-plants).

DUS reports and testing outside of the UK

If a variety falls outside the UK’s DUS testing capability, the Plant Variety Rights Office 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
The UK will approach examination offices in the EU, or another member of the International Union for the Protection of New Varieties of Plants (UPOV), to either purchase a report or commission an examination.

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 or authority.

UK DUS report requests

If you apply for PBR or a variety 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 APHA. APHA will email a copy of your report to the NDA.