Growing Trial Examination Guidance for Protecting New Plant Varieties

Examining Distinctness, Uniformity and Stability 

Plant variety protection can only be granted to a new plant variety after confirming the variety is:
  • distinct (D) from any other variety whose existence is a matter of common knowledge, in any country, at the time of the filing of the application
  • sufficiently uniform (U) and stable (S), or “DUS” in short.
The authority for granting plant breeders’ rights is responsible for the examination, or “DUS Test,”. This examination is based mainly on growing tests, carried out by the authority or by separate institutions, such as public research institutes, acting on behalf of that authority or, in some cases, on the basis of growing tests carried out by the applicant under the supervision of the authority.
UPOV guidance on DUS examination:
  • sets out the principles and international standards to ensure that DUS examination is conducted in a harmonized way throughout UPOV members
  • establishes the basis to facilitate cooperation among UPOV members
  • helps to provide effective protection through the development of harmonized, internationally recognized descriptions of protected varieties.

Explore the UPOV Convention

Guidance and resources

IMAGE: UPOV/TAVEIRA

TGP documents

Test Guidelines Procedures for the examination of distinctness, uniformity and stability (DUS)
IMAGE: cOURTESY OF MARCO  HOFFMAN

Test Guidelines

Detailed guidance for the harmonized examination of distinctness, uniformity and stability (DUS) of new plant varieties
IMAGE: courtesy of ERIC SCHULTE 

TG template

UPOV online tool for drafting Test Guidelines for plant variety examination according to the UPOV Convention

Webinars

Environmental effect in expression of characteristics

Date:  April 21, 2026
8:00 - 09:30 a.m. (Geneva time):  registration link
3:00 -4:30 p.m. (Geneva time):  registration link

Completeness and relevance of variety collections

Date: April 22, 2026
8:00 - 09:30 a.m. (Geneva time):  registration link
3:00 -4:30 p.m. (Geneva time):  registration link

Phytosanitary issues that prevent or delay submission of plant material​

Date: April 23, 2026
8:00 - 09:30 a.m. (Geneva time):  registration link
3:00 -4:30 p.m. (Geneva time):  registration link

Technical webinars on plant variety examination

The following videos provide information on how UPOV members conduct plant variety examination.

Cooperation in DUS Examination

China - Ms. LIU Yanfang, Deputy Director General Professor, Kunming Sub-Center for New Plant Variety Tests, Ministry of Agriculture and Rural Affairs.

Impact of Environmental Variation on Color Trait Expression and Its Challenge to DUS Testing

 

China - Mr. WANG Yufeng, Ph. D., Xinzhou Sub-Center for New Plant Variety Tests, Ministry of Agriculture and Rural Affairs

Evaluation of Spatio-temporal Consistency in Maize DUS Traits

 

Japan - Mr. Yoshiyuki Ohno, Senior Examiner, Plant Variety Protection Office, Intellectual Property Division, Export and International Affairs Bureau, MAFF

Environmental effect in expression of  characteristics in DUS examinations

 

Netherlands (Kingdom of the) - Mr. Wim Sangster, Crop Specialist, Naktuinbouw

Environmental effect in expression of  characteristics in DUS examinations

 

New Zealand - Mr. Scott Gregan, Senior PVP Examiner, Plant Variety Rights Office Intellectual Property Office of New Zealand

Environmental effect in expression of  characteristics in DUS examinations

 

Germany - Ms. Swenja Tams,  Head of Section, General affairs of DUS testing, Bundessortenamt

Conditions for the use of DUS results from other UPOV members

 

Netherlands (Kingdom of the) -  Mr. Marco Hoffman, Senior Policy Officer, Naktuinbouw

Completeness and relevance of Variety collections in DUS examination

 

Phytosanitary matters that impact access to plant material for DUS examination

Japan  - Mr. Yoshiyuki Ohno, Senior Examiner, Plant Variety Protection Office, Intellectual Property Division, MAFF

Phytosanitary matters that prevent or delay submission of plant material

 

New Zealand - Ms. Cecilia Requejo-Jackman, Senior PVR Examiner, Plant Variety Rights Office Intellectual Property Office of New Zealand

Phytosanitary matters that impact access to plant material for DUS examination in NZ

 

United Kingdom - Mr. Peter Scotting, PVS Manager for Plant Breeders Rights and Variety Listing, Animal and Plant Health Agency (APHA)

Phytosanitary matters that prevent or delay submission of plant material for DUS examination

 

IMAGE: UPOV/REZENDE  

Test Guidelines: Development and Use

Guidance on Certain Physiological Characteristics
in DUS

Completeness and relevance of variety collections in DUS examinations

Phytosanitary matters that impact access to plant material for DUS examination

IMAGE: Courtesy of Erik Schulte

Trial Design and Techniques Used in DUS Examination

IMAGE:  UPOV/REZENDE

Crop‑Specific DUS Case Studies

IMAGE:  UPOV/REZENDE
IMAGE:  UPOV/REZENDE