Proficiency Test Programme        
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Scope of the ISTA Proficiency Test (PT) Programme
All ISTA member laboratories are eligible to participate in all PT rounds of the ISTA PT Programme. It is mandatory for ISTA accredited member laboratories (depending on their scope of accreditation) and voluntary for non-accredited laboratories who want to benchmark themselves with accredited laboratories and prepare themselves for accreditation in the future. The goal is not to identify the best seed testing laboratory in the world, but to identify those laboratories that do not meet the minimum standard of performance that is reasonably expected from an ISTA accredited laboratory and to determine if such laboratories are taking reasonable corrective action to bring their performance standard to at least the minimal level.
Non-members of ISTA may participate in the ISTA PT Programme for a flat fee determined and published by the Association. Participation comprises shipment of samples, statistical analysis and reporting to the participating laboratory. Non-members who wish to participate should contact the ISTA Secretariat.

Click here to see the PT Flow Chart


Regular PT rounds are performed three times per year. Normally, a test round starts 1st of April, August and December each year with the shipment of the samples as indicated in the Programme Plan. Each round is made up of three samples for each test (or group of tests) that are analysed for e.g. purity, other seed determination (OSD), germination, moisture, and/or tetrazolium as applicable. PTs for tests other than those mentioned are currently organised by the GMO and Seed Health Committee. The latest information about the upcoming GMO Proficiency Test and Seed Health Proficiency Test rounds are published on their committee websites. ISTA Members are automatically informed about upcoming GMO and Seed Health Proficiency Test rounds by email.

Programme Plan

The ISTA Proficiency Test Committee (PTC), comprising the Chairman and the PT Leaders, select the particular species to be used for the programme over a three year time span between two ISTA Congresses. The species to be used are chosen to represent a size and germination type group and are intended to be generic in representing a crop group. They are species listed in the ISTA Rules Table 2A Part I and III. All species of Table 2A may be part of a laboratory's scope of accreditation. If a laboratory is accredited for one or several of the species mentioned in a crop group, participation in a test round which tests another species of the same crop group is mandatory. A representative species for each Crop Group should be chosen at least once within six rounds.
At the beginning of each PT period, generally after an ISTA Congress, the laboratory will receive the Programme Plan. New member laboratories will receive the Programme Plan together with the membership confirmation letter. Non-accredited laboratories that wish to participate as volunteers will be requested to indicate in which test rounds they wish to participate by returning the completed form to the ISTA Secretariat. Accredited laboratories whose scope does not oblige them to participate in every test round may also indicate the rounds in which they wish to participate as volunteers. Results of voluntary test rounds will be excluded from the accredited laboratory's overall rating. 
Test rounds are identified by a unique numbering system that is as follows: last two numbers of the year in which the test is performed, a number indicating the round of that year plus an abbreviation of the species tested. Hence, 07-2 M.sat means that it is the second round of year 2007 and the species tested is Medicago sativa. This number is applied and referred to in communication to quickly identify the test round concerned.


Before a round starts, the list of participants is generated on the basis of the data available in the Secretariat's data base. This list is made up of laboratories obliged to participate due to their specific scope of accreditation and laboratories having indicated their interest. The mandatory status of every laboratory is determined on the basis of the approved scope of accreditation. The scope of accreditation is defined as described in the document Acc-D-07-Scope of Accreditation Policy.

Last update: 31.08.2016


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