Maintaning a variety

Vegetable and agricultural varieties must have a maintainer to be registered/listed in the National Variety Register.

What does maintenance mean?

Registration in the National Variety Register (NRR) of a vegetable and agricultural variety lasts for 10 years.

In order to trade a variety, a variety must be registered/listed in the National Variety Register. After 10 years, this registration expires and there is the possibility to apply for prolongation. Applying for prolongation keeps the variety registered and maintains its trading position so that the variety can be sold within the EU. After applying for prolongation, the variety is assessed by the inspection service. This involves checking whether the breed is still true to the variety. True to the variety means that the variety is still the same as the DUS variety description that was made when the variety was listed. This means that the variety meets the requirements for maintenance. The cost for applying for prolongation can be found in this year's fee table.

Maintenance inspection of vegetable varieties

Maintainers of vegetable varieties are required to submit a maintenance sample every 5 years. This sample is inspected and must be 'true to variety'. This check is performed by the Naktuinbouw Inspection Department.

Maintenance inspection for agricultural crops

For agricultural crops, maintenance inspection takes place in the Netherlands. This is done through inspection regulations laid down by the NAK.

Obligations of the maintainer

The maintainer is obliged to ensure that the varieties listed in the National Variety Register (NRR) are maintained. The Board for Plant Varieties (the Board) supervises this. The maintainer must ensure that the variety remains true to the variety throughout its life.

The DUS sample is the official reference sample used for maintenance control. If a (new) reference sample is required for maintenance control purposes, it will be requested from the maintainer on behalf of the Board. This sample will be compared with the official reference sample and examined for identity and homogeneity.

The maintainer is always responsible for the timely submission of a proper maintenance sample.

If you would like to become a maintainer of a variety, please send an email to