A prerequisite for the preservation of a variety is the knowledge of the variety description, which allows selecting the variety-typical plants for propagation. Variety descriptions are used to record the typical characteristics of a variety and to inform maintainers and growers. With their help, the authenticity of the variety can be checked by comparing a stock with the available description. Variety descriptions are also important for assessing varietal purity, as they can be used to determine which plants in a stock do not correspond to the varietal type in one or more characteristics and are to be classified as off-types.
For the development of variety descriptions, comprehensive guidance can be downloaded from the websites of the Community Plant Variety Office of the European Union (CPVO) and the International Union for the Protection of New Varieties of Plants (UPOV) for the desired crops. The CPVO instructions are available as "Technical Protocols" and "Guidelines for the Conduct of Tests for Distinctness, Uniformity and Stability". The instructions list the characteristics in which varieties of a species can differ and they list for the respective characteristics the different possibilities of expression with the corresponding assessment note. They also contain basic information on how to carry out the test, such as the minimum number of plants to be tested and the correct timing for recording the characteristics.
The variety descriptions according to UPOV/CPVO record the external characteristics of the varieties. Value-giving properties (e.g. yield or shelf life) and cultivation behaviour (e.g. early or late cultivation, harvest time) as well as resistance or susceptibility to diseases and pests are essential information about a variety that goes beyond this.
In PGRDEU, variety descriptions are available for genebank material of various vegetable species, which were developed in projects of the Federal Office for Agriculture and Food (BLE).
Apart from variety descriptions of the genebank material, which are carried out according to uniform and modern standards, also variety descriptions of historical sources can provide important information about image and use of the varieties in earlier times.
PGRDEU offers historical variety descriptions for nearly 7000 vegetable varieties, which also have been inventoried in a project funded by the BLE.