The IMAG orchard in Wageningen, comprised in 1982 approximately seventy varieties. In Zeewolde almost 360 varieties were planted, among which several of the IMAG-varieties. The main goal of the research in Zeewolde was identification of the collected accessions and observation of resistance to scab and mildew. Also pomological and phenological observations were carried out. Another research aim in Zeewolde was to assess the influence of varieties on the development of other diseases and pests. To monitor this, a series of observation years and a heterogeneous collection of sufficient size was required. The influence of differences in hairiness and leaf texture on the biological control of red spider mite and apple rust mite (Aculus schlechtendali) by predatory mites (Typhlodromus sp.) and the importance of antagonists of scab on leaves of different varieties have been studied too.
In order to develop a diverse collection, the trees in the Zeewolde orchard were screened and phenotyped with the use of existing descriptions from (old) handbooks and literature. Dependent on availability, completeness, and correctness a revised register was made with attention to synonyms. Also a possible overlap with the well-known UK National Apple Collection (Brogdale) was taken into consideration.
After the screening, 184 varieties remained. It was decided to conserve particularly varieties with certain extreme characteristics with respect to fruit size, flowering time, picking time, skin (smooth or russet), etc. To enable an informed choice, a list was made with 20 fruit and tree characteristics, based upon all the observations that were available. Fruit and tree characteristics, eating quality, bitter pit, production, abundance of flowering, second flowering, fruit set drop, June drop, fruit size, russeting, scab, and mildew have been used for the selection, with emphasis on the first three characteristics mentioned. Finally 82 varieties were selected and planted in in the experimental orchard of the former Research Station for Fruit Growing (PFW) in Wilhelminadorp in the province Zeeland, the Netherlands in the spring of 1986; all with 2 x 2 trees on M.9 rootstock.
Ten years later, in Augustus 1996, new trees were made by chipbudding on M.9. In the spring of 1998, these trees were planted in the experimental orchard of Wageningen University & Research in Randwijk. One year later, the trees have been replanted to the current plot. Foreign varieties, research material and wild species have been added. The number of accessions extended from 124 in 2004 to 204 in 2018.
Since January 2002, the collection is under management of CGN and forms part of the National Genetic Resources Program, financed by the Ministry of Agriculture, Nature management and Food quality. In 2017 CGN started to focus more on the conservation of old Dutch varieties. In cooperation with the Dutch Fruit Network (NFN), most of the foreign varieties, research material and wild species are currently replaced by rare Dutch varieties.