On two occasions during May and June, members of the project team carried out field research in the area of the Krupa River (a tributary of the Zrmanja) with the aim of locating and collecting samples of wild grapevine (Vitis vinifera subsp. sylvestris).

During the fieldwork, the team members located sites of wild grapevine and collected the plant material needed for further analyses. Each individual plant was labelled with a tag bearing its corresponding code, enabling reliable tracking and unambiguous identification of each plant. All collected material was documented in a way that allows for its subsequent morphological characterisation and genomic analysis, together with the recording of the associated data on the location and habitat of each plant found.