The GREMPA (Groupe de Recherches Méditerranéennes pour l'Amandier – Pistachier, Mediterranean Research Group for Almond and Pistachio) working group was established with CIHEAM support in the 1970s. The work carried out by this group was fundamentally based on the study and improvement of genetic resources of Mediterranean origin. In turn, in 1990 the FAO created a network aimed at cooperation in nut research. In 1996 an agreement was signed between FAO and CIHEAM in order to create a joint research network, which has been functioning ever since with a considerable level of activity. The network has carried out activities on the following species and topics: Almond, Hazelnut, Walnut, Pistachio, Pecan, Chestnut, Stone pine, Genetic Resources and Economics.
Through the first activities carried out by the network, a database was compiled on a wide range of information of the problems that arose in each country concerning crops, the priorities and programmes of the research teams from the Mediterranean region and the infrastructure available for them. During a second phase, the activity concentrated on the prospection, study and exchange of plant material from which a Research Project was derived, financed by the EC CAMAR Programme, focusing on walnut, almond and pistachio. Collaboration with international organizations as ISHS and Bioversity International (ex- IPGRI) is frequent.
In recent the last years, the network has promoted the participation of researchers from the CIHEAM countries (especially southern and eastern countries) in international scientific events organized by different institutions. GREMPA holds meetings every 4 years (approximately). The network periodically publishes the NUCIS newsletter. It is also working on the edition of germplasm catalogues of various species.