Grafting stone pine onto alternative rootstocks to expand pine nut production

12-year experiment in Os de Balaguer, Lleida, Spain, tests grafting stone pine (Pinus pinea) onto different rootstocks to expand pine nut production, prevent land abandonment, and support sustainable agroforestry. The study compares nursery and in-field grafting methods using 70 rootstocks each of stone pine and Aleppo pine, with 44 trees grafted in nurseries, 68 in the field, and 18 ungrafted. Conducted by CTFC since winter 2011–2012, the project aims to boost high-value pine nut yields (€60/kg on average 2020–2024), restore degraded areas, and generate scientific insights into grafting effectiveness. Part of the AEI-PCPI initiative on sustainable stone pine management.