Future climate change impacts on apple flowering date in a Mediterranean subbasin

Chilling temperatures are important in apple and other fruit production because they are needed to break full dormancy, which is a prerequisite for effective and synchronous bud-break and flowering. Temperature increase related to climate change could lead to inadequate chilling in certain areas, which could affect the suitability for some species or cultivars to survive or yield in that location. The aim of this study was to estimate how climate change could affect flowering date and, consequently, feasibility of the most significant apple cultivars in the lower Fluvià subbasin (correspondent to the Protected Geographical Indication “Poma de Girona”). The estimations are based on a chilling and forcing requirements approach for each apple cultivar in this region, through a statistical analysis. The chilling-forcing sequential model, together with meteorological projections based on two climate change scenarios (B1 and A2), were used to estimate apple flowering dates along the 21st Century. Results show, in general, that apple cultivars could suffer delays on flowering date since the mid century and they could present serious disorders as a consequence of insufficient chilling in the long term in A2 scenario, which could affect crop feasibility in the region.