Flowering Phenology of Olive Cultivars in Two Climates Zones with Contrasting Temperatures (Subtropical and Mediterranean)

Abstract

The olive wide genetic variability can be used to overcome some of the challenges faced by olive growing, including climate warming. One effect of climate warming in olive is the difficulty to fulfill the chilling requirements for flowering due to high winter temperatures. In the present work, we evaluate seven olive cultivars for their adaptation to high winter temperatures by comparing their flowering phenology in the standard Mediterranean climate of Cordoba, Southern Iberian Peninsula, with the Subtropical climate of Tenerife, Canary Islands. Flowering phenology in Tenerife was significantly earlier and longer than in Cordoba. However, genotype seems to have little influence on the effects of lack of winter chilling temperatures as in Tenerife. This even though the cultivars studied have a high genetic distance between them. In fact, all the cultivars tested in Tenerife flowered the three years under study but showing asynchronous flowering bud burst. Only ‘Arbequina’ showed an earlier day of full flowering than the rest of cultivars. The results observed here could be of interest to refine the phenological simulation models and including of the length of the flowering period. More genetic variability should be evaluated in warm winter conditions to look for adaptation to climate warming.