High temperatures have a different effect on vegetative and reproductive processes of 'Picual' and 'Arbequina' olive in Spain

Warmer scenarios forecasted for the Mediterranean region will affect the productivity of olive (Olea europaea L.). In this study, mature trees of 'Picual' and 'Arbequina' growing in the field, were exposed to temperatures 4 degrees C above ambient over five or three years using temperature-controlled open top chambers (OTC). High temperatures advanced flowering and fruit maturation in both cultivars and reduced fruit yield and oil content. Some of the differences between the control and the heated plots were not significant in 'Arbequina', probably due to high tree to tree variability and low replication. These results suggest the need to conduct a cultivar screening for tolerance and sensitivity to high temperatures in order to select those better adapted to these conditions for future plantations.