PHOTOSYNTHESIS AND VEGETATIVE-PRODUCTIVE ACTIVITIES OF THE OLIVE CULTIVARS 'ARBEQUINA', 'LECCINO' AND 'MAURINO' IN A VERY HIGH DENSITY OLIVE GROVE IN CENTRAL ITALY

A three-year-old very high-density olive grove was used in central Italy to compare photosynthesis and vegetative and productive activities of cultivar ‘Arbequina’ against those of cultivars ‘Leccino’ and ‘Maurino’, typical of central Italy. ‘Arbequina’ had low vigor even though its canopy volume was not significantly less than that of ‘Maurino’, which was taller and had a more compact canopy than ‘Arbequina’. The total leaf surface area of ‘Maurino’ was less than that of ‘Arbequina’ and ‘Leccino’. ‘Arbequina’ appears to put more resources into the formation of leaf surface area rather than into skeleton. ‘Leccino’ had high vigor. The productivity of ‘Maurino’ was greater than that of ‘Arbequina’ and similar to that of ‘Leccino’. The production efficiency, calculated as the quantity of product per unit of leaf surface area or trunk section area, was higher in ‘Maurino’ than in the other two cultivars. The greater production efficiency of ‘Maurino’ could be the result of greater net photosynthesis per unit of leaf surface area and better distribution of light into the canopy, due to less empty space in the canopy compared to ‘Arbequina’ and even less in comparison to ‘Leccino’. Although ‘Maurino’ has a LAI that is greater than that of ‘Leccino’, it has better illumination within the canopy that is attributable, only in part, to the smaller canopy size. The satisfactory response of ‘Maurino’ to the wall-training system will be of great interest if these initial findings are confirmed in the next years.