Physiological behaviour of some subtropical species in Mediterranean area

In the last years a diffusion of tropical and subtropical crops in areas climatically similar as the Mediterranean one has been observed. The eco-physiological evaluation is important to understand the possibility of acclimatizing and diffusion. The species observed were avocado (Persea americana Mill.), cherimoya (Annona cherimola Mill.) and feijoa (Feijoa sellowiana Berg.) cultivated in a coastal area of East Sicily. Gas exchanges were measured on the leaves in situ at sunlight to determine CER (CO2 exchange rate) and in darkness to determine the respiration rate, and gross photosynthesis was calculated. In Sicilian climatic conditions the highest CER and gross photosynthesis were observed on avocado leaves and the lowest in feijoa. Moreover, the latter showed markedly the lowest WUE (Water Use Efficiency) and the highest stomatal conductance. The observed carbon net balances showed that avocado had the lowest CO2 respiratory release, while feijoa the highest.