Caractérisation du système conducteur de l'olivier en fonction de son origine biologique.

In Tunisia, olive tree is traditionally propagated using ovules that delays fruiting period. Using herbaceous cutting allows shortening juvenile period and enhancing productivity. The present study aims to understand the hydraulic characteristics of the conducting system of the olive-tree as related to plant material origin. Experiments were carried out within an olive grove "Chemlali", 17 years old conducted in rain-fed conditions on sandy soil in the arid region of Souassi, Gouvernorate of Mahdia (center-east Tunisia) receiving an average rainfall of 250 mm per year. Olive trees were propagated either by ovules or herbaceous cuttings and planted at 14m x 14m (51 trees/ha). Comparative study was made using parameters of water status (wood density and wood relative water contents) and anatomical observations (conducting vessels, hydraulic diameter, surface of the lumen and theoretical hydraulic conductivity). The dynamic of water use by olive shoots was also studied on both olive plant types under plastic house conditions. Results showed that conducting system characteristics of olive trees issued from herbaceous cuttings permitted a good adaptation to water stress. Those of trees issued from traditional propagating method allowed, relatively, more water loss and less water absorption. [ABSTRACT FROM AUTHOR]