Olive tree growth dynamics under semi-arid conditions of AlHaouz region in Morocco

The growth dynamics of olive-tree branch and fruit was investigated. this paper concerned the growth in length of the branch,the extension,the rate and the rhythm of appearance of leaves on its apex; we also investigated the growth of the olive fruit in terms of weight,dry matter and volume. the objective was to simulate the growth dynamics by characterizing the olive tree functioning under climatic conditions of alhaouz region (marrakech,morocco). the obtained results showed that the growth of the branch,the rate and the rhythm of appearance of the leaves vary in a quasi linear way with time. the average observed rate of linear growth of the branch was 0.3 cm/d and the development of the leaves on the apex was approximately made with a plastochron of 5 to 6 days. the period of growth coincides with that of the appearance of the leaves on the apex and lasts 110 days. measurements of the leaves surface s and dimensions (maximum width,w and length,l) carried out on 70 leaves (with variable sizes),made it possible to obtain the adjustment of an equation like montgomery's one that was on the form s=0.71×w×l (r2=0.98). we also adjusted a relation between the volume of the fruit and its dimensions. the growth in weight or volume of the fruit and the accumulation of its dry matter vary in a linear way in two phases (fast phase which lasts 80 days followed by a relatively slow phase which lasts 120 days). this break in the growth dynamics of the fruit can be due to the high thermal gradients which undergoes by olive trees during july and august. regarding the olive fruit,our observations show that during all the growth season,its content of dry matter and its density remain constant (34% for the dry matter and 1.05 g/cm3 for the density).