Olive (Olea europaea L.) is one of the fruit trees which becomes important in the Iranian fruit industry at the near future. It seems that olive tree has potential for resistance to drought conditions of semi-arid regions of Iran. So, there is a high production potential for olive tree in many regions of Iran. In this regard a substantial amount of suitable and vigorous rooted cuttings are essential for establishing new olive orchards. This experiment was conducted to study the effect of water stress and deficit irrigation on growth of young olive plants cv. 'Local Roghani Roodbar'. The amount of irrigation water on vegetative growth of two years old olive plants cv. 'Local-Roghani Roodbar' was evaluated. Treatments were 20, 40, 60, 80 and 100% evapotranspiration (ETc). Generally root, leaf and shoot fresh and dry weight, leaf area, leaf number, plant height, shoot number, shoot length and mineral content showed a good correlation with the amount of applied water. The differences between treatments were significantly different in various measured characters. Plants receiving 20 and 40% ETc showed no increase in their vegetative growth. Plant growth was increased with the other treatments (60, 80 and 100% ETc), although this increase in growth was higher in 80 and 100% ETc treatments. In conclusion plants receiving 80 and 100% ETc. showed better performance than in the other treatments. In addition, plant responses to treatments were correlated with duration of growing season.
