The main pistachio rootstocks used in Turkey are P. vera seedlings. In some places such as Sanhurfa (P. terebinthus), Siirt (P. khinjuk), and Manisa (P. atlantica), other rootstocks are used, but to a lesser extent. In all pistachio-growing regions of Turkey, irrigation is not practised, therefore, in warm and dry places, the pistachio nut yield per unit area is low as the trees come into bearing very late. The purposes of this experiment were to shorten the juvenility period of the trees, improve the quality of the nuts, increase the yield per hectare by irrigation and by using different rootstocks. This experiment was replicated in four locations of Turkey, however only the results of the K. Maras experiment are presented in this paper. In the experiment four rootstocks (P. vera, P. atlantica, P. khinjuk and P. terebinthus) and five cultivars (Sel-14, 'Siirt', 'Ohadi', 'Kerman' and 'Kalehghochi') were used. The orchard was established in April 1997 with potted seedlings of the rootstocks, which were budded in May-June 1998 with the above-mentioned cultivars. In this paper, preliminary results of rootstocks x scion interactions on the growth of scion and stem diameter, flower bud formation and fruit set were studied.