Modern fruit production demands productivity increases, but finds restrictions in the increase of the planted areas. For the culture of the apple tree, productivity increases can be obtained using high density planting systems. The use of the interstock technique in the culture of the apple tree proposes the benefits of two rootstocks: 'Marubakaido' with sufficient anchorage and resistant to the Eriossoma lanigerum and rootstock EM9, vigour reduction and highly productive. The study was developed in the commercial nursery of Randon Agro Silvo Pastoril S.A. (RASIP), located in the municipal district of Vacaria, Brazil. The aim was to evaluate the vegetative development of the apple tree of the cultivar 'Imperial Gala' interstocked with EM9 on the rootstock. The treatments consisted of five interstock lengths: 10, 15, 20, 25 and 30 cm. In the fifth year of implantation the following were valuated: the diameter of the trunk of the interstock 5 cm above the first graft point, the diameter of the trunk of the 'Imperial Gala' 5 cm above the second graft point, the height of the plant, the volume of the tree-head (height, width and length), and the number of fruits per lineal centimetre of branch. For the first four analysed parameters, a similar effect of the different interstock lengths was observed, in other words, with the increase of the length of the interstock a reduction of the vigour of the plants took place. For the parameter number of fruits per lineal centimetre of branch, the behaviour was contrary to the increase of number of fruits increasing the length of the interstock. This situation characterizes the obtaining of a plant adapted to plantings in medium and high densities. In agreement with this study, the use of the interstock technique allows to gather the benefits of the rootstock 'Marubakaido' and to control excessive vigour with the interstock EM9.