For most fruit growers, the ideal tree is one that does not grow too vigorously, demands little labour and produces a good yield of high quality fruits every year. For Belgian apple growers, these requirements are satisfactorily met with the use of M.9 rootstocks. However, there are conditions that demand trees with less vigour, between M.9 and M.27. One way to achieve this is the use of M.27 as an interstock, in the hope that the advantages of M.9 and M.27 will be found in the interstock tree. However, in practice this does not seem to be the case. A second possibility is the use of an alternative rootstock. Because of its higher productivity and lesser vigour, Bud 146 is thought to be the most promising to replace M.9. The reduced colour of the apples from trees on this rootstock is, however, an important handicap, which can quite probably be overcome by paying more attention to thinning. Other rootstocks, such as Ottawa 3, P22, Bud 9, J.TE.E, J.TE.F and J.TE.G and PiAu916 and PiAu733 are no match for M.9. Another rootstock with possibilities is P16, but as yet the experience with this rootstock is still too limited in Belgium to recommend it at this stage. Overall, we can state that M.9 is still a good rootstock. Up to now, we have not found a better rootstock in our trials. Where the vigour of M.9 is too strong, one could consider planting higher above soil level or using less vigorous selections of M.9.