RESEARCH ON DIFFERENT VIRUS FREE CLONES OF THE ROOTSTOCK M 9
Different virus free clones of the rootstock M 9 have been obtained since 1975 in the Virology Department of the Gorsem Research Station. Their behaviour is now studied in comparison with clones obtained in other countries, in stoolbed and also in commercial orchards, using different clones of M 9 grafted with the varieties Golden Delicious, Cox's Orange Pippin and Boscoop (the most cultivated varieties in Belgium). As the trials and observations only started too recently, it is impossible to give valuable conclusions before a few years.
Gilles, G.L. (1977). RESEARCH ON DIFFERENT VIRUS FREE CLONES OF THE ROOTSTOCK M 9. Acta Hortic. 75, 169-174