CHERRY ROOTSTOCK EVALUATION AT EAST MALLING

The sweet cherry cultivars 'Van' and 'Merton Glory', grown on German Weiroot 10 and Weiroot 13 rootstocks, showed no incompatibility, were slightly smaller in size, much more productive but were less well anchored than trees on Colt. Trees on the Belgian Inmil and Damil rootstock clones, grown without supplementary irrigation, were much smaller in stature and less productive than trees on Colt. Several rootstock selections bred at the Justus Liebig University, Giessen, Germany are of similar or less vigour than Colt and induce excellent sweet cherry scion productivity; clone 148/1 has proved particularly promising. Using in vitro techniques and colchicine, hexaploid clones of the normally triploid Colt rootstock have been produced. The sweet cherry 'Merchant' has grown less vigorously on hexaploid than on triploid clones.