CONTROLLING THE SHOOT GROWTH AND CROPPING OF SWEET CHERRY TREES USING ROOT PRUNING OR ROOT RESTRICTION TECHNIQUES

Planting 'Sunburst' sweet cherry trees grafted on 'Colt' rootstock with their roots restricted by a membrane reduced shoot growth by 80% to 94%, compared with unrestricted controls. Floral bud density (numbers of floral buds formed per meter shoot length) and fruit set efficiency (final set/100 floral buds) were increased. No significant reductions in fruit size were recorded for trickle-irrigated root-restricted trees. Root pruning young 'Sunburst'/'Colt' trees, either at full bloom or in the early autumn, reduced shoot growth less severely (by up to 65%) than did root restriction. Root pruning treatments had no consistent effects on floral bud production, fruit set or fruit size.