Root Pruning Has Little Effect on Seyval, Catawba or Concord Grapevines

Abstract Mature grapevines were mechanically root pruned to a depth of 40-45 cm on two sides, 40-50 cm from the trunk. Root pruning 'Seyval blanc’ and ‘Catawba’ (Vitis sp.) at bloom and/or veraison for three years had little effect on the various components of yield or juice composition. Pruning time of ‘Catawba’ was reduced by root pruning. Root pruning vigorous ‘Concord’ vines at bloom for four years resulted in a reduction in weight of cane prunings and pruning time in one of four years. Yield/vine was reduced two of the four years due to a reduction in cluster weight. Increasing levels of soil applied nitrogen to a maximum of 134.4 kg/ha had no effect on growth or cropping of ‘Concord’. Root pruning did not control vegetative growth or improve juice composition of grapes.