ニワウメ及びユスラウメ台がモモ‘大久保’の矮化に及ぼす効果

Abstract

Growth characteristics of ‘Ohkubo’ peach trees grafted on P. persica (wild form, vigorous), P. japonica (dwarfing) and P. tomentosa (dwarfing) rootstocks were investigated for 4 years after grafting. All trees were trained to a slender spindle type. Tree height, trunk diameter and annual shoot growth were smaller in the trees on P. japonica and P. tomentosa than P. persica rootstocks. Many flower budswere formed in the first three years in the dwarfing rootstocks, compared with P. persica rootstocks. This indicates precosity of the trees on the dwarfing rootstocks. Fruit maturation was accelerated and soluble solids content in the fruit was high in the dwarfing rootstocks. Fruit size at harvest was largest in P. persica, followed by P. tomentosa and P. japonica rootstocks. This is mainly due to over-loaded fruit of the trees on the dwarfing rootstocks. Practices such as thinning, picking and pruning could be accomplished from the ground and the amount of shoots pruned per tree was small in the plots of dwarfing rootstocks. Root distribution of the dwarfing rootstocks was confined to small rhizospheres, where P. tomentosa roots were more likely to extend shallow than P. japonica roots. Many suckers were formed from P. japonica rootstocks.