Studies on the frame-work of peach tree

Abstract

It is very difficult to maintain three scaffold limbs of peach trees uniform, because the lowest one is apt to dominate over the others. This study was carried out to clarify the causes of unbalance among the limbs and to find out measures to overcome this trouble.The lowest scaffold limb was apt to become larger than the others especially when the limbs were set up leaving space between them, while when three limbs were set up nearly at the same level, the lowest one was not invariably larger than the others, and limbs tended to be relatively uniform.Recovery in the uniformity among the limbs was sometimes found on the trees planted on the deeply plowed soil, while on the trees planted on the soil not deeply plowed the lowest limb generally retained its dominance over the others.Trees with all fibrous roots removed before planting sent vigorous shoots from the lower part of trunk, while trees with fibrous roots from upper part.Observation on root growth revealed that roots of transplanted trees did not grow during two months after planting, then grew gradually, and a large amount of roots grew at the end of June. Unbalanced growth of limbs was observed since early July.Trees which were field-grafted on the seedling stocks and had tap-root, had relatively uniform scaffold limbs. In those trees, tap-root could be seen distinctly by the end of the season, but it was not distinguished in the next season, as lateralroots developed remarkably.Field grafting and deep plowing of soil may be effective measures to keep scaffold limbs of peach trees uniform in vigor, though even in these cases dominance of lower limbs sometimes observed.When trees are planted on the soil of poor conditions, it may be preferable to train the trees in such a way that the two main scaffold limbs are taken out, then two sub-scaffold limbs are set up on each main limb, forming four scaffold limbs.