On the specific differences of the growth of fruit trees planted in the different amounts of soil

Abstract

One-year-old trees of nine fruit species were planted in each pot with 45.0, 15.0 and 4.3kg of soils respectively, and their growth was measured based on the shoot length and fresh weight of a tree after 2 years.
1. The less the amount of soil per tree, the more inferior the growth was in most of fruit species. The trend was marked with peaches, figs and grapes, followed by walnuts, loquats, apples and pears in the order. However, the result was sorpewhat different with citrus trees and Japanese persimmons, the growth being most superior in the 15.0kg treatment.
2. With lowering amount of soil per tree, the root density in the soil increased greatly, as if this might be one of causes for retarding growth. However, this relation could not account fof the specific differences of the growth induced by the reduced amount of soil. It is only evident that the growth of citrus trees and Japanese persimmons which was not so much influenced even in the 4.3kg treatment was generally very slow, and the growth retarding function of their root-excretions was very weak as reported in the previous paper.