Abstract
1. The growth and fruiting behavior of Satsuma orange trees planted on the various soils originated from different rocks were compared over 9 years from 1957 to ′65. In June, 1957, a 4-year-old treewas planted in each concrete frame of 3.3 square meters in area and 1.2 meters in depth. Soils examined were collected from citrus raising areas in Ehime Pref., and the origins of them were as follows:
Sekizen soil: Paleozoic graywacke and lime stone
Futami soil: Chlorite schist
Ohira soil: Biotite andesite
Yoshida soil: Mesozoic sand stone
Ono soil: Diluvial
Idai soil: Granodiorite
2. Judging from the result of trunk enlargement, Satsuma orange on Sekizen soil showed best growth, following that on Futami soil, and Ohira or Yoshida and Ono or Idai soils in the order. The trees on Sekizen and Futami soil produced much fruits than that on Ono and Idai soil. High significant correlation (r=+0.90) was found between the total yield for 7 years and trunk diameter in 10th year.
3. The qualities of fruits were investigated for 4 years from 6th to 9th year after planting. Matured fruits on Idai soil which colored early showed light orange, and those on Sekizen soil which colored remarkably late showed yellowish-orange. The coloring of fruits on Ono soil showed the tendency of some delaying. The fruits on Futami and Ohira soil colored deeply at the maturity. Those on soils other the above varied the tone of color year by year.
4. In the brix and soluble solids in juice, no difference was observed among fruits on 6 kinds of soil in 1962 and ′63. However, in 1964 and ′65, the contents were high in fruits on Ohira and Futami soil, medium on Sekizen, Yoshida and Ono soil, and low on Idai soil. The content of acid (as citric) in juice throughout the years was high in fruits on Ohira and Futami soil, medium on Sekizen. Yoshida and Ono soil, and markedly low on Idai soil.
5. In the investigation on the three different orchards, whose soils derived from sand stone, chlorite schist and biotite andesite respectively, Satsuma orange showed noticeable differences in the growth of trees, and the yield and qualities of fruits among them, alike the above results in frame experiment.
