Abstract
1. Using three-year-old fruiting Satsuma orange trees, the effects of summer soil moisture (pF 2.3, 4.0) and time of fall nitrogen application (September-, October-, November-. and Non-application) on the fruit quality and flowering in the following year were observed.
2. Coloring of fruit rind was superior in the plot of pF 2.3, and the later the time of nitrogen application, the better was coloring of the rind. On the contrary, it was markedly delayed in the plot of pF 4.0 with September application of nitrogen.
3. Contents of soluble solids and total sugars in fruit juice were higher in the plot of pF 4.0 than those of pF 2.3, and were also much higher in the trees with a delayed nitrogen application. There was no difference of citric acid content among the experimental plots.
4. The number of flowers in the following year were very great in the plot of pF 4.0, and were also increased as nitrogen was applied early. On the contrary, new shoot growth was inferior in the plot of pF 4.0.
5. The content of nitrogen in the spring leaves was increased with fall nitrogen application, especially in the plots of September and October application.
