So called“Abnormal defoliation”of Satsuma orange was studied by sand culture method under the different levels of manganese and calcium in the nutrient solution.
The growth of young tree correlated negatively to the concentration of manganese. In these cases, it appeared that the inhibition of growth going to remarkable as the concentration of calcium become lower.
When the concentration of manganese more increased, the more roots fall into decay, and the brown spots and chlorosis were observed in leaves. At the same time, the negative correlation was found betweeen the concentration of calcium and the occurrence of these symptoms.
In the plant body, it was observed that the manganese content in fibrous roots and leaves become higher than the other parts, it seemed to accumulate in fibrous roots.
Manganese content in plant correlated with the concentration of manganese in nutrient solution. It seemed that the absorption of manganese was carried independently of the needs of plant life.
When the high level of manganese in nutrient solution, the manganese content in plant correlated negatively with the concentration of calcium in nutrient solution.
From the results mentioned above, it was concluded that the“Abnormal defoliation”of Satsuma orange may be due to the excessive absorption of manganese. And it is affected by the concentration of soluble manganese in the culture media.