Abstract
Many Studies (1) have been made on the physiological diseases of rice plants caused by root rot which develops during the plant growth. The view that organic acids; accumulatted in rice paddy soil may be one of the factors impeding the function of roots began only recently to be expressed concerning the low productive paddy fidds. However, studies on the metabolism of these organic acids, especially of saturated lower fatty acids, are mostly fragmental except for a series of studies made by Takai and others (2). To deal with the problem of root injuries and diseases of rice plants, we must establish the magnitude of the organic acid production in relation to the differences in character of soils.