Abstract
T/R value is always greater in the overdamp plot than in the check plot; this inclination is slrown more remarkably with progress in growth. The growth of root-hair is rate in the overdamp plot; even in the part not lignified, the number of root-hairs is only 11 % of that of the check plot. The remarkable retardation in growth of the top appears already in the first decade of March. This may be partly due to the ill-balance of absorption surface of the above-mentioned root and microchemical ill change promoted with the rise of soil temperature, and may be due especially to lignification. As in the overdamp plot, the main root is prevented from growing, the growth of the lateral root, especially of secondary and lower orders is promoted, for its compensation, resulting in the formation of an abnormal root system.
