Abstract
In this paper, the author gives the relative stem curve of Sugi in Kyoto, Oita and Obi districts based on the experimental materials which were used in the author's previous report in this journal.
(1) For the higher part of the stem than one-tenth of the total height from the ground, the series of the normal form quotients in each grade of η0.5 were obtained from the following regression equations:
η0.7=0.467+0.547η0.5
η0.3=-0.142+0.931η0.5
η0.1=-0.196+0.570η0.5
(2) With the same value of η0.5, the series of the normal form quotients of Sugi had not so large difference among districts.
(3) The formula: y=ax+bx2+cx3 was regarded to give an accurate estimation of the series of the normal form quotients of Sugi. Therefore, the author gave the relative stem curve as the regressional one of this formula.
(4) For the lower part of the stem under the influence of the butt swelling, the regression equations were as follows:
η0.91=1.023-0.0235η0.5
η0.92=1.047-0.0483η0.5
η0.93=1.098-0.1085η0.5
η0.94=1.112-0.1124η0.5
η0.95=1.168-0.1673η0.5
(5) From the fact that the HOHENADL'S form quotient exists on the relative stem curve, the author gave it as the variable which depends on η0.5 and the relative length from tip to breast height.
