Abstract
In the present paper, as a part of studies on forage roots and physical properties of grassland soil, I deal with the factors which are related to root tensile strength for forage grasses. In this examination, Italian ryegrass (Lolium multiflorum LAM.) was used. The results obtained are as follows ; (1) There was no significant difference between the external diameter of adventitious root and the root tensile strength. (2) It had not come out clear also that the correlation between the diameter of central cylinder which was a part of root texture and the root tensile strength. (3) Crude fiber content of root wa about 30 percent and it's value made little difference at each growth stage. This result was not consistent with the tensile strength which increased with the growth of grasses. (4) Central cylinder of root took a lignin. This lignification was proceeding with the growth of grasses. (5) It was recognized that the degree of lignification was proportional to the tensile strength of root. (6) It had been suggested that lignification of roots was a main factor for the tensile strength.
