1967 年 29 巻 3 号 p. 137-142
Some physical properties of rice plant during milk ripe stage as related to machine design or farm work were investigated. Tests were made on normal plants selected from five plots, consisting of ordinary, glutinous rice variety, heavy fertilizer, dense planting and bordering plants. The loads to obtain the value of bending, compressive and tensile stress were applied at the center of the 3rd or the 4th internode from the apex of the culm. The apparatus used to apply and measure loads was the tensile tester “Tensilon” and penoscillograph. The results were as follows:
1) The average bending stress values were differed according to the measuring internode and the plot. Comparing the values obtained from each plot, the bordering plot was the maximum and the glutinous rice plot was the minimum. The significant differences among other plots were not indicated by their value. The stress values from the 3rd internode were larger than those from the 4th one.
2) The compressive stress values from the 3rd internode were larger than those of the 4th one, except for the ordinary plot but the stress characteristic of each plot was not indicated.
3) The maximum tensile stress was obtained from the glutinous rice plot. No significant differences obtained from the remaining plots.
4) There was a deep relationship between the degree of lodging and the bending stress value. The larger the value the smaller the degree of lodging.