Force Distribution Measurement of Plant Root Growth Using Gel Medium Embedded with Phosphorescent Beads and Sampling Moiré Method

This study presents a sensor system for measuring plant root force distributions during root growth. A translucent agar gel embedded with a grid of phosphorescent beads was used as a sensor device. The displacement distribution can be measured by photographing the subtle displacement of the beads as roots grow. Time-lapse photography over a 3-day period were performed with radish sprout in this experiment. Then, the sampling moiré method was used for analysis of the displacement distributions. The force vector distributions were estimated by Hooke's law, revealing a maximum force of approximately 0.2 N. The sensor system correlates measured forces with actual root geometries, demonstrating its capability of estimating force distribution during plant root growth.