Recording Leaf Movements with a Strain Gauge

Abstract

IN our pilot studies concerning the effect of space environments on the circadian leaf movements, we have devised a small lightweight leaf movement recording system using a strain gauge coupled to an amplifier and a recorder. The need for such a system was dictated by the physical limitations of an orbiting capsule. We have also found that such a system is useful for earthbound experiments. The small size of the sensing unit makes it possible to place several units on a single plant. The monitored plant can easily be placed in a small control chamber and continuous records of several weeks' duration can be obtained when the movements are recorded on a strip chart recorder.