Non-invasive monitoring of electrical parameters of Schefflera arboricola leaf

Non-invasive 10 GHz microwave sensor and capacitive sensors were used to measure the electromagnetic properties of Schefflera arboricola (a common house plant). The leaf capacitance periodically decreased by 51 pF/hr during the night and increased by 62.3 pF/hr during the day. The microwave reflection also changed periodically during the night and day. These experiments were repeated over extended period of time (4 days) with watering and drought cycles. The wet and dry phases for the measurements gave distinct signature data that can be used to devise a sensor to optimize watering of the plant.