System and method for measuring plant water content and predicting water stress

A method for determining a water content of a plant, comprising:

• securing a leaf of the plant between a pair of opposing jaws of a spring-loaded clip;
• initiating a controlled heating cycle by supplying power to a heating unit disposed on one jaw of the pair of opposing jaws;
• monitoring a temperature change in the leaf using a temperature sensor disposed on another jaw of the pair of opposing jaws;
• determining whether the temperature change has reached a predefined threshold;
• discontinuing heating upon detecting that the temperature change has reached the predefined threshold;
• recording the temperature response of the leaf;
• measuring an electrical property of the leaf using an electrical sensor;
• storing the recorded temperature response and the measured electrical property and environmental data in a memory module;
• and
• analyzing the stored data to determine the water content of the plant.

A mobile robotic platform for measuring a water content of a plant, comprising:

• a mobility system configured to navigate an agricultural environment, the mobility system comprising at least one of a tracked system or a wheeled system;
• a base housing a control unit configured to process measurement data and to control platform operation;
• an articulating arm extending from the base, the articulating arm comprising one or more links interconnected by rotational joints, the articulating arm configured to position a sensing apparatus relative to a leaf of the plant;
• and
• a grasper end effector for measuring properties of the leaf, the apparatus including:
• a pair of opposing jaws, the jaws configured to receive and secure the leaf therebetween;
• a sensing unit disposed on a first jaw of the pair of opposing jaws, the sensing unit configured to measure at least one thermal and electrical property of the leaf;
• a heating unit disposed on a second jaw of the pair of opposing jaws, the heating unit configured to apply controlled heat to the leaf;
• and
• a control unit operably coupled to the sensing unit and the heating unit, the control unit configured to:
• regulate power to the heating unit to achieve a target heat application profile,
• receive data from the sensing unit corresponding to a temperature change and an electrical property of the leaf, and
• analyze the received data to determine the water content of the plant.