On-line Sensor Pendulum-Meter for Determination of Plant Mass

A vehicle-based mechanical sensor (pendulum-meter) was developed to measure the plant mass of crops. For testing under defined conditions, a dynamometer with pendulum-meter, sensory and electronic equipment was developed. The ability and accuracy of the sensor for measuring plant mass in different crops (winter wheat, winter rye, grass, rice) and different growth stages are discussed in this paper. Parameter trials were done for optimising pendulum parameters. The correlations between plant mass and pendulum angle measurements were good (r² < 0.89) for all pendulum parameters, with no significant differences between suitable parameters. The speed of the pendulum-meter causes a linear increase of the measured pendulum angle. The pendulum-meter is of simple construction.