A Multi-Sensor Measuring System for Plant Phenotyping.

Recent advances in plant biology greatly increased plant genotyping efficiency.  There is a great need of apparatus and methods for high-throughput plant phenotyping to dissect the genetics of quantitative traits.  A multi-sensor measuring system, which could be used in plant phenotyping, was developed and field evaluated.  The system included an optical sensor, an ultrasonic sensor, an infrared temperature sensor, a GPS receiver, and a data acquisition unit (DAQ).  The optical sensor measured plant canopy reflectance in four wavebands including blue band (400-500nm), green band (520-570nm), red band (610-710nm), and near infrared band (750-1100nm).  The ultrasonic sensor determined plant height.  The infrared temperature sensor detected plant canopy temperature.  The GPS receiver located the measurement position.  The DAQ was an intelligent device for recording the data from the multiple sensors and the GPS receiver.  The system was installed on a tractor.  The sensors were positioned facing down toward the canopy.  As the tractor travelled across a field, the sensors automatically and continuously scanned plant canopy.  Canopy spectral reflectance, plant height, and canopy temperature were measured non-intrusively.  Data from the sensors were collected along with the spatial coordinates and stored in a memory card.  The data could be downloaded from the card to a computer for data processing.  Using the data, crop spectral indices were calculated, and maps of plant canopy spectral reflectance and canopy temperature were generated using GIS software.  This system was field tested over multiple years and satisfying performance was obtained.