Crop canopy measurement using laser and ultrasonic sensing integration

Abstract. In-season sensing of crop architectonics is important in identifying and preventing potential stresses as well as optimizing crop management logistics. Measurements of chlorophyll content, size and density of the canopy, and/or its temperature have been used as primary in situ diagnostic tools. The goal of this paper is to report on the development of a prototype sensor system that integrates both laser and ultrasonic proximity measurement components in order to identify a crop canopy scanning approach that could be embedded in a portable, low-cost instrument for green vegetable production. The system involves circular scanning of crop canopies to identify fresh biomass under different soil and management conditions. In greenhouse environment an experiment was conducted with kale and lettuce, where R² values were found between 0.74 and 0.93, and mean percentage errors between 4% and 10%. Proper use of this technology will allow farm managers to better plan harvest and shipment schedules under variable plant growth dynamics.