Development of a Movable Bench System for Strawberries and the Potential for Plant Growth Measurement

Abstract A circulating-type movable bench system was installed in a research greenhouse in Miyagi Prefecture. The system is 13.5 m long and 7.7 m wide, and chiefly comprises two longitudinal conveying units, two lateral conveying units, two nutrient supply units, a chemical sprayer, 52 planting benches, and a control unit. The cycle times for each speed mode of lateral convey mode were 44.5 s at low speed, 28.8 s at medium speed, and 23.8 s at high speed. The waiting time can be shortened in high speed mode. A prototype of a plant growth measurement system was then developed in a laboratory to estimate plant height and width using a motion control sensor to capture an RGB image and depth image when the bench passed it. Our results suggest fixed-position observation using the movable bench system to be feasible, although further work will be needed to clarify the accuracy of measurement and the relationship between analysed image data and plant condition.