Development of three-dimensional shape measurement technology for strawberries

Temperature control, fertilization management, and long-day treatments are performed to achieve optimal strawberry (Fragaria × ananassa Duch.) growth control. To date, the efficiency of the control of these parameters relies on visual assessment by the producers who evaluate the plants' status, or on growth surveys performed weekly. Therefore, to perform stable advanced production control, even for less-experienced producers, it is necessary to monitor the growth data of the plant continuously. In this study, we acquired strawberry growth data such as plant height and leaf area using Kinect for Windows v1, a three-dimensional shape measurement instrument, and examined whether it could be used for cultivation management. Kinect accurately measured the height of the strawberry plant. The leaf area measured using Kinect was smaller than the actual measured value. Kinect and environmental measurement equipment that were set up in a large-scale horticultural facility detected variations in growth of strawberry plants and environment data. At each measured location, there was a difference in the amount of solar radiation, and differences in plant height and the layered structure of the leaf area were detected. The results indicate that Kinect can acquire information regarding strawberry growth that are necessary for environmental control over time and may detect variation in strawberry growth due to environmental differences in the greenhouse.