Development of An Automatic Growth Monitoring system for Vegetables Grown in A Plant Factory

In the intentional production of crops in a plant factory, it is necessary to measure the progress of growth of an individual plant. There is a significant positive correlation between several growth indices obtained by image processing and the top fresh weight of lettuce plants (Lactuca sativa L. non-heading type) grown in a plant factory. The horizontal projected leaf area for several days after sowing made it possible to estimate the top fresh weight. Therefore, we have developed an automatic plant growth monitoring system for vegetables grown in a plant factory. This system is organized into five parts, CCD camera with a transfer mechanism, a personal computer for image processing CPU, a image memory unit, a TV monitor and a printer. To evaluate the growth of transplants individually, we have developed growth prediction function with fuzzy inference. Using this function, the growth of lettuce plants grown in a plant factory was estimated continuously and automatically by use of a low-cost automatic plant growth monitoring system with a personal computer.