WORK HOURS AND YIELD FOR LARGE-SCALE TOMATO PRODUCTION IN JAPAN

For economically successful greenhouse management, it's necessary to under-stand and optimize the factors that influence productivity. Work hours and yield are the main elements of productivity. Since the 2000s, greenhouses larger than 1 ha have become popular in Japan. For tomato production, the high-wire training system was introduced. However, the work times and productivities of this system are not yet known. We calculated work hours and tomato yield in a 2-ha commercial greenhouse in Aichi Prefecture. The tomato cultivar ‘Momotaro Haruka’ was grown using the high-wire training system. To measure work hours, one 50-m-long aisle between the beds was recorded on a networked camera, and images of workers were taken at 10-s intervals. The observations began in October 2007 and continued for 27 months. Images were checked by eye. Work activities and their frequency were determined from the images. We defined eight work activities from the images. The annual work time averaged 11,293 h/ha. The longest work activity was working on a raised plat-form, which accounted for 35% of the total, followed by harvesting (31%). Optimizing these activities would therefore decrease total labor requirements. The annual yield averaged 228 t/ha. In all years, monthly yield decreased during the winter. The yield fluctuation complicated management of the work by changing the quantity of workers required. Some activities were excessive and did not increase yield. It will therefore be necessary to rationalize the distribution of the work activities.