Application of automatic system for water stress treatment to produce high soluble solids tomato (Solanum lycopersicum Mill. cv Rinka 409)

The objectives of this study were to confirm the application of automatic system for detecting the water stress and the compatibility of the water stress treatment system for producing high soluble solids tomato fruits in high technology greenhouse. The tomato variety used, "Rinka 409", was grown hydroponically with a high-wire system in high technology greenhouse in Faculty of Agriculture, Ehime University, Japan. The greenhouse has a full controlling system (temperature, relative humidity, carbon dioxide, and light intensity) to support the seasonal change and was adjusted to the real-time condition. Water stress condition of the tomato plant in the high technology greenhouse was detected by measuring the water content in the rockwool slab and by using visual monitoring system. The result showed that the automatically nutrient supplying system using visual monitoring system based on speaking plant approach technology could be used for the detection of water stress in the tomato plant. Using this system, water stress tomato cultivation was detected and the high soluble solids tomato fruits could be produced continuously to fulfill consumer expectation.