IoT of melon plant continuous diagnostic technique using an open chamber system measurement for photosynthesis and transpiration

Faculty of Agricultural Production and Management, Shizuoka Professional University of Agriculture, Japan

^* Corresponding author: sato.nobuyuki@spua.ac.jp

Abstract

Greenhouse growers can utilize techniques to measure the condition of crops, such as growth rate and wilting degree, in addition to environmental information such as temperature, humidity, and solar radiation. These measurements can serve as supplementary data for cultivation management decisions. Among them, photosynthetic rate is a crucial indicator for crop productivity and yield. In this study, we aimed to develop a system that continuously measures the photosynthetic rate, an essential factor in crop biomass production, using an open chamber methodwithin a melon cultivation greenhouse. The measured data is uploaded to thecloud, enabling real-time monitoring of melon photosynthesis throughout the cultivation process. The developed system was implemented at a low cost by utilizing a CO₂ sensor, a singleboard microcontroller, and a cloudbased database service. With this system, the net photosynthetic rate and transpiration rate of melon plants could be continuously measured over an extended period and accessed anytime using a PC or smartphone. Additionally, concurrent measurements of melon plant weight and fruit weight allowed for visualizing the plant’s response to environmental factors, including changes in photosynthesis and transpiration rates due to weather conditions.