In this study,we focus on the plant bioelectric potential response as a low-cost and a high sensitivity evaluation technique of plant physiological activities for an agriculture support system. We developed a cultivation light intensity control system using bioelectric potential response. This system contributes to improvement of the cultivation environment and provides energy saving effect.In addition, we introduced a field effect transistor based on silicon carbide (SiC-FET)gas sensor and evaluated the characteristics of the sensor by changing several parameters. The results showed that iridium gated SiC-FET sensor has high sensitivity to ethylene,and the highest response is achieved at 200 ◦C. We aim at the development of an agriculture support system, which combines the plant bioelectrical potential and the SiC-FET gas sensor response.