Applying Internet-of-Things (IoT) technologies in agriculture not only can reduce the man efforts but also improve the productivity and the efficiency. Through the IoT technologies, one can collect various data like luminosity, temperature, humidity, PH value, etc to analyze and control the facilities. In this study, we focus on exploring the application of the infra-red data on agriculture IoT systems, in addition to the design of our green-house IoT system. Through the infra-red data, we can analyze various biological data of the plants and the fruits. Based on several low-cost devices (like Raspberry pi, NoIR camera, thermal camera, various sensors), some open source platforms, and the Splunk software, we design and build an green-house IoT system that not only collects various environment data but also analyze the biological data of plants via the infra-red data. Some preliminary experiments and analysis are given in this paper. The results show that low-cost infra-red devices could have a great potential contribution to improving agriculture practice.