Jeong-Wook Heo

Effect of Light-Quality Control on Growth of Ledebouriella seseloides Grown in Plant Factory of an Artificial Light Type

Abstract BACKGROUND: Plant factory system of an artificial light type using Light-Emitting Diodes (LEDs), fluorescent light, or metal halide lamp instead of sun light is an ultimated method for plant production without any pesticides regardless of seasonal changes. The plant factory is also completely isolated from outside environmental conditions such as a light, temperature, or humidity compared to conventional greenhouse. Light-environment control such as a quality or quantity in the plant factory system is essential for improving the growth and development of plant species. However, there was little report that the effects of various light qualities provided by LEDs on Ledebouriella seseloides growth under the plant factory system. METHODS AND RESULTS: Ledebouriella seseloides seedlings transplanted at urethane sponge were grown in the plant factory system of a horizontal type with LED artificial lights for 90 days. Yamazaki solution for hydroponic culture of the seedlings was regularly irrigated by the deep flow technique (DFT) system on the culture gutters. Electrical Conductivity (EC) and pH of the solution was recorded at 1.4 ds/m and 5.8 in average, respectively during the experimental period. Number of unfolded leaves, leaf length, shoot fresh and dry weight of the seedlings were three times measured in every 30 days after beginning of the experiment. Blue LEDs, red LEDs, and fluorescent lights inside the plant factory were used as light sources. Conventional fluorescent lamps were considered as a control. In all the treatment, light intensity was maintained at 100 μmol/m

Effects of Artificial Light Sources on Growth and Glucosinolate Contents of Hydroponically Grown Kale in Plant Factory

This study was carried out to investigate the effects of artificial light sources on growth, yield, and glucosinolate content of hydoroponically grown Peucedanum japonicum in plant factory. Treatments were given with LED Blue:White(1:1, B:W), LED Red:Blue:White(2:1:3, RBW), and LED Blue:White(1:1)+Florescent lamp(BW+FL). Number of harvested leaves and leaf weight of BW+FL were higher than BW and RBW. BW+FL in leaf length and RBW in leaf width were significant difference with other treatments. Chlorophyll content and ‘L’ value were not significant difference among the treatments. The ‘a’ and ‘b’ value is the lowest in BW+FL. Glucosinolate content was high in order of glucobrassicin, glucoiberin, sinigrin, gluconasturtiin, progoitrin, glucoraphamin, and epiprogoitrin in all treatments, and total glucosinolate content was the highest in RBW treatment. Moisture, crude protein, crude fat, and ash content of leaves were not different among the treatments. In conclusion, this study showed that light caused growth and secondary metabolites synthesis, and we recommend to further study between light and secondary metabolites for increasing functionality. Additional key words : chlorophyll, crude protein, fluorescent lamp, hydroponics, LED

Effect of Supplementary Radiation on Growth of Greenhouse-Grown Kales

Abstract BACKGROUND: For commercial production of greenhouse crops under shorter day length condition, supplementary radiation has been usually achieved by the artificial light source with higher electric consumption such as high-pressure sodium, metal halide, or incandescent lamps. Light-Emitting Diodes (LEDs) with several characteristics, however, have been considered as a novel light source for plant production. Effects of supplementary lighting provided by the artificial light sources on growth of Kale seedlings during shorter day length were discussed in this experiment. METHODS AND RESULTS: Kale seedlings were grown under greenhouse under the three wave lamps (3 W), sodium lamps (Na), and red LEDs (peak at 630 nm) during six months, and leaf growth was observed at intervals of about 30 days after light exposure for 6 hours per day at sunrise and sunset. Photosynthetic photon flux (PPF) of supplementary red LEDs on the plant canopy was maintained at 0.1 (RL), 0.6 (RM), and 1.2 (RH) μmol/m

Research-platform Design for the Korean Smart Greenhouse Based on Cloud Computing

This study was performed to review the domestic and international smart farm service model based on the convergence of agriculture and information & communication technology and derived various factors needed to improve the Korean smart greenhouse. Studies on modelling of crop growth environment in domestic smart farms were limited. And it took a lot of time to build research infrastructure. The cloud-based research platform as an alternative is needed. This platform can provide an infrastructure for comprehensive data storage and analysis as it manages the growth model of cloud-based integrated data, growth environment model, actuators control model, and farm management as well as knowledge-based expert systems and farm dashboard. Therefore, the cloud-based research platform can be applied as to quantify the relationships among various factors, such as the growth environment of crops, productivity, and actuators control. In addition, it will enable researchers to analyze quantitatively the growth environment model of crops, plants, and growth by utilizing big data, machine learning, and artificial intelligences. Additional key words : agricultural information & communication technology(ICT), artificial intelligence(AI), big data, decision-making support service, smart farm

Colors and Sizes of Insect Screen Net Influence Physical Control of Bemisia tabaci and Frankliniella occidentalis under Controlled Environments

BACKGROUND: The tobacco whitefly(Bemisia tabaci Gennadius) and western flower thrips(Frankliniella occidentalis Pergande) seriously damaged to several greenhouse crops and transmitted plant viruses such as the Tomato Yellow Leaf Curl Virus(TYLCV) and Tomato Spotted Wilt Virus(TSWV). Objective of this study was to elucidate exclusion effects of insect screen nets by various hole sizes and colors for control of the two insect pests in controlled environments such as a closed plant production system.METHODS AND RESULTS: The exclusion effects to various hole sizes of three other colors with 30 individuals of two insect pests was evaluated. B. tabaci was not showed not difference to different colors and sizes. F. occidentalis showed that 0.2 mm black screen was the most effective exclusion than other colors of 0.6 and 0.8 mm.CONCLUSION: The two insects were different reponses to various hole sizes of white and other color screen nets. It was proved that the 0.4 mm white screen net used in this experimental condition was suitable for exclusion of B. tabaci and 0.2 mm black forF. occidentalis.

Implementation of Greenhouse Monitoring and Control System Using a Smartphone and a Computer with Internet

Nowadays there are numerous greenhouse environmental control systems presented on the market. The network system for greenhouse control was developed by using recent technologies of networking and wireless communications. In this paper, a remote monitoring and control system for greenhouse using a smartphone and a computer with internet has been developed, and this system is capable of analyzing data and automatically saving many data. The greenhouse monitoring and control system is composed of a sensor unit, a remote terminal unit (RTU), a local server, a control panel and network cameras. The server commutes with the sensor unit and the RTU by the Zigbee communication. The RTU has AI 8ch, DI 8ch, DO 16channel. The RTU receives the environment data from the Zigbee sensor module and the signal transmitter of sensors. In addition, it sends the operating commands to each control device and receives the operating signal from it. These data can be displayed on a web page and transmitted using the server program to a computer and a smartphone. Daily-based data are saved in a DB server. In abnormal conditions, this server program sends a SMS and e-mail message to a smartphone and a computer and the users have an access in real-time via mobile phone or internet anytime and anywhere. The software is available to support a various web browser, such as. For the security, a smartphone user authentication and target system access control are included in the system developed in this study. The greenhouse environment is managed by the RTU control through the local server connected a smartphone and a computer with internet. Furthermore, all control devices in a greenhouse are remotely monitored and controlled, and they are managed via a camera installed inside of greenhouse. The findings of this study showed that the range of error for control command was within 0.2~0.5% level, which proved that the system is very precise and accurate.