Design and Implementation of Artificial Grow Light for Germination and Vegetative Growth

Abstract

The purpose of this research is to build artificial grow light using LED for growing leafy vegetables from germination to harvesting (vegetative growth). Plants need to capture photons as energy for photosynthesis in 400nm - 780nm spectrum. Different plant species will respond differently to specific light spectrum. Many studies have been done to find optimal light spectrum for plant growth, but there are still many researches to be done because there are still many combinations of light and plants species to be discovered. Specific light spectra combination is called light recipe. This research will help botanist to discover new light recipe for plant species by mixing 6 light spectra with individual intensity and time control. The developed grow light system has graphical user interface that run in Android tablet, and uses MQTT protocol for communication between android application and grow light system. Light recipe and setting are stored in database and the system also has light sensor to monitor light environmental conditions. Grow light consists of 6 types of 3W high power LED with specific color spectrum: Royal Blue, Deep Red, Ultraviolet, Full Spectrum, Far Red, and Natural White. Testing result shows that the system can produce uniform light distribution across the 50 x 50 cm grow area on average 22.6 μmol m-2s-1 using 60° lens. Germination result of lettuce using grow light shows good results compared to sunlight.