Artificial Lighting System Design With PWM Control For Microgreen Ipomoea reptans Poir Growth

Vertical farming uses soil-less methods, either indoors or outdoors, such as aeroponics or hydroponics. Indoor setups include insulated structures, lighting, cooling, and CO2 supply. Unlike outdoor systems that rely on sunlight, indoor farming uses a light-emitting diode (LED), incandescent, or fluorescent lamp. However, the constant light intensity of the lamps can inhibit plant growth, so a light regulation method is needed, one of which uses the PWM method. This study aims to compare the growth rate of microgreen Ipomoea reptans Poir using artificial lighting with and without regulated light intensity levels using the PWM method. PWM adjusts the brightness from 65% - 100% during the day. Analysis showed the linear effect of PWM on lamp voltage and power, also improving power efficiency from 16.3 W without PWM to 13.36 W in lamps with PWM. Comparative results showed that PWM control increased leaf area, limb length, leaf number, and wet weight in plants. Meanwhile, the root length of plants with PWM (9.68 cm) is shorter than plants without PWM (9.98 cm). Overall, plant growth with PWM control is better and more efficient.