Effect of LED lighting on phytochemical content of lettuce plants (green coral and red coral) grown in plant factory condition

Abstract

Light is one of the most important environmental factors that affect plant growth. Lightemitting diodes (LEDs) are alternative lighting that has been shown to have the potential for plant growth and development under controlled conditions in plant factories. Plant factory production technology can increase the productivity and nutritional content of the plant. The phytochemical content of lettuce plants (Green Coral and Red Coral) grown under plant factory conditions with different spectrum LED lights (combination of red and blue LED and red, blue and green LED) were studied. The lettuce was harvested from day 20 until 35 after transplanting with an interval of five days. The result showed that the combination of red, blue and green LED lights is positive in terms of phytochemical content in both lettuce plants. Harvesting at days 30 to 35 after transplanting was effective in presenting a higher value in total chlorophyll, percentage of DPPH inhibition and reduction of total phenolic content in green Coral lettuce compared to early harvesting as it showed a highly significant difference. Besides, the chlorogenic acid content in green and red Coral presented significantly increased when harvesting was done on day 35. The combination of red, blue and green LED greatly affected chlorogenic acid content in both lettuces’ plants. Therefore, the result of the combination of LED and harvesting day might provide new information to improve the nutritional quality of lettuce plants after harvesting.