Abstract

Soilless cultivation with artificial lighting has the potential to augment vegetable crop production, particularly lettuce, but yields are lower compared to natural sunlight, especially in monochromatic light technologies. Research suggests that color blending with light-emitting diodes (LEDs) can enhance production, yet many overlook the importance of nutrient management. The use of sulfur–silica fertilizer, known for enhancing plant growth in low-light stress conditions, supports this assertion. The study employed a randomized complete block design with two factors, each repeated four times. The treatments included three LED light colors: white LED (L1), blue LED (L2), and red LED (L3). Two fertilizer treatments were applied: absence of sulfur–silica fertilizer (P1) and presence of sulfur–silica fertilizer (P2). The study finds that optimal growth of lettuce plants is achieved through the utilization of both red and white LED lights, with red LED yielding the highest fresh leaf weight. The red LED treatments outperform other LED colors in terms of protein, carbohydrate, and total energy production. Introducing sulfur–silica fertilizer can promote superior lettuce growth, albeit at the cost of reduced fresh leaf weight. The application of sulfur–silica fertilizer leads to decreased protein and carbohydrate levels but enhances the overall energy content of the lettuce.

Key words: lettuce, light emitting diodes, sulfur-silica, low light stress