Novel Approach of Using LEDs to Grow Indoor Lettuce Hydroponically

A perennial shrub with green leaves, lettuce is a member of the Asteraceae family, which also includes daisies. Due to this vegetable's great nutritional content, novel growing techniques are urgently needed. Instead of India, it is mainly discovered and consumed in China and the United States. Since lettuce is a winter crop, it thrives at temperatures between 15–20 °C and 6–8 h of daily sunlight. India is a tropical country, so the climate is not ideal for lettuce to grow to the desired extent every year. The use of Light Emitting Diodes (LEDs), a non-thermal source of energy, and hydroponically propagating it are two ways to address this issue without compromising the food's nutritional value. The prior state of the art mentions the hydroponic growing of lettuce with different light wavelengths and intensities (i) Red light (620-750 nm) aids in growth, biomass accumulation, promotes photosynthesis and anthocynin accumulation in leaf, as well as an increase in phenolic content, (ii) Exposure to blue light (460–495 nm) promotes photo-morphogenesis and regulates the stomata's ability to function and produce anthocyanins; (iii) exposure to green light (495.4–570.7 nm) governs leaf expansion, stem stretching, and stomatal conductance. As nutrients and antioxidants are retained by the use of organic or inorganic nutrient solutions in lettuce grown hydroponically, lettuce grown under LED light irradiation yields a higher number of leaves with a healthy appearance, leaf area, and it is not very different from naturally grown lettuce. Thus this field of research reveals that LED lighting is advantageous and suited for lettuce production in every season. The quality of lettuce can be customized by selecting the right LED light intensity and wavelength, which results in great nutritional facts regardless of season. Lettuce, cultivated under the irradiation of LED light yields higher number of leaves with healthy appearance, leaf area and it is not very unlike from naturally grown lettuce as nutrients and antioxidants are retained by the use of organic or inorganic nutrient solutions in which lettuce is grown hydroponically. Hence, LED lightning is beneficial and suitable for production of lettuce every season, quality of lettuce can be tuned by appropriate selection of LED light intensity and wavelength, thereby offering great nutritional values irrespective of season is the outcome of this research.