The Effect of Different Light Intensities and Durations on Yield Values in Lettuce (Lactuca sativa)

Lettuce ( Lactuca sativa L.) is a increasingly common vegetable for human consumption. In lettuce cultivation, light intensity (LI) and duration influence yield and quality. Energy efficiency, longevity, and application flexibility make light-emitting diodes an ideal choice for future agricultural lighting systems. Our study, conducted between Feb and Aug 2022, investigated the effect of different light intensities and durations on the growth and yield of three different lettuce species. The research was carried out for each lettuce species at trial plots with a 0.5 m 2 , 27-separate unit area. The relationships between LI and artificial lighting duration, nitrogen balance index (NBI), and yield values obtained after the harvest were evaluated statistically evaluated. Chlorophyll (Chl), flavonol (Flav), and the Chl-to-Flav ratio (or NBI) in terms of their effect on time at three levels (1st, 26th, and 38th days of harvesting) were evaluated, along with cultivar at three levels [cultivar 1 (C1), ‘Lollo Rosso’, green leaf; C2, ‘Lollo Rosso’, red leaf; and C3, ‘Paris White’, green leaf], LI at three levels of light exposure duration (165.6, 248.4, and 331.2 µmol·m –2 ·s –1 ), and photoperiod (PP) (12, 16, and 20 hours/day). In addition, LI as photosynthetic photon flux density was also investigated. According to the results, the relationships among cultivar, LI, and PP were significant.