Influence of continuous and pulsed light on the yield and phytochemical composition of Capsicum annuum L. cv. 'Padrón'.

Background: Sweet pepper (Capsicum annuum) is of considerable socio-economic importance and is among the most widely cultivated vegetables worldwide, occupying more than 20 000 km. Light-emitting diodes (LEDs), applied in continuous or pulsed modes, can increase yield and improve the phytochemical composition in indoor production systems. However, effective methodologies to define the optimal LED spectrum for maximizing growth across the full cultivation cycle - from seedling to fruit production - under controlled photoperiod conditions (14 h light/10 h dark) with pulsed lighting are lacking.

Results: Pepper crop performance was determined by seedling stem thickness, fruit fresh weight at harvest, and biomass development during the production stage. This was complemented by phytochemical analysis of the fruits (e.g., cinnamic acid derivatives and flavonoids). Full-spectrum LED lighting and pulsed light enhanced growth parameters in seedlings, increased phenol and flavonoid content in fruit, and improved photosynthetic activity in mature plants. In contrast, fruit yield (g per plant) and antioxidant capacity (FRAP) were significantly higher under a simple blue + red LED treatment.

Conclusion: The use of full-spectrum LED lights enhanced the growth and quality of seedling pepper plants, potentially providing a competitive edge in the market. Simple LED spectra can yield more fruit and antioxidants, whereas complete spectra can boost bioactive compounds. Pulsed light lamps can result in reduced energy costs of production, which would also benefit the profitability and sustainability of the system. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.