2018 ASHS Annual Conference

Food safety, environmental impact, and efficient energy usage are growing concerns in horticultural production systems. Producing chili pepper under artificial lighting could be a solution addressing these concerns. Light-emitting diodes (LED) offer the advantages of a narrow light spectrum, low power consumption, and little heat production. The objective of this study was to compare the effects of LED and fluorescent light on the growth of young Hawaiian chili pepper plants in a noncirculating hydroponic system. Chili pepper (Capsicum fruitescens 'Hawaiian') seeds were started in Oasis cubes under T5 high output fluorescent lighting in the lab. Seedlings were then transferred to 5.1-cm net pots, which were placed in 1.9-liter containers containing a hydroponic nutrient solution of Hydro-Gardens' Chem-Gro lettuce formula 8-15-36 hydroponic fertilizer with added calcium nitrate (19% Ca and 15.5% N) and magnesium sulfate (9.8% Mg and 12.9% SO₄). Half of the seedlings were grown under red+blue+white LEDs (110 µmol/m²/s, 12-hr photoperiod) and half under T5 high output fluorescent lighting (111 µmol/m²/s, 12-h photoperiod). At the end of the study, differences among treatments were significant for plant height and stem diameter. Fluorescent lighting resulted in greater plant height, whereas LED lighting resulted in greater stem diameter. There were no significant differences among treatments for leaf chlorophyll content, leaf dry weight, stem dry weight, root dry weight, total plant dry weight, percent dry weight partitioned to the leaves, percent dry weight partitioned to the stems, percent dry weight partitioned to the roots, and shoot-root ratio. In conclusion, LED lighting could be an alternative to fluorescent lighting for young Hawaiian chili pepper plants.