Blue-enriched LED light stimulates flowering in aeroponic Matricaria chamomilla

Abstract

The indoor cultivation of Matricaria chamomilla represents a promising strategy for optimizing medicinal plant production. This research evaluated the effects of LED spectral composition on the morphological and biochemical development of chamomile in an aeroponic system. Three light treatments were applied: Red predominant + Far-red + Blue (Rh + FR + B), Blue predominant + Red + Far-red (Bh + R + FR), and Red + Blue (R + B), with a photosynthetic photon flux density (PPFD) of 255.96 ± 5.8 µmol m−2 s−1. Seedlings were germinated under controlled conditions and later transferred to an aeroponic system with mist irrigation. The treatment Bh + R + FR significantly enhanced flowering, increasing flower and bud production, floral head diameter, and petal length. In contrast, R + B promoted higher chlorophyll accumulation and nitrogen balance index, favoring greater leaf expansion, particularly in pinna length. Although anthocyanin and flavonoid concentrations increased over time in all treatments, their accumulation was not significantly affected by spectral composition. These findings highlight that optimizing chamomile flower production requires a higher proportion of blue light, while a balanced red-to-blue ratio is more effective for maximizing leaf development. This study provides new insights into spectral optimization for controlled M. chamomilla cultivation, supporting its application in the medicinal and aromatic plant industry.