Vegetative Propagation of Six Pachyphytum Species as Influenced by Different LED Light Qualities

Abstract

Pachyphytum, a slow-growing succulent genus, is considered a high-value ornamental plant in high demand as a potted plant. To facilitate and enhance its vegetative propagation, different light-emitting diode (LED) light qualities were used on leaf cuttings. Different light spectrum qualities, i.e., red (peak at 630 nm), blue (peak at 450 nm), purple (peaks at 450 and 650 nm), 3000 K white LED (peaks at 455 and 600 nm), 4100 K white LED (peaks at 455 and 590 nm), and 6500 K white LED (peaks at 450 and 545 nm), were used as treatments for six Pachyphytum species or cultivar, specifically P. compactum, P. glutinicaule, P. machucae, P. oviferum, P. viride, and P. cv. Oviride (P. oviferum × P. viride). The results of this study suggest that the different light qualities studied here significantly affected the growth and development of the Pachyphytum species. The use of blue and 6500 K white LED lights increased survival rates, rooting, and shooting success, while the use of white lights significantly improved shoot and root growth as well as the corresponding fresh and dry weights. However, in terms of the percentage moisture content, the effects of monochromatic red and blue lights, as well as the composite spectral distribution of purple light, were significantly higher compared to the effect of white light. The improvement in root growth and development, and the fresh and dry weights of Pachyphytum species under different light spectra are evidence that the effects of the light quality vary among plant species even when they belong to the same genus. Similarly, the use of different light qualities may be beneficial at certain growth stages for leaf cuttings to promote the optimal development of plant organs. The results of this study provide improved vegetative propagation techniques for Pachyphytum species and other slow-growing succulents propagated through leaf cuttings.

Evaluation of Growth, Flowering, and Chlorophyll Fluorescence Responses of <italic>Viola cornuta</italic> cv. Penny Red Wing according to Spectral Power Distributions

“…Based on this, it seems that 'Penny Red Wing' was able to accumulate more carbohydrates in the shoots since the plant size increase caused by the far-red wavelength increased the canopy size, accordingly, promoting photosynthesis. A previous study has found that Pachyphytum viride has a relatively higher DW under purple LED than under 3000-6500 K white LEDs (Lee and Nam, 2023d), which is in line with the results of this study. Shoot biomass seems to be more affected by far-red wavelength than by green ones, which is similar to the findings for the shoot sizes.…”

“…More diverse experimental approaches seem to be necessary, as the optimum light quality that can improve growth and external quality depends on the species. Lee and Nam (2023d) reported that purple LED used for the propagation of Pachyphytum viride through leaf cuttings were most effective in increasing its biomass and root length. On the other hand, Xie et al (2022) reported that the use of purple LED delayed the yellowing of broccoli (Brassica oleracea var.…”

Biomass and Ginsenosides Content of Ginseng Sprouts upon Exposure to Several White LED Lights with Different Correlated Color Temperatures and Color Rendering Indexes

“…Most studies of lighting systems focusing on vertical farms are investigations of the plant morphology, crop yield and quality under various LED-based combinations red and/or blue and/or green light (Shimizu et al, 2011;Kim and You, 2013;Son et al, 2016a;Si et al, 2024). In addition, white LED have been widely used in both research and commercial vertical farms in recent years given that their broad spectrum can promote crop growth and better yields, with phosphor conversion technology making them easy to manufacture at a reduced cost (Yang et al, 2020;Lee and Nam, 2023).…”