Comparison of Growth and Leaf Color Quality of <italic>Mesembryanthemum cordifolium</italic> f. <italic>variegata</italic> as Affected by Shading Levels

Abstract

Background and objective: <i>Mesembryanthemum cordifolium</i> is a plant belonging to the Aizoaceae family and is native to South Africa and Namibia. As a CAM plant, <i>M. cordifolium</i> exhibits strong resistance to drought stress and can be utilized for the removal of soil salinity and heavy metals. Furthermore, it is an important medicinal crop with anti-inflammatory and antidepressant effects. However, despite its potential benefits, research on the optimal growth environment for <i>M. cordifolium</i> remains scarce.Methods: Therefore, this study selected <i>M. cordifolium</i> f. <i>variegata</i> with high ornamental value as the experimental plant and compared the effects of different shading levels on the growth and leaf color quality of variegated baby sun rose (<i>M. cordifolium</i> f. <i>variegata</i>). Six shading levels (0, 35, 45, 60, 75, and 99%, respectively) were designed using polyethylene (PE) shading films.Results: The results showed that the shoot height, shoot width, dry weight, and chlorophyll content (SPAD units) were highest under the 60% shading level, while leaf length, leaf width, and fresh weight were highest under the 75% shading level. On the other hand, growth was relatively lower under the 0% shading level, which suggests that <i>M. cordifolium</i> f. <i>variegata</i> prefers shade over direct sunlight. On the contrary, <i>M. cordifolium</i> f. <i>variegata</i> showed growth even under the 99% shading level, proving to have strong shade tolerance, but the leaf color quality was lowerst.Conclusion: In conclusion, to significantly increase the size and biomass of plants and improve leaf color quality when cultivating <i>M. cordifolium</i> f. <i>variegata</i> under shading treatment, it is recommended to cultivate it under 60-75% shading levels.

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

“…CIELAB L * , a parameter indicating color lightness in the CIELAB, was high under 3000 and 4100 K white LEDs, at 41.36 and 41.33, respectively. Previous studies on day and night temperatures (Lee et al, 2023), shading levels (Lee and Nam, 2023a;Nam et al, 2022), and light quality (Lee and Nam, 2023c) reported that L * also in- with the parameters of plant growth (Lee and Nam, 2023b;Lee et al, 2022d;2023); and this study also found that under 3000 and 4100 K white LEDs, L * and b * also tended to be inversely proportional to FW and DW. Accordingly, it is expected that b * , like L * , can also be used as a stress index in plants.…”