Light environment and photosynthetic performance in Cornus officinalis: an analysis on SPAD value variations

Cornus officinalis has been traditionally used to treat asthenia, liver and kidney diseases in East Asia. Additionally, its anti-allergic, anti-inflammatory, and antioxidant properties show potential in treating chronic inflammatory skin diseases. The SPAD value represents the amount of chlorophyll in the leaf, and since it can be measured in a non-destructive way, the nutritional status and photosynthetic efficiency of crops can be confirmed. In this study, we tried to find out how the photoenvironment affects the photosynthesis of C. officinalis by checking the SPAD value in the leaves at different times and at different heights. SPAD values were analyzed using ANOVA and T-tests, and the results showed significant SPAD differences among trees (p < 0.001), with Tree 1 having the highest SPAD values. The SPAD values of Tree 2 varied by leaf position, showing 30% lower values below 180 cm (p < 0.001), while other Trees did not show significant differences according to leaf position. These findings highlight that light distribution and leaf positioning could impact photosynthetic efficiency, varying among individual plants. Optimizing these factors in smart farming can enhance crop yield and quality.