Correlations between R, G, and B Values, Pigment Concentration, and Nitrogen Status in Three Ornamental Potted Plants

Abstract

Image technologies have been used for real-time estimation of nitrogen (N) and leaf chlorophyll (Chl) concentrations as well as for photosynthetic properties. The aim of this work was to establish correlations between RGB values and chlorophyll and nitrogen concentrations in three ornamental potted plants. We evaluated the RGB values, nitrogen status, and chlorophyll concentrations in the leaves of Peperomia obtusifolia, Maytenus senegalensis, and Rosmarinus officinalis. The correlation between the RGB values and the chlorophyll and nitrogen concentrations in the leaves was different for each species, since baby rubber correlated with the R and G values, the confetti tree correlated with the G and B values, and rosemary correlated with the R, G, and B values. The correlation between the normalized RGB (rgb) values and the color parameters and the chlorophyll and nitrogen concentrations showed R2 values lower than 0.70 in all species. Moreover, the estimation of vegetation indices was not effective due to the lack of correlations between these indices and the chlorophyll and nitrogen concentrations in the leaves of each species. According to the findings, rosemary exhibited the best association between the RGB values and chlorophyll and nitrogen concentrations in the leaves.