Evaluating Various Colors of Persistent Luminescent Powders on Rose Cut Flowers

Rose cut flowers are popular in everyday bouquets or for special occasions, and tinting of the flowers by means of color addition increases the flowers economical value and aesthetic appeal. This study evaluated red and white luminescent rose cut flowers, which was achieved by applying six persistent luminescent powders. Solutions of each color were prepared by mixing 6 g of powder and 240 ml of deionized water and sprayed four times around the flower head plus a control. Images were taken of the flowers before ultraviolet blacklight exposure and after exposure to be later analyzed with ImageJ software. Daily measurements were taken including vase weight, average floral diameter, and visual deterioration based on scale of 1 to 4. Overall measurements included mean brightness; red, green, and blue measured values; dominant wavelengths of emitted color; flower diameter change rate; relative water percent; solution uptake rate; and vase solution uptake rate. For luminescent brightness mean without ultraviolet, white rose with blue powder had the greatest value. For luminescent brightness after ultraviolet exposure, white rose with green powder had the greatest value. With ultraviolet exposure, white roses with green powder had the greatest value followed by blue, orange, and white. Red powder on white and red roses experienced little to no luminescence before or after ultraviolet exposure. Mean and mode varied in their calculated dominant wavelengths; therefore, it is recommended to use mean values because more similarities in matching of the powder color and the calculated dominant wavelength were reported. Ultimately, white roses are preferred because they seemed to have greater health and luminescence compared with red roses, and green and blue powder would be recommended for luminescent application for brightness.