Phenological Evaluation of Autumn Coloration in Parthenocissus quinquefolia L. using Visual Assessment and Brix Measurement

Direct ground-based visual assessment, those that use repeating photography by a camera, has been conducted. We have found that the changes in phenology are easily visualized using repeat photographs, which were visually examined, and key phenology events, including autumn coloration, were recorded for Parthenocissus quinquefolia L. The sugar content of P. quinquefolia’s parts were found to be in range of 18.95 °Bx to 9.72 °Bx for leaves, in range of 10.99 °Bx to 16.78 °Bx for berries and 5.74 °Bx to 11.70°Bx for stems. However, leaf Brix values showed a correlation with visual color ratings, with higher Brix values corresponding to green colors and lower values corresponding to strong reddish colors. It is clear that autumn phenology has an impact on the sugar content of P. quinquefolia's parts to some extent. It is important to note that the 0Bx properties of leaves and berries were found to be sensitive to sampling parts of P. quinquefolia. It was suggested that the autumn coloration of P. quinquefolia could be effectively monitored through five distinct color stages. Different parts of P. quinquefolia showed various levels of coloration from mid-May to mid-December. However, green and red hues are visible on P. quinquefolia’s leaves in all directions until mid-November, while only leaves in the north-east direction (V) at the end of November show rather early, intense red coloration and maturation compared to others. The light level (lux) also appears to be an important factor in the autumn coloration of P. quinquefolia.