Spectral Detection of Kinetic Stress Dynamics in Ornamental Foliage Plants
Kornél Szalay, Gábor Bércesi, Szilvia Erdei-GallyKinetic shock triggers thigmomorphogenetic responses in plants, posing both an unintended handling risk and a deliberate technique to enhance ornamental value. Detecting its immediate, non-visual impacts remains a challenge. This study used non-destructive contact spectroscopy to detect short-term kinetic stress in three species with distinct leaf anatomies (Alocasia sp., Monstera deliciosa, Ficus elastica) under 20 s and 40 s stimuli. While a pooled global classification model failed due to anatomical variations masking the universal stress signal (70% accuracy), optimized species-specific models revealed distinct dynamics. At 0 min post-stress, high variance and low separability occurred across all species. However, a diagnostic change emerged within 30 min for Alocasia sp. (79.37%) and Ficus elastica (77.50%); the same tendency could not be confirmed for Monstera deliciosa, and further investigation is needed to support this pattern. Ficus elastica’s distinct architecture also proved consistently the least sensitive of three species in the pooled control-versus-treated comparison. A significant dosage effect was captured only in Alocasia sp. (87.50% accuracy). Spectral index analysis showed the dominance of the Normalized Difference Water Index (NDWI), suggesting the change reflects micro-structural leaf turgor modifications rather than biochemical changes. Results indicate that leaf spectroscopy has the potential to diagnose transport injury and monitor conditioning.