Effects of UV-B radiation distance on morphological and biochemical traits of chicory (Cichorium intybus L.) in an aeroponic system

Chicory (Cichorium intybus L.) exhibits significant phytochemical variations in response to environmental stressors. This study investigated the distance-dependent effects of UV-B exposure on the morpho-biochemical traits of chicory using a specialized aeroponic system. Seedlings were transplanted into the system and subjected to varying UV-B distances: a non-irradiated control (RD-0) and three treatment distances (40, 80, and 120 cm; 290–315 nm) in a completely randomized design with three replicates. Results indicated that proximity to the UV-B source induced significant reductions in biomass, leaf area, root volume, and chlorophyll levels, reflecting stress-induced growth inhibition. Conversely, UV-B exposure (particularly at 40 and 80 cm) significantly enhanced anthocyanins, total phenolics, proline accumulation, and antioxidant enzyme activities (CAT, POD, and APX), indicating a robust compensatory defense against oxidative stress. Radar plot analysis revealed that while the control (RD-0) and 120 cm distance optimized vegetative growth, the 40 cm and 80 cm distances maximized antioxidant capacity and secondary metabolite concentrations. These findings demonstrate a clear trade-off between morphological development and stress-induced metabolic elicitation. The study underscores the utility of aeroponic systems for the precise manipulation of environmental factors to balance growth and bioactive compound accumulation. Overall, these results provide critical insights for optimizing cultivation strategies, allowing for the targeted use of UV-B to enhance the medicinal quality of chicory while managing the associated growth-biomass trade-offs.