Effect of Macro- and Micro-Plastics in Soil on Quantitative Phytochemicals in Different Part of Juvenile Lime Tree (Citrus aurantium)

This study aimed at profiling the quantitative phytochemicals in different parts of juvenile C. aurantium cultivated on different plastic-treated clayey soils in a pot experiment under ambient field condition. Three plastic types, namely polyethylene (LDPE), polypropylene (PP) and polystyrene (PS) with seven treatment pattern (single LDPE, PP, PS and mixture: LDPE + PP, LDPE + PS, PP + PS, LDPE + PP + PS) in soil matrix (1% w/w) were experimentally formulated for testing. After harvesting at 2, 4, 6 and 8 months, the tree was separated into three parts [i.e.aboveground (leaves, stem) and belowground (root)] and crude extracts of these parts were obtained with alcohol It was observed that phytochemical contents varied with prolong exposure and in different parts of juvenile C. aurantium. Greater negative effect was observed on the root biomass compared to the aerial biomass except for LDPE + PP (0.32) and LDPE + PS (0.76) in macro-size as revealed by the plastic biomass impact factor. Overall, LDPE showed the most negative effects while the least was shown by the plastic mixture of LDPE, PP and PS. Furthermore, microplastics showed greater negative effects compared to macroplastics. The treatments in some cases showed significant differences (p < 0.05) from the control, especially for microplastics. Overall, the presence of plastics (especially microplastics) in agricultural soils could be undesirable, as most of these phytochemicals have vital roles in developments of drugs for diseases.