Phthalate esters (PAEs) are emerging pollutants which are widely distributed in agricultural environments, and their impacts on crops have attracted considerable attention. PAEs on crops can disrupt their normal physiological metabolism, deteriorate the quality of agricultural products, and pose potential risks to human health through the food chain. Here, based on existing studies, we consolidate recent findings on the occurrence, sources, phytotoxicity, and control measures of PAEs in cash crops. Specifically, the pollution status of PAEs in cash crops was investigated. PAEs enter plants through water, soil, the atmosphere, and packaging materials via wastewater contamination, the degradation of plastic waste, and emissions from industrial processes. PAEs can induce oxidative stress in cash crops, disrupt photosynthetic pathways, and alter soil- and plant-associated microbial communities, leading to physiological and metabolic disorders that significantly reduce the yield and quality of cash crops. Consequently, recent studies have explored and developed more advanced mitigation strategies, such as enzymatic degradation, the use of microbial communities, and the development of new treatment materials and technologies. Overall, this review provides a comprehensive assessment of current research on PAEs in cash crops and offers insights into existing challenges and future prospects for ensuring the quality and safety of agricultural products.

The citrus spiny whitefly, Aleurocanthus spiniferus Quaintance (Hemiptera: Aleyrodidae), is an important pest of tea, Camellia sinensis (L.) Kuntze (Theales: Theaceae). Parasitic wasp, Encarsia smithi Silvestri (Hymenoptera: Aphelinidae), is one of the dominant natural enemies of the whitefly. Generally, the whitefly produces four generations per year in Chinese tea plant growing areas. The wasp adult stages are basically synchronized with the nymphal stages of the whitefly. In an indoor Y-tube olfactometer bioassay, odors from both whitefly-pierced tea leaves and adjacent intact tea leaves significantly attracted the wasps, with elevated amounts of trans-2-hexenal and methyl salicylate (MeSA) detected from these two types of tea leaves. A four-arm olfactometer bioassay verified that these two compounds and their binary blends significantly attracted the wasps. Bud green sticky boards baited with trans-2-hexenal (10⁻² g mL⁻¹), MeSA (10⁻² g mL⁻¹), and five blends of trans-2-hexenal and MeSA (1:1, 2:1, 3:1, 4:1 and 5:1, respectively, v/v) at 10⁻² g mL⁻¹ in hexane solutions captured significantly more wasps than did the un-baited boards, with the 3:1 blend catching the highest number of wasps. To enhance whitefly parasitism by the wasps, from early April to early August, the Attractant 2 lures (each holding a total mass of 80 mg of the 3:1 blend) were hung on tea branches and refreshed every 30 days. Deployment of the controlled release synomone-based attractant lures resulted in 2–3 fold higher parasitism rates by the wasps in the treated plots/sections than those in the CK plots/sections during both the peak periods of whitefly pupae of generation 2 from late July to early August and generation 3 in late August. This study demonstrated that herbivore-induced tea volatiles can be formulated as a synomone-based lure for controlling the whitefly through attracting E. smithi in tea plantations.

Phthalate esters (PAEs) are ubiquitously emerging pollutants in the environment and have a notably high detection rate in tea; they can leach out during consumption and pose potential risks to human health. However, the process of PAEs entering and accumulating in tea plants is undocumented. This study investigated the uptake of PAEs in tea plant seedlings, focusing on both root and foliar pathways under hydroponic conditions. In controlled indoor deposition experiments, PAEs on fresh tea leaves underwent rapid degradation within five days, with the degradation rates ranging from 66.98% to 81.69%; outdoor rates exhibited even higher degradation rates. This degradation process followed first-order kinetics. The results revealed that tea plants were capable of absorbing and translocating PAEs via roots and leaves, culminating in their accumulation in various tea plant tissues. The Root Concentration Factor (RCF) was highest for di(2-ethylhexyl) phthalate (DEHP). Conversely, the shoot concentration factor, Leaf Concentration Factor, and Translocation Factors for the leaves, stems, and roots for the PAEs were inversely related to the RCF. The moderated mediation analysis suggested that root concentration was strongly influenced by translocation-mediated pathways. However, leaf concentration was largely not mediated by the translocation pathways. These findings indicate that both root uptake and foliar deposition can contribute to PAE accumulation in tea plants, providing a basis for source apportionment and for designing targeted control strategies to reduce PAE contamination in tea production systems.