Assessing Pesticide Residue and Spray Deposition in Greenhouse Eggplant Canopies to Improve Residue Analysis

Pesticide residue analysis is critically important for ensuring food safety and regulating international trade. In a greenhouse setting, we assessed pesticide residue and exposure patterns using liquid chromatography–mass spectrometry and Allura Red tracer analysis. Our results show significant effects of eggplant canopy position and spray concentration on deposition parameters. Specifically, spray coverage, spray density, deposition, and residue were generally greater for leaves in the higher canopy. Deposition and residue, unlike spray coverage and spray density, linearly correlated with spray concentration. Pesticide residues on leaves linearly correlated with depositions on artificial targets, and a correction factor was constructed to estimate residues from tracer depositions. This comparative analysis suggests that tracer analysis using Allura Red in combination with artificial targets is a time- and cost-saving alternative to conventional residue analysis for assessing spray parameters under high-volume spraying scenarios. A better understanding of pesticide residue and spray patterns will not only enhance the safety of our food supply chain but also improve pest control efficacy within the sustainable integrated pest management framework.