Residues of Desiccant Herbicides in Sesame Seeds (Sesamum indicum L.) Following Preharvest Application Determined by LC-MS/MS.

As global sesame (Sesamum indicum L.) exports expand, compliance with international Maximum Residue Limits (MRLs) is essential. This study evaluated the effects of different desiccation rates of diquat, saflufenacil, and glyphosate, and its metabolite AMPA, on residue levels in sesame seeds. Desiccation was performed 85 days after planting, and harvest was conducted 10 days after application for diquat and 20 days after application for glyphosate and saflufenacil. Herbicide residues were subsequently determined by LC-MS/MS. Diquat and saflufenacil residues remained below the limit of quantification (LoQ) in all treatments. However, neither herbicide provided satisfactory desiccation, as diquat caused rapid necrosis and seed burning, while saflufenacil showed limited efficacy. Glyphosate promoted slower desiccation with substantial residue accumulation in sesame seeds (23.6-51.7 mg kg-1), exceeding established MRLs, whereas AMPA remained below the LoQ. These findings highlight the need for crop-specific recommendations and residue monitoring programs to support safe sesame production and international trade.