Pesticide application management for the cultivation of soybean and chickpea for food supply chains with zero-residues

The accumulation of pesticide residues in soybean and chickpea grains has been evaluated, in a two-year field experiment carried out in North Italy. Different herbicides, fungicides, insecticides and acaricides active ingredient (A.I), belonging to the most diffused chemical classes labelled for the considered crops, were applied at their maximum label rate according to a full factorial design which consider for each A.I. the effect of the year, the cropping system (only for soybean, by comparing the sowing as main crop or intercrop) and the timing of application. For each crop, herbicides were applied before sowing, at pre- and post-emergence growth stages; while fungicides, insecticides and acaricides were applied at different reproductive growth stages, from flowering to ripening. The European Maximum Residue Levels (MRLs) and the zero-residue claim (contamination < 0.01 mg kg -1 ) were considered as residue thresholds. No pesticide residues were detected in chickpea grains and no residues of herbicides and acaricides were detected in soybean grains, where the occurrence changed only for fungicides and insecticides. Only systemic molecules, such as triazoles, strobilurins and neonicotinoids cumulated in grains, mainly at later timing of application, and two of them, epoxiconazole and acetamiprid exceeded European MRLs. Overall, their concentration was higher in late application timing, low yield level (intercrop) and growing season with lower temperatures. These findings may contribute to the correct management of pesticide field application to guarantee the achievement of the zero-residue claim with a greater consistency in legume food ingredients. • Herbicide residues were never found in chickpea or soybean grains • Fungicides and insecticides accumulated in soybean, but were not detected in chickpea • The pesticide content was affected by the growing season and cropping system • A delayed application increases the risk of insecticide and fungicide accumulation • Field management of pesticides can guarantee the zero residue target in legume