Effects of previous crop residues management through strategic tillage and fungicide application on the agronomic traits and the mycotoxin contamination of wheat

Background The retention of crop residues on the soil surface may increase the risk of Fusarium head blight (FHB) and mycotoxin contamination in wheat ( Triticum aestivum ) grains. Objective This study aims to evaluate the effects of reduced tillage systems (no-tillage or minimum tillage) and continuous ploughing, combined with a fungicide application on regulated and emerging mycotoxins, under natural infection conditions. Methods A 12-year field experiment was conducted within a maize ( Zea mays ) –wheat rotation system. The tillage and fungicide applications were assessed, according to a factorial design, under medium–low and high FHB risk conditions. Fusarium , Alternaria and Claviceps metabolites were analysed by multi-mycotoxin LC–MS/MS. Results Ploughing minimised FHB severity by 81% under high disease risk conditions, while reduced tillage lowered Septoria foliar disease severity and prolonged canopy stay-green during filling. Ploughing under a medium–low FHB risk increased the grain yield by 6%, compared with minimum tillage, while no yield differences among the tillage were observed under high FHB pressure. Triazole fungicide improved the yield by 14% and 35% under medium–low and high FHB risks, respectively. Ploughing, rather than minimum tillage, reduced deoxynivalenol and zearalenone by 75% and 60%, with a fungicide providing comparable effects. Reduced tillage increased the emerging mycotoxins, especially moniliformin and enniatins, but also the toxins produced by the Alternaria species. Ergot alkaloids, whenever detected, increased, albeit only under no-tillage conditions. Conclusion Integrated and adaptive cropping systems that combine residue management and targeted fungicide applications are essential to maintain productivity and food safety.