Large-Scale Evaluation of Official Containment Measures Against Meloidogyne graminicola Golden & Birchfield in European Rice Fields

The root-knot nematode Meloidogyne graminicola is a major rice pest recently introduced into Europe. In Lombardy (northern Italy), an official containment programme has been implemented to limit its spread while allowing rice cultivation to continue in infested areas. This study provides a large-scale evaluation of the field performance of the phytosanitary measures implemented under commercial farming conditions between 2022 and 2025. Field performance differed among management measures and according to the phytosanitary status of fields at the beginning of each annual observation. Trap-cropping showed high operational performance while allowing continued rice production, and crop rotation was also associated with favourable outcomes. In contrast, prolonged post-harvest flooding showed more variable performance under local environmental and operational conditions. Analysis of three-year management programmes further indicated substantial differences among the management sequences implemented in the monitored fields. Programmes combining crop rotation and trap-cropping were among those with the highest observed proportions of hectares meeting the official eradication criterion, although management sequences were not experimentally assigned. Overall, the results show that official containment measures can support the progressive recovery of infested fields under commercial farming conditions. The Lombardy experience provides large-scale operational evidence to inform the development of containment-based strategies for M. graminicola in European rice-growing areas, while highlighting the need to adapt management programmes to local agronomic and environmental conditions.