## 5 Conclusions  
This is the first report in which it has been demonstrated that VOCs produced by a seed-borne quarantine plant pathogen hold considerable promise for improving the diagnostic monitoring of these plant materials, where pathogen infections are often asymptomatic and the sampling consistency for PCR-based tests is difficult to establish as statistically significant. The blend of VOCs identified here for _Cff_ has strong potential to be exploited as a non-invasive early diagnostic marker of _Cff_ infection, particularly in asymptomatic infected seeds, as a contribution to mitigating the spread of this harmful pathogen. Nevertheless, further experiments are ongoing to thoroughly estimate the sensitivity of VOCs as biomarkers by comparing the flux rates of VOCs emitted from _Cff_-infected seeds, both naturally and artificially, with the development of the symptoms assessed using molecular methods. Future research will also focus on developing practical tools for field applications in terms of these results, contributing to the sustainability and health of leguminous crop production. This will involve the design and testing of portable diagnostic devices, such as electronic noses or miniaturized GC-MS instruments, capable of detecting and analyzing VOC emissions directly in the field. Additionally, large-scale validation trials across diverse geographic regions and environmental conditions will be essential to assess the robustness and reproducibility of VOC-based diagnostics. Overall, these findings suggest that VOC fingerprinting could be an innovative method to assist phytosanitary services in rapidly surveying plant materials at ports of entry, by merely sampling the air within the containers where plants and seeds have been stored. This approach has the potential to revolutionize quarantine inspections by providing a non-invasive, rapid, and cost-effective preliminary diagnostic tool, thereby reducing the reliance on time-consuming and labor-intensive laboratory testing. The ability to detect asymptomatic infections without the need for destructive sampling could significantly enhance the efficiency of monitoring programs, particularly for high-risk, seed-borne pathogens like _Cff_. Moreover, the application of this method extends beyond quarantine scenarios, offering opportunities for its adoption in integrated pest management systems, where the early detection of pathogens is critical for preventing outbreaks and ensuring sustainable crop production. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/agronomy15020497/s1](https://www.mdpi.com/article/10.3390/agronomy15020497/s1)]([https://www.mdpi.com/article/10.3390/agronomy15020497/s1](https://www.mdpi.com/article/10.3390/agronomy15020497/s1)), Figure S1: Vials with naturalized Cannellino _Phaseolus vulgaris_ medium inoculated with _Cff_ strains for VOC analysis; Table S1. Identification of volatile organic compounds (VOCs) detected in this study. The table includes the IUPAC name, the corresponding NIST name, and the CAS Registry Number for each compound. The dual listing for 2-methyl-1-butanol/3-methyl-1-butanol reflects the structural similarity and overlapping detection of these isomers; Table S2: Percentage of single VOC out of the total sum of the most abundant VOCs measured in the headspace of vials where pathogenic bacteria were grown (values are the mean of nine replicated measurements \(\pm\) percentage uncertainty). Conceptualization, D.G., S.T. and L.C. ; methodology, D.G. and L.C. ; software, D.G. and L.C. ; validation, D.G., L.C. and S.T. ; formal analysis, D.G., L.C., and S.T. ; investigation, D.G., L.C. and S.T. ; resources, S.T. ; data curation, D.G., L.C. and S.T. ; writing--original draft preparation, D.G. and S.T. ; writing--review and editing, D.G., S.T. and L.C. ; supervision, S.T. ; project administration, S.T. ; funding acquisition, S.T. All authors have read and agreed to the published version of the manuscript.