Background: During storage, fruits and vegetables are susceptible to the pathogens responsible for postharvest decay. Various tools are available to manage these issues, but not all are environmentally sustainable. Low-temperature plasma (LTP) has garnered significant attention among the most promising and eco-friendly solutions. LTP can be applied directly or indirectly, offering versatile applications. One notable indirect application is the utilization of plasma-activated water (PAW). In this study, we investigated the efficacy of an aerosol made by droplets of water nebulized by the effluent gases of a plasma discharge as a delivery method of PAW to substrates. We named this novel application, reported for the first time, plasma-activated fog (PAF). In this work, it was tested as a new alternative technology for fruit decontamination against postharvest fungal pathogens and pesticide residues. Results: PAF was generated via volume dielectric barrier discharge (VDBD) in a jet-like configuration and was applied to evaluate the in vitro effects on the conidial germination of major fungal postharvest pathogens, such as Alternaria alternata , Aspergillus carbonarius , Botrytis cinerea , Cladosporium sp., Monilinia fructicola , Penicillium italicum , Penicillium expansum and Rhizopus sp. Differences in fungal sensitivity to PAF were recorded, with A. alternata showing the lowest sensitivity to treatments. For most species, complete spore inhibition was obtained after 3–5 min of exposure. The efficacy of PAF against fungal rot was assessed on table grapes and strawberries, revealing a reduction in the percentage of rotted fruits exposed to 10 min of treatment, ranging from 45 to 80% on table grapes and from 52 to 74% on strawberries. PAF treatments also reduced pesticide residues on grape bunches and strawberry fruits, with various results depending on the active ingredient, with reductions of up to 96% for abamectin among insecticides and acaricides, and up to 38% for the fungicide fenhexamid. Conclusions: The results obtained in the present work have the potential to refine and optimize PAF treatment conditions for the antimicrobial decontamination of plant products. Graphical

The increasing demand for sustainable agriculture has accelerated research into eco-friendly plant health management, particularly through natural substances rich in bioactive compounds. In this study, various substances, including essential oils, extracts from Aloe vera, artichoke and ornamental plants, by-products from beer and coffee processing, and selected commercial formulations including biostimulants and a plant strengthener, were evaluated for their antimicrobial properties and ability to trigger plant defenses. Notably, Agapanthus spp. exhibited strong antifungal activity against the fungus Botrytis cinerea (Bc), while thyme, tea tree, and lavender essential oils were effective against both Bc and the bacterium Pseudomonas syringae pv. tomato (Pst). Greenhouse trials on tomato plants demonstrated the protective effects of A. vera gel and ornamental plant extracts against Bc and Potato virus Y (PVY), while coffee and artichoke extracts were effective against Pst. An alginate-based formulation containing thyme oil showed enhanced in planta efficacy against the three pathogens. Gene expression analyses revealed early upregulation of PR-1 and PR-4, especially with alginate treatments and A. vera gel at 12 h post-treatment (hpt) while coffee extract triggered the strongest late response at 72 hpt. These findings highlight the potential of plant-derived substances in promoting sustainable plant disease management through both direct antimicrobial action and immune system activation.

Cercospora beticola, the causal agent of Cercospora leaf spot (CLS), is a major pathogen affecting beet (Beta vulgaris) worldwide. Rapid and accurate detection is critical for effective disease control. This study validated a diagnostic framework combining portable quantitative PCR (qPCR) and laboratory-based digital droplet PCR (ddPCR) assays to detect and quantify C. beticola in leaves, seeds, and soil-associated crop residues. We used two portable qPCR systems (Biomeme Franklin^® Three9 and Hyris bCUBE^™) for in-field diagnostics, and ddPCR (Bio-Rad Laboratories) for laboratory analysis. Two rapid DNA extraction protocols, the Sigma-Aldrich REDExtract-N-Amp Plant PCR Kit (brief incubation at 95 °C) and the BN QuickPick Plant DNA Kit (magnetic-bead-based), were evaluated. The optimized portable qPCR assays achieved detection limits of 1 pg μL⁻¹, PCR efficiencies of 96–102%, and R² > 0.98. The ddPCR assay enabled accurate and absolute quantification even at low target concentrations and was resilient to common PCR inhibitors. Both methods proved robust in complex environmental matrices, with a detection threshold of 1% in infected residue soil. The framework’s sensitivity, specificity, and portability support timely on-site CLS diagnosis and informed management. This integrated approach advances portable molecular diagnostics and provides a platform for future field-ready disease surveillance and sustainable crop protection.