Fungal diseases seriously affect agricultural production and the food industry. Crop protection is usually achieved by synthetic fungicides, therefore more sustainable and innovative technologies are increasingly required. The atmospheric pressure low-temperature plasma is a novel suitable measure. We report on the effect of plasma treatment on phytopathogenic fungi causing quantitative and qualitative losses of products both in the field and postharvest. We focus our attention on thein vitrodirect inhibitory effect of non-contact Surface Dielectric Barrier Discharge on conidia germination ofBotrytis cinerea,Monilinia fructicola,Aspergillus carbonariusandAlternaria alternata. A few minutes of treatment was required to completely inactivate the fungi on an artificial medium. Morphological analysis of spores by Scanning Electron Microscopy suggests that the main mechanism is plasma etching due to Reactive Oxygen Species or UV radiation. Spectroscopic analysis of plasma generated in humid air gives the hint that the rotational temperature of gas should not play a relevant role being very close to room temperature.In vivoexperiments on artificially inoculated cherry fruits demonstrated that inactivation of fungal spores by the direct inhibitory effect of plasma extend their shelf life. Pre-treatment of fruits before inoculation improve the resistance to infections maybe by activating defense responses in plant tissues.

The availability of new laser sources that are tunable in the IR spectral region opens new perspectives for differential absorption lidar (DIAL) measurements. A region of particular interest is located in the near IR, where some of the atmospheric pollutants have absorption lines that permit monitoring of emissions from industrial plants and in urban areas. In DIAL measurements, the absorption lines for the species to be measured must be carefully chosen to prevent interference from other molecules, to minimize the dependence of the absorption cross section on temperature, and to optimize the measurements with respect to the optical depth. We analyze the influence of these factors and discuss a set of criteria for selecting the best pairs of wavelengths (λ_on and λ_off) to be used in DIAL measurements of several molecular species (HCl, CO, CO₂, NO₂, CH₄, H₂O, and O₂). Moreover, a sensitivity study has been carried out for selected lines in three different regimes: clean air, urban polluted air, and emission from an incinerator stack.

Plasma-activated water (PAW), generated through Surface Dielectric Barrier Discharge, was tested against microbial contaminants. We assessed how the time of exposure to plasma treatment and the gas flow rate impact the chemical composition of PAW, and, in turn, how it influences these factors influence its efficacy against microorganisms. The effectiveness of PAW treatments was evaluated against the fungal phytopathogen Botrytis cinerea and both pathogenic (Xanthomonas campestris pv. vesicatoria) and beneficial (Bacillus amyloliquefaciens) bacteria. The physicochemical properties of PAW were assessed as the concentration of reactive species, namely, NO₃⁻ and NO₂⁻ and H₂O₂, pH, and oxidation-reduction potential. Higher levels of reactive species and lower pH during longer treatments were associated with greater antimicrobial efficacy. A correlation study and Principal Component Analysis demonstrated that the RONS content in PAW affected antimicrobial activity, with stronger correlations between NO₂⁻, H₂O₂, and fungal inhibition, as well as between NO₂⁻ and bacterial inhibition. Almost complete inhibition was reached after 1 min of treatment for bacteria (log reduction of 4.5 for B. amyloliquefaciens and 5.1 for X. campestris) and after 3 min of treatment for B. cinerea (approximately 90% inhibition of conidial germination). The obtained results contribute to defining optimized treatment conditions using PAW for antimicrobial decontamination of plant products.