4.6.5. Evaluation of the Efficacy of the Nitric-Extract in Preventing Fruit Rot

The antifungal activity of "Nitric-extract", as such, or as a dilution, was recorded at 3 and 5 days after inoculation and expressed as rot severity, rated according to empirical scales, from 1 to 5. This scale was different according to the fruit. For citrus fruits, the scale 25% was as follows: 1. absence of symptoms or signs of the pathogen; 2. slight presence of rot; 3. clear presence of rot and slight appearance of mycelium; 4. rot and clear presence of white mycelium; 5. clear presence of soft rot, white mycelium and sporulation. For apple fruits the scale was as follows: 1. absence of symptoms or signs of the pathogen; 2. slight presence of rot; 3. clear presence of rot and slight appearance of mycelium; 4. presence of rot, white mycelium and slight appearance of sporulation; 5. clear presence of soft rot, white mycelium and sporulation.

All data were subjected to one-way analysis of variance (ANOVA) using the R software (https://www.r-project.org/) (accessed on 9 November 2021). In order to normalize the distributions, data were transformed in square-root values, but untransformed values are reported in the respective graphs. Tukey's HSD (honestly significant difference) post-hoc test was applied to evidence significant statistical differences (*p* ≤ 0.05).

**Author Contributions:** Conceptualization, S.O.C., N.T., G.M. (Giuseppe Meca), G.M. (Giovanni Marletta), A.P. and A.D.; methodology, S.O.C., N.T., G.M., S.E.b., F.L.S., E.I.R. and C.L.M.; software, F.L.S. and C.L.M.; validation, S.O.C., N.T., G.M. (Giuseppe Meca), G.M. (Giovanni Marletta), A.P. and A.D.; formal analysis, N.T., S.E.b. and C.L.M.; investigation, S.E.b., E.I.R., C.L.M. and F.L.S.; resources, S.O.C., A.P., N.T., G.M. (Giuseppe Meca) and G.M. (Giovanni Marletta); data curation, S.E.b. and F.L.S.; writing—original draft preparation, S.E.b. and F.L.S.; writing—review and editing, S.O.C., N.T., G.M. (Giuseppe Meca), A.P., G.M. (Giovanni Marletta) and A.D.; visualization, S.O.C.; supervision, A.D. and S.O.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was funded by the University of Catania, Italy "Investigation of phytopathological problems of the main Sicilian productive contexts and eco-sustainable defense strategies (MED-IT-ECO)" PiaCeRi-PIAno di inCEntivi per la Ricerca di Ateneo 2020–22 linea 2" (5A722192155) and the project "Smart and innovative packaging, postharvest rot management and shipping of organic citrus fruit (BiOrangePack)" under Partnership for Research and Innovation in the Mediterranea Area (PRIMA)-H2020 (E69C20000130001). F.L.S. was supported by a fellowship funded by the BiOrangePack project. This study is part of E.I.R. activity of a Ph.D. student in "Agricultural, Food and Environmental Science", University of Catania; XXXVI Cycle. E.I.R. is supported by a grant funded by the National Operative Program (PON) "Research and Innovation" 2014–2020, line "Innovative doctorates with industrial characterization") (CCI 2014IT16M2OP005).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Raw data can be shared upon reasonable request.

**Acknowledgments:** We are grateful to A. Davies for the English revision of the text.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
