*3.12. Statistical Analysis*

Analysis of variance was carried out for all the data sets. One-way ANOVA with Tukey's honestly significant difference test was carried out to analyze the effects of fertilizers on each of the various parameters measured. The ANOVA and *t*-test were carried out using SPSS software (IBM Corp. 2012). The effects were significant at *p* ≤ 0.05.

Raw data from MTT assays and ROS determinations were first analyzed in Microsoft Excel Spreadsheet software to calculate the relative proliferation and ROS levels ratios, respectively. Then, log-transformed data were imported to GraphPad Prism to apply statistical tests. The Welch and Brown–Forsythe versions of one-way ANOVA were used to compare samples treated with different red onions at different concentrations, while each comparison was evaluated by applying an unpaired *t*-test with Welch's correction. Statistical significance was set at *p* < 0.05.
