## 3 Results and Discussion
### Antioxidant Activity and Compounds  
The analysis of variance of the data about antioxidant activity (hydrophilic antioxidant activity (HAA) and ABTS assay), total phenol content, total ascorbic acid content (TAA), chlorophylls (a, b, and total chlorophyll), and total carotenoids is presented in the Supplementary Material (Table S1). The analysis did not show any significant interaction of the three tested factors, namely salinity (S), biostimulants (B), and harvesting time (H). On the other hand, significant interactions were recorded between B \(\times\) H, S \(\times\) H, and S \(\times\) B for  
Figure 1: Trends in soil electrical conductivity (dS m\({}^{-1}\)) over the six harvesting times (I–VI). Vertical bars above each mean indicate standard deviation (SD; n = 3). specific parameters, e.g., total phenols for the B \(\times\) H interaction; HAA, ABTS, and TAA for the S \(\times\) H interaction; and HAA, ABTS, total phenols, and TAA for the S \(\times\) B interaction. Supplementary Table S3 presents the effect of biostimulant application and harvesting time on HAA, the ABTS assay, total phenols, and TAA content in _Diplotaxis tunifolia_ leaves, regardless of salinity level. As indicated in Supplementary Table S1, the only significant interaction was recorded in the case of total phenol content. The highest total phenol content (Figure 2) was recorded in \(D\). _tenuifolia_ leaves collected from plants treated with the Auxym@biostimulant and harvested at the fourth harvesting time, without being significantly different from the untreated plants harvested at the same harvesting time. On the other hand, the lowest overall value was recorded for the Auxym@biostimulant and the third harvesting time, without being significantly different from untreated plants of the first harvesting time. Moreover, for each biostimulant an increasing trend in total phenols was recorded until the fourth harvest, followed by a significant decline for the last two harvestings, especially in plants treated with biostimulants. In contrast to our study, [PERSON] et al. [50] did not report a significant effect of biostimulants on total phenol content, while they suggested a significant effect of two biostimulants (azoxystrobin and extracts of yeast as well as brown algae) in wild rocket plants grown under nitrogen deprivation conditions. Moreover, [PERSON] et al. [51] suggested a differential response of wild rocket plants to azoxystrobin and nitrogen deprivation depending on the cropping cycle, thus indicating that growing conditions are pivotal for plants' responses to abiotic stressors and/or biostimulant application. Similarly, [PERSON] et al. [52] did not record a significant difference in two successive harvests in terms of the total phenol content of perennial wall rocket plants treated with two biostimulants, whereas TAA content significantly increased for both biostimulants over the control treatment. Moreover, [PERSON] et al. [53] reported a decrease in total phenols in lettuce plants where two successive harvests were implemented, while TAA content showed the opposite trend. On the other hand, [PERSON] et al. [54] did not observe any significant differences in the total phenol content of basil plants in two successive harvests, while [PERSON] et al. [35] indicated an increase in total phenol content in lettuce plants grown in two different seasons (winter and winter-spring) and subjected to two biostimulants (tropical plant extracts and legume-derived protein hydrolysates). The contrasting results in literature reports could be associated with differences in the genotypes tested, since, according to [PERSON] et al. [55], a significant difference in the total phenol content of different basil genotypes was recorded in two successive harvestings. Table 2 presents the effect of biostimulant application and salinity level on HAA, the ABTS assay, total phenols, and TAA content in \(D\). _tenuifolia_ leaves, regardless of the harvesting time. A varied response was recorded depending on the antioxidant activity assay.