## 3 Results  
As no significant interactions arose between the research year and the experimental factors applied, only the average values related to 2022 and 2023 are reported for all the variables examined. Significant interactions arose both between cultivar and biostimulant formulation (Figure 1) and between biostimulant formulation and crop cycle on yield (Figure 2). The application of the protein hydrolysate led to a significant yield increase, compared to the control, in four varieties (+26% in Mars, +25.6% in Naples, +26% in Olivetta, +25% in Tricia). The treatment with _Spirulina platensis_ resulted in a 36.2% yield increase only in the cultivar Venice, compared to the control which was not significantly different from the application of brown algae _Cystoseira tamariscifolia_. No significant differences arose between the cultivars within each biostimulant formulation. Figure 1: Interaction between cultivar and biostimulant formulation on rocket leaf yield. Values followed by different letters are significantly different at \(p<0.05\) ([PERSON]’s test). Figure 2: Interaction between biostimulant formulation and crop cycle on rocket leaf yield. Values followed by different letters are significantly different at \(p<0.05\) ([PERSON]’s test). The interaction between biostimulant formulation and crop cycle on rocket leaf yield is shown in Figure 2. Regarding the untreated control, the autumn crop cycle demonstrated a significantly higher yield compared to the autumn-winter (\(-18.8\%\)), while the winter cut did not significantly differ from the two earlier ones. The application of brown algae resulted in no significant differences between the three crop cycles, which showed an average yield of \(8.5\) t ha\({}^{-1}\). The use of protein hydrolysate led to \(19.3\%\) and \(21.4\%\) higher yield in the autumn-winter and winter crop cycle, respectively, compared to the autumn one. The use of _Spirulina platensis_ did not result in significant differences between the three crop cycles, with an \(8.7\) t ha\({}^{-1}\) average yield. In the first crop cycle, the untreated control led to higher production than the second one but did not significantly differ from the biostimulant treatments. The protein hydrolysate application resulted in the highest yield in the two latest crop cycles, with the untreated control showing the lowest value at the second cut. Significant interactions \"cultivar \(\times\) biostimulant formulation\" and \"biostimulant formulation \(\times\) crop cycle\" on the dry matter content in rocket leaves arose. In Figure 3, we can observe that the application of protein hydrolysate led to the highest dry matter in the cultivars Mars, Olivetta, Tricia, and Naples, though in the latter cultivar it did not significantly differ from _Cystoseira tamariscifolia_; in Venice, no significant differences in dry matter were recorded between the three biostimulants, which showed a better effect than the untreated control. The interaction between biostimulant formulation and crop cycle (Figure 4) was significant on the dry matter accumulation in rocket leaves. The untreated control showed a \(22.4\%\) higher dry matter accumulation in the autumn cycle, compared to the two later ones, whereas the opposite trend was recorded under the protein hydrolysate treatment. The latter application led to the highest dry matter content in rocket leaves in both the second and third crop cycles, whereas the control attained the lowest values. Figure 3: Interaction between cultivar and biostimulant formulation on dry matter in rocket leaves. Values followed by different letters are significantly different at \(p<0.05\) ([PERSON]’s test). No significant interactions between the experimental factors were recorded on the colorimetric parameters of rocket leaves (L*, a*, b*) and, therefore, only the main effects are presented (Table 1).