**5. Conclusions**

All three *Brassica* genotypes can be considered suitable for microgreen production, although micro cauliflower showed the highest yield, as well as a higher content of some mineral elements and α-tocopherol compared to other genotypes, while micro broccoli raab showed the fastest growth rate. The use of a nutrient solution type-like Hoagland and Arnon at half strength allowed us to obtain both high yield and desirable seedling height. By changing the NH4:NO3 molar ratio in the nutrient solution, no differences were found on yield and growing parameters, while the highest β-carotene content was found by using a nutrient solution with a NH4:NO3 molar ratio of 25:75. The lowest nitrate content was found in micro broccoli by using a nutrient solution with a NH4:NO3 molar ratio of 25:75 and in micro broccoli raab by using a nutrient solution with a NH4:NO3 molar ratio of 5:95. Micro cauliflower grown by using a nutrient solution with a NH4:NO3 molar ratio of 25:75 showed the highest dry matter and protein content. From a commercial point of view, we highlight the possibility of producing microgreens of broccoli raab, broccoli and cauliflower by changing the NH4:NO3 molar ratio in the nutrient solution without negatively affecting an important characteristic such as the nitrate content. It could be interesting to assess the optimal strength and NH4:NO3 molar ratio of the nutrient solution to obtain the best yield performance and quality for microgreens of other botanic families. Moreover, quality evaluation during cold storage of fresh-cut microgreens obtained by using nutrient solutions with different strengths and NH4:NO3 molar ratios may be a possible next goal.

**Author Contributions:** Conceptualization, O.D.P., M.R. and P.S.; data curation, O.D.P., M.R., P.C., A.L., F.C. and P.S.; formal analysis, P.S.; funding acquisition, P.S.; investigation, O.D.P., M.R. and P.S.; project administration, P.S.; resources, O.D.P., M.R., P.C., A.L., F.C. and P.S.; supervision, M.R. and P.S.; validation, O.D.P., M.R. and P.S.; visualization, O.D.P., M.R. and P.S.; writing—original draft preparation, O.D.P. and M.R.; writing—review and editing, O.D.P., M.R., P.C., A.L., F.C. and P.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by Italian Ministry of Agriculture and Forestry for financing the project 'Microgreens' for EXPO Milano 2015.

**Acknowledgments:** The authors thank Beniamino Leoni and Nicola Gentile for providing technical assistance during the experiment.

**Conflicts of Interest:** The authors declare no conflict of interest.
