Red, blue and red plus blue supplementary light differently influenced the growth of microgreens, microleaf and baby leaf of two Brassica local varieties

With the development of vertical farming, it is necessary to identify new production techniques that allow for the utilization of limited available space and e!ciently utilize agronomic inputs, including arti"cial radiation. Leafy vegetables are the most cultivated crops in vertical farming systems thanks to their fast growth cycle and limited canopy expansion. For these reasons, microgreens, microleaf and baby leaf are suitable productions for vertical farmings system and, based on the literature, the botanical family of Brassicaceae lends itself well to these productions. During the experimental activity carried out in the greenhouse, two local varieties of Brassicaceae - “cima di rapa” (Brassica rapa L. subsp sylvestris L. Janch. var. esculenta Hort) and “cavolo riccio” (Brassica oleracea L. var. acephala) - were grown for the production of microgreens, microleaf, and baby leaf using linear LED modules with red (R), blue (B), and red + blue (R+B) spectrum as supplementary radiation source. “Cima di rapa” grew faster than “cavolo riccio” and the harvests of microgreens, microleaf, and baby leaf of the "rst genotype was made at 15, 32 and 37 days a'er sowing (DAS), respectively, while for the second genotype it was made 17, 33 and 40 DAS. Regardless of the light treatment, “cima di rapa” showed higher yields than “cavolo riccio”: 15% for microgreens, 45% for microleaf, and more than 80% for baby leaf. In general, the application of supplementary lighting increased the productive performance, with more pronounced e$ects in baby leaf rather than microgreens. Furthermore, the e$ect of spectra on yield and seedling morphology was genotypespeci"c. Finally, considering the yield per unit of surface area, it emerged that for “cavolo riccio” the yield of microgreens resulted approximately 15% higher compared to baby leaf of the same species, while for “cima di rapa” the yield of baby leaf led to a biomass production increase of about 40% compared to microgreens. #ese results demonstrate how genotype selection and knowledge of appropriate cultivation techniques can determine more or less satisfactory outcomes in vertical farming. #e experimental test conducted is part of a research project aimed at identifying production techniques and/or new types of products that enhance the e!ciency of agronomic input utilization in soilless cultivation and vertical farming