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Root growth is often restricted by genetics, cultural factors, and adverse environmental conditions. The application of plant biostimulants can help to promote root growth and to guarantee optimal shoot growth and productivity. An innovative biopolymer-based biostimulant (Quik-Link, Italpollina S.p.A., Rivoli Veronese, Italy) for boosting root growth and improving nutrient uptake by plants was tested in three experiments. In the first experiment, tobacco leaf explants cultured in vitro under Murashige and Skoog basal medium enriched with 1 mL L-1 of Quik-Link showed regeneration of roots while no roots were detected from leaf explants cultured without the addition of Quik-Link in the medium. In the second experiment carried out under greenhouse conditions, tomato plants were transplanted in pots filled with a sandy soil and irrigated after two days from transplanting with a solution containing the biostimulant at three concentrations corresponding to 0, 0.12 or 0.24 mL plant-1. After 12 days from transplanting, tomato plants treated with 0.24 mL plant-1 of biostimulant exhibited a higher root dry biomass and root to shoot ratio than control plants. In the third experiment, carried under field conditions, treatments were defined by a factorial combination of two fertilization levels (conventional and low input fertilization with half-dose of fertilizers used in conventional fertilization plan) and two Quik-Link application rates (0 and 12 L ha-1). Biostimulant application increased marketable yield by 19.2 and 9.7%, under reduced and conventional fertilization regimes, respectively. Quik-Link application increased N, P, and Fe in tomato leaves at flowering/fruit set stage. Fruit quality parameters were only affected by fertilization level with an increase of soluble solids contents with the reduced rate of mineral fertilizers.

Microgreens appeared in the human diet as a decoration of culinary dishes, due to their shape, tenderness and vivid colours. They are currently attracting researchers' attention for their nutraceutical properties. In fact, they were found to be packed with vitamin C, carotenoids and minerals. The genetic aspect is one the most important preharvest factors. Microgreens of the Brassicaceae family are well researched. In our study, six genotypes belonging to the Brassicaceae family: Cress (Lepidium sativum L., 'Curled'), komatsuna (Brassica rapa L. var. perviridis 'Comred F1'), mibuna (Brassica rapa L. subsp. nipposinica 'Japanese greens'), mizuna (Brassica rapa var. japonica 'Greens'), pak choi (Brassica rapa L. subsp. chinensis 'Red Wizard F1'), tastoi (Brassica rapa L. subsp. narinosa), were cultivated in a growth chamber, and analysed to determine colourimetric parameters, nitrate content, minerals, bioactive molecules (chlorophylls, carotenoids, ascorbic acid, total phenols) and antioxidant activity. The results confirmed the hypothesis of genetic variability for the analysed parameters. pak choi and komatsuna had the highest content of macronutrients (P, S, K and Ca). Pak choi had the highest total chlorophylls and total ascorbic acid content. These findings place emphasis on an appealing product like microgreens.

Consumer demand has been increasing and many vegetable farmers have oriented their production plans towards baby leaf vegetables such as lettuce. The management of the nutrient solution as well as the growing conditions could significantly affect the yield and quality of leafy vegetable crops. The aim of the present work was to determine the effects of increasing the level of salinity in the nutrient solution (1, 10 or 20 mM NaCl) during two consecutive growing seasons (spring and autumn) on the yield and quality of Lactuca sativa L. var. acephala grown in floating raft culture. Increased salinity in the nutrient solution decreased marketable yield and dry biomass with more detrimental effect during the warm season. The percentage of yield reduction in comparison to the non-saline control was 7 and 20% in the spring season and 4 and 13% in the autumn growing season at 10 and 20 mM NaCl, respectively. Plants grown in the spring season exhibited higher yield and dry biomass but lower leaf quality than those grown in the autumn season. When averaged over salinity level the lipophylic antioxidant activity, total ascorbic acid, phenols and nitrate contents were significantly increased by 7.1, 20.1, 19.4 and 24.4%, respectively, in plants grown in spring as compared to autumn growing season. The floating system could be considered an efficient and low-cost tool to improve quality aspects through proper management of the salt concentration in the nutrient solution with an acceptable yield reduction.