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To develop sustainable City/Region Food Systems (CRFS), a shift toward more ecofriendly and efficient production systems is needed. On its side, aquaponics systems rely on the equilibrium and interaction between fish, plants, and bacteria and are part of the so-called integrated production systems. Compared to other production techniques, it offers several advantages thanks to its management and operating costs feasibility. Recirculating Aquaponics Systems (RAS) provides the opportunity to finely close the nutrients loop inside an ecosystem and catch the best it can offer. Here we aim to highlight the strengths and weaknesses of RAS systems. In addition, we present as a case study the RAS prototype at the Department of Agricultural Sciences of University of Naples Federico II started in November 2020 to grow leafy vegetables and tilapia fish. Results provide helpful scientific and practical information for small and/or large-scale commercial growers as well as amateurs. Furthermore, our results highlight the suitability of these systems to be embedded in urban areas from rooftop and vertical farms to other controlled environment agricultural (CEA) systems and the opportunity they can offer for abandoned urban spaces.

Deficit irrigation occurrence while maintaining acceptable yield represents a useful tool for vegetables production wherever irrigation water is limited. Lettuce (Lactuca sativa L.) 'Corsica' was grown in the field from May to July in order (1) to investigate the daily and seasonal evapotranspiration (ETc) of lettuce using drainage lysimeter, (2) to determine the crop coefficients (Kc) values, and (3) to study the effects of deficit irrigation on growth, marketable and water use efficiency (WUE). Treatments were: well-watered treatment receiving 100% of ETc (C), water-stressed treatment receiving 80% of ETc (WS1), water-stressed treatment receiving 60% of ETc (WS2), water-stressed treatment receiving 40% of ETc (WS3). Lysimeter measured crop evapotranspiration (ETc) totaled 422 mm, for total irrigation period of 81 days. Seasonal evapotranspiration (ET) of lettuce treatments, varied from 351 mm in the WS1 treatment to 305 mm in the WS2 treatment and 259 mm in the WS3 treatment, while in the control ET totaled 397 mm. The highest yield was recorded in C and WS1, with no significant differences between treatments followed by WS2, while the lowest value was recorded under the severe water stress treatment. A yield response factor (ky) value of 1.17 was determined, and lettuce was found to be sensitive to water stress. The highest values of water use efficiency (WUE), was recorded on WS1 (18.8 kg m-3), followed by the C (17.8), WS2 (16.3) and finally WS3 (15.5) treatment. Applying 80% of ETc resulted in water saving, with the least yield reduction, making more water available to irrigate other crops, and thereby considered optimal strategies for drip-irrigated lettuce in the semi-arid climate.

Light and nitrogen are the main factors commanding horticulture production. Therefore, this study aims at evaluating the effects of two different greenhouse cover films (clear-Film A and diffuse light-Film B) on yield and nutritive value of a ready-to-eat salad lamb’s lettuce (Valerianella locusta L.), grown under several nitrogen regimes (no nitrogen [N0], sub-optimal [N25] and optimal N fertilization [N50] corresponding to 0, 25 and 50 kg ha-1 , respectively). The combination N50 and Film B boosted SPAD index by 10.3% and yield by 91.9% compared to N0 × Film A. Concerning antioxidant activity and bioactive compounds, only total ascorbic acid was positively affected by Film B (9.4%), while there was no effect of this cover film on carotenoids and chlorophyllous pigments, which increased along the increment of nitrogen rates. Nitrate content in leaves was influenced by both factors and it showed increasing values, when nitrogen doses increased, reaching the highest value under N50-Film B conditions (3312.3 mg kg-1 fw). Our study showed that in the Mediterranean area, the use of greenhouse diffuse light film improved lamb’s lettuce yield, but on the other hand incurred significant increase in nitrate level, nonetheless remaining constantly under the legal threshold imposed by the commission regulation (EU). Secondary metabolites, such as total phenols and carotenoids, showed similar values under both films, instead the diffuse light film improved total ascorbic acid content.

Aquaponics is a highly efficient production system that relies on the fish food as the only energy system’s input for growing both fish and vegetables, without chemicals. In Mediterranean climates, during winter, due to the combined effects of low solar radiation and low-temperature levels, plant metabolic activity, growth rate, and nutrient uptake decrease, which may, in turn, cause harmful accumulation of nitrogen compounds for fish in the water. Growers renew the water periodically by discharging nutrients enriched water with severe environmental and economic costs. In winter, aquaponics cultivation cycles can be integrated with supplemental light to guarantee a constant daily light integral (DLI) that could promote plant growth and nutrient uptake. The aim of the study was to evaluate the morpho-physiological response of lettuce (Lactuca sativa L.), escarole endive (Cichorium endivia var. latifolia), and curly endive (Cichorium endivia var. crispum) grown in a floating raft, in combination with tilapia (Oreochromis niloticus L.) in a recirculating aquaponics system (RAS). Plant were grown under natural light (NL) or natural light integrated with 16 h of supplemental white LED lighting (IL, PPFD: 173 µmol m-2 s-1, DLI, 10 mol m-2 d-1). The results showed species-specific morpho-physiological responses, with higher productivity in the endives than lettuce, under both light regimes. Compared to NL, plant biomass and leaf area were promoted under IL, accounting for higher plant photosynthetic rates. IL boosted endive growth, while lettuce leaf expansion and biomass allocation into the canopy were increased. Both lettuce and endives performed well in the adopted RAS system. It appears recommendable to provide a fixed DLI during the winter months to shorten the crop cycle by improving plant growth and nutrient uptake. However, further studies are needed to optimize the lighting application protocols and reduce energy costs too.

In the current scenario of increasing urbanization and food consumption, aquaponic systems are generally regarded as sustainable food production systems. However, its environmental burdens (energy consumption, materials, etc.) were not deeply investigated yet. To assess aquaponics' environmental performance systematically, it is important to take the whole life cycle into account. The aim of this study was to identify and to evaluate the environmental impact of a recirculating aquaponics system (RAS) prototype, using a life cycle assessment (LCA) methodology. Leafy vegetables (i.e., lettuce (Lactuca sativa L.), curly endive (Cichorium endivia var. crispum) and escarole endive (Chicorium endivia var. latifolia)) were grown on floating rafts in combination with tilapia (Oreochromis niloticus L.) at two different lighting regimes (i.e., natural sunlight and natural sunlight integrated with LED supplemental light). Our LCA analysis included four different steps: 1) definition of the goal and scope of the study; 2) life cycle inventory (data collection); 3) life cycle impact assessment (data translation into environmental indicators); 4) interpretation and analysis of the results. Our preliminary results suggest that electricity was the main contributing factor to environmental impact, especially with supplemental light. This LCA study can be useful for providing the groundwork to reduce the potential environmental impact of aquaponics systems.

A closed hydroponic system (Porous Tube Plant Nutrient Delivery System) combined with a horizontal uniaxial clinostat has been designed and built-up to grown leafy vegetables under simulated microgravity conditions. Two research activities were carried out to investigate the effects of clinorotation on growth, yield, and quality of rocket seedlings (Eruca saliva Mill.) and lettuce plants (Lactuca saliva L.), which may constitute a source of health), fresh food for the astronauts during space missions. The percentage of germination of rocket was affected by clinorotation with the highest value observed in the control treatment. The seedling fresh weight of the control treatment, was 19 % higher compared to that of the clinorotation treatment while the opposite trend was observed for chlorophyll a/b ratio. Clinorotation did not influence the quality (total carbohydrates, triglycerides, carotenoids and vitamin C) of the rocket seedlings. Shoot fresh and dry weight, leaf area, specific leaf dry weight, root dry weight and shoot:root ratio were lower in the clinorotated lettuce plants than those grown in the control treatment. Quality parameters (chlorophyll, total carbohydrates and vitamin C) of lettuce plants were negatively affected by clinorotation. Lettuce genotype comparison under simulated microgravity showed that 'Mortadella di primavera' should be adopted for space experiments due to the better growth and productivity.

Research was conducted at the University of Tuscia (central Italy) to validate the propagation system for globe artichoke (Cynara cardunculus var. scolymus) described in a previous paper for a 1-year production cycle. The resulting globe artichoke plants were used in a 2-year field trial to investigate the field response of plantlets obtained with our propagation technique in comparison with plantlets produced by in vitro propagation and by offshoots harvested in commercial fields. The total number of artichoke plantlets obtained with our propagation system was 62.7 plantlets/m2 per year. In the first year, the globe artichoke production (bud number and fresh bud weight) was higher in plants obtained with our propagation system and by micropropagation than in those obtained from offshoots harvested in commercial fields. The production cost of plantlets obtained with our propagation technique was 52% lower than those of the micropropagated plantlets. This could lead to a significant reduction of production costs for artichoke growers, while preserving the advantages of in vitro propagation (disease-free plants and plant uniformity).

Extreme climatic conditions have a severe repercussion on agriculture and on food availability. Ecological means to overcome drought are important to improve agroecosystems sustainability and resilience. The use of an Ecklonia maxima-derivate seaweed extract (SwE) as a tool to mitigate drought constrain in chicory plants grown in greenhouse was evaluated. Plants were cultivated in plastic pots filled with peat and subjected to drought stress by retaining moisture range at 90–100% of water holding capacity (WHC) [well-watered (WW)], 60–70% WHC [moderate drought stress (MDS)] or 30–40% WHC [severe drought stress (SDS)]. Drought stress decreased plant growth traits and yield. However, in plants supplied with SwE, head fresh mass was 7.6% higher than control. Water constrain reduced relative water content (RWC), whereas, SwE improved RWC when plants were exposed to drought. Moreover, water use efficiency (WUE) increased as drought intensity increased and plants exposed to drought significantly improved WUE when supplied with SwE. Drought stress intensity linearly reduced nitrogen use efficiency (NUE) in plants exposed to MDS and SDS, compared with WW plants. SwE application enhanced NUE by 7.7% compared with control plants. Exposing chicory plants to drought stress resulted in a significantly higher N and Mg concentration compared to WW plants. Conversely, drought reduced P and K in leaf tissues. SwE supply increased P, K, Ca and Mg content, whereas reduced N. Chlorophyll was reduced by drought, while SwE supply increased its concentration. Sugars increased as drought stress intensity increased. Water constrain enhanced malondialdehyde, especially in SwE non-treated plants. Drought stress improved proline and total polyphenols in plants supplied with SwE. Biostimulated plants grown under WW or MDS conditions showed higher ascorbic acid level than those exposed to SDS and non-biostimulated. The study proved that SwE application is a useful practice to mitigate drought in chicory plants, safeguarding yield and quality features.

Seaweed extract (SE) application is a contemporary and sustainable agricultural practice used to improve yield and quality of vegetable crops. Plant biofortification with trace element is recognized as a major tool to prevent mineral malnourishment in humans. Mo deficiency causes numerous dysfunctions, mostly connected to central nervous system and esophageal cancer. The current research was accomplished to appraise the combined effect of Ecklonia maxima brown seaweed extract (SE) and Mo dose (0, 0.5, 2, 4 or 8 µmol L−1) on yield, biometric traits, minerals, nutritional and functional parameters, as well as nitrogen indices of spinach plants grown in a protected environment (tunnel). Head fresh weight (FW), ascorbic acid, polyphenols, N, P, K, Mg and nitrogen use efficiency (NUE) were positively associated with SE treatment. Moreover, head FW, head height (H), stem diameter (SD), ascorbic acid, polyphenols, carotenoids as well as NUE indices were enhanced by Mo-biofortification. A noticeable improvement in number of leaves (N. leaves), head dry matter (DM) and Mo concentration in leaf tissues was observed when SE application was combined with a Mo dosage of 4 or 8 µmol L−1. Overall, our study highlighted that E. maxima SE treatment and Mo supply can improve both spinach production and quality via the key enzyme activity involved in the phytochemical homeostasis of SE and the plant nutritional status modification resulting in an enhanced spinach Mo tolerance.

Light and nitrogen strongly affect the growth, yield, and quality of food crops, with greater importance in green leafy vegetables for their tendency to accumulate nitrate in leaves. The purpose of this research was to explore the effect of two greenhouse films (Film A and B) on yield, and quality of spinach grown under different nitrogen regimes (not fertilized—N0%, sub-optimal N dose—N50%, optimal N dose—N100%). Film A and Film B were used as clear and diffused light films, with 75% and 87% thermicity, and 85% and 90% total transmittivity, respectively, where only Film B had a UV-B window. Film B elicited an increase in yield (22%) and soil–plant analysis development (SPAD) index (4.6%) compared to the clear film, but did not affect chlorophyll a, b, and total chlorophyll content. In addition, the diffuse film significantly decreased ascorbic acid in the crop but had no effect on lipophilic antioxidant activity and phenols content, but decreased ascorbic acid content. Finally, nitrate content was strongly increased both by nitrogen dose (about 50-fold more than N0%) and greenhouse films (about six-fold higher under diffuse light film), but within the legal limit fixed by European Commission. Therefore, irrespective of N levels, the use of diffuse-light film in winter boosts spinach yield without depressing quality.

Selenium (Se) is an essential trace element for humans due to its importance in a number of enzymes. Vegetable grafting is a valuable tool to overcome biotic and/or abiotic issues and to increase vigour, yield traits and fruit quality. The present work aimed at testing both different Se concentrations (0.0, 1.0, 2.0 and 4.0 μmol Se L−1) supplied via fertigation and grafting on cherry tomato in soilless culture. Se at 2.0 μmol L−1 improved total fruit yield by 60.0 % and 31.4 % in ungrafted and grafted plants, respectively as compared to the control. Marketable yield was positively affected by Se-biofortification and grafting. Se at 2.0 μmol L−1 improved N use efficiency by 60.3 % and 31.5 % in ungrafted and grafted plants, respectively. Furthermore, Se at 4.0 μmol L−1 and grafting enhanced fruit firmness, SSC, polyphenol content and total carotenoids. Ascorbic acid and lycopene were enhanced by Se-doses and grafting. Fruit Se concentration in ungrafted plants varied from 0.1 mg kg−1 of dry weight (DW) in the control to 8.9 mg kg−1 DW in plants treated with 4.0 μmol Se L−1. Se fruits concentration in grafted plants ranged from 0.08 in the control to 9.8 mg kg−1 DW in plants treated at 4.0 μmol L−1. Non-grafted and grafted plants manifested an increment in the hazard quotient (HQgv) in reaction to Se. HQgv fluctuated from 0.002 to 0.353, with a daily intake for Se below the recommended value. Finally, Se-biofortification (at 2.0 or 4.0 μmol L−1) and grafting succeeded in improving tomato plant performance, nutritional and health-promoting compounds.

Hemp (Cannabis sativa L.) is a multipurpose plant attracting increasing interest as a source for the production of natural fibers, paper, bio-building material and food. In this research we studied the agronomical performance of Cannabis sativa cv. Eletta Campana irrigated with saline water. Under those conditions, we tested the effect of protein hydrolysate (PH) biostimulant application in overcoming and/or balancing deleterious salinity effects. The results of the diverse treatments were also investigated at the physiological level, focusing on photosynthesis by means of a chlorophyll a fluorescence technique, which give an insight into the plant primary photochemical reactions. Four salinity levels of the irrigation solution (fresh water–EC0, and NaCl solutions at EC 2.0, 4.0 or 6.0 dS m−1, EC2, EC4 and EC6, respectively) were combined with 2 biostimulant treatments (untreated (control) or treated with a commercial legume-derived protein hydrolysate (LDPH)). The increasing salinity affected plant photochemistry resulting in lower plant growth and seed production, while the LDPH biostimulant showed a protective effect, which improved crop performance both in control and in salinity conditions. The LDPH treatment improved seeds yield (+38.6% on average of all treated plants respect to untreated plants), as well as residual biomass, relevant in fiber production.

The herbaceous grafting of fruiting vegetables is considered a toolbox for safeguarding yield stability under various distresses and for improving fruit quality. Inoculation with arbuscular mycorrhiza (AM) fungi seems also to be an efficient tool for increasing the assimilation, uptake and translocation of macroelements and microelements, for modulating plant secondary metabolism and for overcoming several forms of plant distress. The present work evaluated the combined effect of grafting the &ldquo, Birgah&rdquo, (B) eggplant onto its wild/allied relatives&rsquo, rootstocks (Solanum torvum (T), S. macrocarpon (M) and S. paniculatum (P)) and AM fungi (R. irregularis) on the yield, fruit quality, nitrogen use efficiency, mineral profile, and nutritional and functional quality. The B/T, B/M and B/P grafting combinations significantly increased the marketable fruit and fruit number compared with those in the ungrafted control. Furthermore, irrespective of the grafting combinations, AM fungi significantly enhanced the marketable fruit, fruit number and nitrogen use efficiency (NUE) by 13.3%, 12.7% and 13.3%, respectively compared to those in the untreated control. Exposing the B/T and B/P grafted plants to the +AM treatment significantly increased the ascorbic acid contents by 17.2% and 10.4%, respectively, compared with those in the ungrafted control. Fruits from the combination B/P &times, +AM had a higher chlorogenic acid content than fruits from the ungrafted control plots. Finally, the B/T &times, +AM and B/P &times, +AM combinations decreased glycoalkaloids by 58.7% and 63.7%, respectively, compared with those in the ungrafted control, which represents a highly important target for eggplant fruit healthiness.

The current research elucidated the agronomical, physiological, qualitative characteristics and mineral composition of lettuce (Lactuca sativa L. var. longifolia) after treatments with a beneficial fungus Trichoderma virens (TG41) alone or in combination with a vegetal biopolymer-based biostimulant (VBP, &lsquo, Quik-link&rsquo, ). The experiment consisted of lettuce plants grown in three N conditions: sub-optimal (0N kg ha&minus, 1), optimal (70N kg ha&minus, 1), and supra-optimal (140N kg ha&minus, 1) N levels. Lettuce grown under 0N fertilization showed a significant increase in fresh yield when inoculated with TG41 alone (45%) and a greater increase with TG41 + VBP biostimulant (67%). At 48 days after transplanting, both the TG41 alone or TG41+VBP biostimulant induced higher values of CO2 assimilation in comparison to the control. The mineral concentrations in leaf tissues were greater by 10% for K and 12% for Mg with the TG41+VBP treatments compared to the untreated lettuce. The lettuce plants receiving either TG41 alone or TG41+VBP biostimulants had a significantly lower nitrate content than any of the untreated controls. In non-fertilized conditions, plants treated with TG41+VBP biostimulants produced lettuce of higher premium quality as indicated by the higher antioxidant activity, total ascorbic acid (+61%&ndash, 91%), total phenols (+14%) and lower nitrate content when compared to the untreated lettuce.

Scolymus hispanicus L. is a wild edible species with wide distribution in the Mediterranean area. Recent research has focused on the domestication of wild edible greens, which is essential for the preservation of agroecosystems and the increase in biodiversity, especially under the adversely changing climate conditions. In the present work, the aim was to evaluate the response of S. hispanicus plants to different fertilization regimes that varied in the amounts of nitrogen, phosphorus and potassium in regard to plant growth and chemical composition of leaves. For this purpose, plants were grown in pots within an unheated greenhouse. Seven experimental treatments were used, including six fertigation regimes (SH1-SH6) and the control treatment (SHC), where no fertilizers were added. Fresh yield was beneficially affected by the treatments that included a high content of P and K (e.g., SH3 and SH5), while lesser amounts of these macronutrients (e.g., SH1 and SH4) resulted in higher chlorophyll content (SPAD index) and leaf area. In terms of mineral profile, high amounts of P and K improved dietary fiber and carbohydrates content, whereas the untreated plants had the highest content of ash, fat and crude protein. Oxalic and quinic acid were the major organic acids detected, with fertigation regimes significantly reducing their content compared to the control treatment. α-tocopherol was the only isoform of vitamin E detected in all the samples, while glucose and fructose were the most abundant sugars, with their highest content detected in control and SH4 treatments, respectively. Scolymus hispanicus leaves were rich in macro and micro minerals, while their contents varied depending on the fertigation regime. Finally, α-linolenic, palmitic, and linoleic acid were the major fatty acids detected, while their contents were beneficially affected by low nutrient inputs (e.g., untreated plants and SH1 and SH2 treatments). In conclusion, the regulation of nutrient solution seems to be an effective practice to increase fresh yield in S. hispanicus without compromising the nutritional profile of the edible product, while low inputs of macronutrients such as P and K may improve the chemical composition of the species, especially in terms of n-fatty acids.

Fresh vegetables and fruits have always been the mainstays of good nutrition as providers of fiber, beneficial phytochemicals (such as vitamins and phenolic compounds), and minerals. Today and in the future, biofortification is a promising strategy to increase the concentration of these compounds. Considering the importance of minerals in human health, the enrichment of fresh produce for consumption has been considered through specific agronomic approaches. This review discusses, in detail, the latest findings on vegetable agronomic biofortification, aimed at increasing the concentration of crucial minerals, such as iron (Fe), zinc (Zn), iodine (I), selenium (Se), molybdenum (Mo), and silicon (Si), in edible portions, focusing on the direct and indirect effects of this strategy. Although agronomic biofortification is considered a feasible technique, the approach is complex due to the many interactions between the microelement bioavailability for both plants and consumers. Therefore, the effects of biofortification on human health and the influence of beneficial and antinutritional compounds were discussed in detail to analyze the advantages and disadvantages of this practice.

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.

Nitrate is the principal source of nitrogen for most higher plants. Particularly leafy vegetables require large quantities of nitrate fertilizer to attain maximal yields. The crop yield and quality as well as nitrate accumulation in leafy vegetables depends upon many preharvest factors such as genetic materials, agronomical and environmental factors. Three greenhouse experiments were carried out in order to assess the effects of preharvest factors (cultivars, plant density and N dose) on yield and quality of spinach (Spinacia oleracea L.). In the first trial four spinach cultivars were compared in terms of yield and quality attributes. The marketable yield of the four cultivars tested was in the following order: ‘Tasman’ = ‘Kookaburra’ > ‘Platypus’ = ‘Regiment’. No significant differences among cultivars were observed for the βcarotene, vitamin C and nitrate contents. In the second trial, treatments were defined by four plant densities (800,000; 1,000,000; 1,200,000; 1,500,000 seeds ha-1). The lowest marketable yield was observed under the lowest plant density, whereas no significant difference was recorded between the other treatments. The highest leaf dry matter, K, and nitrate contents were recorded at 1000000 seeds ha-1. In the third experiment we evaluated the effects of four N fertilizer doses (0, 75, 150 and 225 kg ha-1) on crop performance. Marketable yield increased quadratically with increasing N application with the highest values recorded at both 150 and 225 kg ha-1 indicating a luxury consumption of the nutrient at 225 kg ha-1. Finally, the highest protein and nitrate contents were observed at 225 kg ha-1 of N.

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.

The preservation of local landraces represents a crucial point in biodiversity maintenance and it necessarily starts from a qualitative and morphological characterization. The 'San Marzano' tomato (Solanum lycopersicum L.) is an elongated fruit cultivar particularly suitable for processing and represents one of the most significant horticultural products for the Italian food industry. Five 'San Marzano' landraces ('SM Bellizzi 1', 'SM Bellizzi 2', 'SM Bellizzi 3', 'SM Montoro Inferiore' and 'SM Sarno') characterized by different fruit shapes (pointed, round and hollow) were compared in terms of yield, nutritional and functional quality. The fruit dry matter percentage as well as the juice EC ranged from 4.94 to 7.10% and from 3.04 to 3.80 dS m-1, respectively, with the lowest values observed in 'SM Montoro Inferiore'. The highest total soluble solids content was recorded in both 'SM Montoro Inferiore' and 'SM Sarbo', followed by 'SM Bellizzi 1' and 'SM Bellizzi 3', whereas the lowest values were observed in both 'SM Bellizzi 2' and 'SM Bellizzi 3'. Among the three macronutrients analyzed K was the most abundant macro-mineral, followed by phosphorus and finally nitrate. 'SM Bellizzi 1' was richer in P and K compared to the rest of the landraces tested. The highest levels of hydrophilic and lipophilic antioxidant activities were recorded in 'SM Sarno' and 'SM Bellizzi 3', respectively. Our findings will contribute toward the documentation of nutritional and functional quality profiles of an important collection of niche products such as the SM tomato.

Irrigated agricultural lands are prone to salinity problems which may imperil horticultural crops by reducing growth, yield and even qualitative traits. Eco-friendly approaches such as biostimulant application and in particular protein hydrolysates from vegetal origin are implemented to mitigate salinity stress effects on crops. For this reason, a greenhouse experiment on spinach irrigated with increasing concentrations of saline water (EC = 3 dS m−1 (EC3), 6 dS m−1 (EC6) and 9 dS m−1 (EC9), in addition to non-saline treatment (EC0)) was organized, while plants were subjected to foliar applications of a protein hydrolysate from vegetal origin on a weekly basis. The application of this biostimulant helped mitigate the adverse effects of saline stress, by increasing the SPAD index and total chlorophylls of spinach plants. Yield was significantly boosted under biostimulant treatment in saline conditions and reached the value obtained in control treatment (no biostimulants added) × EC0 in the case of EC 3 and 6 dS m−1. In addition, the number of leaves and plants m−1 was increased under biostimulant treatment, and most importantly the hydrophilic antioxidant activity of spinach, thus a qualitative aspect of great importance was also increased. Such results increase the knowledge on the effects of protein hydrolysates application on an important leafy vegetable and may help growers mitigate saline conditions and maintain high crop yield and high quality of the final product when no other source of irrigation water is available.

Indian jujube or ber (Ziziphus mauritiana Lam.) is a deciduous fruit tree typically cultivated in several semi-arid areas of Asia because of its adaptability to yield-limiting conditions. The present study aimed to assess the effect of four pruning times (i.e., the fourth week of March, second week of April, fourth week of April, and second week of May) and four treatments using stress-mitigating plant bio-regulators (thiourea at 500 ppm and 1000 ppm; salicylic acid at 100 ppm and 150 ppm) as a means to improve both fruit yield and quality post-harvest. To this end, a full factorial experiment lasting two growing seasons was carried out under field conditions in the representative semi-arid region of Rajasthan, the state with the largest production in India. We assessed the vegetative growth of the trees, the fruit size and yield, and some quality parameters (soluble content, acidity, ascorbic acid, and total sugars) as well as the main post-harvest traits (fruit weight loss and spoilage). Overall, pruning during the second week of April had the greatest positive influence on most of the variables studied. For instance, it induced the highest vegetative vigor, allowing the maintenance of relatively higher chlorophyll and relative water content in the leaves. The fruit parameters also responded most positively to the second week of April pruning, a treatment that, compared to the others, induced a higher diameter; a higher amount of TSS (19.6 °Brix), ascorbic acid (86.5 mg/100 g), and total sugar (10.4%); and a better post-harvest shelf-life. Among the plant bio-regulators, the application of thiourea at 1000 ppm had the highest positive influence on the growth parameters, yield, quality, and reduction in spoilage post-harvest. The differences between the doses of PBRs were limited.

Biostimulants are sustainable inputs that can be used to reduce chemical fertilizers dependency while reinforcing nutrient uptake, yield and quality of crops, and modulate plant metabolic processes. Protein hydrolysates (PHs) are prominent biostimulants that guarantee a reduction in yield loss under sub-optimal nitrogen (N) conditions. On these bases, a new Malvaceae-derived PH product was tested along a commercial legume-derived PH on soilless greenhouse-grown lettuce, to comparatively assess their activity under N depletion conditions (1 mM NO3−). Both PHs increased biometric parameters under optimal but to a lesser extent under depleted N conditions. Legume-derived PH promoted greater Fv/Fm, lutein and β-carotene under optimal N conditions and higher catalase and total phenolic acids. In contrast, Malvaceae-derived PH did not affect phenolic acids but increased leaf concentration of Ca, Mg and catalase while reducing H2O2. Biochemical changes were then evaluated through untargeted metabolomics. Metabolomics showed a hierarchically prevalent effect of the N level, with the PHs showing distinctive reprogramming under optimal and depleted N conditions. Among others, phenylpropanoids were mainly down-accumulated in stressed plants, while (polyunsaturated fatty acids) PUFA accumulated following the application of PHs. Notwithstanding, the severe depletion of N cannot be compensated by PHs treatment since biostimulants are used to complement fertilizers use and not to replace it.

Sweet basil (Ocimum basilicum L.) is one of the most common aromatic herbs cultivated all over the world. It is widely used for its aromatic and culinary purposes. Consumer demand for fresh sweet basil has been on the rise and many farmers of leafy vegetables and aromatic herbs have oriented their production schemes to include basil. The genetic material is a key preharvest factor and the major determinant of variation in yield and quality of leafy vegetables. Another important preharvest factor that may modulate yield and nutritional quality of sweet basil could be the growing medium. The aim of this research was to assess in a multi-factorial approach the effects of two sweet basil cultivars (Napoletano and Genovese) and two substrates (rockwool and an innovative inert substrate, SISAL fiber) on plant growth, marketable yield, nitrogen content and nutritional quality. The plant growth parameters, yield and especially the bioactive compounds were mostly affected by the growing media and to a lesser extent by the genetic material. When averaged over growing media, the highest leaf number was observed in 'Genovese' while an opposite trend was recorded for the leaf area. Irrespective of the sweet basil cultivar, plants grown on rockwool exhibited a higher leaf area, leaf fresh weight and dry biomass compared to those grown on SISAL fiber substrate. Contrarily to crop productivity, sweet basil grown on SISAL was characterized by high levels of lipophilic antioxidant activity, total chlorophyll and carotenoids, whereas no significant effect among treatments were recorded on total phenols. Although the yield reduction with SISAL was quite significant, the basil plants grown on this innovative substrate produced leaves with high concentrations of bioactive compounds. Additional researches should focus on elucidating the Genotype × Substrate interaction in order to select the best combinations.

Iron (Fe) is an essential micronutrient for plant growth and productivity and, among other micronutrients, is the one required in higher amounts. In most soils, Fe occurs at relatively high concentrations; nevertheless, in calcareous soils, Fe bioavailability can be very limited, thus leading plants to develop Fe deficiency symptoms. At present, Fe fertilization still represents the most frequent approach adopted in agriculture to prevent or remediate Fe chlorosis. For soil applications, Fe fertilizers are based on Fe chelated with aminocarboxylate synthetic ligands (e.g. HEDTA, EDTA, DTPA, EDDHA), which are effective in maintaining Fe in the soil solution, even in alkaline soils, and thus in increasing its bioavailability for plant uptake. Nevertheless, Fe-aminocarboxylate complexes presents some limitations, related for instance to pH-dependent effectiveness, stability, persistence in the environment and ligand exchange reactions. In this context, vegetal-derived protein hydrolysates might represent good sources of biochelating ligands for developing innovative Fe fertilizers for sustainable agriculture. Protein hydrolysates are composed by small peptides, which, on one hand, can chelate Fe via amino acid side chains, carboxylate groups of C-termini, amine groups of N-termini and N atoms of amide groups of the peptide backbone, whilst, on the other hand, small peptides can also play a signaling role, triggering the acquisition of nutrient and morphogenetic processes in plants. The present paper reviews the current state of knowledge on traditional Fe fertilizers and, on the other side, explores the possible advantages in the application of biochelates as innovative Fe fertilizers. To further corroborate the hypothesis, three experimental trials have been carried out on three horticultural crops (cucumber, tomato, and strawberry) using a Fe-biochelate as Fe source and comparing it with the widely used traditional synthetic chelate Fe-EDDHA. The results in the three crops clearly show that Fe-biochelate is, at least, as efficient as Fe-EDDHA as source of micronutrient, even under circumneutral (pH 6.0) and alkaline conditions (pH 8.0), thus proving that Fe-biochelates can be promising alternatives to synthetic Fe chelates for the Fe nutrition management of crops. Considering the potential drawbacks of synthetic chelates (e.g., leachability, persistence, remobilization of toxic metals in soil), these findings might contribute enhancing the agriculture sustainability. In addition, Fe-biochelate could also find an application in soilless cultivation systems as an alternative to synthetic Fe chelates for Fe enrichment of edible plant tissues (biofortification), increasing their nutritional value.

In the last twenty years, horticulture has focused on producing high-quality food while improving resource use efficiency. The application of nutritional stress is an effective tool to increase the phytochemical content of vegetables while reducing environmental footprint. Microgreens represent an emerging functional food characterized overall by higher levels of phytonutrients than their mature counterparts. The current study examined the effect of using nutrient solution or only distilled water on the nutraceutical performance of lettuce (Lactuca sativa L.) microgreens grown in a peat-based substrate. Our results showed that lettuce microgreens can be effectively grown using only substrate nutrients, incurring a 27% decrease in fresh yield, but a significant increase in total ascorbic acid (+187%), anthocyanins (+35%), and total phenolic acids content (+26%). Of utmost interest, is the near absence of nitrates in water-treated microgreens, which renders this category of fresh vegetables ideal for the production of food dedicated to consumers highly sensitive to nitrates, such as infants. Growing microgreens without providing additional nutrients to those found in a typical peat-based substrate is an important potentiality that adds value to this new class of vegetables and also renders them particularly suitable for home cultivation.

Seed priming is the induction of a particular physiological state in plants by the treatment of natural and synthetic compounds to the seeds before germination, with the aim to boost germination percentage and seedlings performance. The aim of the current research was to assess the influence of three seed priming treatments (control, cold priming and osmo priming) on the total germination percentage and the transplant quality of six vegetable species (artichoke [Cynara scolymus L.], endive [Cichorium endivia L.], fennel [Foeniculum vulgare L.], onion [Allium cepa L.], pepper [Capsicum annuum L.] and tomato [Solanum lycopersicum L.]). The transplants performance was compared in terms of biometric measurements and pigments (chlorophyll and carotenoids). Our results demonstrated that the positive effect of seed priming on total germination was species-dependent. Cold priming makes Cynara scolymus L. seeds reach 65% germination, Cichorium endivia L. seeds 93%, and Allium cepa L. seeds 81%. The osmo priming treatment brings the germination of Capsicum annuum L. seeds to 87%, and the Solanum lycopersicum L. seeds to 83%. Foeniculum vulgare seeds show the highest germination capacity compared to other tested species. Even the morphological traits of the six vegetable transplants were also influenced by the two priming methods in a specific-species manner. Osmo priming increased the total phenols content in Cichorium endivia L. and Solanum lycopersicum L. Finally, In Allium cepa L. both priming treatments reduced chlorophyll b and total chlorophyll content.

High sodium chloride (NaCl) concentration in the irrigation water of greenhouse crops is a typical phenomenon of nursery activities in the south Mediterranean regions and has frequently detrimental effects on plant growth and quality as it may lead to an unbalance of some ions and thus to biochemical and physiological stresses resulting in reduced plant growth, leaf chlorophyll content and net photosynthesis. With the aim to assess the effects of this salt stress on crop responses, a greenhouse cultivation of three potted ornamental shrubs at increasing NaCl concentration (0, 40 and 80 mM) of irrigation water was conducted. Plants of Asteriscus maritimus, Euphorbia × lomi and Murraya paniculata were grown in 7-L containers using a mixture of sphagnum peat, perlite and red soils (1:1:1, v/v/v) under the same irrigation regime for avoiding water stress. Among the three species, the Mediterranean halophyte Asteriscus resulted the most tolerant to salt stress as highest values of many bio-morphological parameters (shoots emission, leaf area, biomass production) were recorded in plants irrigated with 80 mM NaCl, whereas lowest performances were observed in no-treated plants. Euphorbia and Murraya resulted moderately tolerant to salt stress as no significant differences on plant growth and physiological activities were found between control-plants and those irrigated with 40 mM NaCl, while lower values were measured under 80 mM NaCl treatment.

Bitter apple or tumba (Citrullus colocynthis L.) is a prostrate annual herb belonging to the Cucurbitaceae family. It is highly tolerant against multiple abiotic stresses like drought, heat, and soil salinity and can easily grow on very marginal soil, even on sand dunes in hot, arid regions. Tumba fruit is a fleshy berry 5–10 cm in diameter and of a pale yellow color at ripening. The tumba fruit used in this research was harvested from the ICAR-CIAH, Bikaner research farm. The seeds were separated, and their oil was extracted to analyze its physical characteristics and composition (phytochemical compounds, fatty acid profile, etc.). The seeds of the tumba fruit contained 23–25% golden-yellow-colored oil with a specific gravity of 0.92 g/mL. The extracted oil contained appreciable amounts of phytochemical (bioactive) compounds like phenolics (5.39 mg GAE/100 g), flavonoids (938 mg catechin eq./100 g), carotenoids (79.5 mg/kg), oryzanol (0.066%), and lignans (0.012%), along with 70–122 mg AAE/100 g total antioxidant activity (depending on the determination method). The results of fatty acid profiling carried out by GC-MS/MS demonstrated that tumba seed oil contained about 70% unsaturated fatty acids with more than 51% polyunsaturated fatty acids. It mainly contained linoleic acid (C18:2n6; 50.3%), followed by oleic acid (C18:1n9; 18.0%), stearic acid (C18:0; 15.2%), and palmitic acid (C16:0; 12.4%). Therefore, this oil can be considered as a very good source of essential fatty acids like omega-6 fatty acid (linoleic acid), whereas it contains a lower concentration of omega-3 fatty acids (α-linolenic acid) and hydroxy polyunsaturated fatty acids. In addition, it also contains some odd chain fatty acids like pentadecanoic and heptadecanoic acid (C15:0 and C17:0, respectively), which have recently been demonstrated to be bioactive compounds in reducing the risk of cardiometabolic diseases. The results of this study suggest that tumba seed oil contains several health-promoting bioactive compounds with nutraceutical properties; hence, it can be an excellent dietary source.

The quantity and quality of wall rocket (Diplotaxis tenuifolia L.) production are strongly influenced by the cultivation system, in particular the protected environment conditions and nitrogen fertilization. In the present research, we tested two greenhouse cover films (Film1: diffuse light; Film2: clear), to verify the effects on yield and nitrate content (a detrimental factor of quality) of rocket leaves, fertilized with optimal (N2) or sub-optimal nitrogen dose (N1), or unfertilized (N0). In addition, we combined the N fertilization with a biostimulant application, declared by the manufacturer as able to reduce nitrate content. Film1 provided a 36% yield increase over Film2 and allowed an increasing production until the V harvest, opposite to what was recorded under Film2, where the yield increased only until the III harvest. Additionally, biostimulant application boosted the yield (+40%), as well as nitrogen fertilization. Both factors had the best performance under Film1, where N1 yield was even equal to N2-Film2. The nitrate content showed a seasonal trend (lower values in spring harvests) and it was boosted by nitrogen (1096, 3696, and 4963 mg/kg fresh weight, for N0, N1, and N2, respectively) and biostimulant application (3924 vs. 2580 mg/kg fresh weight). Therefore, the use of diffuse-light film seems useful to obtain higher yield with a halved N dose as well as in combination with biostimulant application, but the latter did not confirm the capacity to contain nitrate, at least for this crop and in this cultivation system.

Plant biostimulants are substances (i.e., humic and fulvic acids, protein hydrolysates and seaweed extracts) and microbial inoculants (i.e., mycorrhizal fungi and plant growth promoting rhizobacteria-PGPR) that have been introduced as an efficient, safe and sustainable tool to optimize root system thus boosting crop performance, and nutrient use efficiency as well as enhancing tolerance to environmental stressors in vegetable crop production. The stimulation of biomass production in response to biostimulant application has been often associated to the action of specific signaling molecules on plant metabolism and physiology. Several trials have shown that Cucurbit crops can also benefit from the application of biostimulants. Early application at transplanting or in nursery of arbuscular mycorrhizal fungi (Rhizoglomus irregulare and Funneliformis mosseae) or vegetal biopolymer-based biostimulant on several Cucurbit crops (e.g., cucumber, melon, zucchini) were able to boost root growth and to activate defense mechanisms against environmental stresses (e.g., salinity, soil acidty and alkalinity). Moreover, foliar applications of biostimulant substances during the growing cycle were also effective in promoting crop productivity and increasing nutritional and functional quality in Cucurbit crops. Several examples will be presented and discussed together with possible mechanisms involved.

The goal of sustainable production is to reduce environmental degradation, to maintain agricultural productivity, to promote economic viability, as well as to reduce energy losses. Bedding plant sector is an important part of the nursery industry. Improving cultivation practices that increase the performance of potted ornamentals may become a promising and effectively sustainable strategy to be adopted in ornamental nursery. Among the important group of plant biostimulants soil activator complexes obtained by combination of macroalgae, zeolites, humic acids and soil bacteria improves the chemical-physical and microbiological properties of the substrate. The aim of this study was to assess the effect of a granular soil activator (Agrosil® Turf Algin) alone or in combination with two commercial controlled-release fertilizers (CRF) on growth, ornamental quality, leaf gas exchanges as well as mineral composition of two bedding plants: Begonia semperflorens and Salvia splendens. The plant growth parameters and the ornamental quality recorded in Agrosil-treated bedding plants were species-dependent, and were also affected by CRF type. Our results also demonstrated that the activator application enhanced several growth performance and quality parameters of the two selected bedding plants: plant height, canopy volume, leaf area and colorimetry, number of flowers in both species. The increased crop performance recorded in both species in the treatment B+A could be attributed to an increase in photosynthetic activity as well as to a better nutritional status (higher N, P, and K).

Interest in plant biostimulants is on the rise, compelled by the growing interest of greenhouse growers and private industries in natural substances and beneficial microorganisms able to boost vegetables and ornamentals productivity in a sustainable way. Protein hydrolysates (PHs) and arbuscular mycorrhiza fungi (AMF) are two important groups of plant biostimulants. PHs are generally applied as foliar sprays or near the roots, whereas, AMF are applied as powder, pellet, gel and seed coating. PHs and AMF are widely used in greenhouse crops largely for improving plant nutrient uptake, growth, yield and fruit quality, and also for their ameliorating effect on crop tolerance to abiotic stressors. In the current review article, we give an update about the recent advances in the biostimulant properties of PHs and AMF on vegetables, flower and ornamental crops performance. The agronomical and physiological processes conferring tolerance and/or resistance to several environmental stresses in biostimulant-treated plants will be also elucidated.

Recently the European Union decided to reshape the existing Fertilizers Regulations, under the new regulation that plant biostimulants “shall be a CE marked fertilising product stimulating plant nutrition processes independently of the product’s nutrient content with the sole aim of improving one or more of the following characteristics of the plant and the plant rhizophere or phyllosphere: nutrient use efficiency, abiotic tolerance and product quality”. Plant biostimulants can be divided in two major categories, the non-microbial biostimulants including bioactive substances such as humic acids, protein hydrolysates from vegetal and animal origin as well as seaweed extracts. The second category is the microbial biostimulants including arbuscular mycorrhiza fungi (AMF) and plant growth promoting rhizobacteria belonging to the genera Azotobacter, Azospirillum and Rhizobium spp. In the present paper several case studies on important greenhouse vegetables such as tomato, spinach, zucchini squash and cucumber were reported in order to demonstrate how the application of non-microbial and microbial plant biostimulants can modulate the quality of the product. The application of protein hydrolysate and seaweed extracts improve the fresh yield of both tomato and spinach but differently modulated the quality characteristics in particular lycopene, total ascorbic acid, phenols and nitrate. The application of microbial biostimulant in particular AMF containing Rhizophagus irregular and Funneliformis mosseae was able to improve the macro- and microminerals profile in zucchini squash and cucumber. The present paper concludes by proposing future research toward enhancing product quality of greenhouse vegetables by optimizing biostimulants application and composition.

In many irrigated regions of Mediterranean areas, vegetable farmers are forced to use low quality water (often with elevated salinity) for their crops with important losses in productivity. Sweet basil (Ocimum basilicum L.) is one of the most important aromatic herbs cultivated in Italy under both open-field and protected conditions. The application of endophytic fungi such as mycorrhizal fungi and Trichoderma could be an efficient tool to mitigate the detrimental effect of salinity. A greenhouse experiment was carried out to assess the influence of co-inoculation of endophytic fungi and plant growth promoting rhizobacteria on yield and quality traits under non-saline (1 mM NaCl) and saline (40 mM NaCl) conditions. Increasing the NaCl concentration in the nutrient solution in both inoculated and non-inoculated plants decreased the yield and growth parameters but increased the quality traits in particular the hydrophilic and lipophilic antioxidant activities and total phenols. The microbial-based biostimulant markedly enhanced the marketable fresh yield by 17.0% compared to control plants. The better crop performance of inoculated basil has been attributed to a better pigment biosynthesis (i.e., higher SPAD index). On the other hand, the nitrate content in microbial biostimulant basil plants was significantly reduced by 16.1%, whereas the total phenols increased by 7.7% compared to untreated plants. Overall, the use of beneficial microorganisms could be adopted as a sustainable tool in vegetable cropping systems to mitigate the detrimental effect of saline water.

The unavailability of fresh water is one of the main concerns for horticulture nowadays and it is supposed to get worse in the coming future. Some crops are more vulnerable than others to drought stress such as leafy vegetables. It is therefore essential to identify and select cultivars that can overcome this kind of abiotic stress with limited or no substantial reduction in final yield, and to do it in a fast and effective way. High throughput phenotyping combined with advances in genome sequences provide efficient and reproducible approaches that are facilitating the discovery of genes and cultivars with improved plant performance under sub-optimal conditions. Drought resistance of two different Salanova® cultivars, ‘Aquino’ (green butterhead) and ‘Barlach’ (red butterhead), was tested, by using PlantScreen™, a high-throughput non-invasive imaging platform developed at Photon Systems Instruments (PSI, Czech Republic). The two cultivars performed similarly in both control (70% soil water content) and mild drought stress conditions (40% soil water content). The results demonstrated that ‘Aquino’ grew faster in control conditions at early growth phase, while in later phase it is the red ‘Barlach’ that reached larger biomass. In drought conditions growth performance of both cultivars was rapidly compromised. However, ‘Barlach’ grew better and had improved biomass in both control and mild-drought stress conditions in comparison with ‘Aquino’. Light curve protocol was used to address light use efficiency of the two cultivars. Interestingly, we observed a rapid decline in PS II operating efficiency already three days upon mild drought stress initiation. Nevertheless, there was no obvious difference in the performances between the two cultivars. In conclusion, the results of quantitative analysis of plant growth and photosynthetic performance, allowed to set up a protocol for high-throughput image-based analysis of different morpho-physiological traits associated with the early phase of drought response.

A greenhouse experiment was carried out during the winter growing season in 2015 in Ladispoli (central Italy) to assess the influence of Trichoderma atroviride strain AT10 on shoot fresh biomass and resistance against the soilborne pathogen Sclerotinia spp. of lettuce crop (Lactuca sativa L. ‘Canasta’) grown in a naturally infested soil. T. atroviride strain AT10 was applied five times (1, 11, 24, 34 and 49 days after transplanting) by drip irrigation at a rate of 1 kg ha-1 for each application. Lettuce drop caused by Sclerotinia spp. appeared at 49 days after transplanting where untreated plants (control) showed a higher mortality than plant treated with T. atroviride (4.0 vs. 0.9%). The disease incidence increased significantly at 56 days after transplanting with higher value in control plots than in plots treated with T. atroviride AT10 (4.1 vs. 2.4%). At the end of the trial (61 days after transplanting) the disease incidence reached 8.5% in control plot and 3.3% in treated plots. The efficacy of Trichoderma treatments in reducing the disease incidence in comparison with control treatment was calculated with the Abbott’s formula and varied from 42.1 to 77.2%. The antagonistic activity of T. atroviride strain AT10 against Sclerotinia was demonstrated through in vitro tests. At harvest, lettuce plants inoculated with T. atroviride strain AT10 had a 13% higher shoot fresh weight than untreated plants indicating a phytostimulation action of the endophytic fungus.

The use of biostimulants has gained popularity in recent years as a sustainable approach to increase the yield and quality of horticultural crops. However, information is missing concerning their ability to enhance the concentration of some beneficial elements (macro- and microelements) in the edible tissues of plants, which, in turn, are useful for human health. For this reason, we investigated the effects of different microbial and non-microbial biostimulants on the content of essential macro- and micro-nutrients (P, K, Ca, Mg, Cu, Fe, Mn, Zn, Se) in San Marzano and Datterino tomatoes (Solanum lycopersicum L.) and spinach (Spinacia oleracea L.) by atomic adsorption spectrometry, also estimating the Daily Intake (EDI) and the Nutrient Contribution (NC) of fresh produce. All the biostimulants were able to increase the content of macro- and micro-nutrients in the studied horticultural products. Specifically, compared with control, application of Trichoderma harzianum T22 on the Pixel tomato increased Fe, Zn, Cu, Mn and Se contents by 49.66, 38.68, 129.79, 64.03 and 72.72%. In the San Marzano tomato, higher values of Fe (55.16 µg 100 g−1 fw), Mn (30.63 µg 100 g−1 fw), Zn (20.89 µg 100 g−1 fw), Cu (1.91 µg 100 g−1 fw) and Se (0.266 µg 100 g−1 fw) were obtained after application of a tropical plant extract (TPE) biostimulant. Similarly, compared with control, application of a vegetal-derived protein hydrolysate (VPDH) on spinach increased EDI-Fe, EDI-Zn, EDI-Mn, EDI-Cu and EDI-Se by 98.98, 127.09, 125.93, 68.52 and 230.76%, respectively. Therefore, biostimulants, regardless of their origin and nature, could be an ecological tool for biofortification programs for both fruit and leafy vegetables.

The use of plant biostimulants such as seaweed extracts (SWE) and protein hydrolysates (PH) has grown in the recent years due to their beneficial effects on yield under both optimal and sub-optimal conditions such as salt stress. The comprehension of the mode of action of these two important categories of biostimulants on plant performance will allow to use them more efficiently under different growth conditions. This study aimed to examine the efficacy of a seaweed and plant-based biostimulants on greenhouse lettuce (Lactuca sativa L.) grown under non-saline (0 mM NaCl) and saline conditions (40 mM NaCl) in terms of growth, yield, SPAD index, leaf mineral composition and metabolomic profiling. Shoot fresh weight of lettuce was reduced by 15.3% under 40 mM of NaCl. Nonetheless, it was boosted by both used biostimulants by 9 and 18%, on average, under 0 and 40 mM NaCl salinity, respectively. Na content under saline conditions was reduced in the presence of the biostimulants treatment, where PH reduced it significantly by 15.6% and SWE by 9.4%. On the other hand, Cl content was significantly reduced only under PH treatment. Both biostimulants elicited a broad metabolic reprogramming, involving the accumulation of stress-related compounds such as glucosinolates, terpenoid phytoalexins, and jasmonates. Interestingly, distinctive metabolomic signatures could be observed following the application of the different biostimulants under salinity conditions. In more detail, PH promoted the accumulation of glucosinolates and phytoalexins precursors, while SWE induced a down accumulation of secondary metabolites. Our findings indicate different processes being modulated by PH and SWE, with possible synergistic effects, thus paving the way towards integrated strategies to alleviate the detrimental effects of salinity in lettuce.

In the coming years, the scientific community, extension specialists and horticulturists will have to deal with growing agronomic and horticultural crops under sub-optimal conditions dictated by a global change scenarios. Salinity which is a water or soil quality concern is one of the most serious threats limiting the productivity of vegetables which are highly susceptible to soil and/or water salinity. In vegetable crops, soil and/or water salinity have been reported to disturb biochemical, morpho-physiological, and molecular processes leading to stunted growth and yield reduction. This article gives an overview of the recent literature on salinity response of vegetable crops (in which sodium chloride, NaCl, is the predominant salt) as well as the physiological and molecular mechanisms of salt tolerance. The physiological mechanisms behind the response of vegetable crops to Na+ and Cl- and the functions that directly and/or indirectly affect the produce quality in terms of nutritional and functional quality will be elucidated. In addition, the effects of different salinity sources coming from other ions such as Mg2+, SO42-, HCO3- and Ca2+ are also discussed. Finally, the review paper identifies trendy research areas relevant to salinity as a eustressor for boosting quality of vegetables without compromising yield.

Nowadays, there is a large demand for nutrient-dense fruits to promote nutritional and metabolic human health. The production of commercial fruit crops is becoming progressively input-dependent to cope with the losses caused by biotic and abiotic stresses. A wide variety of underutilized crops, which are neither commercially cultivated nor traded on a large scale, are mainly grown, commercialized and consumed locally. These underutilized fruits have many advantages in terms of ease to grow, hardiness and resilience to climate changes compared to the major commercially grown crops. In addition, they are exceptionally rich in important phytochemicals and have medicinal value. Hence, their consumption may help to meet the nutritional needs of rural populations, such as those living in fragile arid and semi-arid regions around the world. In addition, local people are well aware of the nutritional and medicinal properties of these crops. Therefore, emphasis must be given to the rigorous study of the conservation and the nutritional characterization of these crops so that the future food basket may be widened for enhancing its functional and nutritional values. In this review, we described the ethnobotany, medicinal and nutritional values, biodiversity conservation and utilization strategies of 19 climate-resilient important, underutilized fruit crops of arid and semi-arid regions (Indian jujube, Indian gooseberry, lasora, bael, kair, karonda, tamarind, wood apple, custard apple, jamun, jharber, mahua, pilu, khejri, mulberry, chironji, manila tamarind, timroo, khirni).

Supplementary lighting of specific wavelengths can be used for inducing morphological and physiological responses in different crops, ultimately improving yield and quality. Based on this approach, new greenhouse covering materials are being developed in order to improve the use of sunlight in horticulture. These new-generation greenhouse coverings may incorporate light spectrum modulation agents or fluorescent additives which convert solar UV radiation into visible light. In this work, we tested the agronomical and physiological response of lettuce grown under a greenhouse covered with poly-methyl-methacrylate (PPMA) panels doped with a blend of the rare-earth inorganic material with a photo-luminescent effect. The doped greenhouse elicited a 36% increase in lettuce yield compared to the undoped greenhouse. Chlorophyll and carotenoid content, as well as antioxidant activity and ascorbic acid content, were not affected by greenhouse cover, but the doped panels induced a 22% reduction in total phenolics and a 14% increase in nitrate content in leaves. The greenhouse covering materials also affected the photochemistry of photosynthesis, as the daily fluctuations in both the effective quantum yield (ΦPSII) and the electron transport rate (ETR) were attenuated under the doped greenhouse. Non-photochemical quenching (NPQ) was closely related to the light environment in all experimental conditions, with the highest values at 14:00 h. Our results showed that the red-supplemented light spectrum under the doped greenhouse cover contributed to increased plant growth and yield, with a corresponding effect on the physiology of photosynthesis.

Lettuce (Lactuca sativa L.) is one of the most popular leafy vegetables, appreciated globally as a low-calorie food with bioactive compounds. The application of a low dose of abiotic stress is considered a sustainable pre-harvest strategy to modify the nutraceutical value of horticultural products. In this work, we explored the response of two differently colored (red or green) baby leaf lettuce varieties to four NaCl concentrations in the nutrient solution (from 1 to 30 mM), using a full factorial design. We focused on leaf morphological parameters and possible phytochemical enhancement of the main polyphenols and anthocyanins, analyzed by LC-MS. The response to low-to-moderate salt stress exposure was affected mainly by salt concentration for leaf traits or by the cultivar for leaf color, with very limited factors’ interactions. Multivariate analysis indicated a predominant role of the genotypic factor in shaping differences in the two weeks growing cycle for baby leaf lettuce. Phytochemically, different dose–response models to sub-optimal saline conditions may be applied to the various compounds. A significant hormetic stimulation was present only for cyanidin-malonyl glucoside, the main anthocyanin present in the red cultivar.

Various products are used to mitigate the negative effects of abiotic stress in olive trees. The aim of the research was to examine an anti-transpirant product (Vapor Gard®, V) and a kaolin- based product (Manisol, K) effect on the growth of two-year-old olive tree seedlings under high temperature. The study was conducted in a greenhouse on trees of a native cultivar of Campania (cv. Salella) grown in pot during the growing season from May to September 2020. The experimental design included two products: di-1-p-menthene (product V) and kaolin (product K), applied five times at 20 day intervals compared with a control. The following biometric, physiological, and nutraceutical parameters were evaluated: stomatal conductance, chlorophyll a fluorescence, Soil Plant Analysis Development (SPAD) index, relative water content (RWC), shoots growth, total leaf area per plant, trunk cross-sectional area, dry matter partitioning, total polyphenols, and antioxidant activity. The results obtained showed that the application of di-1-p-menthene (V) was able to induce a significant improvement of shoots growth (+37.22%) and trunk cross-sectional area (+46.60%) and a reduction of the stomatal conductance and an increase of leaf RWC values. Application with kaolin had positive effects on the total polyphenol content, with an increase over the control of 240.33% and higher antioxidant activity values. Further studies are necessary to determine the effect of these products on the biometric, physiological and nutraceutical parameters of mature olive trees cultivated in open field conditions.

Salinity is a major concern in several ecosystems and has a significant impact on global agriculture. To increase the sustainability of horticultural food systems, better management and usage of saline water and soils need to be supported by knowledge of the crop-specific responses to tolerable levels of salinity. The aim of this work was to study the effects of mild salinity on morphological growth and development, leaf color, mineral composition, antioxidant activities, and phenolic profile of sweet basil (Ocimum basilicum L.). Plants grew in hydroponics and were exposed to three nutrient solutions (NSs) differing in the NaCl concentration (either 0, 20, or 40 mM). Inhibitory effects on leaf area, fresh yield, and shoot biomass were evident starting from the lowest NaCl concentration, and they became more severe and wide-ranging at 40 mM, also affecting height and root-to-shoot ratio. Salinity increased the nutritional quality in terms of antioxidant activity and polyphenols in leaves, with a reduction in macroelements at 40 mM NaCl. Moreover, the two mild NaCl concentrations specifically modified the concentration of various phenolic acids in leaves. Overall, the use of a slightly saline (20 mM) NS could be tolerated by basil in hydroponics, strongly ameliorating the nutritional profile in the face of relative yield loss. Considering the significantly higher accumulation of bioactive compounds, our work implies that the use of low-salinity water can sustainably increase the nutritional value and the health-promoting features of basil leaves.