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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.

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.

In order to evaluate the effects of beneficial microorganisms on greenhouse tomato “plum” grown under salinity conditions, research was carried out in Naples (southern Italy), by evaluating two arbuscular mycorrhizal fungi (AMF) treatments (Micoseeds Plus by Msbiotech, Myco Apply DR by Sumitomo, and a non-inoculated control) in factorial combinations with four soil electrical conductivities (1, 2, 3 or 4 mS cm-1 EC), by using a split plot design with three replicates. The mycorrhizal index increased from 1 to 2 mS cm-1 in plant roots inoculated with AMF, whereas in the control it decreased when the soil EC increased from 1 to 3 mS cm-1; the control attained lower values of mycorrhizal index than AMF treatments at any soil EC. AMF inoculated plants matured two days later than the control plants, but showed higher yield at all soil ECs. The plants grown under the 4 mS cm-1 soil EC matured four days earlier compared to 1 mS cm-1; the inoculation with beneficial microorganisms resulted in the best production performance under the 3 mS cm-1 soil EC due to both higher fruit number and mean weight, whereas the control plants attained the highest yield under both 2 and 3 mS cm-1 soil EC. The highest values of fruit dry residue and soluble solids as well as polyphenols, ascorbic acid and lycopene content were recorded under both of the AMF inoculations, and 4 mS cm-1 soil EC. The application of beneficial microorganisms as an environmentally friendly tool resulted in the improvement of tomato yield and quality performances both in normal and in saline soils.

Tobacco is an annual cash crop widely cultivated over the world, which generally needs great amounts (N) of nitrogen to achieve the best yield and quality. However, with a view to sustainable and environmentally friendly agriculture, also for this crop, the reduction in N fertilization is a priority, but without negatively affecting the yield and quality of the cured product. Therefore, field experiments were conducted during 2002 and 2003 on light air-cured (Burley) tobacco at three different locations of the Campania region (Southern Italy) where high-quality light air-cured (Burley) tobacco is traditionally cultivated. At each location, the following six N fertilization treatments were compared with four replications (blocks): (i) a not fertilized control (N0), (ii) 50 kg N ha−1 (N50), 90 kg N ha−1 (N90), 130 kg N ha−1 (N130), 170 kg N ha−1 (N170), 210 kg N ha−1 (N210). The yield of cured leaves appeared positively influenced by N fertilization but not at a rate higher than 170 kg ha−1. N fertilization directly influenced nitrates and the total N content of cured leaves at all locations. The greater values of both parameters were reached at N130 or N90, respectively, at Vitulazio (CE), N170 at Bellizzi (SA), and N90 at San Giorgio del Sannio (BN). The fire holding capacity increased with N fertilization up to N170 treatment (12–13 s at CE and BN but just 8 s at SA). L* (brightness) decreased with increasing N fertilization giving cured leaves less bright and opaquer. The a/b ratio (a*, green/red, b*, blue/yellow) increased with N treatments producing cured leaves of dark hazelnut. The best scores were assigned to cured products obtained by plants fertilized with 170 kg N ha−1. N-use efficiencies were negatively influenced by N fertilization. The best NUE and N-uptake efficiency was recorded in 2002 at Vitulazio (CE), in spite of a higher NO3-N before N fertilization than other locations.

Phytoextraction of potentially toxic elements (PTEs) is eco-friendly and cost-effective for remediating agricultural contaminated soils, but plants can only take up bioavailable forms of PTEs, thus meaning that bioavailability is the key for the feasibility of this technique. With the aims to assess the phytoextraction efficiency on an agricultural soil contaminated by Cr, Zn, Cd, and Pb and the changes induced by plants in PTE bioavailability and in human health risk due to dietary exposure, in this work we carried out a mesocosm experiment with three successive croppings of Brassica juncea, each followed by Rocket salad as bioindicator. Brassica juncea extracted more Zn and Cd than Cr and Pb, significantly reducing, after three repeated croppings, the bioavailable element concentrations in soil as a result of plant uptake and soil pH changes. For Cd, this reduction did not bring the bioavailable amounts obtained by soil extraction with NH4NO3 below the trigger value of 0.1 mg kg&minus, 1 set by some European countries. Nevertheless, the Hazard Quotient for Cd in Rocket salad decreased across three repeated croppings of Brassica juncea. This indicated the beginning of a re-equilibration process between soil PTE forms of different bioavailability, that are in a dynamic equilibrium, thus stressing the need to monitor the possible regeneration of the most readily bioavailable pool.

Scientists, extensions specialists, and growers are seeking sustainable agricultural practices that are able to cope with these objectives in order to ensure global food security and minimize environmental damage. The use of mulching films and plant biostimulants in agriculture seems to be a valid solution for tackling these rising concerns. A greenhouse experiment was conducted in order to elucidate the morpho-physiological and nutritive characteristics of lettuce (Lactuca sativa L.) in response to foliar application of a tropical plant extract (PE) biostimulant and the use of plastic mulches. Two biodegradable mulch treatments (Mater-Bi&reg, 1 and Mater-Bi&reg, 2) were compared to black polyethylene (LDPE) and bare soil. Biodegradable mulch film Mater-Bi&reg, 1 produced a comparable marketable fresh yield to the commercial standard polyethylene (LDPE), whereas Mater-Bi&reg, 2 exhibited the highest crop productivity. When averaged over biostimulant application, lettuce plants grown with biodegradable film Mater-Bi&reg, 2 exhibited superior quality traits in terms of K, Ca, total ascorbic acid, and carotenoids content. The combination of film mulching (LDPE, Mater-Bi&reg, 1 or Mater-Bi&reg, 2) with the tropical plant extract biostimulant exhibited a positive and significant synergistic effect (+30%) on yield. The PE-biostimulant induced higher values of SPAD index and total chlorophyll content when compared to untreated greenhouse lettuce. The mineral content of leaf tissues was greater by 10% and 17% (for P and Ca, respectively) when compared to the untreated lettuce (no PE application). Nitrate content was significantly reduced by 23% in greenhouse lettuce plants receiving PE as compared to the untreated control. The positive effect of Mater-Bi&reg, 2 film on the ascorbic acid content has also been highlighted when combined with the biostimulant application, where a major amplification of total ascorbic acid (+168%) was recorded in comparison to the untreated lettuce. Overall, our work can assist leafy vegetables growers in adopting good agricultural practices, such as biodegradable plastic mulches and vegetal-derived biostimulants, to improve the sustainability of greenhouse production.

In recent years, the demand for green leafy vegetables is increasing. In order to satisfy this trend, the leafy crops are cultivated under high energetic inputs, especially high doses of nitrogen (N) fertilization that leads to a nitrate accumulation in leaves, sometimes overcoming the legal threshold set by the European Community for their commercialization. The nitrate in leaves can be dangerous for human health because in the human body it can be converted into nitrite, which can cause methemoglobinemia or create cancer-causing compounds. In order to overcome this problem, a correct N management is needed, especially using technical means which can improve the nitrogen use efficiency. In this study, we evaluated the possible effect of two important plant biostimulants on yield and quality traits (nitrate, antioxidants activity, carotenoids) of baby leafy lettuce, grown in a greenhouse with three levels of nitrogen input. Nitrogen doses were 0, 10 (sub-optimal) and 20 (optimal) kg ha-1, N0, N10 and N20 respectively. The biostimulants were Ecklonia maxima seaweed extract (3 ml per liter) (named Bio 1), legume-derived protein hydrolysate (Bio 2) and non-treated control (Control). The treatments were distributed in a randomized complete-block design with three replications (3 N levels x 3 Biostimulant applications x 3 replications). Biostimulant applications of seaweed extracts and legume-derived protein hydrolysate improved yield and LAI: 13.4% and 12.0% increase over non treated plants, respectively. The highest yield was reached at 20 kg N ha-1. Application of foliar biostimulants stimulated the antioxidant systems of plants, improved leaves color and increased chlorophyll and carotenoids content. The nitrate concentration in leaves was increased under higher levels of N fertilization, meeting the EC legal limit at N20 treatment in plants sprayed by E. maxima seaweed extract. Therefore, in our growth conditions, it seems possible to reduce nitrogen input at 10 kg N ha-1, by applying additional applications of biostimulants to reduce the yield gap upon application of N20 treatment.

The global increasing demand of lettuce is pushing farmers to boost their production through several technical means, including mulching and nitrogen fertilization. However, from an environmental protection perspective, the role of scientific research is to limit the excessive use of some chemical approaches. This research aims to evaluate the possible effects of two mulching films (black polyethylene, PE, and brown photoselective film, BF) and two treatments with a plant growth-promoting product, containing Trichoderma spp., (non-treated, - Control and treated with RYZO PEP UP, - TR), on the productive and qualitative traits of lettuce grown under four regimes of nitrogen (0, 30, 60 and 90 kg ha&minus, 1, N0, N30, N60, and N90, respectively). The marketable yield increased at higher nitrogen levels, but without differences between the N60 and N90 doses. The photoselective film elicited marketable yield, with an 8% increase over PE. N fertilization also improved photochemical efficiency (higher Soil Plant Analysis Development and chlorophyllous pigments biosynthesis), as well as antioxidant activities (lipophilic&mdash, LAA and hydrophilic&mdash, HAA) and bioactive compounds (phenols and total ascorbic acid&mdash, TAA). Interestingly, Trichoderma spp. had a positive effect on these qualitative parameters, especially when combined with mulching films, where the increase generated by PE-TR treatment over the all other treatments was 16.3% and 16.8% for LAA and HHA, respectively. In all treatments, the nitrate leaves content was consistently always within the legal limit imposed by the European community. Overall, although Trichoderma spp. did not engender a marked effect on yield, probably due to the short crop cycle, its positive effect on some quality traits is an interesting starting point for further research.

Little is known about the effects of inoculation with beneficial microorganisms under diversified crop rotations on agronomic performance of the high-value vegetable crop tomato (Solanum lycopersicum L.). A greenhouse experiment was conducted to evaluate the interactive effect of crop precession with two native species, faba bean (Leguminosae) and barley (Graminaceae), and inoculations with commercial arbuscular mycorrhizal fungi (AMF), and phosphate solubilizing Streptomyces roseocinereus MS1B15 on tomato plant growth, yield, fruit quality and the contents of various mineral nutrients. The overall results revealed that crop inoculation with S. roseocinereus MS1B15 significantly increased tomato growth and yield while crop precession showed no differences among tested treatments. Plant nutrient assimilation was significantly increased by both inoculations and was differentially modulated under faba bean and barley rotations. Furthermore, fruit quality demonstrated significant variations between treatments: whereas the inoculations significantly increased tomato vitamin C, crop rotations increased antioxidant compounds and organic acids. Overall, faba bean rotation combined with S. roseocinereus MS1B15 inoculation showed the best benefits for tomato plants, increasing most of the biometric variables evaluated in this study. Such combinations could be recommended as a sustainable and feasible model for tomato production.

Soil solarization is usually performed with polyethylene plastic films, which are often disposed of by taking them to landfills, burying them in soil, burning them or occasionally recycling them, and these approaches have a great impact on the environment. Therefore, the use of biodegradable films seems to be an interesting eco-sustainable alternative to traditional films. The effect of soil solarization carried out by using biodegradable mulch or traditional polyethylene plastic film was determined under greenhouse conditions. The response of the soil was assessed by chemical determinations and microbiological culture-dependent and culture-independent approaches to evaluate the microbial biodiversity, biological status and quality of the soil. The biodegradable film avoided a high ammonia concentration in the soil, thanks to both lower soil water content and slightly lower temperature than polyethylene film, and these conditions probably have been optimal for growth of nitrifying bacteria, which were more efficient in BIO, as highlighted not only by lower ammonia value but also by higher nitrate value. Both films did not affect organic matter and total nitrogen content. Moreover, the modifications of the environmental and ecological conditions associated with the different film covers applied to the soils affected prokaryotic and eukaryotic populations, leading to the establishment of a new dominant microbial community. Interestingly, microbiological analyses highlighted a different behavior modulated with the two films indicating different times of recovery post stress. Overall, the results highlighted the potential of biodegradable film that appears to be a suitable replacement for traditional polyethylene plastic film for soil solarization, with great environmental benefits.

Nitrogen is the primary technical means responsible for food production increase, but on the other hand, wise management is needed because its excessive use can have a negative impact on the environment and on green leafy vegetable quality, such as that rocket. Rocket has the characteristics of accumulating nitrate in leaves with possible impacts on human health. In order to overcome this issue, researchers are focusing their attention on the use of alternative means, such as plant biostimulant application. The scope of this study was to assess the effect of legume-derived protein hydrolysate(LDPH) and tropical plant extract(TPE), combined with various doses of nitrogen (0 kg ha&minus, 1 non-fertilized, N0), 60 kg ha&minus, 1 (sub-optimal, N1), 80 kg ha&minus, 1 (optimal, N2), and 100 kg ha&minus, 1 (supra-optimal, N3)), in order to reduce nitrogen use, boost yield, and enhance the chemical and nutritional value of leaves without significantly accumulating nitrate. Both vegetal-based plant biostimulants enhanced plant growth, boosted the marketable yield (especially at N0 and N1 levels, by 38.2% and 28.2%, respectively, compared to the non-treated control), and increased the SPAD (Soil Plant Analysis Development) index and leaf pigments content, such as chlorophyll and carotenoids, especially in treated-LDPH rocket. The plant-based biostimulants also produced a major amplification in lipophilic antioxidant activity (+ 48%) and total ascorbic acid content (average + 95.6%), especially at low nitrogen fertilization levels, and maintained nitrate content under the legal European Comission limits.

Nitrogen (N) fertilizers play a crucial role in agriculture, representing a powerful tool for farmers for increasing yields throughout the seasons under both optimal and suboptimal conditions. At the same time, their synthetic/chemical nature could have several influences on ecosystems and human health. For this reason, there is an urgent need to find new and more sustainable means of production to increase plant productivity and optimize nitrogen use. An experiment was conducted in a plastic tunnel to assess the response of baby lettuce crop to the foliar application of three plant biostimulants (PBs): Legume-derived protein hydrolysate (LDPH) &lsquo, Trainer&reg, &rsquo, tropical plant extract (TPE) &lsquo, Auxym&reg, and seaweed extract (SwE) from Ecklonia maxima &lsquo, Kelpak&reg, under different N rates of 0, 10, 20 and 30 kg N&middot, ha&minus, 1. The responses of baby lettuce plants were assessed in terms of yield, growth parameters and physicochemical composition of the leaves. The fresh yield of baby lettuce in both biostimulant-treated and untreated plants was positively affected by increasing N rates from 0 to 20 kg N&middot, 1, reaching a plateau thereafter indicating luxury N conditions at 30 kg N&middot, 1. However, high N fertilizer application (20 and especially 30 kg N&middot, 1) resulted in undesirable decreases in antioxidant activities and total ascorbic acid (TAA). Under non-fertilized regimens, foliar PBs application boost growth and yield of baby lettuce in comparison to non-treated plants. Foliar spray with LDPH and especially SwE elicited significant increases in marketable fresh yield (averaging 14%, 6% and 7% at 10, 20 and 30 kg N&middot, 1, respectively) compared to TPE and untreated plants. Improved agronomical performance of baby lettuce under optimal (10 kg N ha&minus, 1) and especially suboptimal N regimens (0 kg N ha&minus, 1) was associated with increasing photochemical efficiency and a better activity of photosystem II (higher Soil Plant Analysis Development-SPAD index and chlorophyllous pigments biosynthesis). The application of LDPH enhanced antioxidant capacity and TAA in baby lettuce leaf and did not increased nitrate content as recorded in SwE and TPE treatments. Overall, plant biostimulants may be considered as a sustainable tool of production to increase leafy vegetable productivity in low fertility soils.

Research has been increasingly focusing on the environmentally friendly biostimulation of vegetable crop performances under sustainable farming management. An experiment was carried out in southern Italy on Diplotaxis tenuifolia to assess the effects of two plant biostimulants (Legume-derived protein hydrolysate, Trainer&reg, Tropical plant extract, Auxym&reg, ) and a non-treated control, in factorial combination with three crop cycles (autumn&ndash, winter, and winter&ndash, spring) on leaf yield, photosynthetic and colour status, quality, elemental composition, antioxidant content and activity. Both biostimulants prevalently contain amino acids and soluble peptides, showing the major effects on crop performances, though Auxym also has a small percentage of phytohormones and vitamins. The biostimulants enhanced plant growth and the productivity of perennial wall rocket. The winter&ndash, spring cycle led to higher leaf yield than the winter one. The two plant biostimulants enhanced leaf dry matter, oxalic and citric acids, Ca and P concentrations, phenols and ascorbic acid content as well as antioxidant activity, but did not increase nitrate content. A presumed mechanism involved in the enhancement of crop production could be attributed to the improvement of mineral nutrient availability and uptake. The winter&ndash, spring cycle elicited higher antioxidant content and activity than winter crops. Our current study shows that both the legume-derived protein hydrolysate and tropical plant extract represent an effective tool for boosting the yield, nutritional and functional quality of vegetable produce in the view of sustainable crop systems.

An optimized nitrogen (N) fertilization may have a positive effect on leafy vegetables by increasing growth, yield and nutrient content of plants. Nevertheless, crop performance must be coupled with an increase in Nitrogen Use Efficiency (NUE) in order to limit external N inputs and to avoid N surpluses associated with environmental and health problems. The aim of the current study was to assess the effects of a legume-derived plant hydrolysates (LDPH, Trainer&reg, ) and N fertilization levels (0, 2.25 and 4.5 g N m&minus, 2 for spinach and 0, 2.5 and 5.0 g N m&minus, 2 for lamb&rsquo, s lettuce, N0%, N50%, N100%, respectively) on agronomical, biochemical, qualitative responses and NUE of these two important greenhouse leafy vegetables. Spinach and lamb&rsquo, s lettuce were sprayed four times during the growing period (at a concentration of 4 mL L&minus, 1 of LDPH). In baby spinach, the LDPH application elicited a significant increase at the three levels of N fertilization: +16.8%, +14.2%, and 39.4% at 0, 2.25 and 4.5 g N m&minus, 2, respectively. Interestingly, in lamb&rsquo, s lettuce, the N50% plants treated with LDPH reached similar values of marketable yield in comparison to treated and non-treated plants under N100% conditions. The presumed mechanism involved in the enhancement of yield response in the two leafy greens could be associated to a better activity of the photosystem II (higher SPAD index), biochemical (higher content of chlorophyll a, b and total) and leaf nitrate status. The foliar application of LDPH produced a major fortification in lipophilic and hydrophilic antioxidant activities (+11.6 and 6.3% for spinach and lamb&rsquo, s lettuce, respectively). The biostimulant application also improved N-use efficiency and N-uptake efficiency compared to untreated plants: +17.8% and +18.8%, and +50% and +73.3%, for spinach and lamb&rsquo, s lettuce, respectively.

The present study addresses the effects of Trichoderma-based biostimulants and nitrogen (N) fertilization levels on agronomic performance and functional quality of two important greenhouse leafy vegetables: lettuce and rocket. A factorial analysis of the relative effects of Trichoderma-based biostimulants (Trichoderma harzianum strain T22 and Trichoderma virens strain GV41) and N fertilization levels (sub-optimal, optimal, and supra-optimal) was carried out to evaluate crop productive behavior (marketable and unmarketable yields, leaf dry matter content, and biomass production), nitrogen nutrition (N uptake, apparent N recovery, and nitrogen use efficiency (NUE)) as well as phytochemical qualitative components (antioxidant activity and total polyphenols). The soil plant analysis development (SPAD) index in both leafy vegetables and leaf colorimetry only in rocket were mainly affected by N fertilization levels but not by Trichoderma-based biostimulants. The contribution of native mineral N was 60 and 100 kg N ha−1 of the total uptake in lettuce and rocket, respectively, and N surpluses were observed in both crops, even under optimal fertilization conditions. Trichoderma virens GV41-based biostimulant increased lettuce marketable yield and biomass production, both under optimal and sub-optimal fertilization. In addition, the same treatment increased NUE up to 116% under recommended N fertilization, that was also associated to an increase in phenol content and antioxidant activity. Rocket showed a clear effect of the Trichoderma virens GV41 treatment, only in absence of fertilization, demonstrating an increase in marketable yield and N uptake. Thus, the inoculation of rocket with this Trichoderma biostimulant can be considered as a useful management tool in leafy vegetable cropping systems for the efficient use of residual fertilizers from previous crops, enhancing NUE within the crop rotations. Nevertheless, the application of microbial biostimulant treatments requires good monitoring of soil N fertility in order to avoid an overexploitation of soil N supplying potential.

Plant-derived protein hydrolysates (PHs) are gaining prominence as biostimulants due to their potential to improve yield and nutritional quality even under suboptimal nutrient regimens. In this study, we investigated the effects of foliar application of a legume-derived PH (0 or 4 ml L&minus, 1) on greenhouse baby spinach (Spinacia oleracea L.) under four nitrogen (N) fertilization levels (0, 15, 30, or 45 kg ha&minus, 1) by evaluating morphological and colorimetric parameters, mineral composition, carbohydrates, proteins, and amino acids. The fresh yield in untreated and biostimulant-treated spinach plants increased in response to an increase in N fertilization from 1 up to 30 kg ha&minus, 1, reaching a plateau thereafter indicating the luxury consumption of N at 45 kg ha&minus, 1. Increasing N fertilization rate, independently of PH, lead to a significant increase of all amino acids with the exception of alanine, GABA, leucine, lysine, methionine, and ornithine but decreased the polyphenols content. Interestingly, the fresh yield at 0 and 15 kg ha&minus, 1 was clearly greater in PH-treated plants compared to untreated plants by 33.3% and 24.9%, respectively. This was associated with the presence in of amino acids and small peptides PH &lsquo, Trainer&reg, &rsquo, which act as signaling molecules eliciting auxin- and/or gibberellin-like activities on both leaves and roots and thus inducing a &ldquo, nutrient acquisition response&rdquo, that enhances nutrients acquisition and assimilation (high P, Ca, and Mg accumulation) as well as an increase in the photochemical efficiency and activity of photosystem II (higher SPAD index). Foliar applications of the commercial PH decreased the polyphenols content, but on the other hand strongly increased total amino acid content (+45%, +82%, and +59% at 0, 15, and 30 kg ha&minus, 1, respectively) but not at a 45-kg ha&minus, 1-rate. Overall, the use of PH could represent a sustainable tool for boosting yield and nitrogen use efficiency and coping with soil fertility problems under low input regimens.

With the aim of assessing the effects of beneficial microorganisms on greenhouse tomato &ldquo, plum&rdquo, grown under salinity conditions, research was carried out in southern Italy from summer to winter, by comparing two arbuscular mycorrhizal fungi (AMF) based formulates (Rizotech Plus, Myco Apply DR) and a non-inoculated control, in factorial combination with four soil electrical conductivities (1.5, 3.0, 4.5, 6.0 mS&middot, cm&minus, 1 EC). The highest root colonization was 83% at 3.0 mS&middot, 1 under AMF-based treatments and 34% at 1.5 mS&middot, 1 in non-treated control, the latter attained lower values than AMF treatments at any soil EC. Harvest occurred 3.5 days earlier in control plants, six days earlier under 6.0 mS&middot, 1 EC compared to 1.5 mS&middot, 1. The inoculated plants always showed higher yield than the control ones and the highest production at 4.5 mS&middot, 1 EC, control plants attained the highest yield under 3.0&ndash, 4.5 mS&middot, 1 EC. The highest values of most fruit quality indicators, mineral elements and antioxidant compounds and activity were recorded under AMF-based formulates inoculation and 6.0 mS&middot, 1 soil EC. Beneficial microorganisms proved to be an effective environmentally friendly tool for improving tomato yield and quality performances in both normal and soil salinity conditions.

Rapid analytical techniques were used to analyze the lipid fraction and to characterize phenolic compounds in Italian walnuts (Chandler cv.) grown in the same experimental orchard under different agronomical conditions. Lipid components such as fatty acids, sterols and tocopherols were determined by capillary gas chromatography using a flame ionization detector. Linoleic and linolenic acids were the most representative ω-6 and ω-3 essential dietary fatty acids present. A total lipid chromatogram was used to simultaneously determine free sterols and tocopherols. Walnuts contained substantial amounts of γ- and δ-tocopherol, which explains their antioxidant properties. Sitosterol, Δ5-avenasterol and campesterol were the major free sterols found. Micellar electrokinetic chromatography was used to analyze simple and complex phenols (tannin profile), while the total phenol amount and the antioxidant activity of phenolic extracts were assessed by spectrophotometric assays with Folin-Ciocalteu and ABTS•+ reagents, respectively. The total phenol content was higher than most foodstuffs. Moreover, more than 96% of the phenolic fraction belonged to the tannin class. Statistical analysis of the data showed that higher levels of nitrogen fertilization led to a significant increase in linoleic acid. This effect can induce a faster oxidation of lipid fraction of walnuts. Nevertheless, major nitrogen fertilization and irrigation were able to enrich walnuts in phenolic compounds. PRACTICAL APPLICATIONS Walnuts (Juglans regia L.) are a good source of essential fatty acids, tocopherols and phenolic compounds that contribute to reducing the risk of coronary heart disease, and also inhibit the oxidation of human plasma and low density lipoproteins. In this work, the applicability of fast analytical determinations was utilized to discriminate different walnut samples. Total lipid chromatogram was used for the simultaneous determination of the profile of sterols and tocopherols; micellar electrokinetic chromatography was used for the phenolic separation, which takes less than 10 min. The proposed methods are ideal for routine analysis of the lipidic and phenolic fractions in order to control the quality of walnuts.