Agronomic, nutraceutical, and organoleptic performances of wild herbs of ethnobotanical tradition

There is a lack of information on how to grow wild herbs as nutraceutical foods. Ten wild herbs were collected in natural and/or anthropized environments and assessed for their agronomic performance as fresh-cut (or ready-to-eat) leafy vegetables and their nutraceutical and organoleptic attributes. Seed dormancy prevented acceptable germination in many species. However, a physiological seed treatment (soaking with sodium hypochlorite followed by incubation for 3 mo at 4°C in sand moistened with potassium nitrate solution) allowed satisfactory germination, usually above 80%. Cultivation in alveolar containers produced highly diversified fresh-cut productivity (250-550 g·m-2), lower than that of lettuce (Lactuca sativa L.; 16 >900 g·m-2) grown as a reference fresh cut green vegetable. Antioxidant power was often much 17 greater in wild herbs (20.0 to 62.0 mmol Fe2+·kg-1 FW) than in lettuce (21.0 mmol Fe2+·kg-1 18 FW). Evaluation of the sensory profile indicated that softness and sweet taste of lettuce were 19 generally preferred to the more robust flavors of wild herbs. Hardness and bitter taste produced a poor appreciation of most wild herbs. However, exceptions were evidenced due to characteristics of spiciness [Alliaria petiolata (M.Bieb) Cavara & Grande] and/or crunchiness (Silene vulgaris [Moench] Garcke). Frequent distrust for most herbs was expressed as an example of food neofobia that generally occurs for unknown bitter flavors. Most of the wild herbs were not suitable as fresh-cut leafy vegetables, but some species could be ingredients for mixed products with better flavor and health properties

Modelling transpiration of greenhouse gerbera (Gerbera jamesonii H. Bolus) grown in substrate with saline water in a Mediterranean climate

Gerbera plants were grown in semi-closed rockwool culture under greenhouse conditions in different seasons in a Mediterranean climate. The plants were irrigated using either fresh (FW; 1.0 mol m−3NaCl)or moderately saline (SW; 9.0 mol m−3NaCl) water. In autumn, NaCl concentration did not influence significantly plant growth, flower production and transpiration (E), which instead were reduced in springin the plants irrigated with SW. In both seasons, water salinity did not affect leaf stomatal resistance (rl),which was determined by the inversion of the Penman–Monteith (PM) equation or measured with a diffusion porometer. The PM formula and two regression equations were calibrated and validated for estimating the hourly rate of daytime transpiration (Ed); a regression model was also fit to nocturnal transpiration (En). Regression models predicted Edas a function of vapour pressure deficit (VPD) and/or the radiation intercepted by the canopy. Leaf area index (LAI), which is required by all the equations, was modelled as function of crop thermal time (i.e. growing degree days). The PM model predicted Ed using a constant value of rl. Model calibration and validation were performed using independent data sets. The irrigation with FW or SW did not require a different calibration of transpiration models. Both PM formula and regression equations provided accurate estimates of Ed; fitted equations explained between 80% and96% of the variance in measured Ed. A linear regression of En against (LAI·VPD) accounted for 92% of measured En

Innovative Controlled-Release Polyurethane-Coated Urea Could Reduce N Leaching in Tomato Crop in Comparison to Conventional and Stabilized Fertilizers

Large amounts of fertilizers are being used in agriculture to sustain growing demands for food, especially in vegetable production systems. Soluble fertilizers can generally ensure high crop yields, but excessive leaching of nutrients, mainly as nitrate, can be a major cause of water pollution. Controlled-release fertilizers improve the nutrient use efficiency and lower the environmental hazard, usually without affecting the production. In this study, an innovative controlled-release coated urea fertilizer was compared to conventional nitrogen (N) fertilizers and a soluble ammonium-based fertilizer containing a nitrification inhibitor, in a round table tomato cultivation. Both the water and N balance were evaluated for each treatment, along with the yield and quality of the production. The experiment was repeated in three different seasons (spring, autumn and summer-autumn) in a glasshouse to prevent the effect of uncontrolled rainfall. The results indicated that N leaching decreased by increasing the percentage of coated urea. The application of at least 50% total N as coated urea strongly reduced N leaching and improved N agronomic efficiency in comparison with traditional fertilizers, ensuring at the same time a similar fruit production. Due to reduced leaching, the total N amount commonly applied by growers could be lowered by 25% without detrimental effects on commercial production

Modelling plant yield and quality response of fresh-market spinach (Spinacia oleracea L.) to mineral nitrogen availability in the root zone

Spinach is one of the most important green-leafy vegetables, consumed worldwide, and its intake is beneficial for human beings. In this crop, produce yield and quality are closely related to plant nitrogen (N) nutrition. A precise supply of N is also essential for high environmental and economic sustainability. Main aims of the work were: i) to establish relationships between produce yield or quality and mineral N availability in the root zone; and ii) to define an optimal mineral N level to be maintained in the root zone for spinach. Eight experiments were carried out during a four-year-long period under typical Mediterranean climate conditions. Different amounts of N fertilisers were supplied leading to twenty different levels of mineral N in the root zone. Experimental measurements included climate parameters, plant growth, tissue and soil analyses, produce yield and quality indicators. A segmented linear model significantly represented the relationship between crop yield (1.7 to 21.7 t ha–1) and soil mineral N concentration (7.6 to 41.0 mg kg–1). Basing on this model, an optimal mineral N threshold was fixed at 23.4 mg kg–1. Above this threshold, crop yield did not show any significant variations as well as tissue characteristics and produce quality. Plants grown under suboptimal N levels showed reduction in growth, tissue mineral (nutrients) content, and SPAD index. The proposed models could be implemented in fertilisation protocols for the optimization of N supply and the estimation of spinach growth and yield

Boron accumulation and tolerance in sweet basil (Ocimum basilicum L.) with green or purple leaves

Background and aims There is a wide variability in plant tolerance to boron (B) toxicity, which is often associated with the ability to limit B accumulation. This study was conducted on two cultivars of sweet basil (Ocimum basilicum L.) with different B tolerance: ‘Tigullio’, less tolerant and with green leaves; ‘Red Rubin’, more tolerant and with purple leaves. The main goal was to verify whether the greater B tolerance of ‘Red Rubin’ is attributable to an exclusion mechanism. Methods In three greenhouse experiments, plants were grown hydroponically with solution B concentration ranging from 0.25 (control) to 25 mg L−1. Results Tissue B concentration increased with increasing B supply. Boron concentrations in root and leaf tissues were comparable in ‘Tigullio’ and ‘Red Rubin’ or even higher in the purple cultivar. Boron supply did not affect the leaf concentration of total phenolic compounds and other nutrients. Leaf concentrations of total phenols and rosmarinic acid were remarkably higher in ‘Red Rubin’ than in ‘Tigullio’. Conclusions The greater B tolerance of ‘Red Rubin’ was associated with the ability to withstand higher concentrations of this element in plant tissues rather than to reduced B accumulation in the shoot. The high phenolic content was thought to contribute to the B tolerance of ‘Red Rubin’

Nutrient Extraction in Pansy Fertigated with Pure, Diluted, Depurated and Phytodepurated Leachates from Municipal Solid Waste

The disposal of municipal solid waste (MSW) in landfills might result in serious environmental pollution. The goal of the present assay was to assess if MSW wastewater (pure or treated) can be used as a potential source for fertilizers, studying its effects on plant biometric parameters as well as on anion concentrations and anion partitioning of the bedding plant Viola × wittrockiana Gams. (pansy), to detect possible harmful impacts on plants. The treatments tested were: W9.0 (pure wastewater, EC 9.0 dS m−1), W4.5 (diluted wastewater, EC 4.5 dS m−1), DW4.5 (depurated wastewater, EC 4.5 dS m−1), PW4.5 (phytodepurated wastewater, EC 4.5 dS m−1), and T (tap water, the control, EC 1.5 dS m−1). The treatment with pure wastewater negatively affected plant fresh weight, water content (on a fresh weight basis), leaf area, plant height and width, and the number of leaves and flowers due to an accumulation of SO42− in plant tissues. Phytodepurated wastewater improved plant fresh weight, water content, plant height and width, the number of leaves and flowers, and reduced the leaf area because this treatment decreased SO42− concentrations in wastewater by half. Pansy plants also showed high levels of nutrients (N, P, and Mg) when compared with fertigation with pure and diluted landfill leachate. These results show that phytodepurated wastewater from MSW can be used for the fertigation of pansy plants

Essential Oil from Origanum vulgare Completely Inhibits the Growth of Multidrug-Resistant Cystic Fibrosis Pathogens.

Essential oils (EOs) are known to inhibit the growth of a wide range of microorganisms. Particularly interesting is the possible use of EOs to treat multidrug-resistant cystic fibrosis (CF) pathogens. We tested the essential oil (EO) from Origanum vulgare for in vitro antimicrobial activity, against three of the major human opportunistic pathogens responsible for respiratory infections in CF patients; these are methicillin-resistant Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Antibiotic susceptibility of each strain was previously tested by the standard disk diffusion method. Most strains were resistant to multiple antibiotics and could be defined as multi-drug-resistant (MDR). The antibacterial activity of O. vulgare EO (OEO) against a panel of 59 bacterial strains was evaluated, with MIC and MBC determined at 24, 48 and 72 hours by a microdilution method. The OEO was effective against all tested strains, although to a different extent. The MBC and MIC of OEO for S. aureus strains were either lower or equal to 0.50%, v/v, for A. xylosoxidans strains were lower or equal to 1% and 0.50%, v/v, respectively; and for S. maltophilia strains were lower or equal to 0.25%, v/v. The results from this study suggest that OEO might exert a role as an antimicrobial in the treatment of CF infections

Exploring the Anti-Burkholderia cepacia Complex Activity of Essential Oils: A Preliminary Analysis

In this work we have checked the ability of the essential oils extracted from six different medicinal plants (Eugenia caryophyllata, Origanum vulgare, Rosmarinus officinalis, Lavandula officinalis, Melaleuca alternifolia, and Thymus vulgaris) to inhibit the growth of 18 bacterial type strains belonging to the 18 known species of the Burkholderia cepacia complex (Bcc). These bacteria are opportunistic human pathogens that can cause severe infection in immunocompromised patients, especially those affected by cystic fibrosis (CF), and are often resistant to multiple antibiotics. The analysis of the aromatograms produced by the six oils revealed that, in spite of their different chemical composition, all of them were able to contrast the growth of Bcc members. However, three of them (i.e., Eugenia caryophyllata, Origanum vulgare, and Thymus vulgaris) were particularly active versus the Bcc strains, including those exhibiting a high degree or resistance to ciprofloxacin, one of the most used antibiotics to treat Bcc infections. These three oils are also active toward both environmental and clinical strains (isolated from CF patients), suggesting that they might be used in the future to fight B. cepacia complex infections