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

Wild edible plant species grown hydroponically with crop drainage water in a Mediterranean climate: Crop yield, leaf quality, and use of water and nutrients

There is an increasing interest in the cultivation of wild edible plants (WEP) in consideration of their quality attributes and salt tolerance, which makes these species good candidates for cascade cropping systems (CCS). In these systems, saline effluents from a salt-sensitive donor crop are used to irrigate a receiving crop with greater salt tolerance. The objective of this study was to evaluate two WEP species, Picris hieracioides (PH) and Plantago coronopus (PC) as candidate crops for CCS. Both species were grown hydroponically with saline effluent from a semi-closed substrate culture of tomato (the donor crop). Both PH and PC were grown in floating system for 36 days during spring using one of the following nutrient solutions: i) standard nutrient solution (CNS, control); ii) NaCl-enriched (50 mmol L-1) standard nutrient solution (SNS); iii) effluent from tomato substrate culture (TE); iv) artificial effluent (ATE), i.e. a nutrient with ion concentrations and salinity level (approximately 50 mmol L-1 NaCl) very close to those of TE. Compared with CNS, leaf production was significantly reduced in both TE (-33.6%) and ATE (-33.6%) plants of PH, and only in TE (-23.3%) plants of PC. In both species, leaf Na content increased in SNS (+858.1% in PH; +279.4% in PC), TE (+704.7% in PH; +226.3 in PC) and ATE (+697.7% in PH; +229.4% in PC) plants compared with the controls. Leaf antioxidant capacity was positively correlated with total phenol content and, in PC, increased in SNS (+74.3%), TE (+53.9%) and ATE plants (+37.7%) compared with the controls. In conclusion, both PH and PC could be grown in CCS with saline greenhouse hydroponic effluents since the moderate reduction of leaf production could be partially compensated by reduced production costs because of zero costs for fertilisers. The growth inhibition observed in both WEPs species cultivated with the hydroponic effluent was primarily due to its high salinity with minor or no effects due to the suboptimal nutrient levels and/or the presence of phytotoxic root exudates or microbial metabolites

Multidisciplinary integrated characterization of a native Chlorella-like microalgal strain isolated from a municipal landfill leachate

To date, more than one-hundred taxa of green unicellular coccoid organisms have been wrongly included under the genus Chlorella. This is mainly due to the incomplete characterization resulting from studies that have not adopted and integrated the description of cell morphology, metabolic characteristics and genomic features. In this work, a new native Chlorella-like microalgal strain named “SEC_LI_ChL_1”, is described through a multimethod study. This strain was isolated from a pond where municipal landfil leachate flwed before wastewater treatment. The molecular characterization and the phylogenetic reconstructions based on two different DNA marker regions (i.e. the concatenated SSU and ITS rRNA gene and the complete 18S rRNA gene) were combined with light and transmission electron microscope observations, in addition to the analysis of metabolic traits under four different growing conditions (i.e. autotrophy, heterotrophy, mixotrophy and reduced autotrophy). The two separate phylogenetic analyses highlighted that the strain falls within the Chlorella-Micractinium clade, but with two different placements. According to the morphological-ultrastructural and metabolic analyses, “SEC_LI_ChL_1” shares some features with different Chlorella-like microalgae. Interestingly, two peculiar traits rarely or never previously described in Chlorella-like microalgal strains were observed: the association of the cells with endocellular bacteria, and the presence of doublets (i.e. two-celled microalgae aggregates not due to cell division)

Weeds for weed control: Asteraceae essential oils as natural herbicides.

The aim of this study was to test the botanical family of Asteraceae as a source of natural herbicides. Twenty Asteraceae species were collected during flowering time and evaluated in terms of the yield and quality of essential oils (germination inhibition and growth of weeds). Half the species showed a sufficient yield of essential oil (from about 0.1% to 1.43%) when testing these phytochemicals in vitro as germination inhibitors of two typical weeds, Amaranthus retroflexus and Setaria viridis. Despite the higher tolerance of S. viridis, the concentration of 100 lg L 1 of essential oils of the two Artemisia species and Xanthium strumarium could totally inhibit germination. In addition, at 10 lg L 1, the same essential oils showed full inhibition of A. retroflexus seeds. A comparison of their effectiveness at suboptimal doses led to a further selection of the most promising sources of essential oils. After their chemical characterisation, the essential oils were tested as post-emergence herbicides on seedlings of the above-cited weeds. After spraying the weeds at different concentrations (10, 100 and 1000 mg L 1) during two different phenological stages of weed seedlings (cotyledons and the third true leaf), the essential oils of Artemisia annua and X. strumarium showed the best performance. The essential oils of X. strumarium were then tested again on both weeds to monitor the dynamics of plant injury. A reduction in plant fresh weight (about 20%–30% after 10 days) and chlorophyll content (destroyed, after the same amount of time) was found, thus confirming the total and rapid effectiveness of these essential oils. In summary, A. annua and X. strumarium have elicited considerable agronomic interest and appear to be suitable as a source of essential oils to act as natural herbicides

Advances in irrigation management in greenhouse cultivation

The advantages of greenhouse include the ability to secure better conditions than outdoor environment for crop growth and development, increased off-season production and autonomy from external weather conditions. This chapter provides an up-to-date critical overview of scientific advances in irrigation management for greenhouse vegetables and ornamentals. The chapter presents a technical design of a typical greenhouse irrigation system, before covering water balance and crop evapotranspiration techniques as well as the use of high-tech moisture sensors for irrigation scheduling. In the context of enhancing the water use efficiency of greenhouse crops, the chapter also discusses innovative management practices such as biostimulants and grafting. Finally, the chapter concludes by looking ahead to future prospects and research breakthroughs

A reflection of the use of the life cycle assessment tool for agri-food sustainability

In pursuit of agricultural sustainability and food security, research should contribute to policy-making by providing scientifically robust evidence. Life cycle assessment (LCA) is an excellent candidate for generating that evidence, thereby helping the selection of interventions towards more sustainable agri-food. The purpose of this article is proposing a basis for discussion on the use of the LCA tool for targeting and monitoring of environmental policy interventions in agri-food. The problem of reducing the environmental burden in agri-food can be tackled by acting on the supply and/or demand sides and may benefit from the collaboration of supply chain stakeholders. Agri-food policies that most benefit from LCA-based data concern cross-border pollution, transaction costs following the adoption of environmental standards, adoption of less polluting practices and/or technologies, and business-to-consumer information asymmetry. The choice between the methodological options available for LCA studies (attributional, consequential, or hybrid models) depends on the purpose and scope of the study. The possibility of integrating the LCA with economic and social impact assessments-e.g., under the life cycle sustainability assessment framework-makes LCA an excellent tool for monitoring business or sectoral-level achievements with respect to UN 2030 Sustainable Development Goals

Growth, Evapotranspiration and Mineral Content of Gerbera Under Combined Salinity and Excess Boron

Gerbera is a very important plant widely grown for cut flowers. To check the influence of salinity and boron excess in nutrient solution, nine treatments as factorial combination of three sodium chloride (NaCl) (1, 15 and 30 mM) and three boron (B) (0.1, 1 and 2 mM) concentrations in the nutrient solution were applied during the gerbera cultivation. The effects of experimental treatments on gerbera growth, flowering and the interaction in morphological and nutritional aspects were tested. The formation of leaves, stems and flowers, flower dry mass and evapotranspiration (ET) were more negatively affected when plants were irrigated with 2 mM B than with 0.1 mM B concentration. High levels of boron (1 and 2 Mm) in nutrient solution resulted in leaf chlorosis and necrosis. The severity of leaf burn was correlated with leaf B content. Salinity acted as a protector against boron content in leaves and flowers at 1 Mm B. However, at the 2 Mm B in nutrient solution, leaf B accumulation was not reduced by the presence of NaCl but also increased with the increased levels of salinity. The external levels of boron used in this study, which were found to be the highest in the literature, and the high sensitivity of gerbera to boron, suggested that boron acted as the dominant factor. Lower external boron concentrations would be needed to establish to what extent salinity would be able to mitigate the negative effects of boron

Host compatibility and fertilization level modulate mycorrhizal establishment and growth of two ornamental shrubs

We evaluated mycorrhizal responses of two container-grown ornamental shrubs, Photinia × fraseri and Lantana camara cultivated in soilless substrate with two fertilization regimes and inoculated with two mycorrhizal inocula, a commercial one (Symb) and an experimental one (MicroLab). Fertilization rate, inoculum type and plant genotype differentially affected mycorrhizal colonization, plant growth and mineral nutrition. At high fertility levels a significant reduction of mycorrhizal colonization occurred in both shrubs inoculated with Symb, while MicroLab successfully colonized L. camara roots. In P. fraseri MicroLab increased shoot dry weight at low fertility by 44.3% and 78.6% compared with control and Symb, respectively. In L. camara Symb increased plant height and shoot fresh weight at both fertility levels, compared with MicroLab and Control. Our work shows that host plant/mycorrhizal symbionts compatibility and fertilization may modulate the establishment and performance of mycorrhizal symbioses in container-grown woody ornamental

Growth, Evapotranspiration and Mineral Content of Gerbera Under Combined Salinity and Excess Boron

AbstractGerbera is a very important plant widely grown for cut flowers. To check the influence of salinity and boron excess in nutrient solution, nine treatments as factorial combination of three sodium chloride (NaCl) (1, 15 and 30 mM) and three boron (B) (0.1, 1 and 2 mM) concentrations in the nutrient solution were applied during the gerbera cultivation. The effects of experimental treatments on gerbera growth, flowering and the interaction in morphological and nutritional aspects were tested. The formation of leaves, stems and flowers, flower dry mass and evapotranspiration (ET) were more negatively affected when plants were irrigated with 2 mM B than with 0.1 mM B concentration. High levels of boron (1 and 2 Mm) in nutrient solution resulted in leaf chlorosis and necrosis. The severity of leaf burn was correlated with leaf B content. Salinity acted as a protector against boron content in leaves and flowers at 1 Mm B. However, at the 2 Mm B in nutrient solution, leaf B accumulation was not reduced by the presence of NaCl but also increased with the increased levels of salinity. The external levels of boron used in this study, which were found to be the highest in the literature, and the high sensitivity of gerbera to boron, suggested that boron acted as the dominant factor. Lower external boron concentrations would be needed to establish to what extent salinity would be able to mitigate the negative effects of boron