Benedetta Chiancone

Intensive agriculture relies heavily on synthetic fertilizers, which contribute to green‐house gas emissions and to the degradation of soil quality and microbial biodiversity. In line with circular‐economy principles, the conversion of organic biomass into biostimulants through fermentation has emerged as a sustainable strategy to support plant performance. This study evaluated the use of solid‐state fermentation with lactic acid bacteria (LAB) to produce an experimental biostimulant from retail lettuce waste and assessed its agronomic and microbial effects on soilless‐grown strawberry. A design of experiments approach, a statistical, multivariate method for systematically planning experiments and modelling the relationships between process factors and measured responses, was used to model the fermentation process and to identify the key factors driving microbial growth. Strain selection was the main determinant, and fermentation with Lactiplantibacillus plantarum at 25°C for 24 h was identified as the optimal condition, reaching 8.6 Log CFU g ⁻¹ . When applied to strawberries, the fermented biostimulant enhanced plant growth, root development and fruit production in a dose‐ and stage‐dependent manner, with the highest dose increasing fruit number by approximately 3.7‐fold and markedly raising fruit fresh weight and phenolic content relative to the untreated control. Metabolic profiling of the rhizosphere revealed stage‐dependent shifts in carbon‐source utilization, while qPCR showed that the inoculated L. plantarum persisted in the rhizosphere for several weeks after application, despite a progressive decline in abundance. Overall, fermented lettuce biomass shows promise as a sustainable biostimulant capable of improving strawberry growth and fruit quality, offering a circular‐economy route for the valorization of retail vegetable waste. These findings should be regarded as preliminary and warrant further formulation and field‐scale validation.

Biochar has been widely investigated for its potential to improve substrate properties and plant performance, offering a potential partial replacement for peat in soilless cultivation amid declining peat availability. However, information on its short‐term physiological and molecular effects during the early establishment of container‐grown blueberry plants remains limited. This study evaluated the short‐term effects of biochar incorporation (0% (BC0), 5% (BC5), and 10% (BC10)), as a partial replacement of a peat‐based substrate, on growth, photosynthetic traits, and gene expression in potted highbush blueberry ( Vaccinium corymbosum L.), cv. “Sierra”, at the establishment stage (25–40 cm in height). A non‐fertilized commercial biochar was incorporated into the substrate in April 2024, and plant responses were evaluated in September 2024. Plant height was not affected by BC5, while BC10 reduced it by 10%. Leaf chlorophyll content (SPAD) decreased following both biochar treatments, while maximum PSII efficiency (Fv/Fm) remained unaffected. Gas‐exchange analyses indicated that BC10 plants exhibited altered light‐response traits, including lower dark respiration and a reduced light‐compensation point, although no significant changes were observed in V _cmax or J _max . Gene expression analysis showed consistent upregulation of growth‐related genes (SAUR49, STP, TCH4, DRM1) in biochar‐treated plants, whereas defence‐related genes (AOS, CHIB, JAS5, NPR1) displayed heterogeneous responses. Overall, biochar application modulated physiological and transcriptional processes in young blueberry plants, highlighting early responses occurring during establishment rather than direct improvements in growth. Within the tested range, results suggest that partial substitution of the substrate with biochar (5–10% v/v) does not enhance short‐term growth and may induce dose‐dependent effects. These findings should be interpreted as preliminary and hypothesis‐generating, supporting the need for further studies integrating substrate chemistry, plant physiology, and long‐term performance across multiple growing seasons under northern European climate conditions.

Tomato production increasingly requires high‐yield plants and fruits with enhanced firmness and resistance to mechanical damage in order to reduce post‐harvest losses. Pre‐harvest treatments‐ may play a key role in modulating these quality attributes. This study investigated the effect of biochar, used as a partial replacement of agriperlite (2% and 4% v/v), and wood distillate (WD) on vegetative growth, yield, fruit quality, and mechanical properties of cherry tomato ( Solanum lycopersicum L., cv. Cikito) grown in a soilless system. Particular attention was given to mechanical parameters, including initial and mean firmness, apparent modulus of elasticity, deformation indices, absorbed energy, and elasticity. Biochar application, especially at 4% in combination with WD, significantly increased total yield and fruit number, while WD alone enhanced individual fruit weight and juice yield, particularly at the first harvest. Mechanical analyses showed that biochar improved fruit firmness and tissue stiffness, whereas WD promoted greater deformation and elasticity, indicating contrasting effects on post‐harvest behavior. Fruit color ‐ varied according to harvest stage, with significant biochar–WD interactions affecting L* and b* values. Overall, the use of biochar as a partial substitute for conventional soilless substrates together with WD application, represents a promising strategy to enhance plant performance and to modulate key mechanical and technological attributes of tomato fruits. However, further optimization of WD application timing and frequency is required to ensure agronomic effectiveness while maintaining economic and environmental sustainability.

Sacha inchi (P. volubilis L.), an ancient oilseed crop native to the Amazon, is gaining attention for its high nutritional value particularly due to its ω-3-, -6-, -9-rich oil. However, most research has focused mainly on oil characterization, neglecting the potential of its by-products, such as the Sacha inchi oil-press cake (i.e., the solid residue after oil extraction). This study explores the chemical composition of Sacha inchi oil press-cake powder, focusing on fatty acid and amino acid profiles, antinutrient factors, total phenolic content, antioxidant activity, and the bioactivity of its extracts on cellular models. Fatty acid analysis revealed a high proportion of polyunsaturated fatty acids, especially α-linolenic acid (42.52%), making it a valuable resource for health-promoting applications. The protein content was also significant (41.86%), with a balanced amino acid composition, including essential amino acids such as leucine, valine, and isoleucine, which are vital for muscle protein synthesis and energy metabolism, in food and/or feed applications. Antinutritional factors were detected, including saponins (1050.1 ± 1.1 mg/100 g), alkaloids (2.1 ± 0.5 mg/100 g), and tannins (6.2 ± 0.9 mg/100 g). While these phytotoxins could limit their use in food applications, their potential antimicrobial activity highlights promising pharmacological opportunities. Total phenolic content (TPC) and antioxidant activity (AO) were evaluated using two extract mixtures differing in composition and polarity, with the acetone/water/acetic acid solvent (80/19/1 v/v/v) showing the highest antioxidant properties. The extract obtained showed cytotoxic effects against Panc-1 cancer cells, highlighting its potential in nutraceutical and pharmaceutical applications. This study underscores the unexploited potential of Sacha inchi by-products, such as the oil press-cake, as a sustainable resource of bioactive compounds for functional products, supporting circular bio-economy strategies by plant-based waste and local biodiversity valorization.

Biostimulants boost plant growth, productivity, and nutrient retention, and can be produced from agri-food waste via microbial fermentation. In this study, undersized and unsold kiwifruits were fermented with Lactiplantibacillus plantarum to produce a fermented kiwifruit-based biostimulant (FKB). FKB was applied to soilless tomato plants (cv. Solarino) at two concentrations (50 and 100 mL L⁻¹) at the root level, every two weeks throughout the crop cycle. Fruits were analyzed for technological and chemical parameters, including color, texture, total soluble solids, titratable acidity, sugar/acid ratio, pH, electrical conductivity, total polyphenol content, antioxidant activity, and lycopene concentration. Additionally, metataxonomic analysis characterized the substrate microbial community at the beginning and the end of cultivation. Overall, the results indicate a dose-dependent effect of FKB on fruit quality parameters, with the highest concentration showing the most pronounced effects, specifically for the fruit firmness (8.02 N for FKB at 100 mL L⁻¹ vs. 7.25 N for the Control). Moreover, both tested concentrations were associated with increased antioxidant activity (on average +28%), and lycopene content (on average +57%) compared with the Control fruits. While overall microbial diversity remained largely unchanged, the relative abundance of bacterial taxa associated with nutrient cycling and plant–microbe interactions was modulated by the biostimulant, indicating subtle but potentially functionally relevant shifts in the rhizosphere microbiota. These findings suggest that fermented kiwifruit biomass can serve as an effective biostimulant, improving both fruit quality and the functional structure of the rhizosphere microbial community in soilless tomato cultivation.

The global production of blueberries (Vaccinium corymbosum L.) has increased rapidly due to rising demand for antioxidant-rich fruits, making this crop increasingly important worldwide. Because blueberries require acidic soils, soilless systems offer a promising alternative by optimizing nutrient availability and reducing soil-related limitations. Among sustainable amendments, biochar (BC) improves water retention, porosity, and microbial activity, while wood distillate (WD), rich in bioactive compounds, can enhance plant resilience and growth. Although often used separately, their combined application may exert synergistic effects on substrate fertility and plant performance. This study investigated the effects of BC and WD, alone and in combination, on the growth, yield, and fruit quality of the ‘Cargo’ blueberry cultivar grown in a soilless system. Two distinct harvests were conducted during the growing season, and statistical analyses were performed independently for each, assessing treatment effects in relation to harvest timing. Moreover, the metabolic activity of the substrate’s microbial community was evaluated to assess the impact of the treatments. Results showed that BC application, particularly at 10%, significantly enhanced plant yield and fruit quality, increasing total phenolic content and antioxidant activity, while WD exhibited variable, dose-dependent effects on growth and biochemical traits, highlighting species-specific responses in soilless blueberry cultivation.

Hop is a perennial, deciduous climbing plant best known for its use in beer production. Recently, in line with the Green Strategy of Agenda 2030 and increasing market demand, research and industry interest in natural products has grown. In this context, hop biomass waste (HW), such as leaves, stems and non-standardized cones discarded after cone harvesting, has been shown to contain a wealth of bioactive compounds. These compounds offer promising applications in several productive sectors, including the pesticide industry. This study aims to evaluate the effect of extracts obtained from powdered HW (HWP) on two quarantine phytopathogenic bacteria: Erwinia amylovora (EA), the causal agent of fire blight in Rosaceae, and Xanthomonas campestris pv. campestris (Xcc), the causal agent of black rot in crucifers. Both diseases are highly destructive and economically impactful, necessitating the search for effective and eco-friendly alternatives. Various extracts were prepared, including two hydroalcoholic ones (ethanol/water 80:20 and 70:30), one ethanolic extract, and one methanolic extract. The potential mechanisms of action were investigated, with a focus on bacterial membrane permeability, biofilm formation and removal, and antioxidant activity, assessed using the Folin–Ciocalteu test. The in vitro analyses demonstrated that HWP extracts exhibit significant antibacterial activity against both EA and Xcc by altering bacterial membrane permeability, inhibiting biofilm formation, and promoting biofilm removal. The Folin–Ciocalteu test confirmed the presence of polyphenols, suggesting antioxidant activity. In planta tests provided realistic insights into the interaction between plants, bacteria, and extracts, showing promising results for the use of HWP extracts in controlling these phytopathogens. The study highlights the high efficacy, eco-friendliness, and sustainability of low-cost HWP extracts as a potential strategy for controlling fire blight and black rot. HWP extracts could serve as an alternative to traditional synthetic pesticides and antibiotics, promoting more sustainable and environmentally friendly agricultural practices, in line with Sustainable Development Goal 2 of the 2030 Agenda.

Increasing awareness of the adverse effects of agrochemicals is driving farmers to adopt more sustainable strategies for enhancing plant growth. Biostimulants have gained significant attention in both academic research and the horticultural industry as promising tools to promote growth, improve stress tolerance, and enhance crop performance, while reducing environmental impacts. This study, conducted from March to July 2024, evaluated the effects of different experimental biostimulants (EBs) on the growth, development, and productivity of wild strawberry plants ( Fragaria vesca L., cv. “Malga”) cultivated under greenhouse soilless conditions. Despite their diverse origins, all tested EBs were sustainably derived from circular economy processes: (i) a suspension of freeze‐dried microalgae ( Tetraselmis chuii ) (MA), (ii) a suspension of a lyophilized microbial mixed culture of purple non‐sulfur bacteria (PNSB), and (iii) a hydro‐alcoholic extract of pulverized hop biomass (HE). The EBs were applied weekly to the substrate: MA and PNSB at concentrations of 5% and 10%, and HE at 15 and 30 mL/L. Morphological and physiological parameters were recorded weekly until plant uprooting, while biochemical analyses were performed on leaves and fruits at the end of the trial. Application of EBs significantly enhanced plant growth and yield. MA treatments resulted in the greatest plant height, antioxidant activity, and total phenolic content; PNSB promoted the highest total root length and both fresh and dry biomass; and HE at 30 mL/L produced the greatest fruit number per plant. These results underline the potential of biostimulants to optimize strawberry production in controlled environments and contribute to more sustainable agricultural practices.

Strawberry [ Fragaria × ananassa (Weston) Rozier] cultivation is increasingly shifting toward soilless systems due to soilborne disease pressures and sustainability concerns. Peat, the traditional substrate of choice, faces ecological and economic challenges, driving the search for alternative materials. Biochar, a carbon‐rich byproduct of biomass pyrolysis, offers benefits such as enhanced water retention and nutrient dynamics, while wood distillate (WD), a secondary pyrolysis product, functions as a biostimulant promoting plant growth and stress resilience. This study evaluated the effects of biochar (0, 2% and 4% wt/wt) and WD (0, 2.5 mL/L, 5 mL/L and 10 mL/L on the substrate and 3 mL on the leaves) on soilless strawberry cultivation. Biochar had minimal impact during early growth but improved plant height, root length, and leaf area at harvest, particularly at higher concentrations, while at lowest doses, fruit yield and most quality parameters were unaffected, with slight improvements in colour and soluble solids. WD treatments, especially at 2.5 and 5 mL/L, enhanced several morphological and physiological traits. While neither amendment significantly increased yield or bioactive compound accumulation, both demonstrated potential to improve plant vigour and fruit quality. These findings support the use of biochar and WD as sustainable inputs in resource‐efficient, climate‐resilient strawberry production systems.

Hop (Humulus lupulus L.) is recognised for its abundance of bioactive compounds, which make it a valuable natural resource. While much of the research has focused on the cones, hop leaves remain relatively unexplored, particularly in terms of changes occurring throughout the plant's growing cycle. In this context, the present study aims to characterize extracts from the leaves of the hop variety ‘Cascade,’ harvested monthly over the growing season. The extracts obtained were evaluated for total (poly)phenolic content, antioxidant capacity, and (poly)phenolic profile using UPLC‐ESI‐QqQ‐MS/MS. Additionally, their antimicrobial activity was assessed. The results highlighted the presence of bioactive compounds with antioxidant potential, with some variations observed at different stages of growth. Our analysis identified 29 distinct compounds, with their concentrations fluctuating throughout the plant's life cycle. Furthermore, the leaf extracts exhibited antimicrobial activity against Listeria monocytogenes and Staphylococcus aureus, particularly during the early stages of the plant's growth.