Search Results (158)

Tagetes patula is a widely cultivated ornamental plant and a natural source of bioactive compounds. This study evaluated the effects of cultivation–substrate systems on growth, flowering, lutein and zeaxanthin accumulation, substrate microbiological properties, and pest and disease occurrence in three T. patula cultivars (‘Csemő’, ‘Robusta kénsárga’, and ‘Orion’) grown under two greenhouse (peat-based substrate and hydroponics) and three field conditions (peat-based and two peat-free substrates). Greenhouse hydroponics markedly enhanced vegetative growth, resulting in the highest plant height, stem diameter, and shoot biomass, whereas peat-based greenhouse substrates produced the lowest vegetative performance. Flowering responses were more moderate and largely cultivar-dependent: peat-based field conditions supported the highest inflorescence numbers, cv. ‘Orion’ produced the greatest inflorescence biomass, and cv. ‘Robuszta kénsárga’ showed the strongest flowering intensity in peat-based systems. Cultivar ‘Csemő’ consistently accumulated the highest lutein and zeaxanthin concentrations among cultivars. Substrate moisture and microbial activity differed substantially among systems, with peat-free substrates frequently exhibiting elevated enzymatic activity. No fungal diseases were detected; thrips occurred only in greenhouse systems, and spider mites were restricted to cv. ‘Orion’ under hydroponic conditions. Overall, hydroponic and peat-free systems enhanced vegetative growth and microbial activity, whereas flowering and carotenoid accumulation were primarily cultivar-specific, as further supported by correlation analysis and PCA. These findings demonstrate that sustainable peat alternatives and hydroponic systems can effectively support high-quality T. patula production and carotenoid yield. Full article

The exploration of Doggerland, the prehistoric landscape that once connected Britain to the continent, remains one of Europe’s most significant archeological challenges. This paper presents a study into the palaeolandscape and the paleoenvironmental development of Doggerland, through the geochemical analyses of a core (ELF019) taken from the southern North Sea. The thermal properties divided the core into three sedimentary zones based on the variations in organic matter and carbonate content. Organic biomarkers were used to distinguish between terrestrial and aquatic vegetation inputs, revealing alternating freshwater, terrestrial, and marine input influences. Chemostratigraphy defined six depositional zones that corresponded with the identified thermal and biomarker data. Radiocarbon dating of peat-derived humic fractions anchored the key environmental transition between freshwater and saline deposition to the Greenlandian period of the Lower Holocene (10,243–10,199 Cal BP). The integrated geochemical evidence suggests a transformation from freshwater silts, low organic content, and sandy clay deposit to saline clay marine deposit. The progressive transformation may reflect the inundation sequence that led to the final submergence of Doggerland. Full article

Amid global freshwater scarcity and soil salinization, brackish irrigation is a potential alternative, yet its effects under low-leaching soilless systems remain unclear. We tested brackish irrigation (30 mmol L⁻¹ NaCl; EC ≈ 4.8 dS m⁻¹, including fertilizer) on lettuce (Lactuca sativa L.) grown in peat–perlite substrates with non-saline (CK), mildly saline (M), and moderately–severely saline (S) initial salinity. Substrate moisture and bulk electrical conductivity (EC_b) were monitored at upper, middle, and deep layers with multi-depth sensors; lettuce physiological and growth traits were measured. Under negligible drainage, salt moved downward promptly after irrigation in CK, accumulated at the surface in M, and remained high with spatiotemporal variability in S. Brackish irrigation had minimal effects on biomass and water use efficiency in CK and M, but significantly reduced both in S. These findings support tailoring brackish irrigation to initial salinity severity and motivate future work to measure drainage and calibrate EC indices to establish operational thresholds. Full article

The demand for ready-to-eat salads made from leafy vegetables such as wild rocket (Diplotaxis tenuifolia L.) continues to increase, driven by consumer preference for convenience foods with high levels of bioactive compounds. However, reducing the environmental impact of wild rocket production requires both organically enriched growing substrates and sustainable alternatives to conventional plastic packaging. This study assessed the effects of three cultivation substrates and three biodegradable packaging materials (polylactic acid (PL), cellulose kraft (CK), and kraft-reinforced polylactic acid (PLK)) on the postharvest performance of wild rocket stored at 4 °C for 7 and 14 days. Plants were grown in coco peat (CP), coco peat supplemented with livestock compost (90:10; CP+LC), and coco peat mixed with mushroom compost (50:50; CP+MC). Yield and key pre- and postharvest quality attributes, including nitrate accumulation, phenolic content, antioxidant capacity, colour, and weight loss, were evaluated. The CP+LC substrate resulted in the highest harvest yield, whereas CP promoted higher phenolic content and antioxidant capacity. Among the packaging materials, PLK provided the most balanced internal atmosphere, effectively reducing dehydration and condensation while preserving superior sensory quality after 14 days of storage. Overall, the combination of organic compost amendments, particularly CP+LC, with PLK bio-based packaging represents a promising and sustainable strategy for maintaining postharvest quality and reduce the environmental footprint of minimally processed wild rocket within short food supply chains. Full article

Horticultural reliance on non-renewable peat faces critical sustainability challenges. Low-temperature biochar (LTB) presents a promising alternative, offering higher biochar yields and lower energy inputs compared to conventional high-temperature biochar. However, LTB’s distinct physicochemical properties necessitate empirical validation of its efficacy as a peat substitute. This study investigated rice straw-derived LTB (pyrolyzed at 350 °C for 10 or 30 min) as a peat substitute at different ratios (10%, 20%, 40%), combined with three Hoagland nutrient solution concentrations (25%, 50%, 100%), on the growth, substrate properties, and fruit quality of dwarf tomato. The results show that a 10–20% LTB substitution improved substrate physical properties (reduced bulk density, increased porosity) and promoted plant growth (biomass, height). Conversely, a 40% LTB substitution inhibited growth, primarily attributed to osmotic stress caused by excessively high substrate electrical conductivity (EC). At the optimal 10–20% rates, tomato yield and fruit quality (soluble solids, lycopene, vitamin C) were significantly enhanced. Most importantly, a comprehensive evaluation revealed that 10–20% LTB substitution allowed for a 50% reduction in nutrient solution concentration while achieving a comprehensive performance comparable to the full-strength nutrient control. This study indicates that LTB could effectively replace a portion of peat, potentially enhancing dwarf tomato yield and quality while reducing chemical fertilizer dependency by up to 50%. These findings point toward a possible pathway for more resource-efficient horticultural practices. Full article

Microgreens have gained increasing popularity due to their cooking versatility, ease of cultivation, and high nutritional value. The use of alternative organic substrates, such as vermicompost and insect frass, offers a promising alternative to peat. This study has evaluated the integration of Tenebrio molitor and Hermetia illucens frass, along with vermicompost, in a microgreen production, while assaying several concentrations (25%, 50%, 75%, and 100%) as replacements by weight. After a preliminary assay aimed at determining the optimal frass and vermicompost levels, we assessed the agronomic, nutritional, and microbiological performances of microgreens. The preliminary results revealed phytotoxic effects of T. molitor frass, while the addition of H. illucens frass or vermicompost did not significantly impact microgreen production. In the second experiment, the interaction between plant species and substrate composition significantly influenced the leaf area, plant height, and mineral content. Partial replacement of peat with H. illucens frass or vermicompost enhanced leaf area and plant height, with a notable increase in iron content in the mizuna microgreens grown with H. illucens frass, compared to the control with peat. Additionally, microbiological safety was ensured, and a complete absence of Salmonella spp. and E. coli was observed in the plants, in accordance with European food safety regulations. Full article

Modern agriculture relies heavily on chemical inputs to sustain productivity, yet their intensive use poses environmental and health risks. Sustainable strategies based on biostimulants have emerged as promising alternatives to reduce agrochemical dependence. Among these compounds, humic substances (HS) stand out for their ability to modulate plant growth and activate defense responses. This study aimed to evaluate the effects of HS from different sources—vermicompost (Vc) and peat (Pt)—on the salicylic acid (SA)-mediated defense pathway in tomato plants (Solanum lycopersicum cv. Micro-Tom) infected with Oidium sp. The HS were characterized by solid-state ¹³C CPMAS NMR to determine the relative distribution of carbon functional groups and structural domains, including alkyl, O-alkyl, aromatic, and carbonyl carbon fractions, as well as hydrophobicity-related indices. Enzymatic activities of lipoxygenase, peroxidase, phenylalanine ammonia lyase, and beta 1,3-glucanase were determined spectrophotometrically, and RT-qPCR quantified gene transcription levels involved in SA signaling and defense (MED25, MED16, MED14, NPR1, ICS, PAL, LOX1.1, MYC2, JAZ, jar1, CAT, POX, SOD, APX, ERF, PR-1, PR-2, PR-4 e PR-5). Both HS significantly reduced disease severity and activated key SA-related defense genes, including the regulatory gene NPR1 and the effector genes PR1, PR2 and PR5, with Pt providing greater protection. Notably, HS amplified defense-related gene expression and enzymatic activities specifically under infection, showing a stronger induction than in non-infected plants. These results demonstrate that structural differences among HS drive distinct and enhanced defense responses under pathogen challenge, highlighting their potential as sustainable tools for improving plant immunity in agricultural systems. Full article

Peat, a vital component of horticultural growing media (GM), is recognized by the Intergovernmental Panel on Climate Change (IPCC) as a solid fossil fuel which significantly contributes to the depletion of fossil resources and greenhouse gas emissions. This study evaluated the partial replacement of peat with three locally available by-products—wood fiber (WF), coffee silverskin (CS), and brewers’ spent grain (BSG)—in the cultivation of potted ornamental sage through an integrated environmental–economic approach. Ten GM formulations were modeled, with peat substitutions ranging from 0 to 40% (v/v) across one hectare of greenhouse production (90,000 pots). Environmental impacts were assessed using the EPD 2018 method in SimaPro, while eco-efficiency was calculated as the ratio of the environmental impact costs resulting from the different energy consumptions (EUR) to related revenues (EUR). Results revealed only minor variations among impact categories when comparing the alternative growing media with the peat-based control (0PR), with the exception of the Abiotic Depletion of Fossil Fuels (ADff), which showed a consistent decrease at higher peat replacement levels. Treatments with 40% substitution performed best, particularly BSG40 and CS40, with the lowest eco-efficiency ratios (≈approximately 11.4%). WF40 also showed favorable outcomes (≈12.7%), confirming that a 20–40% peat replacement offers the optimal balance between environmental sustainability and economic viability. Overall, partial peat replacement using local by-products effectively reduces the consumption of fossil resources without significantly impacting other environmental indicators, promoting circularity and competitiveness in ornamental plant production. Full article

Peppers are of substantial economic importance and hold a prominent position among vegetables rich in health-promoting compounds, which drives continuous efforts to develop improved cultivation strategies. The study aimed to determine the effects of substrate type and depolymerized chitosan on the physiological parameters, the chemical composition of leaves and fruits, and the yield of two bell pepper cultivars: ‘Marta Polka’ and ‘Oda’. The plants were grown in a 100% peat substrate and in a mixture of peat, wood fiber (Pinus sylvestris), and green compost (2:1:1 v/v/v), with or without drenching with a solution of depolymerized chitosan. Results indicated that the growing medium, chitosan application, cultivar type, and their interactions altered several physiological, morphological, and biochemical traits. The highest total fruit weight fresh (471.23 g plant⁻¹) was obtained for the ‘Marta Polka’ cultivar grown in peat drenched with chitosan, whereas the lowest (192.02 g plant⁻¹) was recorded for ‘Oda’ grown in a substrate mix without the biostimulant. Net CO₂ assimilation rate, stomatal conductance, fresh weight of fruit, and antioxidant activity (ABTS and FRAP assays) were improved in the ‘Oda’ cultivar grown in the substrate mix and treated with depolymerized chitosan compared with plants grown in 100% peat without chitosan. The ‘Marta Polka’ plants grown in the substrate mix and treated with chitosan had a higher net CO₂ assimilation rate, photosynthetic water-use efficiency, total free amino acid content, and antioxidant activity (FRAP assay) than those grown in peat alone and not treated with the biostimulant. The results demonstrate that both substrate composition and the response to depolymerized chitosan are cultivar-specific, and that wood fiber and compost can serve as ecological alternatives to peat, enhancing overall pepper fruit quality. Full article

The mobilization of complex microbial communities from natural resources can be a valuable alternative to the use of single-species biofertilizers when it comes to the decomposition of plant residues. However, the functioning and interaction of microorganisms within these communities remain largely unexplored. Our task was to investigate the cellulose-degrading community using the biofertilizer BAGS (peat-based compost with straw) as an example and define its active component. For this, we monitored the succession of the biofertilizer’s taxonomic composition during two consecutive rounds of its six-month composting process, varying in the applied mineral fertilization. The amount of added nitrogen significantly affected the performance of the biofertilizer, contributing to its high cellulolytic activity. Based on the network analysis, the biofertilizer’s mature phase was determined, and its characteristic ASVs (amplicon sequence variants) were described. Metagenomic analysis of this phase revealed MAGs (metagenome-assembled genomes) corresponding to these ASVs, which contained genes for cellulose and aromatics degradation, as well as genes for nitrogen and sulfur pathways, including anaerobic nitrate reduction and thiosulfate oxidation. Thus, we propose that the cellulose-decomposing bacterial component of BAGS, associated with the mature phase, occupied different trophic niches, not limited to cellulose degradation, which should be considered when designing natural or artificial microbial systems for the decomposition of plant residues. Full article

Having high porosity and biocompatibility, carbon-based materials are promising candidates for tissue engineering applications, particularly as substitutes for biological tissues. This study investigates the growth and viability of osteoblasts on four different activated carbon (AC) materials and correlates biological responses with their physicochemical and morphological properties. Two materials derived from non-renewable sources—AC1, a laboratory-synthesized carbon derived from anthracite, and AC3, a commercial activated carbon (Norit GCN 830) derived from coal—and two commercial activated carbons derived from renewable sources—peat, AC2 (Norit PK1-3), and wood, AC4 (ROX 0.8)—are studied. Results showed that AC1 exhibited the highest porosity (3072 m²/g), with higher phenolic and oxygen-containing surface groups but lower cell viability. In contrast, AC2, AC3, and AC4 displayed lower porosity compared to AC1 (755, 1040, and 1083 m²/g, respectively) and fewer surface phenolic groups but sustained osteoblast proliferation. Notably, AC4 demonstrated superior performance, characterized by regions of fibrous surface, pores in the meso- and microscale range (<50 nm), and enhanced cell viability and proliferation. AC2 also showed favorable results, ranking second for cell growth support. These findings suggest that biomass-derived ACs, particularly AC4 and AC2, provide favorable environments for osteoblast viability and proliferation. AC costs were estimated at 15 to 38 times lower than those for hydroxyapatite and bioceramics, which are widely used for bone cell growth. Thus, ACs made from renewable sources are promising candidates for tissue engineering applications, offering sustainable and effective alternatives for biomedical use. Full article

Conventional methods for obtaining pure durum wheat lines are time-consuming and low-throughput, making speed breeding (SB) a promising alternative. This study investigated SB optimization using far-red (FR) light. Plants were grown under three red/far-red (R/FR) ratios (6.6, 1.0, 0.4) and on three substrates (peat, soil mixture, mineral wool). Reducing the R/FR ratio significantly accelerated flowering, with the most substantial reduction (R/FR = 0.4) shortening the time to flowering by 4.1–4.2 days. The extent of this acceleration and a concurrent negative impact on spike productivity (vegetative weight of dried spikes, the number of spikelets, and the number of grains per spike) were both dependent on the substrate type. Furthermore, a positive correlation was found between the duration of the sowing-to-flowering period and spike productivity components (spike length and number of grains per spike). Increasing the proportion of FR light enhanced the 1000-grain weight and did not affect the germination rate or regenerative capacity. Modifying the SB for durum wheat by adding FR light (R/FR = 0.4) is a useful strategy for increasing its efficiency, and the negative impact of FR light can be mitigated by adjusting mineral nutrition. Full article

The soil of the Trifinio region, the tri-national territory between Guatemala, Honduras, and El Salvador, is damaged by the expansion of monoculture, which decreases fertility and causes problems for local farmers. Furthermore, the region also faces issues of erosion and soil contamination. As an alternative to soil cultivation, soilless systems can be adopted, not requiring fertile soil, and significantly increasing yields and resource use efficiency. To encourage soilless technique application in the region, the aim of this study was to compare 18 different substrate mixes to identify the most suitable for the local cultivation of cucumber (Cucumis sativus L.). The substrates were obtained comparing three rates of peat and compost (0%, 20% and 40%, by volume) in factorial combination, with the remaining being either coir or pumice (filling component). Plant growth, flower setting, physiological status (relative chlorophyll content and leaf temperature), and plant production were evaluated. Highest yield was achieved with 20% peat, while compost (20% and 40%) was able to increase fruit length and improve the relative chlorophyll content, but did not affect total production. However, when focusing on environmental sustainability as an important standpoint, a peat-free substrate should be utilized even though the results favored the 20% peat treatment for production. Considering that the differences in production in favor of 20% peat treatment were of limited practical relevance. In regard to the filling components (coir and pumice) yields were unaffected and only minor parameters were changed. Based on the results obtained, a substrate consisting of 60% coir and 40% compost resulted in the best option for the soilless cultivation of cucumber in the Trifinio region, with both materials being sustainable and easily available for local farmers. Full article

The replacement of peat in horticultural substrates is a priority for sustainable plant production. This study evaluated compost and vermicompost, derived from vine pruning and sewage sludge, as partial peat substitutes in cucumber (Cucumis sativus L.) seedling production. Germination, early growth traits, growth efficiency indices, and leaf nutrient contents were assessed, and the relationships among variables were explored using correlation analysis and principal component analysis. Five substrates were tested: peat-perlite alone (control) and mixtures containing 10%, 20%, or 40% compost or vermicompost as peat replacements. Results showed that incorporating 10% vermicompost significantly improved germination, seedling vigor, and biomass accumulation, with performance comparable to, or exceeding, the control. In contrast, higher proportions of compost or vermicompost negatively affected germination and seedling quality. Nutrient analysis revealed that 10% vermicompost enhanced Ca and K accumulation, traits positively correlated with growth, whereas 20% compost and 20% vermicompost were associated with higher P and Mg contents but reduced seedling performance. Overall, these promising findings demonstrate that a low proportion of vermicompost (10%) is sufficient to successfully partially replace peat in cucumber seedling production, benefiting both performance and sustainability, whereas higher compost or vermicompost levels disrupt nutrient balance and limit this species’ growth. Full article

The increasing demand for sustainable substrates in agriculture and urban greening calls for alternatives to peat, whose extraction poses significant environmental risks. This study assesses the potential of olive pomace biochar (OB), wood biochar (WB), and green compost (GC), alone or in combination, to partially replace peat in growing media and improve substrate properties and plant development. Ten different substrates were formulated by substituting 10–20% of a commercial peat-based substrate with these organic amendments, using the commercial substrate alone as a control. The effects of such replacements were evaluated in the following experiments: a germination test conducted in Petri dishes using four forage species (Medicago polymorpha, Lolium perenne, Festuca arundinacea, and Lolium rigidum); and two parallel pot experiments lasting 100 days each (one with M. polymorpha and L. perenne, and another with young Olea Europaea var. Arbequina saplings). This study evaluated the impact on plant development, as well as the physical properties and composition of the substrates during the incubation process. Germination and survival of forage species were comparable or improved in most treatments, except those including 20% OB, which consistently reduced germination—likely due to high electrical conductivity (>10dS/m). In the pot experiments, substrate pH and total carbon content increased significantly with biochar addition, particularly with 20% WB, which doubled total C relative to control. Both forage species (Medicago polymorpha and Lolium perenne) and the olive saplings (Olea Europaea) exhibited normal growth, with no significant differences in biomass, water content, or physiological stress indicators when compared to the control group. Nutrient uptake was found to be stable across treatments, although magnesium levels were below sufficiency thresholds without triggering visible deficiency symptoms. Overall, combining compost and biochar—particularly WB and GC—proved to be a viable strategy to reduce peat use while maintaining substrate quality and supporting robust plant growth. This approach proved effective across the different plant varieties tested, including Medicago polymorpha, Lolium perenne, and young olive plants, which together encompass a wide spectrum of agronomic and horticultural applications as well as contrasting growth and nutrient requirements. Adverse effects on early plant development can be avoided by carefully selecting and characterizing biochars, with specific attention to salinity and C/N ratio. This finding is crucial for the successful large-scale implementation of sustainable alternatives to peat. Full article