Search Results (74)

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

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 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

Standardized pharmaceutical-grade cultivation of Cannabis sativa L. increasingly relies on soilless systems for precision, reproducibility, and regulatory compliance. This review examines the role of inert and semi-inert growing media in indoor cannabis production, focusing on their physical properties, agronomic performance, and sustainability. A systematic literature search was conducted using databases such as Scopus, Web of Science, and Google Scholar, emphasizing peer-reviewed original research, experimental trials, and relevant review articles. Evaluated substrates include rockwool, coconut coir, peat-based blends, perlite, vermiculite, expanded clay, foamed glass, phenolic foam, and biochar. Findings show that substrate selection strongly affects vegetative growth, rooting, and flower yield, while cannabinoid concentrations remain primarily genotype-driven under stable environmental and nutritional conditions. Substrate-specific traits such as aeration, water-holding capacity, and nutrient buffering significantly influence biomass production and resource-use efficiency. Rockwool remains the industry standard due to its uniformity and compatibility with fertigation systems, but renewable alternatives like coconut coir and biochar are gaining traction. This review underscores the importance of substrate selection in cannabis cultivation and identifies research gaps in genotype-specific responses and the development of sustainable growing media. Full article

The transformation of organic by-products derived from waste into value-added resources represents a promising strategy to advance circular economy principles and bolster environmental and agricultural sustainability, especially in soilless cultivation. This study evaluates the viability of three organic by-products—wood fiber (WF), coffee silverskin (CS), and brewer’s spent grains (BSGs)—as partial peat replacements in horticultural substrates. Ten growing media formulations were assessed, incorporating increased doses (0–40% v/v as peat replacement-PR) of each alternative by-product. The effects on physical and hydraulic substrate properties, along with plant growth traits, were examined using two ornamental Salvia genotypes, ‘Victoria’ and ‘Amistad’. To synthesize the multivariate growth data into a single, biologically meaningful metric, based on the first principal component, a Growth Index (GI), a PC1-derived index, was calculated, providing a powerful, unified metric to rank substrate efficacy. WF-based substrates exhibited increased porosity and diminished water retention, whereas media enriched with CS and BSG enhanced moisture availability, particularly at 20–40 PR. The bulk density was highest at PR40 for both WF and BSG treatments, and at PR20 in CS-based substrates. Electrical conductivity increased in CS and BSG treatments with rising PR levels. The results on the vegetative growth of ornamental sages have highlighted that differential PR rates are required depending on the specific organic by-product and plant genotype. In ‘Victoria’, GI indicates that a 20% replacement of peat with BSG provided the optimal conditions for holistic plant development; the lowest GI for WF substrates across nearly all peat replacement levels indicated that it was the most detrimental alternative for this cultivar. In ‘Amistad’, the analysis of the GI scores revealed that the CS20 and BSG20 of peat replacement yielded the highest overall growth, with GI scores significantly greater than those of the peat control. CS10 and BSG40 also showed high GI scores in ‘Amistad’. WF10 had GI scores similar to those of the peat control. In general, the GI-based approach confirms that moderate inclusion of brewer’s spent grain (BSG20) is a highly effective peat replacement for both genotypes. At the same time, coffee silverskin (CS) is particularly effective for the ‘Amistad’ genotype. This analysis underscores that optimal substrate formulation is not only dependent on the amendment type and rate but also critically on the plant genotype. Full article

Sustainable alternatives to peat in horticultural substrates are increasingly sought. This study assessed the use of coffee silverskin (CS), a byproduct of coffee roasting, as a substrate component for rooting and growing ornamental plants—Buddleja, Lythrum, and Veronica. Plants were cultivated in peat-based substrates with 0%, 25%, 50%, and 75% CS addition. In order to determine the effect of substrate modification with CS, the following parameters were analyzed: rooting efficiency, plant growth, pigment content, physiological indices (SPAD, Fv/Fm, NFI), and substrate properties. A 25% CS addition supported high rooting success (94.4% on average) without negatively affecting root or shoot traits, and even improved flowering earliness. At 50% CS, Buddleja showed moderate tolerance, while Lythrum and Veronica performed poorly. The substrate with 75% CS addition significantly reduced rooting and growth across all species. Elevated pH and electrical conductivity in high-CS substrates likely contributed to plant stress. Physiological indicators confirmed minimal stress at 25% CS, but increased stress response at 75%. Overall, CS can replace up to 25% of peat in substrates without compromising plant performance, offering a sustainable alternative in nursery production. However, higher CS levels require structural or chemical adjustments to reduce compaction and stress effects. Further research is needed to improve CS-based substrate formulations for broader horticultural use. Full article

Environmental concerns drive the search for sustainable organic alternatives in horticultural substrates. This review critically examines three agro-industry renewable byproducts—wood fiber, coffee silverskin, and brewer’s spent grain—as partial peat substitutes. We aimed to comprehensively analyze their origin, processing methods, current applications, and key physical, hydrological, and chemical properties relevant to horticultural use. In soilless culture, wood fiber can be used as a stand-alone substrate. When incorporated at 30–50% (v/v) in peat mixtures, it supports plant growth comparable to peat; however, higher proportions may restrict water and nutrient availability. Coffee silverskin demonstrates high water retention and nutrient content, but its inherent phytotoxicity requires pre-treatment (e.g., co-composting); at concentrations up to 20%, it shows promise for potted ornamental crops. Brewer’s spent grain is nutrient-rich but demands careful management due to its rapid decomposition and potential salinity issues; inclusion rates around 10% have shown beneficial effects. In conclusion, when used appropriately in blends, these bio-based byproducts represent viable alternatives to reduce peat dependence in vegetable and ornamental cultivation, contributing to more sustainable horticultural practices. Future research should optimize pre-treatment methods for coffee silverskin and brewer’s spent grain, investigate long-term stability in diverse cropping systems, and explore novel combinations with other organic waste streams to develop circular horticultural substrates. Full article

This study investigates the use of hop cone residues as a sustainable alternative to peat in seed coating formulations for the delivery of biocontrol agents such as Trichoderma. Some native isolates, T. velutinum T029 and T. harzianum T019 and T059, were tested for their development on peat and hop residues using qPCR. The results showed significantly higher fungal growth in hop cones, indicating their value as a carbon-rich substrate. Seed germination tests on various species showed that hop-based coatings did not inhibit germination and in some cases improved it. Field trials confirmed that bean seeds coated with hops 24 h before sowing outperformed those coated with peat, particularly in integrated production systems, in terms of germination. The results of this study suggest a new area of research: using hop residues in sustainable seed treatments could promote the valorization of agricultural residues, while improving crop establishment and reducing the dependence on synthetic inputs. Full article

Invasive alien species are one of the main threats to global biodiversity, and pose significant management challenges in several areas outside their natural range. In southern Mediterranean Europe, the invasion of Acacia species is particularly severe and its control requires costly and often ineffective actions. The use of vermicompost derived from these species to replace peat-based substrates in horticulture offers a promising alternative to mitigate their economic and environmental impacts while enhancing the sustainability of their control. This study explored the potential of vermicompost produced from the fresh aboveground waste biomass (leaves + stems + flowers) of Acacia dealbata and Acacia melanoxylon (75:25 w/w), two of the most aggressive Acacia species in the Mediterranean, using Eisenia fetida over twelve weeks. In essence, this study aimed to evaluate the quality of the produced vermicompost and its suitability as a partial substitute for potting substrate in the production of cucumber (Cucumis sativus) seedlings for transplant. Four substrate mixtures containing 0%, 10%, 30%, and 50% of Acacia vermicompost (w/w), combined with commercial peat-based potting substrate and perlite (20%) were tested in polystyrene seedling trays. Seedling emergence, growth, and leaf biochemical parameters (photosynthetic pigments, phenolics, soluble sugars and starch, and total thiobarbituric acid-reactive substances—TBARSs) were evaluated. The results showed that the addition of Acacia vermicompost to the commercial substrate did not affect its germination but significantly enhanced seedling growth, particularly in mixtures containing 30% and 50% Acacia vermicompost. In addition, the absence of accumulation of TBARSs also reflected the superiority of these two treatments. These findings suggest that vermicompost derived from A. dealbata and A. melanoxylon biomass can be a viable peat-based substrate alternative for horticultural production, with the dual benefit of promoting sustainable agricultural practices and contributing to invasive species management. Full article

Lettuce is the most widely consumed leafy vegetable in the world. Its quality and yield depend highly on the growing conditions, including the growing substrate. Peat is commonly used as a growing substrate, but there is an increasing interest in finding alternatives to reduce peat usage. One potential alternative is vermicompost, and this study aims to investigate the impact of vermicompost as an additive to a peat substrate on the quality of lettuce seedlings and yield. This research was carried out in a greenhouse covered with a polymer film at the Institute of Horticulture of the Lithuanian Agricultural and Forestry Research Center. Lettuce seedlings were grown in peat with varying amounts of vermicompost (0%, 10%, 20%, 30%, 40%, or 50% vermicompost). Various parameters such as lettuce growth, biometric data, the content of pigments in the leaves, and the accumulation of elements (N, P, K, Ca, Mg) were evaluated. The addition of vermicompost, regardless of its amount, significantly increased plant height (from 7.5 cm in control up to 10.9–11.3 cm with vermicompost), the number of leaves (up to 4.2–4.6), the leaf area (up to 107–131 cm²), and the percentage of dry matter accumulation (up to 6.4–7.5%). Vermicompost also had a positive effect on photosynthesis, resulting in higher yields and a better quality of lettuce. The summarized research results demonstrate the potential of using vermicompost in the production of high-quality lettuce. Full article

Native plant species used for ecological restoration in urban and degraded areas are typically cultivated by ornamental and forestry nurseries. In the face of climate change, it is crucial to produce plants that can withstand transplant stress while promoting the use of sustainable materials, such as peat-free substrates. Replacing peat with locally sourced organic materials offers a promising strategy to enhance plant resilience to abiotic stress while improving sustainability. This study evaluated the effects of alternative growing media on the growth and post-transplant performance of Viburnum lantana L. under standard nursery conditions. Three substrate mixtures were tested: (i) peat:pumice 70:30 v:v (PP); (ii) coconut coir dust:pumice 70:30 v:v (CP); (iii) coconut coir dust:green compost 55:45 v:v (CGC). After one year in the nursery, half of the plants were sampled in late spring for biometric, eco-physiological, and nutrient analyses, while the remaining plants were transplanted into a degraded area providing only a single irrigation event during the trial. Approximately 100 days after transplant, biometric and eco-physiological parameters were assessed. Plants grown on CGC demonstrated the highest transplant success, while those grown on PP and CP exhibited greater leaf necrosis, with PP plants also showing significant defoliation. These findings highlight CGC as a viable and sustainable alternative to peat-based substrates, particularly for post-transplant survival in degraded areas prone to drought stress. Full article

Accurately determining the hydraulic properties of soilless growing media is essential for optimizing water management in container-based horticulture and agriculture. The very rapid estimation of hydraulic properties using a Mini Disk Infiltrometer has great potential for practical use compared to the very time-consuming standard methods. The objectives of this study were (1) to calibrate simulated cumulative stepwise infiltration under different suctions with the measured data from Mini Disk Infiltrometer, (2) to evaluate the efficiency of the Hydrus-2D inverse model to predict water dynamics through substrates, (3) to compare the substrate hydraulic parameters obtained through the numerical inversion model to those obtained via laboratory methods, and (4) to provide recommendations on how to effectively use the MDI-based method for practical applications. This study employs numerical inversion of Mini Disk Infiltrometer (MDI) data to estimate the hydraulic parameters of three different growing media, namely white peat, thermally treated wood fibre (WF4), and Seedling substrate. Infiltration experiments were conducted under suction-controlled conditions using varying initial moisture contents, followed by numerical simulations using the Hydrus-2D model and the Van Genuchten equation to describe the hydraulic parameters. The results demonstrated strong agreement between observed and simulated infiltration data, particularly under moistened conditions, with high R² > 0.9 values indicating the model’s effectiveness. However, discrepancies were observed for substrates in their initial dry state, suggesting limitations in capturing early-stage infiltration dynamics. The findings highlighted the potential of numerical inversion methods for estimating substrate hydraulic properties but also revealed the need for methodological refinements. Modifying the Van Genuchten model or exploring alternative approaches such as the Brooks and Corey model may enhance accuracy. Extending the suction range of measurement techniques is also recommended to improve parameter estimation. This study provides important evidence that the inverse method based on MDI is an effective tool for rapidly determining the hydraulic functions of substrates, which are important in promoting sustainable horticultural practices. Future research should focus on refining parameter estimation methods and addressing model limitations to enhance the reliability of hydraulic property assessments in soilless growing media. Full article

Peat is widely used as a soilless growing medium due to its favorable physicochemical properties. However, its extraction has a significant environmental impact, highlighting the need for sustainable alternatives. Repurposing residues from olive oil (OR) and wine (GR) production offers a potential solution to reduce peat dependency and promote agricultural circularity. This study investigated the effects of incorporating different ratios of OR and GR (0, 5, 10, 20, and 40% v/v) into peat-based substrates for the cultivation of chrysanthemum (Chrysanthemum morifolium cv. Pina Colada). The addition of OR and GR altered the physicochemical properties of the substrate mixtures. All mixtures maintained electrical conductivity below the maximum threshold for container media (≤0.5 mS cm⁻¹). While GR increased pH, it remained within suitable ranges at 5–10% incorporation. Adding OR decreased total porosity, while GR addition at ≥20% increased it. OR-amended substrates were associated with reduced plant growth, flower production, chlorophyll fluorescence, and relative chlorophyll content, with these effects intensifying at higher OR levels. These outcomes, combined with increased total phenolics, flavonoids, antioxidant activity, and antioxidant enzyme activities, suggest a high stress response, as indicated by increased malondialdehyde and hydrogen peroxide levels. In contrast, GR at ≤ 20% did not induce oxidative stress or negatively affect growth, physiological, or nutritional indices, making it a viable component of peat-based substrate mixtures. The suboptimal performance of OR highlights the need for improved valorization through composting, optimized application rates, and combination with other substrates or residues to enhance its suitability as a horticultural substrate component. Full article

This study evaluates the efficacy of innovative peat-free organic substrates and liquid fertilizers as alternatives to traditional peat substrates in the cultivation of Fagus sylvatica L. and Quercus robur L. seedlings in a newly established forest in Southern Poland. The experiment was conducted in a 2 × 2 × 4 experimental layout using a randomized complete block design, comprising eight treatments that combined four substrate types (three novel organic substrates and one peat-based control) with two types of fertilizers (solid and liquid). After one year of growth, biomass and nutrient allocation in the roots, shoots, and leaves of the seedlings were analyzed. The results showed that while solid fertilization enhances biomass accumulation, liquid fertilization supports more uniform growth across different substrates, particularly in oak seedlings. Also, peat substrates recorded the highest nutrient allocation. However, one novel substrate (R22) performed comparably, indicating its potential as a viable peat alternative. Significant interspecies differences were observed, with beech seedlings allocating more biomass to aboveground organs, while oak seedlings favored belowground nutrient allocation. These findings suggest that while peat substrates and solid fertilizers currently provide better outcomes, the innovative R22 substrate shows promise for sustainable forestry practices. Further refinement of the liquid fertilizer was recommended to enhance effectiveness. Full article