Search Results (186)

Drought represents one of the major constraints limiting maize productivity in southeastern Europe, particularly under non-irrigated conditions. This study evaluated the effectiveness of foliar biostimulants derived from animal collagen and keratin hydrolysates in mitigating drought stress and improving maize performance in southern Romania during a six-year field experiment (2020–2025). During the screening phase (2020–2022), four formulations (FM1, FM2, KC, and K2) were applied at two rates (5 and 10 L ha⁻¹) and compared with an untreated control. Significant effects of biostimulant formulation and dose were identified for plant height and grain yield (p < 0.001). Duncan’s multiple range test showed that K2 applied at 10 L ha⁻¹ achieved the highest mean grain yield (87.71 q ha⁻¹), significantly exceeding the untreated control (70.94 q ha⁻¹). Based on these results, K2 was selected for long-term validation during 2023–2025 and subsequently evaluated across the entire six-year experimental period. Mean grain yield increased from 52.06 q ha⁻¹ in the untreated control to 58.74 and 64.91 q ha⁻¹ following K2 application at 5 and 10 L ha⁻¹, respectively. Yield improvements were particularly pronounced during years characterized by severe precipitation deficits, when relative yield increases reached up to 41.9%. Economic analysis demonstrated positive net returns in all experimental years, with average profits of 108.6 EUR ha⁻¹ and 206.9 EUR ha⁻¹ for the 5 and 10 L ha⁻¹ application rates, respectively. The results demonstrate that keratin-based biostimulants derived from industrial by-products can improve maize productivity, enhance drought resilience, and contribute to circular-economy approaches in sustainable agriculture. Full article

Commercially mature products obtained by fractionation or extraction of phototrophic microalgal biomass remain concentrated in four categories: whole-cell Spirulina/Chlorella, C-phycocyanin, astaxanthin, and DHA-rich oils. Little diversification of these fractionated, mid-tier products has followed the decline in upstream costs. Whole-cell feed and live-culture markets, agricultural biostimulants, and fermentation-derived ingredients are commercially active but lie outside this phototrophic downstream-processing scope. Reported open-pond biomass production costs have fallen from ~US$10 kg⁻¹ in the 1990s to sub-US$1 kg⁻¹ nth-plant projections, yet no substantial product diversification has occurred. This review brings together three complementary lines of evidence: a bibliometric analysis of 1995–2025 publications showing that downstream fractionation, biorefinery, and integrated process design account for only 9.3% of food-core microalgal research; institutional surveys documenting the same four dominant categories across Europe, China, and global markets; and a meta-analysis of 53 whole-biomass cost rows from 16 techno-economic assessments. These sources indicate consistently that downstream processing is a necessary, though not sole, constraint on commercial diversification. A four-tier unit-operation roadmap is proposed-cell disruption at commodity energy cost, fractionation with functional ingredient preservation, decolorization and desalting at food-ingredient unit cost, and standardized transferable workflows-each linked to a quantitative threshold and to the product categories it would unlock. Closing the microalgal processing technology gap now depends less on demonstrating feasibility than on meeting these thresholds. Full article

Ascophyllum nodosum extracts (ANE) are widely used biostimulants associated with improvements in plant growth, productivity, nutrient acquisition, and abiotic stress tolerance. However, the molecular mechanisms linking extract composition to plant signaling and physiological responses remain incompletely resolved. ANE contains a complex mixture of bioactive constituents, including polysaccharides, osmolytes, phenolic compounds, and phytohormone-like molecules. Their composition varies according to biomass source, environmental conditions, and extraction methodology, contributing to variability in biological activity. Current evidence suggests that ANE functions mainly as a signaling modulator rather than a direct nutrient source. ANE treatment has been associated with early cellular responses, including cytosolic Ca²⁺ influx, reactive oxygen species (ROS) generation, and mitogen-activated protein kinase (MAPK)-associated signaling events. However, many proposed mechanisms remain unresolved, and a considerable proportion of the available mechanistic evidence originates from studies using purified ANE-derived polysaccharides or related elicitor systems. ANE-associated responses include modulation of nutrient transport, primary metabolism, hormonal regulation, transcriptional reprogramming, and stress-responsive pathways, contributing to improved root development, nutrient acquisition, and defense-related responses. Nevertheless, limited knowledge of receptor-mediated perception mechanisms, signaling hierarchies, and extract-dependent variability continues to constrain mechanistic understanding and reproducibility. Future research should prioritize receptor identification, bioassay-guided fractionation, integrated multi-omics approaches, and improved standardization of extraction and formulation procedures. These advances will be essential for establishing robust mechanistic models and supporting the development of evidence-based ANE biostimulants for sustainable crop production. Full article

Natural extracts derived from plants and algae are increasingly recognized for their ability to modulate plant growth and physiological processes due to their rich content of bioactive compounds. Depending on their composition and concentration, these extracts may act as biostimulants, enhancing germination, stress tolerance, and antioxidant activity, or may exhibit inhibitory effects. This study aimed to determine the effects of extracts from Ascophyllum nodosum, Fucus vesiculosus, and Sideritis scardica, prepared using different solvents, on germination parameters, early growth, chlorophyll content, chlorophyll a fluorescence parameters, secondary metabolite levels (phenolic compounds and flavonoids), and antioxidant activity in mung bean (Vigna radiata L.). The results showed that aqueous and hydroethanolic extracts were generally safe for germination, maintaining high germination capacity, whereas 10% ethanolic extracts exhibited pronounced inhibitory effects, reducing germination energy to as low as 8%. Secondary metabolism was markedly affected, particularly by S. scardica extracts, with dose-dependent changes observed in total phenolic and flavonoid contents. Despite these biochemical alterations, chlorophyll fluorescence parameters remained stable, indicating the absence of photoinhibitory stress. Overall, the results indicate that the biological activity of the extracts depends strongly on solvent type and concentration, which determine whether they act as biostimulants or inhibitors by modulating early growth, metabolism, and physiological status. These findings provide a basis for the development of optimized plant- and algae-based biostimulant formulations. Full article

Agroecosystems are perpetually subjected to environmental factors. Driven by a shifting global climate, soil moisture deficits represent an increasingly frequent threat to crop productivity. In farming, however, these abiotic stressors seldom occur in isolation, as fields are invariably compounded by biotic weed pressure. Consequently, investigating plant responses to such combinatorial, multi-faceted stress is paramount to evaluating the realistic efficacy of modern agrotechnical interventions. A 2-year, three-factor pot experiment was conducted at the Research and Education Station in Swojczyce, belonging to the Wrocław University of Environmental and Life Sciences. The aim of the study was to examine the response of winter wheat (Triticum aestivum L., cv. Agil) to drought stress during the period when cereal plants were at the 51–65 BBCH developmental stages. Additionally, in some pots with winter wheat, Apera spica-venti (L.) Beauv. was sown as a weed to evaluate the effects of biotic stress. To observe the mitigation of stressors, three different types of biostimulants were used—a silicon-based preparation and two seaweed-based preparations derived from Ecklonia maxima (Osbeck) Papenfuss and Ascophyllum nodosum (L.) Le Jolis, respectively, representing structural, morphological, and biochemical defense strategies. Drought stress significantly and negatively affected the length of the wheat main stem, lateral tillers, and lateral spikes, as well as the weight of the main wheat spike. The simultaneous occurrence of drought stress and A. spica-venti competition resulted in the greatest cumulative reduction in main spike weight. Furthermore, drought stress was associated with an increase in nitrogen/protein content and potassium content in wheat straw. The presence of A. spica-venti significantly reduced both the weight of the main wheat spike and the number of non-productive tillers. The limited effectiveness of biostimulants may be associated with the severity and timing of stress exposure during reproductive development. Full article

Seaweed-derived biostimulants are a promising strategy for improving crop performance in sustainable agriculture. In this context, this study evaluated the effects of foliar application of Kappaphycus alvarezii extracts, obtained from two Brazilian regions (São Paulo: Kal-SP and Santa Catarina: Kal-SC), at different concentrations (1%, 3%, 5%, and 7%) on the growth, biochemical profile, essential oil yield, and rhizosphere microbiome of Ocimum basilicum under field conditions. Morphological analysis indicated that the 5% and 7% concentrations increased plant height, biomass, root development, and inflorescence production, with biomass gains of up to 51% and essential oil production increases of up to 142% compared to the control. Biochemical responses varied by extract origin, with Kal-SC promoting greater increases in photosynthetic pigments, antioxidant activity, and carbon-related metabolites, whereas Kal-SP induced only minor metabolic changes. The algal biostimulant modulated essential oil yield and composition, promoting treatment-dependent shifts in major terpenoid compounds. Microbiome analysis showed no significant changes in alpha diversity, but significant shifts in beta diversity and functional groups, such as Bacillaceae, indicating rhizosphere reorganization. Overall, the effectiveness of K. alvarezii-based biostimulants depends on concentration and biomass source, highlighting their potential as sustainable agricultural bioproducts and the importance of standardized extraction for consistent outcomes. Full article

Low-molecular-weight chitosan derivatives emerged as promising plant growth biostimulants due to their favorable properties, such as biocompatibility, antibacterial and antifungal activity, enhancement of stress resistance, and yield improvement. In the present study, we evaluated the effect of pea seed priming with two types of chitooligosaccarides (aminochitooligosaccaride and chitooligosaccaride hydrochloride) applied at concentrations of 100 and 500 mg/L under non-stress conditions and 50 mM chronic NaCl stress. We characterized the seed surface topology by atomic force microscopy, the germination process by evaluation of seed germinability and synchrony, root emergence, seed imbibition capacity and ion leakage. Early plant growth and physiological performance were further evaluated in 14-day-old seedlings by measuring leaf water potential, Na⁺ accumulation in roots and leaves, photosystem II activity, leaf pigment content, and membrane stability. The results revealed changes in seed coat topology, i.e., higher surface roughness in 100 and 500 mg/L chitooligosaccaride hydrochloride and 500 mg/L aminochitooligosaccaride primed variants. Concentration-dependent effects of the two chitooligosaccarides under both non-stress and salt stress conditions were evident in 14-day-old seedlings. Under chronic salt stress, seed priming with 100 mg/L chitooligosaccharide hydrochloride and 500 mg/L aminochitooligosaccharide produced the most pronounced improvements in the primary photochemical reactions of photosynthesis, particularly the performance index on an absorption basis and the total performance index. Moreover, the investigated chitooligosaccharide, particularly chitooligosaccaride hydrochloride, preserved membrane integrity and maintained flavonol and anthocyanin levels, indicating a strong protective effect against salt stress. Overall, the data indicate beneficial effects on pea physiological status following seed priming with chitooligosaccarides under chronic salt stress conditions. This highlights the approach as a promising strategy for enhancing plant resilience in challenging environments, and it is worth further investigation and verification at the whole-plant level. Full article

The jalapeño pepper (Capsicum annuum L.) is a crop of great economic and nutritional importance worldwide; however, increasing yield and quality under conditions of reduced synthetic inputs remains a significant challenge, mainly due to restrictions in plant nutrition and stress response capacity; in this context, plant-based biostimulants, such as Ricinus communis extracts, are of particular interest due to their potential to modulate plant metabolism, promote growth, and favor the accumulation of bioactive compounds. In this study, the effect of a foliar-applied biostimulant derived from a methanolic extract of Ricinus communis L. on the physiological, agronomic, and biochemical parameters of jalapeño peppers was evaluated under open field conditions. A randomized complete design with five treatments was established: three extract concentrations (T50: 50 mg L⁻¹, T75: 75 mg L⁻¹, and T100: 100 mg L⁻¹), a commercial biostimulant (Pepton 85/16 ^®), and an absolute control. Significant differences (α ≤ 0.05) were observed between treatments T50, T75, and T100 with the application of castor bean and the absolute control in stem diameter, fruit number, yield, and polar and equatorial fruit diameter, as well as phenols, flavonoids, and antioxidant capacity (ABTS and DPPH). The application of R. communis extract (T50, T75, and T100) significantly improved plant performance compared to the control, particularly in yield (up to 270%), fruit number (73%), shoot biomass (up to 38%), and root development (up to 32%). Furthermore, increases in chlorophyll content and in antioxidant-related compounds were observed, including phenols, flavonoids, ABTS, and DPPH (up to 17%). Spearman correlation analysis revealed strong associations between structural and metabolic variables, highlighting the relationship between stem diameter, fruit traits, and bioactive compound accumulation, as well as the link between chlorophyll content and reproductive performance. The ¹H NMR analysis indicated the presence of secondary metabolites such as ricin, unsaturated fatty acids, and phenolic compounds; however, their isolation and relationship with the biostimulant activity of the extract require further specific studies. Overall, foliar application of R. communis extract improved the growth, productivity, and biochemical attributes of jalapeño pepper, highlighting its potential as a sustainable alternative for crop management. Full article

Agricultural waste streams represent an underutilized source of bioactive compounds with potential to enhance crop resilience under climate stress. We previously showed that volatile compounds (VCs) emitted from waste shiitake fungi beds (WSFBs) promote early rice seedling growth under controlled conditions. Here, we evaluated whether these early-stage effects persist after transplanting and translate into agronomic benefits under field conditions, including the record high temperatures (HTs) of the 2023 growing season in Niigata, Japan. Seedlings of two japonica cultivars, Nipponbare and Koshihikari, were exposed to WSFBs-derived VCs using a non-contact system and subsequently grown in paddy fields across two seasons (2023–2024). WSFBs-VCs-treated (+VCs) plants exhibited enhanced seedling vigor, increased tiller and panicle numbers, higher grain yield per plant, greater 1000-grain weight, and reduced grain chalkiness. Gas exchange measurements at the reproductive stage during the 2023 record HT showed that +VCs plants maintained higher net photosynthetic rate, stomatal conductance, intercellular CO₂ concentration, and transpiration rate, while intrinsic water-use efficiency showed a modest decline consistent with transpirational cooling. Controlled-environment assays revealed enhanced physiological stability supported by upregulation of cytokinin and stress-responsive genes under acute heat stress. Together, these results demonstrate that short-term exposure to WSFBs-derived VCs enhances rice performance under field conditions, including during extreme heat, and highlight their potential as low-cost, waste-derived biostimulants that support sustainable, circular, and climate-resilient rice production. Full article

Natural resources play a fundamental role in ensuring global food security, while agricultural production itself strongly influences their demand, extraction, and availability. This article discusses natural strategies for increasing crop productivity within the framework of sustainable intensification, focusing on the integrated role of plant biostimulants and micronutrients. Both groups of substances are analyzed from a resource-oriented perspective, highlighting their potential to be derived from renewable sources, particularly agro-industrial by-products and plant biomass. Plant extracts obtained from fruit, vegetable, and cereal processing residues contain numerous bioactive compounds, including phenolics, amino acids, peptides, and organic acids, which can stimulate plant growth, improve nutrient uptake, and enhance tolerance to abiotic stress. Micronutrients such as Fe, Zn, Mn, Cu, and B are also strategic resources in crop production because they regulate key metabolic processes and influence the efficiency of macronutrient utilization. Their effectiveness, however, depends strongly on chemical form and bioavailability in soil–plant systems. The novelty of this work lies in integrating perspectives from plant physiology, coordination chemistry, and resource management to propose a conceptual framework in which plant-derived extracts and micronutrient complexes act as complementary tools supporting circular and resource-efficient agricultural systems. Full article

The use of biostimulants in agriculture is increasing; however, their effects on raspberry remain insufficiently understood. The aim of this study was to evaluate the impact of foliar-applied biostimulants on yield and growth in three primocane raspberry cultivars grown under field conditions using multispectral imaging based on unmanned aerial vehicles. An experiment included a control and four foliar biostimulant treatments based on animal-derived amino acids, plant-derived amino acids, seaweed extract, and seaweed extract combined with animal-derived amino acids. Biostimulant effects on primocane raspberry were found to vary substantially depending on cultivar, environmental conditions, and formulation type, with measurable impacts on both yield formation and vegetative growth. These responses were further supported and characterized using multispectral UAV-based mutlispectral imaging, which enabled effective detection of treatment-related physiological changes. This approach was based on the analysis of relative percentage changes between consecutive measurements of selected vegetation indices, allowing the identification of dynamic physiological responses over time. These findings highlight the need for a more targeted approach to biostimulant use, taking into account cultivar-specific responses and environmental variability. Future research should extend this framework to a broader range of genotypes, cultivation systems, and biostimulant formulations, while integrating remote sensing with other analytical methods to better understand plant physiological responses. Such developments may support the transition toward data-driven and precision-guided biostimulant application strategies in sustainable crop production. Full article

Abiotic stresses severely constrain crop productivity by disrupting cellular redox homeostasis and hormone signaling. Although individual stresses differ in origin, plant responses converge on a conserved regulatory system centered on reactive oxygen species (ROS) and phytohormone crosstalk. Controlled ROS production in chloroplasts, mitochondria and the apoplast functions as a signaling mechanism that interacts dynamically with abscisic acid, auxin, ethylene, jasmonate and cytokinin pathways through shared regulatory nodes, including nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and redox-sensitive transcriptional cascades. Endogenous metabolites, including phenolics, terpenoids, carotenoids, alkaloids, polyamines, glutathione and signaling peptides, are embedded within this network and modulate its amplitude and sensitivity. In parallel, non-microbial biostimulants derived from seaweeds, higher plants, protein hydrolysates and humic substances have been widely reported to enhance crop performance under abiotic stress. However, mechanistic integration between biostimulant research and plant stress signaling remains limited. In this review, we propose that terrestrial plant- and algal-derived biostimulants act not as external substitutes for hormones or antioxidants but as modulators of endogenous ROS–hormone signaling hubs. We first synthesize the current understanding of redox–hormone integration under abiotic stress, then examine endogenous metabolites as intrinsic regulators of this network, followed by an analysis of biostimulants in relation to shared regulatory nodes. By positioning biostimulant action within the established redox–hormone network, we provide a mechanistic framework that links stress biology with agronomic application and supports rational strategies to enhance crop resilience. Full article

A critical challenge for modern agriculture is the adoption of sustainable and effective strategies, also in the medicinal and aromatic plant (MAP) sector. In many areas, MAP cultivation remains dependent on traditional farming systems, with a lack of innovative techniques. This study investigates the effect of the foliar application of two protein hydrolysates, one animal-derived (PH 1) and one plant-derived (PH 2), on oregano (Origanum vulgare L.) cultivated under rainfed conditions in a representative area of Sicily (Italy). The aim was to evaluate whether these types of biostimulants could enhance production yield compared to untreated plants. Results showed that both protein hydrolysates induced significant improvement of the agronomic responses compared to the control. Specifically, treatments stimulated a substantial enhancement in fresh biomass (increases from 1.9 to 6.5 t ha⁻¹) and dry biomass (increases from 0.9 to 2.4 t ha⁻¹). Total phenolics and antioxidant activity decreased by 15–24% and 7–15%, respectively, compared to control plants during the two years. However, the aromatic profile of the essential oils was not significantly affected by foliar application of the two protein hydrolysates. The use of these foliar biostimulants represents a sustainable and highly effective strategy to maximize productive parameters while maintaining the chemical stability required by the market, offering a significant contribution to the optimization of oregano cultivation. Full article

Compost-based biostimulants (CBB) have emerged as a promising tool in sustainable agriculture, offering an eco-friendly approach to improving soil health, crop productivity, and environmental resilience. Derived from the controlled biodegradation of organic waste, CBB contains a diverse array of beneficial microorganisms, humic substances, and bioactive compounds that act synergistically to stimulate plant growth and soil biological activity. Mechanistically, CBB enhances nutrient acquisition by increasing plant-available nitrogen and phosphate solubility, promoting root development through phytohormone synthesis, and improving stress tolerance by modulating plant defense pathways and antioxidant activity. Additionally, their application enhances soil structure, microbial diversity, and carbon sequestration, making them integral to climate-smart agriculture. Despite their growing relevance, several challenges impede the widespread adoption of CBB. Variability in compost quality, lack of standardized production protocols, limited field-scale validation, and inconsistent regulatory frameworks hinder reproducibility and commercialization. Addressing these gaps requires interdisciplinary research that integrates microbiology, biochemistry, agronomy, and data science to better understand how microbial metabolites interact and optimize formulation strategies. Future research should prioritize the standardization of composting methods, long-term multi-crop field evaluations, and integration with precision agriculture tools for real-time soil monitoring. Policy harmonization, quality assurance frameworks, and farmer education are also vital for ensuring safe and effective use of CBB. Full article

Cardoon (Cynara cardunculus var. altilis DC.) is a Mediterranean crop valued for biomass production and bioactive compounds; however, information on the use of biostimulants in soilless systems remains limited. This study evaluated the effects of two biostimulants, a legume-derived protein hydrolysate (PH) and an Ascophyllum nodosum seaweed extract (SW), applied as weekly foliar sprays, on growth, physiological performance, mineral composition, and phytochemical traits of cardoon cultivated in a floating system. Biostimulant application significantly affected plant performance, inducing distinct treatment-dependent responses. Both PH and SW increased fresh and dry biomass compared with untreated plants. SW predominantly promoted vegetative growth, chlorophyll content, and nutrient accumulation, whereas PH markedly enhanced nutraceutical quality by increasing total phenolic content and antioxidant activity, reaching 64.4 mg GAE g⁻¹ dry extract and the lowest IC₅₀ value (172 µg mL⁻¹). Harvest timing modulated the magnitude of biostimulant effects, with maximum biomass yield observed at intermediate developmental stages (up to 8.17 kg m⁻²), while phenolic concentration and antioxidant capacity declined at later stages. Multivariate analyses confirmed that PH and SW induced complementary metabolic strategies. Overall, the biostimulant type emerged as the primary driver of plant response, with harvest timing acting as a modulating factor. Targeted biostimulant management, therefore, represents a promising strategy for optimizing the productivity and phytochemical quality of cardoon in soilless cultivation systems. Full article