Search Results (84)

Magnesium (Mg) deficiency is common in acidic orchard soils and can limit fruit crop growth and quality. This study evaluated whether foliar-applied magnesium oxide nanoparticles (MgO NPs) could improve Mg nutrition and fruit quality in ‘Ninghaibai’ loquat grown under Mg-deficient acidic soil conditions. Pot and field experiments were conducted using water as the control and MgSO₄-50eq as an equimolar Mg comparator. MgO NPs showed a concentration-dependent effect, and 200 mg/L produced the best overall performance among the tested concentrations. At this concentration, total biomass increased by 47.27%, compared with CK, accompanied by enhanced chlorophyll accumulation, antioxidant enzyme activities, and Mg uptake. In fruit, 200 mg/L MgO NPs increased soluble solids content by 45.67% and reduced titratable acidity by 53.26%, while also improving fruit size and sugar–acid balance. Leaf transcriptome analysis suggested that MgO NPs altered the expression of genes involved in metabolism, stress response, and secondary metabolite biosynthesis. At the 50 mg/L level, MgO NPs produced stronger responses than the equimolar MgSO₄ treatment in Mg uptake, nutrient acquisition, and several fruit-quality traits. However, excessive application at 500 mg/L weakened growth and quality improvement. Overall, foliar application of 200 mg/L MgO NPs may represent a promising strategy for improving loquat growth and fruit quality under the tested Mg-deficient conditions. Full article

In rocky mountainous regions characterized by shallow, barren soils and water scarcity, non-rainfall water, such as condensation, plays a crucial ecological role in mitigating seasonal drought in forest trees. To enhance the water-use capacity of vegetation, this study utilized a previously developed eco-friendly PVA–CS/SA–Ca²⁺ hydrogel. The primary objective was to elucidate the synergistic mechanisms by which the hydrogel optimizes condensed water utilization and drives the ecophysiological recovery of Pinus tabuliformis and Platycladus orientalis, two keystone afforestation species in northern China. Utilizing a controlled environmental chamber to simulate the condensation and humidification process, the experiment established three treatments: a control group (CK), a pot-sealed group (PS, to isolate soil water absorption), and a hydrogel-amended group (Hydrogel-Root Wrapping, HRW). To comprehensively evaluate the water utilization mechanisms, the amount of condensed water captured by the system was quantified, and hydrogen isotope tracing techniques were employed to precisely track water transport pathways and contribution rates. Concurrently, key physiological parameters were systematically determined, including leaf water potential, stomatal conductance, leaf water content, net photosynthetic rate, and transpiration rate. The results demonstrated the following: (1) the hydrogel significantly enhanced the condensation water capture capacity of the system. The net mass gains of the Pinus tabuliformis and Platycladus orientalis systems under the HRW treatment reached 26.3 g and 32.9 g, respectively, which represented 1.17 and 1.30 times those of the CK treatment, and 1.52 and 1.54 times those of the PS treatment. (2) Isotope tracing confirmed that both tree species possess significant Foliar Water Uptake (FWU) capacity. Following condensation, the δ²H values in the leaves of Platycladus orientalis and Pinus tabuliformis surged to 113.5‰ and 85.3‰, respectively, with stem δ²H values increasing by 31‰ and 22‰ compared to their initial baseline. (3) The introduction of the hydrogel in the HRW treatment provided 11.2% and 10.9% of the stem water supply for Platycladus orientalis and Pinus tabuliformis, respectively, thereby reducing their dependence on soil water by 8.3% and 13.1%. In contrast, there was no significant difference in the fractional contribution of condensation water to stem water between the PS and CK treatments. (4) Regarding physiological responses, the application of the hydrogel material effectively improved the physiological status of the plants. The leaf water potentials of Pinus tabuliformis and Platycladus orientalis increased to −0.15 MPa and −1.32 MPa, respectively. Concurrently, stomatal conductance (3.25 and 3.64 mm·s⁻¹) and leaf water content (58.4% and 67.4%) were significantly higher than those in the other treatments. In summary, the hydrogel can significantly enhance the capture, conversion, and utilization efficiency of condensation water by vegetation, effectively optimizing the water supply dynamics of the system. This provides key theoretical and technical support for ecological afforestation in difficult sites within rocky mountainous areas. Full article

Aquaponics is a resource-efficient agricultural system, yet its overall productivity is frequently constrained by micro- and macronutrient deficiencies, particularly iron (Fe) and potassium (K). Currently, the efficacy of combined dietary Fe and K supplementation in optimizing nutrient management in these systems remains unclear. Therefore, a 60-day feeding trial was conducted to evaluate the effects of four dietary Fe and K levels—CK (basal diet without added Fe or K), T1 (Fe 0.1 g/kg + K 2.5 g/kg), T2 (Fe 0.2 g/kg + K 5.0 g/kg), and T3 (Fe 0.3 g/kg + K 7.5 g/kg)—on the growth and quality of lettuce (Lactuca sativa) and the physiological responses of crucian carp (Carassius auratus). The results demonstrated that the T2 treatment was suitable for enhancing system productivity. Compared with the CK group, the lettuce plant height, biomass, and net photosynthetic rate in the T2 group exhibited marked increases of 25.3%, 16.0%, and 26.4%, respectively. Furthermore, the vitamin C content increased by 52.2%, while the nitrate content notably declined by 32.2%. Plant nutrient analysis revealed that the combined Fe and K supplementation markedly promoted the foliar uptake of P, Mn, and Zn (peaking in the T2 group), whereas Cu and S contents increased linearly with the supplementation dose, reaching its maximum in the T3 group. Regarding fish health, the weight gain rate (WGR) of crucian carp in the T2 group peaked at 41.0%, and the feed conversion ratio (FCR) improved to 1.76. Additionally, the dietary supplementation maintained the stability of water quality parameters of the recirculating system. These findings indicate that a combined dietary inclusion of 0.2 g/kg Fe and 5.0 g/kg K can simultaneously enhance the yield and quality of both plants and fish. This approach provides a novel optimization strategy for mitigating acute water quality shocks, while also highlighting the inherent boundaries of competitive ion antagonism in aquaponic nutrient management. Full article

Wheat (Triticum aestivum L.) productivity in saline soils is often constrained by nutrient imbalance, water scarcity, and ionic stress, particularly in arid regions such as the Nile Delta of Egypt. This study evaluated the combined effects of biochar (2.4 t ha⁻¹) and 1% foliar seaweed extract under varying nitrogen application levels on soil chemical properties, wheat growth, yield, nutrient uptake, and N-use efficiency indices over two consecutive winter seasons (2023/2024 and 2024/2025). A factorial field experiment with three replicates was conducted using four nitrogen rates: 0%, 50%, 75%, and 100% of the recommended application (168 kg N ha⁻¹), combined with four treatments: control, seaweed extract, biochar, and their integration. Combined analysis showed that the highest grain yield was obtained under full nitrogen with biochar and seaweed extract (7085.75 kg ha⁻¹), although this was not significantly different from several integrated treatments, particularly those involving 75% nitrogen with amendments. The 75% N + biochar + seaweed extract treatment achieved comparable yield while significantly improving nitrogen-use efficiency indices, including recovery efficiency, agronomic efficiency, and partial factor productivity. Biochar and seaweed extract improved soil organic carbon, cation exchange capacity, and nutrient availability, while electrical conductivity was not significantly affected. These results indicate that nitrogen input can be reduced by up to 25% without yield loss when combined with these amendments, while enhancing nutrient-use efficiency. However, conclusions regarding salinity stress mitigation remain indirect due to the absence of physiological measurements. Overall, this integrated approach supports more sustainable wheat production in saline soils. Full article

In the current context of environmental sustainability and reduced agricultural inputs, biostimulants represent one of the most efficient, eco-friendly and innovative strategies to preserve plants from biotic and abiotic stresses and to ensure sustainable agriculture. Ranging from benefic microorganisms, seaweed extracts, and humic acids to complex carbohydrates such as polysaccharides and oligosaccharides, these biostimulants are able to increase plant growth, photosynthetic efficiency, root development and nutrient uptake when they are applied during seed priming as foliar sprays or as liquid and solid soil amendments. The mechanisms underlying their effective action on plants are mainly related to the enhancement of antioxidant defenses and the regulation of hormonal pathways, particularly auxin homeostasis and transport. Several studies reported the relevance of biostimulant application in promoting root growth. In plants, roots play crucial roles, performing a variety of functions such as nutrients and water uptake, mediating stress perception and adaptation, influencing the rhizosphere microbiome, and providing structural support. The effectiveness and perception of polysaccharide-based biostimulants (PBs) are highly dependent on crucial factors, including the degree of depolymerization and the chemical modifications such as acetylation, methylation, sulfation, and oxidation. Furthermore, not all receptors and co-receptors involved in the recognition of PBs have yet been identified. However, there remain many gaps in our understanding regarding the interaction between biostimulants and roots, which is still far from fully elucidated. For these reasons, the present review provides a comprehensive overview of current research on biostimulants–root interactions, with a particular focus on polysaccharide-based biostimulants. It highlights the mechanisms involved in their recognition by plants roots, from perception to response, and the subsequent signaling cascades and the molecular pathways activated, with special emphasis on existing knowledge gaps and future research perspectives. Full article

Sandy soils in arid and semi-arid regions of Egypt are characterized by poor structure, low fertility, and a limited capacity to retain irrigation water, which collectively constrain nutrient availability and crop productivity under arid conditions. Despite these limitations, improving the performance and sustainability of sandy soils has become essential to meet increasing agricultural demands. Therefore, this study aimed to evaluate the individual and combined effects of biochar, mineral NPK fertilization, and seaweed extract on the growth performance, biomass production, nutrient status, and overall productivity of spearmint (Mentha spicata L.) cultivated in sandy soil. Field experiments were conducted over two successive growing seasons (2024 and 2025) at the Agricultural Research Station, Al-Marashda, Qena Governorate, Egypt, using a split-plot design with biochar application (0 and 12.5 ton ha⁻¹) as the main factor and foliar growth stimulants (control, NPK, NPK + 2 mL L⁻¹ seaweed extract, and NPK + 4 mL L⁻¹ seaweed extract) as sub-factors. Results revealed that biochar application significantly improved all vegetative growth parameters, herbage fresh and dry yields, essential oil percentage, oil yield per plant, photosynthetic pigment concentrations, and leaf N, P, and K contents compared with untreated soil. Foliar application of NPK fertilizer, particularly when combined with seaweed extract, further enhanced plant performance. The greatest improvements across all measured traits were consistently obtained from the integrated application of biochar at 12.5 ton ha⁻¹ combined with foliar spraying of NPK (5 g L⁻¹) and seaweed extract 4 mL L⁻¹. This treatment produced the highest biomass accumulation, essential oil yield, chlorophyll content, and nutrient uptake during both seasons. The findings conclude that integrating biochar with balanced mineral fertilization and natural biostimulants represents an effective and sustainable strategy for improving productivity and essential oil yield of spearmint grown in nutrient-poor sandy soils. Full article

Dew formation occurs frequently and in substantial amounts, serving as an important water source with significant ecological implications for plant growth. Although previous studies have demonstrated that dew can supplement leaf water, quantitative evidence of leaf dew absorption under different dew intensities remains limited. In this study, a stable isotope tracer experiment was conducted to quantify dew absorption under varying dew amounts and to analyze absorption rates and influencing factors across different plant species. Results showed that all four species were capable of absorbing dew, mainly due to specialized leaf surface morphology and microstructures. At a dew intensity of 0.1 mm, Tillandsia ionantha, whose leaves are densely covered with shield-like trichomes, exhibited an extremely high dew absorption rate of 92%. In contrast, the leaf surface of purple shamrock (Oxalis triangularis ‘Purpurea’) is covered with abundant hydrophobic trichomes that strongly restrict dew entry, resulting in a very low absorption rate of only 1.43%. Dew absorption varied markedly among species under different dew amounts. Under dew intensities of 0.1, 0.2, and 0.3 mm, T. ionantha showed consistently high absorption rates of 92%, 89.60%, and 71.74%, respectively, whereas Epipremnum aureum exhibited much lower rates of 3.72%, 6.15%, and 2.45%. Moreover, under a dew intensity of 0.2 mm, dew absorbed by E. aureum leaves could be transported to the roots, indicating internal redistribution of foliar-absorbed water. Overall, dew represents an important supplementary water source for plants, and interspecific differences in leaf surface morphology and microstructures lead to substantial variation in dew absorption capacity. These findings provide experimental evidence for understanding species-specific strategies of dew utilization and have implications for the efficient use of dew as a water resource. Full article

Balsam fir is an important specialty horticultural crop in eastern North America and commonly harvested for use as Christmas trees. Postharvest quality is a major challenge for producers, who are particularly concerned about postharvest needle retention. It was hypothesized that pyroligneous acid (PA) would help increase postharvest needle retention in balsam fir when supplied via xylem or foliage. This project first identified foliar spraying as the best application method, then designed a multivariate experiment with two factors. The first factor was foliar treatment (control, water, 1% PA, 2% PA, and 4% PA). The second factor was time, where branches were evaluated for needle abscission at 0, 2, 4, 6, and 8 weeks after harvest. The experiment was replicated 5 times and needle abscission, water uptake, chlorophyll, carotenoids, flavonoids, total phenolics, membrane injury, proline, and H₂O₂ production were all measured in response. Postharvest abscission reached 100% over the 8-week experiment and water uptake decreased by over 80%. Chlorophyll, proline, membrane injury, and H₂O₂ production all increased over time. Although PA did not improve needle retention compared to the control under the tested conditions, 4% PA spray increased proline concentration by 40% while decreasing membrane injury by 26%. Ultimately, PA did not consistently improve needle retention but did induce proline accumulation and membrane protection. Full article

Zinc oxide nanoparticles (ZnO NPs) have garnered increasing attention in agriculture due to their potential to enhance plant growth and nutrient use. This research investigates the concentration-dependent effects of ZnO NPs on young crabapple (Malus robusta) plants, addressing gaps in understanding how different concentrations influence plant development. A hydroponic experiment was conducted, applying foliar treatments of 200 mg L⁻¹ ZnSO₄ (S200) and 200, 500, and 1000 mg L⁻¹ ZnO NPs (N200, N500, N100). The control group (CK) was treated with deionized water (dH₂O). Growth parameters, antioxidant enzyme activity, and nutrient contents were measured to evaluate the impact of ZnO NPs on plant development and nutrient uptake. The results showed that N200 enhanced growth, increasing plant height by 22.64%, total dry weight by 49.36%, and root length by 116.07%. In contrast, N500 and N1000 induced oxidative stress, elevating H₂O₂ and MDA by 32.02~54.43% and inhibiting growth. N200 also improved nutrient uptake, increasing K, Ca, Fe, and Zn uptake fluxes by 84.92%, 112.12%, 185.15%, and 149.92%, respectively, whereas N1000 suppressed overall nutrient uptake but increased root Ca accumulation by 64.59%. These findings suggest that ZnO NPs can enhance plant growth and nutrient utilization at low concentrations, with potential implications for agricultural practices involving nanoparticle (NP)-based fertilizers. Full article

Cultivation practices such as fruit thinning and soil management with ground covers are commonly applied in Citrus orchards, yet their physiological impact on young trees remains poorly documented. This study evaluated the effects of manual fruit thinning and weed-control mesh on vegetative growth, fruit development, and leaf mineral composition of Citrus sinensis L. Osbeck cv. ‘Navelina’ grafted on Citrus macrophylla. A six-month field experiment was conducted in southeastern Spain under semi-arid Mediterranean conditions using six treatments that combined different soil coverage and subsurface drainage systems. After physiological fruit drop, trees were standardized to ten fruits per plant. Vegetative parameters (canopy and trunk dimensions), fruit growth (size, juice content), and foliar nutrient concentrations were monitored. Trees with ground cover showed significantly greater canopy expansion and juice yield compared to uncovered controls. A negative correlation between fruit number and canopy-to-fruit volume ratio highlighted the trade-off between vegetative vigor and fruit load. Foliar analysis revealed lower micronutrient concentrations (Fe, Mn, B, Zn) in uncovered trees, suggesting reduced nutritional status. These findings demonstrate that combining early thinning with weed-control mesh promotes vegetative vigor, improves juice yield, and enhances nutrient uptake, providing practical insights for optimizing orchard establishment and early Citrus productivity in water-limited environments. Full article

Excess sodium in soil disrupts ionic balance and limits water uptake, negatively affecting growth and stolon production in strawberry plants. This study assessed the effects of chitosan (CTS), brassinosteroids (BRs), and thidiazuron (TDZ) on stolon performance and physiological responses of strawberry cv. ‘Portola’ under saline conditions. A greenhouse experiment included seven treatments: CTS, BRs, CTS + BRs combinations, TDZ, and an untreated control. Foliar applications were used to evaluate impacts on nutrient uptake, photosynthetic pigments, oxidative stress, and stolon production. BRs alone [2.53 × 10⁻⁶ μM] significantly increased crown diameter (+43%), stolon number (+65%), stolon length (+4%), and daughter plant formation (+8%), while reducing leaf sodium by 60% and improving Mg²⁺/Na⁺ and K⁺/Na⁺ ratios. The CTS + BRs combination enhanced phenolic content and produced the heaviest first daughter plants (6.1 g). TDZ, however, resulted in weaker stolons, lower chlorophyll a content, and reduced K⁺/Na⁺ ratios, suggesting a need for dose optimization. Overall, BRs, alone or with CTS, improved salt tolerance and stolon propagation through enhanced ion regulation, photosynthesis, and antioxidant defenses. These findings advance understanding of how biostimulants modulate metal ion homeostasis, antioxidant signaling, and growth in salt-sensitive crops, offering strategies to mitigate salinity stress in strawberry cultivation. Full article

Brazil leads tropical agriculture, yet annual yield losses from insect pests and concerns over water contamination, non-target impacts, and resistance sustain demand for safer, more efficient control tools. This review synthesizes advances in nanopesticides for Brazil’s major crops (soybean, sugarcane, coffee, and citrus) and is organized into five parts, comprising concepts and definitions; formulation families; modes of action; efficacy evidence from laboratory, greenhouse, and field studies; and environmental and human health risk considerations. Evidence indicates that nano-enabled delivery can increase on-target deposition, prolong residual activity, and match or exceed control at reduced active ingredient loads by improving foliar adhesion, transcuticular transport, plant uptake, and spatiotemporal targeting with pheromone-releasing nanofibers and other dispensers. Because nanoformulations can alter exposure pathways and environmental fate, this review emphasizes nano-specific physicochemical characterization under use conditions, fate and transport in Oxisols and Ultisols, and tropical waters, ecotoxicity panels that include pollinators, aquatic invertebrates, soil biota, and vertebrate surrogates, and scenario-based exposure assessment for applicators, residents, and consumers. The review closes with practical guidance for Brazil: head-to-head efficacy benchmarks against commercial standards, the standardized reporting of release and characterization data, and a nano-specific environmental risk assessment checklist to help realize efficacy gains while protecting environmental and human health. Full article

Given the critical role of manganese (Mn) as an essential micronutrient in wheat growth and development and the high efficiency of foliar fertilization in optimizing nutrient uptake and improving crop quality, this study aimed to elucidate the regulatory effects of exogenous manganese sulfate application on wheat grain yield and carotenoid accumulation. Methods: Field experiments were conducted from 2022 to 2024 at the Shuitou Experimental Station of the Cotton Research Institute, Shanxi Agricultural University (35°11′ N, 111°05′ E), using the wheat cultivar ‘Jinmai 110’. Foliar applications of manganese sulfate were administered at concentrations of 0.5 g/kg, 1.0 g/kg, and 1.5 g/kg, with water serving as the control (CTRL). Spraying was conducted on the upper canopy during the flowering and grain-filling stages, applied every 7 days for a total of three times. Samples for transcriptomic analysis were collected within 24 h of the final application. At maturity, yield-related traits and grain carotenoid contents were assessed. Results: Foliar application of 1.0 g/kg MnSO₄ significantly enhanced both grain yield and carotenoid content in wheat. Transcriptome sequencing revealed that treatment with 1.0 g/kg manganese sulfate (M2) resulted in 4761 differentially expressed genes (DEGs), including 2933 upregulated and 1828 downregulated genes, relative to CTRL. Gene Ontology (GO) analysis showed that in the M2 vs. CTRL comparison, 819 GO terms were significantly enriched among upregulated DEGs and 630 among downregulated DEGs. Specifically, upregulated genes were associated with 427 biological process terms and 299 cellular component terms, while downregulated genes were linked to 361 biological processes and 211 cellular components. Enriched functions primarily included cellular processes, metabolic processes, catalytic activity, and binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed 809 annotations for upregulated DEGs and 330 for downregulated DEGs, mainly related to photosynthesis, carotenoid biosynthesis, phenylpropanoid biosynthesis, and plant hormone signal transduction. In total, 43,395 alternative splicing (AS) events were identified from 17,165 genes, including 445 upregulated and 319 downregulated AS events, primarily enriched in photosynthesis and plant hormone-related pathways. Conclusion: Foliar application of manganese sulfate significantly modulates gene expression in wheat grains, thereby improving both yield and carotenoid accumulation. Key biological processes affected include photosynthesis, plant hormone signal transduction, and the carotenoid biosynthetic pathway. The interactions among these regulatory networks constitute a complex molecular mechanism through which exogenous Mn influences agronomic traits. These findings provide mechanistic insights and practical implications for enhancing wheat productivity and nutritional quality through foliar manganese application. Full article

Biochar has attracted interest in viticulture for its potential to enhance nutrient uptake and improve grapevine physiology under changing climatic conditions, particularly in Mediterranean regions. However, the widespread adoption of biochar has been limited due to economic and logistical constraints associated with its large-scale application. To address these barriers hindering the widespread adoption of biochar, this study investigates the effects of foliar-applied water suspensions of biochar at concentrations of 300 mg/L (B300), 600 mg/L (B600), and 1200 mg/L (B1200), compared to a water-only control (C), as a practical alternative application method. The research focused on Malvazija istarska (Vitis vinifera L.), an indigenous Croatian grapevine variety, conducted in an experimental vineyard in Poreč, Croatia. The key physiological parameters examined included photo-synthetic activity, leaf water potential, the elemental composition of the grapevine leaves, and grape yield. Foliar applications were administered three times during the growing season, with five replicates per treatment. The results indicated that biochar treatments had no significant impact on photosynthetic activity, suggesting that foliar application did not cause leaf shading. However, higher biochar concentrations (B600 and B1200) led to increased leaf concentrations of nitrogen (2.1–3.8%), potassium (10.1–18.4 g/kg), sulfur (2.2–2.5 g/kg), boron (65.1–83.6 mg/kg), and manganese (42.4–69.8 mg/kg) compared to B300 and C treatments. Conversely, magnesium content decreased (2.1–2.7 g/kg), likely due to potassium–magnesium antagonism. Furthermore, the B600 treatment produced the highest grape yield (2.67 kg/vine), representing up to a 37% increase compared to other treatments. These findings suggest that the foliar application of biochar can be an effective and sustainable strategy to enhance vineyard productivity. Moreover, it offers a circular economy approach by valorizing grapevine pruning waste as a biochar source. Full article

Silicon has emerged as a beneficial element in mitigating water deficit in various crops, although the underlying mechanisms still require further investigation. This study evaluated the foliar content of nutrients (N, P, K, and Ca) and proline, antioxidant activity, growth, water use efficiency, and yield of cowpea cultivars subjected to two irrigation depths (50% and 100% of crop evapotranspiration) and a foliar application of silicon (orthosilicic acid). A field experiment was conducted in a split-plot scheme using the randomized block design with four replications in a semi-arid region of northeastern Brazil. Silicon supplementation increased the foliar contents of N, P, and Ca; stimulated proline synthesis; and enhanced the activity of the SOD, CAT, and APX enzymes. These changes promoted growth, improved water use efficiency, and increased crop yield. The results indicate that foliar silicon application mitigates the effects of water deficit in cowpea plants while enhancing crop performance under full irrigation (100% of crop evapotranspiration), leading to higher yields even under favorable water conditions. Full article