Unlocking the potential of biostimulants in sustainable agriculture: Effect of wood distillate on the nutritional profiling of apples.

In this work, we report the investigation of the effect of exposure of apple trees to the bioeffector wood distillate (WD), a plant biostimulant used for improving the nutritional profiling of crop plants. We measured the effect by evaluating the biochemical and nutritional profile of both pulps and skin of fruits. WD (0.2 %, v/v) was applied once a week by foliar application, from May 2023 until September 2023. The results indicate that the WD-treated apples have a significant increase in several analyzed parameters (i.e., phenols, flavonoids, tannins, total antioxidant power, sugars, pectin, free amino acids, and mineral element content), especially in the pulp. These data were also confirmed by NMR and LC-ESI-MS techniques. This study pointed out that WD could be a handy tool for the cultivation of fruit trees.

Analysis of the Mechanism of Wood Vinegar and Butyrolactone Promoting Rapeseed Growth and Improving Low-Temperature Stress Resistance Based on Transcriptome and Metabolomics.

Rapeseed is an important oil crop in the world. Wood vinegar could increase the yield and abiotic resistance of rapeseed. However, little is known about the underlying mechanisms of wood vinegar or its valid chemical components on rapeseed. In the present study, wood vinegar and butyrolactone (γ-Butyrolactone, one of the main components of wood vinegar) were applied to rapeseed at the seedling stage, and the molecular mechanisms of wood vinegar that affect rapeseed were studied by combining transcriptome and metabolomic analyses. The results show that applying wood vinegar and butyrolactone increases the biomass of rapeseed by increasing the leaf area and the number of pods per plant, and enhances the tolerance of rapeseed under low temperature by reducing membrane lipid oxidation and improving the content of chlorophyll, proline, soluble sugar, and antioxidant enzymes. Compared to the control, 681 and 700 differentially expressed genes were in the transcriptional group treated with wood vinegar and butyrolactone, respectively, and 76 and 90 differentially expressed metabolites were in the metabolic group. The combination of transcriptome and metabolomic analyses revealed the key gene-metabolic networks related to various pathways. Our research shows that after wood vinegar and butyrolactone treatment, the amino acid biosynthesis pathway of rapeseed may be involved in mediating the increase in rapeseed biomass, the proline metabolism pathway of wood vinegar treatment may be involved in mediating rapeseed's resistance to low-temperature stress, and the sphingolipid metabolism pathway of butyrolactone treatment may be involved in mediating rapeseed's resistance to low-temperature stress. It is suggested that the use of wood vinegar or butyrolactone are new approaches to increasing rapeseed yield and low-temperature resistance.

Effect of Combined Application of Wood Vinegar Solution and Biochar on Saline Soil Properties and Cotton Stress Tolerance.

Biomass pyrolysis by-products, such as biochar (BC) and wood vinegar (WV), are widely used as soil conditioners and efficiency enhancers in agriculture. A pot experiment was conducted to examine the effects of WV, both alone and in combination with BC, on soil properties in mildly saline soil and on cotton stress tolerance. The results demonstrated that BC and WV application, either individually or together, increased soil nutrient content. The combined application was more effective than the individual applications, resulting in a 5.18-20.12% increase in organic matter, a 2.65-15.04% increase in hydrolysable nitrogen, a 2.23-58.05% increase in effective phosphorus, and a 2.71-29.38% increase in quick-acting potassium. Additionally, the combined application of WV and BC led to greater improvements in cotton plant height, net photosynthetic rate (Pn), leaf nitrate reductase (NR), superoxide dismutase (SOD), and catalase (CAT) activities compared to the application of BC or WV alone. The enhancements in this study varied across different parameters. Plant height showed an increase of 14.32-21.90%. Net photosynthetic rate improved by 13.56-17.60%. Leaf nitrate reductase increased by 5.47-37.79%. Superoxide dismutase and catalase showed improvements of 5.82-64.95% and 10.36-71.40%, respectively (p < 0.05). Moreover, the combined treatment outperformed the individual applications of WV and BC, resulting in a significant decrease in MDA levels by 2.47-51.72% over the experimental period. This combined treatment ultimately enhanced cotton stress tolerance. Using the entropy weight method to analyze the results, it was concluded that the combined application of WV and BC could enhance soil properties in mildly saline soils, increase cotton resistance, and hold significant potential for widespread application.

Biochar and wood vinegar altered the composition of inorganic phosphorus bacteria community in saline-alkali soils and promoted the bioavailability of phosphorus.

As an important part of the ecosystem, saline-alkali soils are in urgent need of efficient and environmentally friendly soil conditioners. Biochar and wood vinegar are regarded as organic soil improvement and plant growth regulators to improve soil physicochemical properties and promote crop growth. However, the mechanism of how inorganic phosphorus bacteria increase phosphorus when biochar and wood vinegar applied to saline-alkali soils is not clear. Herein, the present study was designed to investigate the effects of biochar and wood vinegar with different rates on physicochemical properties of saline-alkali soils and inorganic phosphorus bacteria diversities and to discuss the mechanism of biochar and wood vinegar on available phosphorus by pot experiments. The application of biochar and wood vinegar exhibited an effect on the decrease in pH and salt contents and the increase in soil porosity, soil nutrients, and hundred-grain weight of rice. The 600 kg ha-1 biochar and 1800 kg ha-1 wood vinegar group showed the most significant increment in available phosphorus, alkaline phosphatase, acid phosphatase, and neutral phosphatase activities, with the increases of 49.24%, 40.35%, 48%, and 149%, respectively. The 600 kg ha-1 biochar and 1200 kg ha-1 wood vinegar group significantly enhanced microbial biomass phosphorus concentrations by 41.29%. Moreover, biochar and wood vinegar shifted inorganic phosphorus bacteria composition structure and promoted its diversities, more so at a higher rate of wood vinegar application. The dominant species of inorganic phosphorus bacteria were Proteobacteria, Gammaproteobacteria, Alphaproteobacteria, Pseudomonas, and Rhizobium in saline-alkali soils. The Alphaproteobacteria and Hydrogenophaga were the key microorganisms reducing pH and salt contents and increasing available phosphorus contents in saline-alkali soils. In conclusion, the application of biochar and wood vinegar was a useful strategy to improve saline-alkali soils.

Enhancement of nutrient use efficiency with biochar and wood vinegar: A promising strategy for improving soil productivity.

BACKGROUND: The co-application of biochar and wood vinegar has demonstrated the potential to enhance premium crop production. The present study reveals the effects of co-applying rice husk biochar and wood vinegar (both foliar and soil application) on soil properties and the growth of Chinese cabbage (Brassica chinensis L.) in a two-season pot experiment. RESULTS: The soil pH, electrical conductivity and dissolved organic carbon contents in combination treatments of wood vinegar and biochar were increased more when wood vinegar was applied to soils rather than to leaves, and the parameters were observed to surpass those for chemical fertilizer treatments. The biomass of Chinese cabbage shoots was significantly increased by 60.8- and 27.3-fold in the combined treatments compared to the control when 1% wood vinegar was sprayed to the leaves (WF1) in 2022 and 2023, respectively. Higher contents of vitamin C, soluble protein and soluble sugar were also observed in the combined wood vinegar and biochar treatments compared to chemical fertilizer treatments and the control; for example, the vitamin C content of plant shoot in WF1 was 21.3 times that of the control. The yield and quality of plants were decreased across all treatments in 2023 compared to 2022 but the combination treatments still displayed superiority. CONCLUSION: The co-application of wood vinegar and biochar enhances the growth and improve the quality of Chinese cabbage through improving the soil properties and plant photosynthesis. Moreover, the foliage application of wood vinegar is more preferable compared to soil application. © 2024 Society of Chemical Industry.

Wood Distillate Interactions with Urea in Soil: A First Step to Developing a Slow-Release Next-Generation Fertilizer.

We tested the ability of wood distillate (WD) to interact with urea in agricultural soil. WD is a sustainable material that has been addressed as a promising alternative to synthetic soil corroborants. However, there is little information about the effect of WD on the nitrogen cycle. In this study, soils with different amounts of WD and with/without urea were tested for ammonium, urease, nitrate/nitrite, and potential nitrification activity at different points in a 30 day time frame. High concentrations of WD (1-2%) inhibited the hydrolysis of urea and the oxidation of ammonium to nitrate. Thermal desorption coupled to GC-MS and high-performance liquid chromatography-tandem mass spectrometry characterization allowed us to reveal that WD-urea interactions mainly involve lignin-derived compounds in the distillate, such as catechol, resorcinol, and syringol. This study provides the first evidence of a strong interaction between WD and urea in soil that could be used to develop slow-release fertilizers.

Phytotoxicity and hormesis in common mobile organic compounds in leachates of wood-derived biochars.

Although addition of pyrolyzed organic materials (biochars) to soil generally results in increased growth and physiological performance of plants, neutral and negative responses have also commonly been detected. Toxicity of organic compounds generated during pyrolysis, sorbed by biochars, and then released into the soil solution, has been implicated as a possible mechanism for such negative effects. Conversely, water-soluble biochar constituents have also been suggested to have "hormetic" effects (positive effects on plants at low concentrations); however, no specific compounds responsible have been identified. We investigated the relative phytotoxicity-and possible hormetic effects-of 14 organic compounds common in aqueous extracts of freshly produced lignocellulosic biochars, using seed germination bioassays. Of the compounds examined, volatile fatty acids (VFAs: acetic, propionic, butyric, valeric, caproic, and 2-ethylbutyric acids) and phenol, showed acute phytotoxicity, with germination-based ED50 values of 1-30 mmol L-1, and 2-ethylbutyric acid showed ED50 values of 0.1-1.0 mmol L-1. Other compounds (benzene, benzoic acid, butanone, methyl salicylate, toluene, and 2,4-di-tert-butylphenol) showed toxic effects only at high concentrations close to solubility limits. Although phytotoxic at high concentrations, valeric and caproic acid also showed detectable hormetic effects on seedlings, increasing radicle extension by 5-15% at concentrations of ~ 0.01-0.1 mmol L-1. These data support the hypothesis that VFAs are the main agents responsible for phytotoxic effects of lignocellulosic biochar leachates, but that certain VFAs also have hormetic effects at low concentrations and may contribute to positive effects of biochar leachates on early plant development in some cases. Supplementary Information: The online version contains supplementary material available at 10.1007/s42773-024-00339-w.

Wood fiber biomass pyrolysis solution as a potential tool for plant disease management: A review.

Wood vinegar is a high-value acidic byproduct of biomass pyrolysis used for charcoal production. It is widely used in agriculture and forestry. The adverse effects of synthetic fungicides on the environment and human health have prompted the increasing use of biofungicides as alternatives to traditional products in integrated plant disease management programs. In recent years, there has been an increasing interest in the potential of wood vinegar as a disease management tool in agriculture and forestry. In this paper, the composition and preparation process of wood vinegar and its application in agriculture and forestry were introduced, and the effect and mechanism of wood vinegar against fungi, viruses and bacteria were summarized. The potential of wood vinegar as a sustainable and eco-friendly alternative to conventional chemical fungicides is also discussed. Finally, some suggestions on the application and development of wood vinegar were put forward.

Hormetic Effect of Wood Distillate on Hydroponically Grown Lettuce.

The addition of biostimulants to nutrient solutions of hydroponically grown crops to speed up plant growth and improve plant yield and quality has been attracting more and more attention. This study investigated the effects of wood distillate (WD) addition to hydroponically grown lettuce (Lactuca sativa L.) plants. Two concentrations of WD, 0.2% and 0.5%, were added to the nutrient solution, and biometric (i.e., leaf fresh weight, root fresh weight, root length and root surface area), photosynthetic (i.e., chlorophyll a, chlorophyll b, and carotenoid content) and biochemical (i.e., electrolyte leakage, total polyphenols, total flavonoids, and total antioxidant power content) parameters were evaluated. The effects of WD were hormetic, as the 0.2% concentration stimulated biometric and biochemical parameters, while the 0.5% concentration inhibited plant growth. Based on these results, it can be suggested that the addition of 0.2% WD to the nutrient solution has a stimulating effect on the growth of lettuce plants, and could be a successful strategy to boost the yield of crops grown hydroponically.

The Potential of Wood Vinegar to Replace Antimicrobials Used in Animal Husbandry-A Review.

The indiscriminate use of antimicrobials in animal husbandry can result in various types of environmental contamination. Part of the dose of these products is excreted, still active, in the animals' feces and urine. These excreta are widely used as organic fertilizers, which results in contamination with antimicrobial molecules. The impacts can occur in several compartments, such as soil, groundwater, and surface watercourses. Also, contamination by antimicrobials fed or administrated to pigs, chickens, and cattle can reach the meat, milk, and other animal products, which calls into question the sustainability of using these products as part of eco-friendly practices. Therefore, a search for alternative natural products is required to replace the conventional antimicrobials currently used in animal husbandry, aiming to mitigate environmental contamination. We thus carried out a review addressing this issue, highlighting wood vinegar (WV), also known as pyroligneous acid, as an alternative antimicrobial with good potential to replace conventional products. In this regard, many studies have demonstrated that WV is a promising product. WV is a nontoxic additive widely employed in the food industry to impart a smoked flavor to foods. Studies have shown that, depending on the WV concentration, good results can be achieved using it as an antimicrobial against pathogenic bacteria and fungi and a valuable growth promoter for poultry and pigs.

Physiological and Biochemical Mechanisms of Wood Vinegar-Induced Stress Response against Tomato Fusarium Wilt Disease.

Wood vinegar, a by-product of charcoal biomass pyrolysis, has been used as a biofungicide in plant disease management because of its antimicrobial properties. However, the physiological and biochemical mechanisms through which wood vinegar alleviates biotic stress are poorly understood. In this study, pot experiments were conducted to investigate the resistance and regulation mechanism of wood vinegar prepared from different raw materials (ZM) and from a single raw material (SM) in controlling tomato (Solanum lycopersicum "Bonny Best") Fusarium wilt at different concentrations (0.3%, 0.6%, 0.9%, 1.2%, and 1.5%). The results showed that ZM and SM had significant control effects on tomato fusarium wilt under different concentrations in the same growth cycle. Under biotic stress, the two kinds of wood vinegar significantly increased the plant height, stem diameter, leaf area and yield of tomato under the concentration of 0.3%, 0.6%, 0.9% and 1.2%, and significantly reduced the content of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in tomato leaves. The effect of 0.9% treatment was the most significant, ZM and SM significantly increased tomato yield by 122% and 74%, respectively, compared with CK under 0.9% treatment. However, the plant height, stem diameter and leaf area of tomato were significantly reduced under 1.5% treatment, but the content of soluble sugar, soluble protein and vitamin C in tomato fruit was the best. Compared with CK, ZM significantly increased by 14%, 193% and 67%, respectively, and SM significantly increased by 28%, 300% and 159%, respectively. Except for 0.3% treatment, both significantly increased the activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) in tomato leaves. The response intensity of two kinds of wood vinegar-physiological and biochemical-to tomato disease resistance, growth and development, showed ZM > SM. The disease index of tomato showed highly significant negative correlation with plant height, stem thickness, leaf area and antioxidant physiology CAT, and highly significant positive correlation with MDA and H2O2 content. In conclusion, ZM was more effective than SM in enhancing tomato disease resistance by promoting tomato growth and development, decreasing leaf MDA and H2O2 content, and inducing antioxidant enzyme activity in leaves at moderate concentrations.

Allelopathic effects of Eucalyptus extract and wood vinegar on germination and sprouting of rapeseed (Brassica rapa L.).

Eucalyptus plantations are usually characterized by low biodiversity due to allelopathy effects. Wood vinegar is considered a complex growth regulator that can promote plant growth at low concentrations. However, there is information scarcity about the co-application of eucalypt leaf water extract and wood vinegar on plants. This study aimed at clarifying whether wood vinegar can protect seed germination against suppression by eucalypt-induced allelopathy. We examined germination behavior and seedling elongation characteristics in rapeseed (Brassica rapa L.) treated with different solutions of wood vinegar and eucalypt leaf water extract. The results showed that eucalypt leaf water extracts, wood vinegar solutions, and their mixture allelopathically suppressed seed germination rate. After rapeseed sprouting, eucalypt leaf water extracts promoted root elongation, stem elongation, and fresh weight elongation. Malondialdehyde content was also lower under the influence of eucalypt leaf water extract. Mixture of high concentration of eucalypt leaf water extract and lower concentration of wood vinegar significantly promoted root elongation. Therefore, both eucalypt leaf water extract and wood vinegar are complex plant growth regulators, which can be used to inhibit or stimulate plants at different ontogenic stages. During the seed germination period, both eucalypt leaf extracts and wood vinegar could be used as weed inhibitors. Conversely, during the period of sprouting (seedling establishment), low concentrations of eucalypt leaf extracts and wood vinegar can promote growth.

Reducing nitrogen leaching using wood vinegar treated in urea-fertilized soil.

Wood vinegar (WV) is known to retard the release of ammonium (NH4+) from urea by inhibiting urea hydrolysis. However, the effect of WV on nitrogen leaching in soil is not known, and there are few studies on the effect of WV on microbial activity although WV exhibits antibacterial properties against pathogens in agriculture. Therefore, the purpose of this study was to investigate the effect of WV on controlling nitrogen leaching and soil microbial activity. Soils were treated with urea and WV, and the available inorganic nitrogen concentrations in the soil were compared with those from soils treated with N-(n-butyl)thiophosphoric triamide (NBPT), a commonly used urease inhibitor. The nitrate concentration in the soil was significantly decreased in the WV treatment, although the ammonium concentration was not affected by the WV treatment. Basal soil respiration was significantly increased in the WV and NBPT treatments although the microbial biomass was increased in the urea only treatment. The ammonium nitrogen concentration in the leachate was not significantly different in the WV and urea-treated soil compared to the urea-only treatment. However, the nitrate leaching increased in the soil treated only with urea at 16 days after the treatment although there was no statistically significant difference in the total leached nitrate. Therefore, WV can be used to reduce nitrogen leaching and enhance soil microbial activity.

Potential of Biochar as a Peat Substitute in Growth Media for Lavandula angustifolia, Salvia rosmarinus and Fragaria × ananassa.

Peat has long been the primary substrate for the production of ornamental and horticultural plants in pots. Today, peat is no longer considered a renewable resource due to its very lengthy regeneration time. Biochar, a solid by-product of biomass pyrolysis, has been proposed as an agricultural soil amendment. We investigated the effects of two types of biochar, namely biochar from pruning wood waste and biochar activated with wood vinegar ("smoked biochar"), on two ornamental plants (Lavandula angustifolia and Salvia rosmarinus) and on strawberries (Fragaria × ananassa). For both types of biochar, we measured the following parameters: the pH, density, electrical conductivity, humidity, calcium carbonate, total carbon, nitrogen, potassium, calcium, magnesium, sodium, and water retention. For peat, we measured the following parameters: the pH, electrical conductivity, total carbon, and total nitrogen. Our results showed an overall increase in plant growth, particularly in L. angustifolia when using 10% and 50% biochar concentrations and a 10% concentration of biochar activated with wood vinegar. In S. rosmarinus, we observed a slight increase in the total plant weight with the application of 10% smoked biochar (biochar activated with wood vinegar). Finally, in F. × ananassa, we observed an increase in the plant weight and fruit production when 10% biochar was applied. On the other hand, when high concentrations of biochar (50% and 100%) and especially smoked biochar were applied, we observed a significant reduction in the growth of all plants. We concluded that biochar and biochar activated with wood vinegar showed remarkable biological activity with marked phytotoxicity at high concentrations. They promoted plant growth when applied diluted and their use as partial peat substitutes could help support more sustainable horticultural practices.

Dose-Dependent and Species-Specific Effects of Wood Distillate Addition on the Germination Performance of Threatened Arable Plants.

Wood distillate (WD) is a bio-based product applied to crop plants for its known action in terms of growth promotion and yield enhancement, but studies are lacking on its effects on the germination of arable plants. To test such effects, we applied WD at six different concentrations on the diaspores of three threatened arable plants: Bromus secalinus, Centaurea cyanus, and Legousia speculum-veneris. For all the studied species, the effect of WD was dose-dependent and species-specific. In B. secalinus, the germination percentage (GP) decreased at 0.125% WD but then remained stable at higher concentrations up to 1%. At 2% WD, almost no germination was observed. Mean germination time (MGT) was not influenced up to 1% WD but significantly increased at 2% WD. The germination rate index (GRI) and germination energy (GE) remained unaffected up to 1% WD but decreased at 2% WD. In C. cyanus, WD had no effects on GP and GE at any concentration. MGT showed no difference with the control up to 1% WD, but significantly increased at 2% WD. GRI increased only at low concentrations (0.125% and 0.25%). The germination performance of L. speculum-veneris was unaffected up to 0.25% WD for all the tested parameters. From 0.5% WD, a reduction in GP, GRI, and GE and an increase in MGT were observed. At 2% WD, germination was totally blocked. Our results suggest that using WD at low concentrations (<0.5%), those commonly used in arable crops, does not affect the germination of the three investigated plant species.

Exploring sustainable alternatives: Wood distillate alleviates the impact of bioplastic in basil plants.

The growing interest in bioplastics and bio-based crop management products in agriculture is driven by the Sustainable Development Goals of the 2030 Agenda. However, recent research has raised concerns about the sustainability of bioplastics due to their potential negative impact on crop growth and yield, with implications for the environment and human health. In this study, wood distillate (WD) was evaluated as a natural enhancer of plant growth and defence system to mitigate the negative impact of a starch-based bioplastic on basil (Ocimum basilicum L.) plants. The study analyzed physiological and biochemical changes in basil plants subjected for 35 days to single or combined treatments of WD and bioplastic by measuring biomarkers of healthy growth, such as soluble proteins, sugars, vitamin C, and malondialdehyde (MDA). The results showed that WD promoted basil development, whereas the presence of bioplastic hindered it. Interestingly, WD did not affect sugars but increased vitamin C by 12 %, which is considered a positive effect as changes in sugar levels could indicate plant stress. In contrast, bioplastic resulted in reduced sugars (-41 %) and increased (+17 %) MDA level, while vitamin C content remained unchanged. However, when WD was added to plants grown with bioplastic, it elevated the levels of all examined parameters, except for sugars and vitamin C, which experienced reductions (-66 % and 33 %, respectively). Intriguingly, despite this reduction, the observed direct correlation between sugar and vitamin C contents was maintained, indicating that the decrease in sugar content may have reached a critical threshold. This study suggests that the use of WD has the potential to alleviate the adverse effects of bioplastic on basil growth and development and highlights the importance of adopting sustainable practices in agriculture, as well as the need for a critical assessment of the environmental impact of new technologies and products.

Coordinated Regulation of Central Carbon Metabolism in Pyroligneous Acid-Treated Tomato Plants under Aluminum Stress.

Aluminum (Al) toxicity is a major threat to global crop production in acidic soils, which can be mitigated by natural substances such as pyroligneous acid (PA). However, the effect of PA in regulating plant central carbon metabolism (CCM) under Al stress is unknown. In this study, we investigated the effects of varying PA concentrations (0, 0.25 and 1% PA/ddH2O (v/v)) on intermediate metabolites involved in CCM in tomato (Solanum lycopersicum L., 'Scotia') seedlings under varying Al concentrations (0, 1 and 4 mM AlCl3). A total of 48 differentially expressed metabolites of CCM were identified in the leaves of both control and PA-treated plants under Al stress. Calvin-Benson cycle (CBC) and pentose phosphate pathway (PPP) metabolites were considerably reduced under 4 mM Al stress, irrespective of the PA treatment. Conversely, the PA treatment markedly increased glycolysis and tricarboxylic acid cycle (TCA) metabolites compared to the control. Although glycolysis metabolites in the 0.25% PA-treated plants under Al stress were comparable to the control, the 1% PA-treated plants exhibited the highest accumulation of glycolysis metabolites. Furthermore, all PA treatments increased TCA metabolites under Al stress. Electron transport chain (ETC) metabolites were higher in PA-treated plants alone and under 1 mM, Al but were reduced under a higher Al treatment of 4 mM. Pearson correlation analysis revealed that CBC metabolites had a significantly strong positive (r = 0.99; p < 0.001) association with PPP metabolites. Additionally, glycolysis metabolites showed a significantly moderate positive association (r = 0.76; p < 0.05) with TCA metabolites, while ETC metabolites exhibited no association with any of the determined pathways. The coordinated association between CCM pathway metabolites suggests that PA can stimulate changes in plant metabolism to modulate energy production and biosynthesis of organic acids under Al stress conditions.

Green remediation of Ni, Zn, and Cu in an electroplating contaminated site by wood vinegar with optimization and risk assessment.

Wood vinegar (WV) is a renewable organic compound, possessing characteristics such as high oxygenated compound content and low negative impact on soil. Based on its weak acid properties and complexing ability to potentially toxic elements (PTEs), WV was used to leach Ni, Zn, and Cu contaminated soil in electroplating sites. In addition, the response surface methodology (RSM) based on the Box-Behnken design (BBD) was established to clarify the interaction between each single factor, and finally completed the risk assessment of the soil. The amounts of PTEs leached from the soil climbed with the increase of WV concentration, liquid-solid ratio, and leaching time, while they surged with the decrease of pH. Under optimal leaching circumstances (the concentration of WV= 100 %; washing time= 919 min; pH= 1.00), the removal rates of Ni, Zn, and Cu could reach 91.7 %, 57.8 %, and 65.0 %, respectively, and the WV-extracted PTEs were mainly from the Fe-Mn oxides fraction. After leaching, the Nemerow integrated pollution index (NIPI) decreased from an initial value of 7.08 (indicating severe pollution) to 0.450 (indicating no pollution). The potential ecological risk index (RI) dropped from 274 (medium level) to 39.1 (low level). Additionally, the potential carcinogenic risk (CR) values reduced by 93.9 % for both adults and children. The results revealed that the washing process significantly reduced the pollution level, potential ecological risk, and health risk. Coupled with FTIR and SEM-EDS analysis, the mechanism of WV removal of PTEs could be explained from three aspects: acid activation, H+ ion exchange, and functional group complexation. In summary, WV is an eco-friendly and high-efficiency leaching material for the remediation of PTEs polluted sites, which will maintain soil function and protect human health.

The Antifungal Effect of Pyroligneous Acid on the Phytopathogenic Fungus Botrytis cinerea.

In recent years, climate change has intensified harsh periods of rain alternating with periods of drought, leading to an increase in the presence of phytopathogenic fungi. In this study, we want to analyse the antifungal properties of pyroligneous acid against the fungal phytopathogen Botrytis cinerea. Through the inhibition test, we observed that the application of different dilutions of pyroligneous acid rarefied the growth of the fungal mycelium. Furthermore, we have seen through the metabolic profile that B. cinerea is not able to use pyroligneous acid as a resource or even grow in close contact with this resource. Moreover, we observed that the pre-incubation of the fungus in pyroligneous acid leads to a reduction in biomass production. These results give us hope for the possible use of this natural substance as a possible substance to protect plantations from pathogen attacks.

Foliar Application of Oil Palm Wood Vinegar Enhances Pandanus amaryllifolius Tolerance under Drought Stress.

Drought stress severely threatens plant growth, yield and survivability. Wood vinegar, formed by the condensation of smoke produced during biochar production, has been shown to promote plant growth and enhance stress tolerance. They have now been recognized as a sustainable alternative and are frequently used exogenously to support plants coping with environmental stress. This study aimed to evaluate the efficacy of oil palm wood vinegar (OPWV) in mitigating the adverse effects of drought stress on Pandanus amaryllifolius. The optimal concentrations and frequencies of OPWV application were determined before the drought treatment. The results showed that the imposed drought stress negatively affected the plant growth parameters but applying OPWV at 1:500 dilution at 3-day intervals for 12 days increased its tolerance. These include increased leaf relative water content, root-to-shoot ratio, relative stem circumference, chlorophyll pigments and antioxidant enzyme activities. In contrast, the drought-stressed plants treated with OPWV showed decreased relative electrolyte leakage, hydrogen peroxide, proline, malondialdehyde, and enhanced drought-responsive gene expressions, such as HSP70, GAPDH, and Thau, while ENO and ß-Fruc were reduced. These biostimulatory effects of OPWV might be due to several antioxidant compounds, such as anthranilic acid, tetrasiloxane, syringol, guaiacol, and catechol. Altogether, our results showed the effectiveness of OPWV in alleviating the adverse effects of drought stress, and as such, OPWV could be potentially applied in agriculture.