Untreated Plants Research Articles

Drought stress mitigation and improved yield in Glycine max through foliar application of zinc oxide nanoparticles.

The impact of climate change on agricultural production is apparent due to declining irrigation water availability vis-à-vis rising drought stress, particularly affecting summer crops. Growing evidence suggests that zinc (Zn) supplementation may serve as a potential drought stress management strategy in agriculture. Field studies were conducted using soybean (Glycine max var. Saba) as a model crop to test whether foliar application of zinc oxide nanoparticles (ZnO-NPs) or conventional Zn fertilizer (ZnSO4) would mitigate drought-related water stress and improve soybean yield. Each fertilizer was foliar applied twice at a two-week interval during the flowering stage. Experiments were concurrently conducted under non-drought conditions (70% field capacity) for comparison. Results showed drought significantly reduced relative water content, chlorophyll-a, and chlorophyll-b in untreated control plants by 35.7%, 47.7%, and 41.4%, respectively, compared to non-drought conditions (p < 0.05). Under drought conditions, ZnO-NPs (200mg Zn/L) led to 33.1% and 20.7% increase in chlorophyll-a and chlorophyll-b levels, respectively, compared to ZnSO4 at 400mg Zn/L. Likewise, catalase, peroxidase and superoxide dismutase activities increased by 62.6%, 39.5% and 28.5%, respectively, with ZnO-NPs (200mg Zn/L) under drought compared to non-drought conditions. Proline was significantly increased under drought but was remarkably suppressed (~ 54% lower) with ZnO-NPs (200mg Zn/L) treatment. More importantly, the highest seed yield was observed with ZnO-NPs (200mg Zn/L) treatment under drought (39% higher than untreated control) and non-drought (79.4% higher than control) conditions. Overall, the findings suggest that ZnO-NPs could promote seed yield in soybean under drought stress via increased antioxidant activities, increased relative water content, decreased stress-related proline content, and increased photosynthetic pigments. It is recommended that foliar application of 200mg Zn/L as ZnO-NPs could serve as an effective drought stress management strategy to improve soybean yield.

Microbiomes of urban trees: unveiling contributions to atmospheric pollution mitigation

Urban trees are crucial in delivering essential ecosystem services, including air pollution mitigation. This service is influenced by plant associated microbiomes, which can degrade hydrocarbons, support tree health, and influence ecological processes. Yet, our understanding of tree microbiomes remains limited, thus affecting our ability to assess and quantify the ecosystem services provided by trees as complex systems. The main hypothesis of this work was that tree microbiomes concur to hydrocarbon biodegradation, and was tested through three case studies, which collectively investigated two tree micro-habitats (phyllosphere and tree cavity organic soil—TCOS) under various conditions representing diverse ecological scenarios, by applying different culture-based and molecular techniques and at different scales. The integration of all results provided a more comprehensive understanding of the role of microbiomes in urban trees. Firstly, bacterial strains isolated from the phyllosphere of Quercus ilex were characterized, indicating the presence of Plant-Growth Promoting bacteria and strains able to catabolize PAHs, particularly naphthalene and phenanthrene. Secondly, naphthalene biodegradation on artificially spiked Hedera helix leaves was quantified in greenhouse experiments on inoculated and untreated plants. The persistence of the inoculated strain and community structure of epiphytic bacteria were assessed by Illumina sequencing of V5–V6 hypervariable regions of 16S rRNA gene. Results showed that naphthalene degradation was initially faster on inoculated plants but later the degradation rates became similar, probably because bacterial populations with hydrocarbon-degrading abilities gradually developed also on non-inoculated plants. Finally, we explored bacterial and fungal biodiversity hosted by TCOS samples, collected from six large trees located in an urban park and belonging to different species. Microbial communities were characterized by Illumina sequencing of V5–V6 hypervariable regions of bacterial gene 16S rRNA and of fungal ITS1. Results indicated TCOS as a distinct substrate, whose microbiome is determined both by the host tree and by canopy environmental conditions and has a pronounced aerobic hydrocarbon degradation potential. Overall, a better assessment of biodiversity associated with trees and the subsequent provision of ecosystem services constitute a first step toward developing future new microbe-driven sustainable solutions, especially in terms of support for urban green planning and management policy.

Foliar application of silver (Ag-NPs) and copper (Cu-NPs) nanoparticles enhances phenotypic traits and oil quality in Brassica napus L.

Nanotechnology represents a burgeoning field of science that enables advanced research across various domains. In recent years, there has been a notable increase in the utilization of silver nanoparticles (AgNPs) for diverse agricultural and industrial applications. Similarly, copper nanoparticles (CuNPs) have significant attention in agriculture due to their cost-effectiveness and practicality. This study aimed to investigate the potential impact of silver and copper nanoparticles on enhancing both the yield and quality of Brassica napus L. cultivar CON-1. The combined foliar application of green synthesized silver and copper nanoparticles at varying concentrations (0, 5, 10, 15, 20, 25, 30, and 35mg/L) resulted in notable improvements in the growth, yield and quality of Brassica napus L. compared to untreated plants. Particularly, the concentration of 25mg/L for both silver and copper nanoparticles demonstrated superior outcomes in terms of plant height, number of primary and secondary branches/plant, number of siliques /plant, number of seeds/silique, siliqua length, 1000-seed weight, biological yield/plant, seed yield/plant, oil yield/plant, and harvest index. Furthermore, the nanoparticles effectively reduced the accumulation of erucic acid in the oil, thereby enhancing the overall oil quality of canola. In summary, the application of silver and copper nanoparticles shows promising potential in improving the productivity and quality of Brassica napus L., highlighting their role as beneficial agricultural additives in modern farming practices.

Enhanced Resistance to Pinewood Nematode Disease in Pinus densiflora Induced by Fungal Elicitor from Penicillium chrysogenum

Pine wilt disease, caused by the pine wood nematode (Bursaphelenchus xylophilus), poses a serious threat to forests in Korea. In this study, we investigated the resistance of Pinus densiflora to B. xylophilus following treatment with a fungal elicitor derived from Penicillium chrysogenum through trunk injection and soil drenching. Soil drenching with the fungal elicitor led to increased accumulation of two key defensive compounds: pinosylvin monomethyl ether (PME) and dihydropinosylvin monomethyl ether (DPME) in the needles. In untreated control plants inoculated with B. xylophilus, 67.9% died within five months, whereas only 33.3% of plants pretreated with the elicitor succumbed. Trunk injection of the fungal elicitor also significantly enhanced PME production. The PME concentration in the needles peaked at 155.4 µg/g dry weight (DW) four weeks post-elicitor injection. To assess the impact of elicitor treatment on nematode resistance, we monitored the downward movement of B. xylophilus in plants two months post-injection of fungal elicitor. Nematodes were introduced at the upper internodal segments of branches, and their mobility to the lower segments was measured. In elicitor-treated trees, the movement and population of B. xylophilus were significantly reduced, highlighting the effectiveness of the treatment. These results demonstrate that fungal elicitor treatments, through soil drenching or trunk injection, can enhance the resistance of P. densiflora to B. xylophilus. This eco-friendly approach offers a promising strategy for managing pine wilt disease in susceptible pine species.

Mechanisms of calcium-induced protection against lead toxicity in Ulmus umbraculifera L.: a physiological and biochemical perspective.

Lead (Pb) is a toxic stressor in the soil, which affects plant morphological and physiological events differently. A pot study was initiated to characterize the effect of calcium (Ca) application (20 and 40 mM) on Ulmus umbraculifera L. under Pb treatment (200 and 400 µM). The results revealed that higher levels of Pb significantly reduced plant height (48.3%), total dry weight (44.7%), leaf area index (45%), chlorophyll a (53.7%), chlorophyll b (51.4%), carotenoids (37.8%), and Fv/Fm ratio (20.4%) compared to untreated plants. However, the Ca application improved the aforementioned physiological features. Additionally, Pb toxicity disrupted oxidative status in the plants by increasing malondialdehyde (MDA), methylglyoxal, superoxide anion, and H₂O₂, which also induced the activities of SOD, GR, APX, and CAT. In contrast, Ca decreased MDA, methylglyoxal, superoxide anion, and H₂O₂ by enhancing SOD, CAT, GR, and APX activities compared to the control. Notably, ascorbate (AsA), dehydroascorbic acid (DHA), glutathione (GSH), oxidized glutathione (GSSG) levels, and AsA-DHA and GSH-GSSG ratios changed significantly with Pb and Pb + Ca treatments. According to our findings, monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glyoxalase (Gly) I, and Gly II activities increased with Pb treatment; however, Ca application further promoted their activities. Furthermore, Pb treatment significantly suppressed the uptake of mineral nutrients and increased Pb accumulation, whereas Ca application improved the uptake of these elements and lowered Pb content. These observations confirmed that the positive effects of Ca application on photosynthetic efficiency, nutrient absorption, and enzymatic and non-enzymatic antioxidants enhanced plant tolerance under Pb toxicity.

Chitosan nanoparticles alleviate chromium toxicity by modulating metabolic homeostasis and promoting chromium sequestration in Zea mays L.

Chitosan nanoparticles (CSNPs) have been proposed as a potential alternative in alleviating chromium (Cr) toxicity. However, the mechanisms underlying remains poorly understood. This study investigates the effects of CSNPs on carbon/nitrogen metabolism, cell wall Cr binding capacity, and antioxidant activity in Zea mays L. under Cr stress. Cr stress decreased the total dry weight (DW) by 48.5 %. By contrast, the total DW was reduced by only 26.2 % in CSNPs-treated plants. Analysis of transcriptomic, enzyme activity, and metabolite content data, CSNPs-treated plants exhibited a higher level of relatively stable Carbon and Nitrogen metabolism than untreated plants. CSNPs application resulted in a substantial increase in the levels of sucrose and soluble protein by 78.0 % and 19.4 % in the leaves, and 60.0 % and 59.7 % in the roots, respectively. Meanwhile, CSNPs increased the contents of glutathione, phytochelatin, and cell wall polysaccharide. This increase resulted in a higher retention of Cr in vacuole and cell wall. Additionally, CSNPs alleviated the oxidative damage by improving antioxidant activity. Overall, our results suggest that CSNPs alleviates Cr toxicity by modulating metabolic homeostasis and promoting Cr sequestration in maize plants. This study provides new insights into the mechanisms underlying CSNPs-mediated Cr stress response with potential implications for crop production.

Effect of In Vitro Pretreatment with Ag-Containing Amino Acid Nanofibers on Biometrics and Antioxidant Activity in Drought-Stressed Ex Vitro-Adapted Stevia rebaudiana Bertoni

Biotechnological methods prevent the destruction of natural populations of medicinal plants due to climate change and developing agriculture. This study evaluates the effects of in vitro pretreatment with two types of silver-containing amino acid nanofibers (NF-1%Ag and NF1-Ag salt) on the drought tolerance of ex vitro soil-adapted Steviia rebaudiana Bertoni. The duration of the drought was five days. The data suggested that the pretreatment with the studied nanofibers during plant propagation enhanced the plant tolerance to drought stress manifested in a smaller decrease in plant biomass accumulation and a smaller increase in sugar content. The pretreatment with the two tested nanoparticles of well-watered plants increased the leaf fresh biomass accumulation of the ex vitro-adapted S. rebaudiana compared to the untreated WW control plants. The highest values were reported at 10 mg L−1 NF1-Ag salt. Five days of drought led to a decrease in the leaf fresh biomass compared to the WW plants, with the recorded lowest reduction again at 10 mg L−1 NF1-Ag salt. These observations correlate with antioxidant activity improvement. The results show that adding 10 mg L−1 NF1-Ag salt to the MS medium led to higher ex vitro-adapted S. rebaudiana resistance to water deficit than 100 mg L−1. This paper discusses the impact of the selected nanofibers on parameters characterizing plant growth and antioxidant activity of drought-stressed ex vitro-adapted Stevia rebaudiana plants.

Single or Blended Application of Non-Microbial Plant-Based Biostimulants and Trichoderma atroviride as a New Strategy to Enhance Greenhouse Cherry Tomato Performance.

The need to increase yield and enhance the sustainability of crop production systems has led to the development and employment of natural products, such as plant biostimulants. In recent years, a number of reports have researched the effects of biostimulants on plant performance; however, few studies have focused on the mutual application of microbial and/or non-microbial biostimulants. This research, conducted in the framework of the SO.MI.PR.O.N regional project, aimed to investigate the single or mutual application of three biostimulants, a tropical plant extract (PE), a vegetal protein hydrolysate (PH), and Trichoderma atroviride, on 'Creativo' F1 cherry tomato plants cultivated during two growing cycles (2022-2023 and 2023-2024). Our results showed that plants treated with the combination Tricho + PE + PH had statistically significant higher fresh shoot biomass (+64.2%, 1647.0 g plant-1), total fruit production (+37.9%, 1902.5 g plant-1), marketable fruit production (+52.9%, 1778.5 g plant-1), and average weight of marketable fruits (+53.1%, 17.0 g) compared to control plants (untreated plants). Furthermore, biostimulant treatments, especially T. atroviride, variably enhanced cherry tomato fruits' qualitative traits, such as firmness, total soluble solids, ascorbic acid, lycopene, and total polyphenols compared to control plants. Overall, the best combinations to increase tomato fruit qualitative features were PE + PH, Tricho + PE, and Tricho + PH. From an economic point of view, the best treatment for achieving the highest net return was PE. This study underlines that biostimulant features (yield, qualitative aspects, and economic profitability) can be supported through the application of specific biostimulant combinations.

Detection of Viruses and Elimination of Sweet Potato Feathery Mottle Virus in High-Yielding Varieties of Sweet Potato (Ipomoea batatas) from Ethiopia

Sweet potato (Ipomoea batatas L. Lam.) is a major source of food in many parts of Ethiopia. In recent years, viral diseases have become the main threat to sweet potato production in Ethiopia. Previous virus survey studies carried out from 1986 to 2020 reported eight viruses infecting sweet potato in Ethiopia. Consequently, obtaining and multiplying virus-free planting materials have been difficult for farmers and commercial multipliers. This study was conducted to detect viruses infecting the five sweet potato varieties used as source plants and compare the virus elimination efficiency between meristem cultures from untreated and heat-treated mother plants and production of virus-free sweet-potato-planting materials. Seven common viruses were tested for, using grafting to Ipomoea setosa, enzyme-linked immunosorbent assay (ELISA) and reverse-transcription polymerase chain reaction (RT–PCR) before and after elimination procedures as screening and confirmatory methods. The sweet potato feathery mottle virus (SPFMV) elimination efficiencies of meristem cultures from untreated (grown at 25 ± 1 °C) and heat-treated (grown at 39 ± 1 °C) potted plants of sweet potato varieties were evaluated and compared. Sweet potato feathery mottle virus (SPFMV) was detected in 12 of the 15 source plants tested. Triple infections of SPFMV, sweet potato chlorotic stunt virus (SPCSV), and sweet potato virus C (SPVC) were detected in one of the fifteen plants. This study reports the detection of SPVC for the first time in sweet potato plants from Ethiopia. The cutting of meristems from heat-treated plants further increased the percentage of virus-free plantlets by ca 10% to ca 16%, depending on the plant variety. Elimination efficiency also seemed to vary among varieties: the greatest difference was observed for ‘Tola’, and the least difference was observed for ‘Guntute’. The present study provided protocols for detecting viruses and generating virus-free sweet-potato-planting materials in Ethiopia.

Investigating the positive effects of salicylic acid on peppermint (Mentha piperita l.) under different soil salinity conditions: comprehensive morphological, mineral, and biochemical analyses

This study explored the effects of salicylic acid on the growth and biochemical responses of peppermint (Mentha piperita L.) under different soil salinity levels, a major challenge in agricultural productivity. The experiment was conducted using a factorial design with salicylic acid applied at concentrations of 0, 5, 10, and 50 ppm, combined with sodium chloride-induced salinity at 0, 1,000, 2,000, and 3,000 mg kg–1 soil. Results demonstrated that increasing soil salinity negatively impacted plant growth, reducing plant height, leaf number, and the dry weight of aerial parts. Salinity stress also led to reduced nutrient uptake, particularly for essential elements like calcium and potassium, while increasing sodium levels in plant tissues. However, the foliar application of salicylic acid, especially at 50 ppm, significantly improved growth parameters and mitigated the detrimental effects of salinity. Notably, at the highest salinity level (3,000 mg kg–1), salicylic acid enhanced plant height by 11.1% and leaf number by 30.9% compared to untreated plants. Salicylic acid also boosted biochemical responses, such as increasing total phenolic and flavonoid content, which are critical for stress tolerance. This study underscores the potential of salicylic acid as a stress mitigator, promoting better growth and physiological resilience in peppermint under saline conditions, offering valuable insights for improving crop performance in salinity-affected regions.

Exploring the Role of Endophytes in Cannabis sativa L. Polyploidy and Agricultural Trait Improvement

Here, we examine the effects of ploidy variation in Cannabis sativa L. cell lines on the plant host genotype-associated microbiome. The endophytic microbiome has a protocooperative role in improving plant health and productivity and represents an alternative to synthetic chemical fertilizers and pesticides in sustainable agriculture. This study assessed the effects of seed endophytes on diploid and triploid Haze hemp cultivars. Key phenotypic characteristics were evaluated, revealing significant differences in seed germination in vitro as well as vegetative growth and flowering in phytotron conditions. Endophyte-treated triploid plants exhibited significantly taller heights compared to diploids (p &lt; 0.01). These treated triploid plants also showed longer leaves at nodes 2, 6, and 8, except at node 4, indicating a plant in transition from vegetative growth to the generative developmental stage. Additionally, triploids treated with endophytes displayed the highest number of axillary branches, while endophyte-treated diploids had the fewest (p &lt; 0.05). Both cultivars treated with endophytes exhibited a higher number of inflorescences compared to untreated control plants. This study revealed for the first time a direct correlation between the shifts in diameter of the stem and the biomass in both tested hemp hosts, in association with endophytic microbiomes.

Evaluation of the toxicity of translaminar insecticides against the soybean tentiform leafminer (Lepidoptera: Gracillariidae), a potential new pest of soybean.

Macrosaccus morrisella (Fitch) (Lepidoptera: Gracillariidae) is a leaf-mining microlepidopteran native to North America recently reported feeding on soybean in the United States and Canada. Control methods for the management of this pest remain unknown. The insecticides Agri-Mek SC (abamectin) and Endigo ZXC (lambda-cyhalothrin + thiamethoxam) were evaluated for: (i) effects against immature stages of M. morrisella in potted soybean plants; (ii) effects against adults of M. morrisella through different routes of exposure; and (iii) efficacy of field applications against M. morrisella. In the experiment with immature stages, when either insecticide was applied to potted plants with M. morrisella in serpentine or blotch mines, significantly fewer adults emerged compared to the untreated plants. In contrast, adult emergence from potted plants treated with either insecticide when M. morrisella was in tentiform mines did not differ from untreated plants. In the experiment with adults, the survival of M. morrisella exposed to either insecticide through oral exposure or residual contact + oral exposure was significantly lower than that for residual contact exposure alone, which in turn was lower than the untreated control. Within each exposure route, the response to the 2 insecticides did not differ. In the field experiment, at 21 days after insecticide application, the mean percentage of leaf area mined was significantly lower in plots treated with Endigo ZCX compared to plots treated with Agri-Mek SC or those left untreated. These results suggest that Endigo ZXC and to a lesser extent Agri-Mek SC may have potential for management of M. morrisella.

Biological Acclimatization of Micropropagated Al-Taif Rose (Rosa damascena f. trigintipetala (Diek) R. Keller) Plants Using Arbuscular Mycorrhizal Fungi Rhizophagus fasciculatus

Tissue culture is used to multiply Al-Taif rose (Rosa damascena f. trigintipetala (Diek) R. Keller) plants in order to meet the demands of the fragrance, cosmetic, and floriculture industries. The use of arbuscular mycorrhizal fungus (AMF) could potentially improve plant growth and acclimatization performance to ex vitro conditions. Thus, in the current study, we investigated how AMF Rhizophagus fasciculatus influences the growth, establishment, and physiological performance of micropropagated Al-Taif rose plants during the acclimatization stage. The growth and physiological parameters of the AMF-treated plants were evaluated after a 12 week growth period in the growth chambers. The plants treated with AMF exhibited greater height (25.53 cm) and biomass growth values for both shoot fresh weight (0.93 g/plant) and dry weight (0.030 g/plant), more leaves (11.3/plant), more leaf area (66.15 cm2), longer main roots (15.05 cm/plant), total root length (172.16 cm/plant), total root area (64.36 cm2/plant), and biomass from both fresh weight (383 mg/plant) and dry weight (80.00 mg/plant) of the plants. The plants treated with AMF also exhibited increased rates of net CO2 assimilation, stomatal conductance, and transpiration compared to the control plants. The proline content in the leaves and roots was significantly lower in the AMF-treated plants than untreated plants. The Fv/Fm ratio, which serves as an indicator of the intrinsic or maximal efficacy of Photosystem II (PSII) demonstrated a notable decline in the untreated Al-Taif rose plants. These results elucidate the advantageous impact of AMF colonization on micropropagated Al-Taif rose plants, thereby enhancing their resilience against adverse ex vitro conditions.

Mitigation strategy of saline stress in Fragaria vesca using natural and synthetic brassinosteroids as biostimulants.

Bassinosteroids (BRs) can induce plant defence responses and promote plant growth. In this work, we evaluated the effect of a natural (EP24) and a synthetic (BB16) brassinosteroid on strawberry (Fragaria vesca ) plants exposed to saline stress. Treated plants showed higher shoot dry weight and root growth compared to untreated control plants. In BR-treated plants, crown diameters increased 66% and 40%, leaf area 148% and 112%, relative water content in leaves 84% and 61%, and SPAD values 24% and 26%, in response to BB16 and EP24, respectively. A marked stomatal closure, increased leaflet lignification, and a decrease in cortex thickness, root diameter and stele radius were also observed in treated plants. Treatments also reduces stress-induced damage, as plants showed a 34% decrease in malondialdehyde content and a lower proline content compared to control plants. A 22% and 15% increase in ascorbate peroxidase and total phenolic compound activities was observed in response to BB16, and a 24% increase in total flavonoid compound in response to both BRs, under stress conditions. These results allow us to propose the use of BRs as an environmentally safe crop management strategy to overcome salinity situations that severely affect crop yield.

A Novel Enterococcus-Based Nanofertilizer Promotes Seedling Growth and Vigor in Wheat (Triticum aestivum L.).

Excessive use of chemical fertilizers poses significant environmental and health concerns. Microbial-based biofertilizers are increasingly being promoted as safe alternatives. However, they have limitations such as gaining farmers' trust, the need for technical expertise, and the variable performance of microbes in the field. The development of nanobiofertilizers as agro-stimulants and agro-protective agents for climate-smart and sustainable agriculture could overcome these limitations. In the present study, auxin-producing Enterococcus sp. SR9, based on its plant growth-promoting traits, was selected for the microbe-assisted synthesis of silver nanoparticles (AgNPs). These microbial-nanoparticles SR9AgNPs were characterized using UV/Vis spectrophotometry, scanning electron microscopy, and a size analyzer. To test the efficacy of SR9AgNPs compared to treatment with the SR9 isolate alone, the germination rates of cucumber (Cucumis sativus), tomato (Solanum lycopersicum), and wheat (Triticum aestivum L.) seeds were analyzed. The data revealed that seeds simultaneously treated with SR9AgNPs and SR9 showed better germination rates than untreated control plants. In the case of vigor, wheat showed the most positive response to the nanoparticle treatment, with a higher vigor index than the other crops analyzed. The toxicity assessment of SR9AgNPs demonstrated no apparent toxicity at a concentration of 100 ppm, resulting in the highest germination and biomass gain in wheat seedlings. This work represents the first step in the characterization of microbial-assisted SR9AgNPs and encourages future studies to extend these conclusions to other relevant crops under field conditions.

Impact of Poultry Manure-Derived Biochar and Bio-Fertilizer Application to Boost Production of Black Cumin Plants (Nigella sativa L.) Grown on Sandy Loam Soil

Biochar derived from poultry manure increases nutrient availability and promotes plant growth. This study investigated the effect of biochar with mycorrhizal and/or plant growth-promoting rhizobacteria on soil fertility, chemical properties, oil, and seed yield of Black Cumin (Nigella sativa L.) plants. A split-plot design with three replicates was employed, with biochar derived from poultry litter (BC) applied at rates of 0, 5, and 10 t ha−1, with beneficial microbes such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) affecting the growth of Black Cumin plants, and some soil properties, such as pH, electrical conductivity (EC), soil organic matter (SOM) and fertility index (FI), showing significant differences (p ≤ 0.05) among biochar and/or bio-fertilizer treatments. All biochar treatments with or without bio-fertilizers significantly increased pH, EC, OM and FI in comparison to the control treatment. The results demonstrated that applying biochar at the highest rate (10 t ha−1) increased fresh and dry capsule weights by 94.51% and 63.34%, respectively, compared to the control treatment (C). These values were significantly increased by 53.05 and 18.37%, compared to untreated plants when combined with AMF and PGPR. Furthermore, when biochar was applied in conjunction with both AMF and PGPR, fresh and dry capsule weights saw significant increases of 208.84% and 91.18%, respectively, compared to the untreated control treatment. The interaction between biochar, AMF, and PGPR significantly improved plant growth, yield, soil properties, and the fixed and volatile oil content of Black Cumin. These findings suggest that the combined application of biochar, AMF, and PGPR enhances nutrient availability and uptake, leading to improved growth and higher yields in Black Cumin plants, resulting in increased yield production.

Immunomodulating melatonin-decorated silica nanoparticles suppress bacterial wilt (Ralstonia solanacearum) in tomato (Solanum lycopersicum L.) through fine-tuning of oxidative signaling and rhizosphere bacterial community

BackgroundTomato (Solanum lycopersicum L.) production is severely threatened by bacterial wilt, caused by the phytopathogenic bacterium Ralstonia solanacearum. Recently, nano-enabled strategies have shown tremendous potential in crop disease management.ObjectivesThis study investigates the efficacy of biogenic nanoformulations (BNFs), comprising biogenic silica nanoparticles (SiNPs) and melatonin (MT), in controlling bacterial wilt in tomato.MethodsSiNPs were synthesized using Zizania latifolia leaves extract. Further, MT containing BNFs were synthesized through the one-pot approach. Nanomaterials were characterized using standard characterization techniques. Greenhouse disease assays were conducted to assess the impact of SiNPs and BNFs on tomato plant immunity and resistance to bacterial wilt.ResultsThe SiNPs and BNFs exhibited a spherical morphology, with particle sizes ranging from 13.02 nm to 22.33 nm for the SiNPs and 17.63 nm to 21.79 nm for the BNFs, indicating a relatively uniform size distribution and consistent shape across both materials. Greenhouse experiments revealed that soil application of BNFs outperformed SiNPs, significantly enhancing plant immunity and reducing bacterial wilt incidence by 78.29% in tomato plants by maintaining oxidative stress homeostasis via increasing the activities of antioxidant enzymes such as superoxide dismutase (31.81%), peroxidase (32.9%), catalase (32.65%), and ascorbate peroxidase (47.37%) compared to untreated infected plants. Additionally, BNFs induced disease resistance by enhancing the production of salicylic acid and activating defense-related genes (e.g., SlPAL1, SlICS1, SlNPR1, SlEDS, SlPD4, and SlSARD1) involved in phytohormones signaling in infected tomato plants. High-throughput 16 S rRNA sequencing revealed that BNFs promoted growth of beneficial rhizosphere bacteria (Gemmatimonadaceae, Ramlibacter, Microscillaceae, Anaerolineaceae, Chloroplast and Phormidium) in both healthy and diseased plants, while suppressing R. solanacearum abundance in infected plants.ConclusionOverall, these findings suggest that BNFs offer a more promising and sustainable approach for managing bacterial wilt disease in tomato plants.Graphical

Mathematical approach used for the assessment of foliar application of biostimulant and fertilizers to coriander varieties (Coriandrum sativum L.)

The biostimulants and fertilizers applied as foliar spray or directly to soil play a crucial role in enhancing the development and quality of coriander by supplying essential macro- and micro-nutrients. The ecological approach to reducing soil fertilizers prioritizes the utilization of foliar nutrients. The objective of this study was to investigate the impact of foliar applying products on the seed yield, essential oil content and composition of coriander cultivars in Central Bulgaria. The field trial was carried out on alluvial-meadow soil type in the region of Plovdiv, Central Bulgaria, in the period 2020–2022. The experiment was conducted using the approach of fractional parcels with four repetitions. Three foliar products were examined in the relevant rates: Energy 20–8–60 – 25 L ha−1; Fulvin 40–22 – 80 L ha−1; Isabion – 30 L ha−1. The treated plants were compared to an untreated control. The tested products were applied in the end of the budding stage to five coriander varieties: Yantar, Moroccan, Mesten Drebnoploden, Thüringen and Marino. Results showed that the application of foliar products, compared to the control, led to an increase in seed yield by 4.2–9.6 % and essential oil content up to 11.8 %. Statistical analysis has demonstrated that the utilization of the Energy 20–8–60 has the most significant impact on the concentration of essential oils, while Isabion has the biggest influence on the quantity of seeds produced. The Isabion biostimulant increased the content of the main compound – β-linalool in the essential oil of Moroccan variety up to 8.9 % and Marino and Mesten Drebnoploden by 3.6 and 5.4 % respectively, compared to the control. The foliar application of Energy 20–8–60 fertilizer led to a decrease of β-linalool percentage in Marino, Moroccan, Mesten Drebnoploden and Thüringen. All studied varieties exhibited the presence of aldehyde 2E-tridecen-1-al under the impact of foliar fertilizers, whereas the untreated plants did not.

Application of Pyroligneous Acid as a Plant Growth Stimulant Can Improve the Nutritional Value of Soybean Seed

Farmers today are using biochemical treatments to improve their crop yields. Commercialized organic biostimulants exist in the form of pyroligneous acid generated by burning agricultural waste products. During the 2023 growing season, we demonstrated that soil treatment with a commercial pyroligneous acid product, Coriphol™, manufactured by Corigin Solutions, Inc., stimulated plant growth and significantly improved yield with an optimal treatment dose of 2 gal. acre−1. In the present work, we examined the effect of this treatment on soybean nutritional content using seed harvested from the 2023 season. Total mean seed protein content for untreated control plants was 32.26 ± 0.49% of dry mass and increased 10.8% to 35.64 ± 0.64% with treatment. This increase resulted in a net reduction in total free amino acid content, although levels of the essential dietary amino acid, lysine, were boosted 6-fold. Total lipid content was unaffected by treatment with mean levels of 21.61 ± 0.70% of dry mass noted. Treatment, however, reduced saturated fatty acid content by roughly 40%, and reduced the polyunsaturated content of linoleic acid in favor of the monounsaturated fatty acid, oleic acid. Finally, Coriphol™ treatment did not impact seed content of eight essential micronutrients including Na, Mg, K, Ca, Fe, Ni, Cu, and Mo, but did significantly boost Zn and Mn levels. Altogether, these results demonstrate that soil treatment with the growth stimulant Coriphol™ has the potential to improve the dietary nutritional value of soybean.

Efficacy of Bacillus spp. Isolates for Application as Biofertilizer in Tomato (Solanum lycospersicum L.) Cultivation

Certain species of Bacillus are considered rhizobacteria that promote plant growth, inhibit the growth of plant pathogens and deleterious rhizospheric microorganisms. The aim of this study was to determine the stimulatory effect of Bacillus subtilis KBM1 and Bacillus venezensis KBM1 on the growth and disease reduction of tomato plants in Côte d'Ivoire. In this respect, three substrates consisting of soil only, sawdust only and a mixture of soil and sawdust were inoculated with the two bacteria, then left to ferment for twenty-four (24) hours. The biofertilizers obtained after fermentation were used to assess their effects on the development of potted tomatoes. Growth parameters, infection rate and mortality rate of tomato plants were measured regularly during 6 weeks of cultivation. A search for tomato pathogenic fungi was carried out to demonstrate the efficacy of Bacillus strains isolates on plant health. The results obtained showed that Bacillus subtilis KBM1 and Bacillus venezensis KBM1 had a positive impact on plant growth of tomato plants grown. Infection and mortality rates of 0% were observed for tomato plants grown on the three substrates inoculated with these two bacteria. No pathogenic fungi were isolated from the organs of tomato plants grown on the three substrates fermented with the bacteria. However, on untreated control plants, a variety of pathogenic fungi, namely Fusarium sp, Phytophtora sp, Cladosporium sp, Rhizoctonia sp, Colletotrichum sp, Penicillium sp, Rhizopus sp and Trichoderma sp were observed. However, the Bacillus subtilis KBM1 treatment stood out from Bacillus venezensis KBM1 with the best results for the growth parameters measured. In view of these results, these two bacteria could be used to produce an effective biofertilizer for tomato cultivation in Côte d'Ivoire.