Purpose: Considering that the field dodder is one of the most dangerous parasitic weeds that causes serious damage to cultivated crops, this study aimed to evaluate the efficiency of different control methods against field dodder and the damage caused by the field dodder to eggplant. As well, to determine the isothiocyanate content of turnip and broccoli plants using GC-MS analysis. Research Method: This study was conducted during 2020 and 2021. The experiment examined control methods involving turnip and broccoli as pre-cultivation plants, later both incorporated into the soil separately during specific growth stages, and then both covered and uncovered with black polyethylene mulch, and black polyethylene mulch alone. Controls included plots free of field dodder (Control 1) and plots totally infested with field dodder (Control 2). Finally, all plots were cultivated with eggplant seedlings on rows. Findings: The efficacy of control methods against field dodder in eggplant plots reached 95.81% in TM (turnip+BP mulch) , 92.30% in BM (broccoli+BP mulch), 91.25% in M (black polyethylene mulch alone), 68.26% in T (turnip alone), and 62.58% in B (broccoli alone) treatments. The highest eggplant yield of 8.396 tons/da was achieved in TM treatment. The field dodder caused a yield loss in eggplant by 82.16%, a decrease in eggplant height by 31.12%, and by 58.99% in the number of eggplant fruits in the Con 2 treatment, where the plots were fully infested with filed dodder. Originality/value: The efficiency of cruciferous plants against field dodder is attributed to their isothiocyanates content as the highest percentage of isothiocyanate compounds was found in turnip by 56.6% and the lowest in broccoli by 30.47%.
Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici, threatens global tomato production, with losses reaching 80%. Although chemical fungicides are effective, their prolonged use risks resistant strains, reduces soil biodiversity, and causes environmental damage, highlighting the urgent need for ecofriendly alternatives. This study investigated the viability of Salvia officinalis (sage) methanolic extract as a biocontrol agent against Fusarium wilt (FW), employing a comprehensive approach that incorporates in vitro, in vivo, and molecular docking techniques. Four distinct isolates of F. oxysporum were identified through molecular techniques, and their virulence was assessed by examining the presence of tomatinase genes. The antifungal properties of S. officinalis extract were found to be compelling, with a total phenolic content of 64.15 mg GAE/g and a remarkable antioxidant activity of 97.04%. In laboratory tests, S. officinalis exhibited potent antifungal activity, inhibiting mycelial growth by between 52.00% and 88.67% at a concentration of 20 mg/ml. Additionally, in vivo experiments demonstrated a significant reduction in disease severity in treated tomato plants. Molecular docking analyses revealed strong binding affinities between key phytochemicals in the extract and target receptors such as tomatinase, highlighting the potential of the extract as a sustainable and effective alternative to chemical fungicides for managing FW in tomato crops.
Hemolymph enables communication between organs in insects and ensures necessary coordination and homeostasis. Its composition can provide important information about the physiological state of an insect and can have diagnostic significance, which might be particularly important in the case of harmful insects subjected to biological control. Galleria mellonella Linnaeus 1758 (Lepidoptera: Pyralidae) is a global pest to honey bee colonies. The hemolymph of its larvae was examined after infection with the soil fungus Conidiobolus coronatus (Constantin) Batko 1964 (Entomophthorales). It was found that after one hour of contact with the fungus, the volume of the hemolymph increased while its total protein content decreased. In larvae with a high pathogen load, just before death, hemolymph volume decreased to nearly initial levels, while total protein content and synthesis (incorporation of 35S-labeled methionine) increased. The hemolymph polypeptide profile (SDS-PAGE followed by autoradiography) of infected insects was significantly different from that of healthy larvae. Hemocytes of infected larvae did not surround the fungal hyphae, although they encapsulated small foreign bodies (phase contrast microscopy). Infection had a negative effect on hemocytes, causing oenocyte and spherulocyte deformation, granulocyte degranulation, plasmatocyte vacuolization, and hemocyte disintegration. GC-MS analysis revealed the presence of 21 compounds in the hemolymph of control insects. C. coronatus infection caused the appearance of 5 fatty acids absent in healthy larvae (heptanoic, decanoic, adipic, suberic, tridecanoic), the disappearance of 4 compounds (monopalmitoylglycerol, monooleoylglycerol, monostearin, and cholesterol), and changes in the concentrations of 8 compounds. It remains an open question whether substances appearing in the hemolymph of infected insects are a product of the fungus or if they are released from the insect tissues damaged by the growing hyphae.
Corn is the second most widely farmed grain for human consumption. Low corn productivity due to damage caused by pests has led to using pesticides to control pest infestations. However, the uncontrolled application of pesticides on corn harms both environmental and human health. Accordingly, field experiments followed good agricultural practices to investigate the dissipation pattern and terminal residues of chlorfenapyr and methomyl in corn and compare the values with established safety limits. Gas chromatography-tandem mass spectrometer coupled with the quick, easy, cheap, effective, rugged, and safe technique was used to analyze residues of chlorfenapyr and methomyl in corn. The average recoveries varied from 94% to 105%, with relative standard deviations (RSDs) of 8%-13% for chlorfenapyr and from 99% to 111%, with RSDs of 10-16% for methomyl. Chlorfenapyr and methomyl residues degraded in corn following a first-order kinetic model, with an estimated half-life (t(1/2)) of 3.9 and 2.8 days, respectively, and significant degradation (91.4%-98.1.5%, respectively) after 14 days. Although the maximum residue limits of chlorfenapyr and methomyl for corn are yet to be formulated in Egypt, the long-term dietary risk for those pesticides was acceptable, with arisk quotient < 100%, according to the national assessments. These findings are required to guide the correct and safe application of these insecticides in Egypt.
Medium-density fiberboards (MDFs) have been widely used to replace natural wood in structural and non-structural applications (mostly in furniture). On the positive side, the use of MDF has certainly reduced the level ofdeforestation. However, there is a need to develop a safe and effective treatment method for waste MDF as the presence of chemical additives in MDF and the generation of fine wood dust pose environmental and health challenges. Thermal decomposition of MDF taps into the waste-to-energy approach that has been broadly utilized in the disposal of organic-based wastes. Along this line of inquiry, this study entails three aims; (i) to compute thermodynamics and kinetic functions that govern the decomposition of MDF at conditions encountered at real pyrolytic and combustion conditions in waste incinerators; (ii) to acquire the temperature-dependent profiles of decomposition products; and (iii) to report ultimate and proximate analyses of MDF. Under both pyrolytic and combustion conditions, the thermal decay of MDF exhibits three stages that reflect its structural composition. Pertinent thermo-kinetic parameters were computed using model-fitting and iso-conversational formalisms. The nitrogen content in MDF peaked at 6.3%; significantly higher than that of natural wood (i.e., 1%) and originated from the use of urea formaldehyde resin. Chemical analysis indicates that nitrogenated (i.e., N , N-Dimethylacetamide) and oxygenated (i.e., catechol) products dominate the composition of the non-condensable fraction upon pyrolysis and oxidation of MDF. Such a finding calls for the importance of a post-treatment catalytic process that converts N- and O-containing products into pure hydrocarbons. The high nitrogen content in char of MDF indicates its potential utilization as soil nutrients. Values and insights reported herein are to establish a technical foundation for a biorefinery or a thermal facility that uses waste MDF as a feedstock.
Root-knot nematodes (RKNs) are a vital pest that causes significant yield losses and economic damage to potato plants. The use of chemical pesticides to control these nematodes has led to environmental concerns and the development of resistance in the nematode populations. Endophytic fungi offer an eco-friendly alternative to control these pests and produce secondary metabolites that have nematicidal activity against RKNs. The objective of this study is to assess the efficacy of Aspergillus flavus (ON146363), an entophyte fungus isolated from Trigonella foenum-graecum seeds, against Meloidogyne incognita in filtered culture broth using GC-MS analysis. Among them, various nematicidal secondary metabolites were produced: Gadoleic acid, Oleic acid di-ethanolamide, Oleic acid, and Palmitic acid. In addition, biochemical compounds such as Gallic acid, Catechin, Protocatechuic acid, Esculatin, Vanillic acid, Pyrocatechol, Coumarine, Cinnamic acid, 4, 3-indol butyl acetic acid and Naphthyl acetic acid by HPLC. The fungus was identified through morphological and molecular analysis, including ITS 1-4 regions of ribosomal DNA. In vitro experiments showed that culture filtrate of A. flavus had a variable effect on reducing the number of egg hatchings and larval mortality, with higher concentrations showing greater efficacy than Abamectin. The fungus inhibited the development and multiplication of M. incognita in potato plants, reducing the number of galls and eggs by 90% and 89%, respectively. A. flavus increased the activity of defense-related enzymes Chitinas, Catalyse, and Peroxidase after 15, 45, and 60 days. Leaching of the concentrated culture significantly reduced the second juveniles' stage to 97% /250 g soil and decreased the penetration of nematodes into the roots. A. flavus cultural filtrates via soil spraying improved seedling growth and reduced nematode propagation, resulting in systemic resistance to nematode infection. Therefore, A. flavus can be an effective biological control agent for root-knot nematodes in potato plants. This approach provides a sustainable solution for farmers and minimizes the environmental impact.
Seaweed extracts from Sargassum cristaefolium at 10% concentrations, effectively inhibited the mycelial growth of Colletotrichum gloeosporioides. According to the available literatures, the GC-MS analysis identified various compounds in these extracts that had a antifungal, antibacterial and antioxidant properties as per previous report. In both pot culture trials and field settings, the application of seaweed extracts via bulb treatment, soil drench, and foliar spray resulted in a notable decrease in the occurrence of twister blight disease. Among the treatments, treatment three, involving bulb treatment with S. cristaefolium at a 10% concentration, soil drench with the same seaweed at a 10% concentration and foliar application of S. cristaefolium at a 10% concentration, demonstrated a remarkable 69.39% reduction in twister blight, showcasing efficacy comparable to biocontrol agents and chemical fungicides. In pot culture conditions, increased levels of peroxidase, polyphenol oxidase, and phenylalanine ammonia lyase were observed, suggesting their involvement in enhancing resistance against disease. Histopathological examinations further revealed reduced tissue damage in treated plants. Additionally, protein content in both leaves and bulbs exhibited an increase in treated plants. This comprehensive study not only underscores the potential of seaweed extracts as effective biostimulants for disease management but also highlights their positive influence on overall plant health and productivity.
Purpose Fly ash (FA) is a waste byproduct produced in large quantities by coal-fired power stations. Its accumulation causes environmental issues, so it needs safe disposal of FA to reduce its accumulation. Herbal medicines like Mentha arvensis are being investigated worldwide for the prevention and treatment of a wide range of disorders because of their remarkable therapeutic benefits and absence of side effects when compared to current medications. Methods The aim of the study was to determine the effect of different concentrations of fly ash on growth, biochemical parameters, and constituents of essential oils of M. arvensis. Results The findings demonstrated that FA improved some important physical and chemical properties of soil. The use of FA-amended soil (10%) significantly improved the growth performance, photosynthetic pigments, protein, proline, antioxidant activity, and mineral contents. Conversely, the higher fly ash doses (25%) resulted in oxidative stress by increasing lipid peroxidation and electrolytic leakage levels, which negatively affected all of the aforementioned parameters. A confocal microscopic examination of the roots of M. arvensis revealed that fly ash at concentration of 25% resulted in membrane damage. In addition, alcohols, phenols, allenes, ketenes, isocynates, and hydrocarbons were among the functional groups found in the control and 10% of fly ash. Gas chromatography-mass spectrometry analysis of essential oils of M. arvensis treated with 10% fly ash revealed the presence of 32 bioactive components. Conclusions It is possible to use the 10% FA concentrations to increase plant growth and decrease the accumulation of FA that pollutes the environment.
Pleistocene yedoma sediments store large amounts of soil organic matter (SOM) and are vulnerable to permafrost degradation. Here we contribute to our understanding of yedoma SOM dynamics and potential response to thaw, by molecular characterization of samples from a 5.7 m yedoma exposure, as well as upper permafrost samples that were previously incubated, using Thermally assisted Hydrolysis and Methylation (THM-GC-MS). In general, the SOM is derived from aliphatic material (including cutin and suberin), phenols (lignin, sphagnum acid), polysaccharides and N-containing components (largely microbial SOM). Soil organic carbon (SOC) content and molecular SOM composition follow a sawtooth pattern where local maxima in SOC coincide with lignin and aliphatic material that experienced only slight degradation, and minima with degraded plant-derived SOM and microbial tissue, representing a stratified cryopedolith. The SOC-depleted top 0.9 m (active layer and transition zone) is enriched in microbial SOM probably due to recent thawing. Comparison with CO2 respiration rates indicates that SOM of microbial origin (low C/N) is more labile than aliphatic SOM from well-preserved plant tissue (high C/N). However, we argue that the more stable aliphatic SOM in SOC-rich layers might also be vulnerable to decay, which could, due to its abundance in SOC-rich layers, dominate overall Yedoma C losses due to thermal erosion.