Nematicidal Efficacy Research Articles

The Combination Effect of Purpureocillium lilacinum Strain (AUMC 10620) and Avermectin (B1a and B1b) on Control Citrus Nematode Tylenchulus semipenetrans (Cobb) Under Laboratory and Field Conditions

This study investigates the nematicidal efficacy of Purpureocillium lilacinum strain (AUMC 10620) combined with avermectin (B1a and B1b) against the citrus nematode Tylenchulus semipenetrans, both in vitro and in vivo. Laboratory experiments tested four concentrations of P. lilacinum (2.5, 5, 10, and 15 × 107 spores/mL) mixed with 250 ppm avermectin, assessing their effects on nematode juveniles (J2) and eggs. Results showed significant increases in juvenile mortality and egg hatching inhibition with the combined treatments compared to individual applications. The highest concentration (15 × 107 spores/mL + 250 ppm avermectin) achieved 100% juvenile mortality and 83.33% egg hatching inhibition after 72 h. Field trials confirmed the superior efficacy of the combined treatment, with P. lilacinum (15 × 107 spores/mL) and avermectin (1000 ppm) reducing nematode populations by 70.85% in mandarin trees and 70.77% in sweet orange trees after three weeks, compared to the 83.59% and 81.76% reduction, respectively, achieved by oxamyl. These findings suggest that mixtures of P. lilacinum and avermectin can serve as effective, eco-friendly alternatives for controlling nematodes in citrus orchards.

Bioactive flavonoids from Leucosceptrum canum with nematicidal efficacy and mechanistic insights through acetylcholinesterase inhibition and docking study

Bioactive flavonoids from Leucosceptrum canum with nematicidal efficacy and mechanistic insights through acetylcholinesterase inhibition and docking study

Spatiotemporal Dynamics of Trunk-Injected Pesticide Residue for Management of Pine Wilt Disease in Pinus koraiensis

This study focused on the persistence, distribution, and efficacy of trunk-injected pesticides in Pinus koraiensis (Korean pine) with regard to controlling pinewood nematodes (PWNs, Bursaphelenchus xylophilus), the causative agent of pine wilt disease (PWD). In this study, we compared pesticide residues in the needles and branches of Korean pine, revealing significant declines in pesticide residues over time after treatments were applied. Notably, abamectin residues decreased from 0.2325 mg/kg to 0.0901 mg/kg in branches over a period of 18 months. In contrast, emamectin benzoate showed a variation in residue decline depending on the formulation, with the residue level in branches decreasing from 0.1220 mg/kg to 0.0328 mg/kg over the same period. From a spatial perspective, the results revealed minimal differences in pesticide residue at varying tree heights, although a decrease in upper canopy residue was observed in some cases. The nematicidal efficacy test demonstrated that none of the treated trees developed PWN symptoms. Overall, the findings suggest that the trunk-injected pesticides abamectin and emamectin benzoate can persist for two years, with the residue levels being sufficient to prevent PWN propagation, even when the levels are below critical inhibition concentrations.

Improving the Efficacy against Cucumber Root-knot Nematode and Alleviating the Phytotoxicity of Fluopyram by Optimizing the Application Method

The root-knot nematode disease (RKN) caused by Meloidogyne incognita is a devastating threat to the production of crops, especially greenhouse vegetables. Fluopyram, a new nematicide, has been widely used by root drenching one-by-one plants for the management of RKN. However, as a common non-fumigation nematicide, its distribution in soil was often the key limiting factor that determined the efficacy and efficiency. To optimize the utilization of fluopyram against RKN, the control efficacy of application methods including blending-of-soil, root-irrigation, drip-irrigation, and furrow-irrigation and the correlation between nematicide distribution and efficacy were studied. The toxicities of fluopyram and abamectin to nematodes collected from different sources and backgrounds exhibited limited differences from crop and region. Compared to the control, all nematicide treatments reduced root galling by M. incognita in cucumber and increased the yield of cucumber. Blending-of-soil treatment and root-irrigation treatment were more beneficial for increasing the distribution area of nematicides in soil, then promoting the control efficacy of nematicides against RKN and improving cucumber production. This work showed that the application of fluopyram by blending-of-soil has the same efficacy as by root-irrigation in controlling RKN in cucumber production, moreover is more efficient and can be an alternative option.

In vitro and in vivo studies of Vitex negundo-derived silver oxide nanoparticles against Meloidogyne incognita (Root-knot nematode) on tomato plants

Meloidogyne incognita (M. incognita) is an important obligatory pest affecting a large number of horticultural crops. The pest is widely distributed in tropical, subtropical, and warmer regions of the world. M. incognita induces root gall formation that interferes with nutrient supply leading to stunted growth, wilting, chlorosis and significant drop in plant productivity. In recent years biogenic nanoparticles have emerged as an alternative approach for controlling agricultural pests. The current study investigates the nematicidal potential of green-synthesized silver oxide nanoparticles derived from Vitex negundo against second-stage juvenile (J2) and eggs of M. incognita. The maximum mortality (97.20 %) of M. incognita was found after 96 h of treatment. The lowest egg hatching (7.40 %) in comparison with the control (86.93 %) was found in 500 ppm concentration after six days of exposure. The bioassay results revealed that both juveniles and eggs generally showed a concentration-dependent response. The in vivo treatment with biogenic nanoparticles showed reduced gall formation and increased plant growth in tomato plants. Maximum reduction in the galls and plant growth parameters was observed in higher concentrations (1000 ppm) of VND-AgONPs after 60 days compared to untreated inoculated control. To best of our knowledge, this is the first report of the nematicidal efficacy of VND-AgONPs against J2 and eggs of M. incognita. These biogenic nanoparticles could be recommended for managing Root-knot nematodes due to their higher efficacy, cost-effectiveness, and environmentally safe nature.

Efficacy of microbiological nematicides in controlling root-knot nematodes in tomato

Root-knot nematodes (RKNs) are considered a limiting factor for tomato production, causing substantial economic losses. Several control measures have been used to control RKNs in infested areas, such as crop rotation or succession with non-host species, using resistant cultivars, and applying chemical and biological nematicides. Here, we examined the control effect of six microbiological products (Ag109 - Bacillus velezensis, Votivo Prime - B. firmus, Quartzo - B. subtilis and B. licheniformis, Veraneio - B. amyloliquefaciens, Nemat - Purpureocillium lilacinum, and Rizotec - Pochonia chlamydosporia) against different species of Meloidogyne in tomatoes cultivated in a greenhouse and evaluated these products under field conditions to verify their impact on root-associated nematode populations and agronomic and physicochemical traits of fruits from grafted and non-grafted tomato plants. For the greenhouse studies, higher pathogenicity was observed for tomato with M. javanica and M. enterolobii compared to M. incognita. The microbiological nematicides were more effective in controlling M. javanica and M. enterolobii, while for M. incognita, the evaluated products were ineffective. Regarding the field studies, most of the microbiological nematicides evaluated effectively increased production per plant. However, when analyzing the Meloidogyne population in the field, applying microbiological nematicides showed no nematode control in plants without rootstock. On the other hand, in the grafted plants, the Ag109, Veraneio, Rizotec, and Nemat treatments boosted the reduction in the Meloidogyne population in the roots, with average reductions of 68.47, 57.97, 77.29, and 56.70%, respectively. These results indicate the effectiveness of integrated management of microbiological nematicides and resistant rootstock in tomato. Furthermore, combining these two control measures resulted in no change in the nutritional quality of tomato fruits.

Exploring the bio-efficacy of biocontrol agents in mitigating <i>Meloidogyne incognita</i> menace in carrot cultivation

The nematicidal efficacy of liquid formulation of Pochonia chlamydosporia, Bacillus subtilis, Purpureocillium lilacinum, Trichoderma viride and vermiculite formulation of Rhizophagus intraradices were challenged against Meloidogyne incognita under glasshouse conditions. The in vivo experiment were piloted to test the potential of these biological agents by soil drenching of liquid formulation @ 1 ml/ pot or soil application of vermiculite formulation @ 1g/pot/dose. Their effect was compared with the granular application of Carbofuran @ 1g/pot/dose. All the liquid bioformulations investigated were capable of enhancing plant growth and lowering the pathogenicity and parasitic success of M. incognita in carrots. The soil drenching of P. chlamydosporia caused a significant reduction of galls in the root (51%), nematode population in the root (43.6%), egg mass in the root (65.3%) and infective juvenile population in soil (51.8%) over other treatments and Carbofuran.

Anti‐Phytopathogenic and Phytotoxic Effects of Annona glabra Lin. and Annona muricata Lin. Seed Extracts: In vitro and In vivo Assessment, Bioactive Compound Quantification, and Mechanism Involved

AbstractBuilding upon prior research demonstrating the excellent antifungal and nematicidal efficacy of Annona squamosa Lin. seed extracts, this study extends its scope to investigate similar properties in seed extracts from two other Annonaceae species: Annona muricata Lin. and Annona glabra Lin. The focus is on assessing their effectiveness against tomato late blight (TLB) and wheat leaf rust (WLR) diseases, as well as their broader antifungal activity against Colletotrichum sp. and Fusarium sp. The A. glabra seed extract exerted a superior control efficacy against TLB (85 % at 62.5 μg/mL) and WLR (75 % at 125 μg/mL) in vivo. The two Annonaceous extracts also exhibited in vitro antifungal inhibition against Colletotrichum sp. and Fusarium sp., as well as toxicology against pine wilt nematodes and Artemia salina. Besides, they showed phytotoxicity against Raphanus sativus seed germination. Squamocin G, a potent bioactive acetogenin, was isolated from A. glabara, which was found to occur at high contents in the following ascending order in A. glabra, A. muricata and A. squamosa dichloromethane extracts. To investigate the antifungal mechanism, molecular docking and molecular dynamic of squamocin G ligand were also performed for the first time at the active site of succinate dehydrogenase and β‐tubulin.

In vitro nematicidal efficacy of brassica-derived isothiocyanates against the root lesion nematode, Pratylenchus penetrans

Summary Brassica plants naturally produce glucosinolates as secondary metabolites hydrolysed to biocidal isothiocyanates (ITCs). As such, they have the potential for nematode management through a strategy known as biofumigation. Pratylenchus penetrans causes significant yield losses in many important crops. Understanding the relative impact of different ITCs on the motility and mortality of this nematode species could provide some insights into the selection of relevant brassica biofumigants. The effects of 3.125, 6.25, 12.5, 25, and 50 μg ml−1 of pure Allyl, 2-Phenylethyl and Benzyl ITCs on the motility and mortality of P. penetrans were evaluated in laboratory in vitro assays. Motility was assessed after incubating the nematodes in ITCs for 24, 48 and 72 h with distilled water as a negative control. Motile and non-motile nematodes were counted. After motility assessment at 72 h, nematodes were rinsed and incubated in water for 48 h, after which live and dead nematodes were counted. Nematodes were considered dead if they remained non-motile after probing with a picking needle. Nematode motility and mortality were significantly affected by the type of ITC, concentration and time of exposure. The number of non-motile nematodes increased with increasing concentration and time of exposure across all tested ITCs. The ED50 values (concentration required to cause 50% non-motility) of Allyl, 2-Phenylethyl and Benzyl were 37.4, 12.8 and 8.6 μg ml−1 after 24 h exposure. The ITC with potentially the greatest nematicidal effect was Benzyl (LD50 = 3.2 μg ml−1), followed by 2-Phenylethyl (LD50 = 5.2 μg ml−1), and Allyl (LD50 = 9.9 μg ml−1). The LD50 of all ITCs were not different from the ED50 after 72 h, meaning the effects of ITCs could be considered irreversible. This study suggests that brassica biofumigants that produce Benzyl, Allyl and 2-Phenylethyl ITCs are promising candidates for biofumigation of P. penetrans.

Characterization of finger millet extracts and evaluation of their nematicidal efficacy and plant growth promotion potential.

Plant-parasitic nematodes pose a significant threat to finger millet crops, potentially causing yield reduction of up to 70%. Extracts derived from finger millet varieties contain potent bioactive compounds that can mitigate nematode damage and promote plant growth. This study aimed at isolating and characterizing bioactive compounds from the finger millet varieties Ikhulule, Okhale-1, and U-15; evaluating the impact of Ikhulule and U-15 extracts on the mortality of the root lesion nematode Pratylenchus vandenbergae; assessing the growth promotion effects of Ikhulule and U-15 extracts on the finger millet variety Okhale-1; and determining the efficacy of these extracts in managing plant-parasitic nematodes under greenhouse conditions. Extracts were obtained from both leaves and roots and tested invitro for nematode mortality and invivo for growth promotion and nematode control. The results showed that finger millet extracts exhibited strong nematicidal properties invitro, achieving a mortality rate of up to 98% against P. vandenbergae nematodes. Applying these extracts to finger millet shoots significantly reduced nematode populations in both soil and roots and decreased the reproductive factor to below one (1), indicating an effective nematode control. The study attributes the enhanced nematicidal effects of finger millet extracts to their bioactive compounds, particularly dodecanoic acid, phytol, 1,1,4a-trimethyl-6-decahydro naphthalene, 2,3-dihydro-benzofuran, 2-methoxy-4-vinylphenol and ethyl ester, and hexadecanoic acid. These findings suggest that finger millet-derived extracts offer a natural solution for nematode management and broader agronomic benefits, ultimately contributing to overall plant health and productivity.

Efficacy of nematicides, Tricuran-P (Trichoderma harzianum T-22) and chicken manure on cucumber root-knot nematode populations, plant growth and soil enzyme activities

Efficacy of nematicides, Tricuran-P (Trichoderma harzianum T-22) and chicken manure on cucumber root-knot nematode populations, plant growth and soil enzyme activities

Bringing light into the dark—plant electrophysiological monitoring of root knot nematode infestation and real-time nematicide efficacy

Bringing light into the dark—plant electrophysiological monitoring of root knot nematode infestation and real-time nematicide efficacy

Efficacy of chemical and biological nematicides for the management of stem and bulb nematode, Ditylenchus dipsaci, in garlic

Efficacy of chemical and biological nematicides for the management of stem and bulb nematode, <i>Ditylenchus dipsaci</i>, in garlic

Exploiting the nematicidal compounds from guava endo microbiome against root-knot nematodes, Meloidogyneenterolobii

Guava root-knot nematode, Meloidogyne enterolobii has emerged as a major threat in tropical and sub-tropical countries across the globe. These nematodes utilize their esophageal gland-secreted protein, M. enterolobii Translationally Controlled Tumour Protein (MeTCTP) for successful parasitism on guava plants. Our current study was focused on identifying the biomolecules produced by nematicidal endophytic bacterial strains crucial for suppressing MeTCTP. Results of our study exhibited that among different isolates Bacillus cereus (GREB1) demonstrated superior nematicidal efficacy and biomolecules from this strain, such as 2,1,3-benzothiodiazole (−6.0 kcal/mol), 2 hexen-1-ol (−5.1 kcal/mol) and heptanoic acid (−4.5 kcal/mol), exhibited notable binding affinity to MeTCTP protein in docking studies. Molecular dynamics simulation studies underscored the stability, dynamics, and binding mechanisms of these biomolecules with MeTCTP. Furthermore, the results of the in vitro assay with identified biomolecules proved that 2,1,3 benzothiadiazole @ 200 ppm had 99% juvenile mortality. The probit analysis revealed the LC50 concentration of 2,1,3 benzothiadiazole (52.17 μg/mL), 2 hexen-1- ol (84.37 μg/mL) and heptanoic acid (141.93 μg/mL) respectively. Integrating in-silico and in-vitro bio-efficacy assays, our study provides a pivotal foundation for novel biomolecules against guava nematodes. Moreover, the study lays the foundation to formulate a novel solution comprising potent biomolecules to curb M. enterolobii populations, offering a promising avenue for effective crop protection.

Assessment of nematicidal efficacy of some biomaterials against Meloidogyne incognita on eggplant (Solanum melongena L.)

Assessment of nematicidal efficacy of some biomaterials against Meloidogyne incognita on eggplant (Solanum melongena L.)

Biosynthesis of Cry5B-Loaded Sulfur Nanoparticles using Arthrobotrys oligospora Filtrate: Effects on Nematicidal Activity, Thermal Stability, and Pathogenicity against Caenorhabditis elegans.

Cry5B, a crystal protein produced by Bacillus thuringiensis (Bt), is a bionematicide with potent nematicidal activity against various plant-parasitic and free-living nematodes. This protein, however, is susceptible to destruction by ultraviolet light, proteolytic enzymes, and high temperatures. This study aims to produce Cry5B protein for bionematicidal use and improve its stability and nematicidal efficacy by loading it intoArthrobotrys oligospora-mediated sulfur nanoparticles (AO-SNPs). Based on the mortality assay, the Cry5B protein exhibited dose-dependent nematicidal activity against the model organismCaenorhabditis elegans. The nematicidal activity, thermal stability, and pathogenic effects of Cry5B-loaded AO-SNPs (Cry5B-SNPs) were compared to those of free Cry5B. After 3 h of exposure to heat at 60 °C, Cry5B-SNPs had greater nematicidal activity than free Cry5B protein, indicating the effective formulation of Cry5B-SNPs that could be used as an alternative to current nematicide delivery strategies.

Evaluation of the nematicidal efficacy of an aqueous extract of Eupatorium odoratum on Radopholus similis nematode infestation in banana ( Musa acuminata “Cavendish”) in a micro plot experiment and under field trial conditions

Eupatorium odoratum is known for its ability to resist nematode infestations that attack the root systems of banana plants. An aqueous extract of the leaves and stems of E. odoratum (named EEOL) represents a natural solution that we investigated for its potential to control the harmful nematode, Radopholus similis, in Cavendish banana plants. Our research into EEOL’s efficacy spanned two distinct environments: a micro plot experiment model and a field model. Various concentrations of EEOL were examined to assess its efficacy in alleviating R. similis infestations and in mitigating their adverse effects on Cavendish banana plants. In the micro plot experiment model, the concentration of the original solution, diluted at ratios of 1:30×, 1 : 16×, 1 : 8×, 1 : 4×, and 1 : 2×, ranged from 1.76 to 28.16 mg · ml -1. In the field model, the corresponding rates varied from 6.03 to 96.54 l · ha -1. Key parameters, including infection rates, root necrosis indices, plant growth metrics, percentage of fallen trees, and harvest yields, were meticulously monitored and assessed. The results demonstrated that EEOL significantly reduced infection rates ( p &amp;lt; 0.05), decreased root necrosis indices ( p &amp;lt; 0.05), and promoted increased plant height, pseudostem circumference, and leaf area ( p &amp;lt; 0.05) in both models. Furthermore, it lowered the percentage of fallen trees ( p &amp;lt; 0.05) and enhanced harvest yields ( p &amp;lt; 0.05) in the field model. Notably, observations in the field model revealed that EEOL, particularly at a dosage of 96.54 l · ha -1, exhibited effectiveness equivalent to the conventional chemical nematode control method, fenamiphos ( p &amp;gt; 0.05). The study’s findings underscore the promising potential of EEOL in effectively managing R. similis infestations and improving the yield and quality of Cavendish banana plants. The aqueous extract of the stem and leaves of E. odoratum emerged as an effective nematode management solution for banana cultivation, in both the micro plot experiment and field conditions.

Green Nano-synthesis: Salix alba Bark-Derived Zinc Oxide Nanoparticle and their nematicidal Efficacy against root knot nematode Meloidogyne incognita

Background: Plant parasitic nematodes (PPNs) are considered major agriculture pests, causing significant damage to crops by directly targeting the plant root system to prevent water and nutrient uptake. One of its major species, Meloidogyne incognita, is considered a serious threat to agriculture crop production worldwide. The current study was intended to evaluate the potential of Nanoparticles synthesized from Salix alba bark extract as nematicidal agent.Methods: Phytochemical analyses of Salix alba bark extract were conducted, and nanoparticles of the same extract were synthesized and characterized using UV-vis spectroscopy, XRD (X-Ray Diffraction), SEM (Scanning Electron Microscopy) and EDX (Energy Dispersive X-ray Spectroscopy) techniques. Results: The qualitative phytochemical analysis of Salix alba bark extract revealed the presence of phenolics, flavonoids, reducing sugars, and saponins. When applied on juveniles of the plant parasitic nematode Meloidogyne incognita, the nanoparticles demonstrated a dose and time-dependent impact. After 24 hours, the highest concentration (1000 µg/ml) of nanoparticles exhibited the greatest mortality, reaching 82.2%, while the lowest concentration resulted in a mortality rate of 34.5%. Similarly, at the 48-hour mark, the highest mortality (92.2%) was observed with 1000 µg/ml of nanoparticles, whereas the lowest concentration yielded a mortality rate of 54.5%. Extending the observation period to 72 hours, the mortality rate peaked at 98.33% with the highest nanoparticle concentration (1000 µg/ml), and the lowest mortality rate was recorded at the lowest dose, amounting to 72.5%. These results underscore the dose and time-dependent efficacy of Salix alba bark-derived nanoparticles against Meloidogyne incognita. Conclusion: Our findings suggest that zinc oxide nanoparticles synthesized from Salix alba bark can be an effective agent against plant parasitic nematode Meloidogyne incognita. Further experiments are recommended to study the impact of these nanoparticles on other biotic stresses.

Eco-Friendly Silver Nanoparticles Synthesized from a Soybean By-Product with Nematicidal Efficacy against Pratylenchus brachyurus.

This study explores an eco-friendly approach to synthesizing silver nanoparticles (AgNPs) using soybean leaf extracts, employing a reaction with silver nitrate at 65 °C for 2.5 h. Optimal results were achieved at extract concentrations of 3.12 and 6.25 mg of the leaf mL-1, termed 3.12AgNP and 6.25AgNP, respectively. UV-Vis spectrophotometric analysis between 350 and 550 nm exhibited a peak at 410-430 nm, along with a color transition in the suspensions from pale yellow to brown, indicating successful synthesis. Dynamic light scattering (DLS) further delineated the favorable properties of these AgNPs, including nanometric dimensions (73-104 nm), negative charge, and moderate polydispersity, portraying stable and reproducible synthesis reactions. The bioreduction mechanism, possibly expedited by leaf extract constituents such as amino acids, phenolic acids, and polysaccharides, remains to be fully elucidated. Notably, this study underscored the potent nematicidal effectiveness of biosynthesized AgNPs, especially 6.25AgNP, against Pratylenchus brachyurus, which is a common plant-parasitic nematode in tropical soybean cultivation regions. In vitro tests illustrated significant nematicidal activity at concentrations above 25 µmol L-1, while in vivo experiments displayed a pronounced nematode population diminishment in plant roots, particularly with a 6.25AgNP rhizosphere application at concentrations of 500 µmol L-1 or twice at 250 µmol L-1, attaining a reproduction factor below 1 without any morphological nematode alterations. This research highlights the potential of 6.25AgNPs derived from soybean leaf extracts in forging sustainable nematicidal solutions, marking a significant stride toward eco-friendly phytonematode management in soybean cultivation. This novel methodology signals a promising avenue in harnessing botanical resources for nematode control and propelling a greener agricultural horizon.

Efficacy of five nematicides against root-knot nematode when applied via single and double drip tapes in a Florida sandy soil.

The efficacy of drip-applied nematicides depends on adequate product distribution, which can be difficult in sandy soils. Three new non-fumigant nematicides (fluazaindolizine, fluensulfone, fluopyram), together with two old nematicides, oxamyl and metam potassium, were evaluated when applied via single and double drip tapes to control root-knot nematode in cucumber and squash in Florida between February 2020 and December 2022. Nematicide applications via double drip tapes resulted in lower root gall infection (and tend to have higher yield) as compared to a single tape for fluopyram, but no difference was noted between single and double tapes for oxamyl and fluazaindolizine. Fluensulfone response was somewhere in between and metam potassium had higher squash yield when applied with double tapes. Root-knot infection was higher in cucumber than in squash, and metam potassium had the highest yields and lowest nematode infection compared to other nematicide treatments. The benefit of double versus single drip tapes depended on the type of nematicide that was applied and was evident for nematicides that have poor water solubility like fluopyram. Some benefit was noted for metam potassium, but no or limited benefit was noted for oxamyl, fluazaindolizine and fluensulfone. © 2023 Society of Chemical Industry.