Nematode Meloidogyne Research Articles

Molecular and functional characterization of chemosensory genes from the root-knot nematode Meloidogyne graminicola

BackgroundRoot-knot nematode Meloidogyne graminicola has emerged as a major threat in rice agroecosystems owing to climate change-induced changes in cultivation practices. Synthetic nematicides are continually being withdrawn from the nematode management toolbox because of their ill effects on the environment. A sustainable strategy would be to develop novel nematicides or resistant plants that would target nematode sensory perception, which is a key step in the host finding biology of plant-parasitic nematodes (PPNs). However, compared to the extensive literature on the free-living nematode Caenorhabditis elegans, negligible research has been performed on PPN chemosensory biology.ResultsThe present study characterizes the five chemosensory genes (Mg-odr-7, Mg-tax-4, Mg-tax-4.1, Mg-osm-9, and Mg-ocr-2) from M. graminicola that are putatively associated with nematode host-finding biology. All the genes were highly transcribed in the early life stages, and RNA interference (RNAi)-induced downregulation of each candidate gene perturbed the normal behavioural phenotypes of M. graminicola, as determined by examining the tracking pattern of juveniles on Pluronic gel medium, attraction to and penetration in rice root tip, and developmental progression in rice root. In addition, a detrimental effect on nematode chemotaxis towards different volatile and nonvolatile organic compounds and host root exudates was documented.ConclusionOur findings enrich the existing literature on PPN chemosensory biology and can supplement future research aimed at identifying a comprehensive chemosensory signal transduction pathway in PPNs.

Trichoderma erinaceum AND Trichoderma virens IN THE CONTROL OF Meloidogyne incognita IN Solanum lycopersicum

In this study, the antagonistic potential of Trichoderma erinaceum 10-15 and T. virens 32-09 against the nematode Meloidogyne incognita was evaluated in tomato (Solanum lycopersicum L.) plants. A solution of 106 conidia mL-1 of each strain was inoculated on tomato plants, and the variables of nematode control, galling index, eggs per gram of root, and females per gram of root were determined. The in vitro antagonism of Trichoderma filtrates on the hatching of eggs and J2 juveniles of M. incognita was evaluated. The results were used for analysis of variance and comparison of means using the Tukey method (p ≤ 0.05). Control variables of the phytopathogen on S. lycopersicum were determined by measuring the area under the disease progress curve (AUDPC), the Weibull parameter, the coefficient of determination, and the final severity of root damage. T. erinaceum 10-15 showed a greater inhibitory effect on M. incognita, relative to T. virens 32-09. Both strains evaluated showed significant differences in comparison to the uninoculated control, resulting in a 60 % reduction in juvenile stage mobility and egg hatching, as well as greater control of the phytonematode in the AUDPC variables, Weibull parameter, and final severity under controlled conditions. The strain T. erinaceum 10-15 showed a better antagonistic effect on egg formation at 68 days, at 60.3 %, and on reducing the number of M. incognita females with at 60 days, at 80.6 %. Both T. erinaceum 10-15 and T. virens 32-09 were found to be potential biocontrol agents of M. incognita in S. lycopersicum.

Laboratory Evaluation of Efficiency of some Normal and Nano Amino Acids in Hatching Eggs and Vitality of J2 Second Instar Juveniles in Root-knot Nematode Meloidogyne spp.

Tomato affected by several pathogenic factors, including root-knot nematodes (Meloidogyne spp.). This research was conducted to evaluate the efficacy of three amino acid Arginine, Serine, and Leucine, in their normal and Nano forms, at three different concentrations (10, 20, 30 ppm). The evaluation was performed under laboratory conditions to assess their effectiveness in inhibiting egg hatching and the viability Second stage Juveniles (J2) of the targeted nematode species. The laboratory results demonstrated the efficiency of all treatments in reducing the percentage of unhatched eggs, particularly at higher concentrations. The Nano-form of the three amino acids at a concentration of 30 ppm exhibited the highest efficacy compared to the normal form and showed significant superiority over the control treatment. After 72 hours, the percentage of unhatched eggs for Arginine, Serine, and Leucine Nano-amino acids was (21.00, 31.33, and 30.67), respectively, with a kill rate of (79%, 68.88%, and 69.33%) compared to the control treatment, which recorded 75% unhatched eggs and a kill rate of 25%. The impact of these treatments on the viability Second stage juveniles(J2) also varied significantly with different concentrations, showing a dose-dependent effect over time and significant differences compared to the control group. The highest concentration of 3000 ppm was the most effective, resulting in the highest kill rate for Arginine, Serine, and Leucine Nano-amino acids, which reached (95.27%, 90.27%, 88.89%), respectively, compared to the control treatment, which had a kill rate of 48.60%.

Vineyard soil texture and pH effects on Meloidogyne hapla and Mesocriconema xenoplax

AbstractNorthern root‐knot nematode (Meloidogyne hapla) and ring nematode (Mesocriconema xenoplax) are the most prevalent plant‐parasitic nematodes of wine grapes in the Pacific Northwest, but M. hapla is most important in eastern Washington and M. xenoplax in western Oregon. These regions differ edaphically where Washington soils are minimally weathered and alkaline while Oregon soils are highly weathered and acidic. To examine the effect of soil texture and pH on nematode reproduction, an alkaline, sandy loam soil (pH 7.9) from Washington and an acidic loam soil from Oregon (pH 5.4) were modified to the other pH extreme, and to a middle pH of 6.9. Tomatoes were planted into each soil/pH combination, and either 500 M. hapla second‐stage juveniles or M. xenoplax individuals were added to each pot. After 7 weeks, plants were harvested, three roots collected for analysis, remaining roots and leaves dried and weighed, and nematode population densities determined as eggs on roots (M. hapla) and nematodes in soil (M. xenoplax). Soil texture (sandy loam or loam) had no effect on either nematode, but M. hapla reproduction was greater in the lowest pH soil while M. xenoplax was unaffected by soil pH. Mesocriconema xenoplax parasitism reduced root length and root tip number, whereas M. hapla increased root mass in the highest pH Washington soil. Under these experimental conditions, it appears vineyard soil texture in the Pacific Northwest is not a determining factor in population growth of these nematodes, but M. hapla performed better at low pH.

Response of soybean and tomato plants under dual inoculation with Glomus sp. and root-knot nematode Meloidogyne incognita

The arbuscular mycorrhiza fungus Glomus can increase plant’s water and nutrient uptake and provide protection against plant parasitic nematodes. This study aimed to determine the response of soybean and tomato plants under inoculation with Glomus sp. and root-knot nematode Meloidogyne incognita at different application times in pot experiments. On soybean, Glomus sp. alone or in combination with M. incognita significantly increased plant height, while simultaneous inoculation of both microorganisms significantly increased the root dry weight. The total leaf P content of soybean however, significantly decreased in response to all inoculation methods. On tomato plants, Glomus alone significantly increased tomato shoot dry weight, total plant dry weight, and the total leaf P content. The final nematode population, the number of nematodes penetrating the root, and the root gall scores were not significantly impacted by either Glomus or M. incognita inoculation The inconsistent effect of Glomus inoculation on plant growth and total leaf P content as well as the inability of Glomus to reduce M. incognita infestation may be contributed by the extent of root colonization by Glomus and variability in the species of Glomus.

The Relationship Between Tomato Yellow Leaf Curl Virus Resistance Gene and Root Knot Nematode Meloidogyne spp. Resistance Gene in Tomato Plants

Tomato Mi-1.2 resists root-knot nematodes. Mi, or a similar gene, may also be responsible for resistance to Bemisia tabaci whitefly in Mi-bearing commercial tomato varieties. Mi-1.2 is the only resistance gene that fights root-knot nematodes, aphids, and whiteflies. Mi is useful in integrated pest control strategies because these pests are the most damaging to tomato crops worldwide. Ten tomato varieties were produced to determine which are resistant to TYLCV and the root-knot nematode Meloidogyne spp. and whether these genes are linked. TYLCV-free nurseries were used to grow these tomato varieties. To assess these cultivars’ sensitivity and resistance to TYLCV, they were transferred to the plastic house and planted during Bemisia tabaci insect activity. These types were planted in soil contaminated with nematode eggs and juvenal, vaccinated, and reported every 15 days for disease incidence. Class H cultivars were vulnerable to nematodes and the virus, while class Gres were TYLCV-resistant. The rest of the cultivars were TYLCV-resistant, nematode-resistant, or both.

Identification of Oryza glaberrima as a potential resistance source to rice root-knot nematode, Meloidogyne graminicola

Abstract The root-knot nematodes (RKN) (Meloidogyne graminicola) are a devastating threat to rice worldwide. The cultivated germplasm is either susceptible or moderately resistant to rice RKN. Therefore, there is a need to identify resistance sources against M. graminicola as an eco-friendly management strategy. The present study evaluated the host response of Oryza sativa genotypes comprising basmati, non-basmati improved varieties, their advanced breeding lines (83) and Oryza glaberrima accessions (42) against M. graminicola in the nematode-infested plot for two consecutive years. All O. sativa genotypes exhibited susceptible responses, while O. glaberrima accessions showed variable levels of resistance. Three of the O. glaberrima accessions (IRGC102196, IRGC102538 and IRGC102557) were highly resistant. M. graminicola significantly affected plant growth parameters in susceptible genotypes compared to resistant O. glaberrima accessions. The results were supported by histopathological studies that showed apparent giant cell formation in PR121 while penetration and development of M. graminicola juveniles were low in the O. glaberrima acc. IRGC102196. In silico analysis indicated that none of the reported nematode resistance genes from different crops had homology with the rice genome. The two anti-nematode genes (Oryzacystatin-I and Oryzacystatin-II) from O. sativa japonica revealed homology with O. sativa cv. PR121 and O. glaberrima acc. IRGC102206. Comparative analysis of these genes between PR121 and O. glaberrima acc. IRGC102206 resulted in the identification of SNPs/InDels that could be associated with nematode resistance. The identified SNPs/InDels could be validated, and further molecular studies are needed to provide insights into the resistance mechanism against rice RKN.

Valorization of the essential oil from Drypetes gossweileri S. Moore (Putranjivaceae): in vitro, in vivo, and in silico nematicidal activity

The chemical composition, insect antifeedant, in vtro/in vivo nematicidal activity, phytotoxicity, and in silico nematicidal activity of the essential oil (EO) of the African medicinal plant Drypetes gossweileri were studied. Chemical analysis using GC/MS indicated that benzyl isothiocyanate (96.23%) was the major compound, followed by benzyl cyanide (1.38%). The biocidal effects of this oil were tested against insect pests and root-knot nematodes. All the insect species tested were significantly affected by the oil according to their feeding adaptations (Spodoptera littoralis and Myzus persicae were less affected than Rhopalosiphum padi) with efficient doses (EC50) of 29.4 8.3 μg/cm2, 14.744 8.3 μg/cm2, and 8.3 μg/cm2, respectively. The oil was highly effective against juveniles J2 of the nematode Meloidogyne javanica, with LC50–LC90 values of 0.007 mg/mL–0.0113 mg/mL. D. gossweileri EO at minimum lethal concentrations (MLC) and below strongly inhibited egg hatching in vitro, whereas soil treatment caused a strong suppression of nematode population, infection frequency, and multiplication rate. The EO inhibited ryegrass (Lolium perenne) germination at 0.4 mg/mL, while at 0.1 mg/mL, its effects on germination, root and leaf growth were moderate (32.4%, 8.4%, and 18.3%, respectively). The tomato (Solanum lycopersicum) germination was not affected by the EO, but the root growth was reduced (56% at 0.1 mg/mL) at a dose 10 times higher than the LD50 calculated for M. javanica J2 mortality. Molecular docking of the nematicidal effects of the oil using PyRx revealed a strong interaction between potassium chloride transporting KCC3 (PDB ID: 7D90) and benzyl cyanide at a distance of 2.20 A° with GLN C:350, followed by benzyl isothiocyanate at a distance of 2.78 A° with ARG B:294. The in vivo nematicidal effects of D. gossweileri EO on M. javanica penetration and reproduction in tomato roots further support the potential of this EO as a nematicidal agent with insect antifeedant effects, which could be used by local farmers for crop protection.

Biological enhancement of the cover crop Phacelia tanacetifolia (Boraginaceae) with the nematophagous fungus Pochonia chlamydosporia to control the root-knot nematode Meloidogyne hapla in a succeeding tomato plant

Root-knot nematodes cause global economic losses in a wide range of crops. We investigated the potential of seed coatings of the cover crop Phacelia tanacetifolia (Boraginaceae) when inoculated with the nematophagous fungus Pochonia chlamydosporia (Hypocreales: Clavicipitaceae) to protect subsequently grown tomato plants from root galling caused by the root-knot nematode Meloidogyne hapla (Tylenchida: Meloidogynidae). Therefore, seeds of P. tanacetifolia were coated with P. chlamydosporia blastospores and planted in M. hapla-infested pots. After 50 days of growth in infested soil, M. hapla eggs were extracted from P. tanacetifolia roots and quantified. Tomato plants grown in the remaining soil served as bioindicator of M. hapla infestation as expressed by the gall index. Results showed that seed coating of P. tanacetifolia with P. chlamydosporia (290 ± 51 CFU per seed) reduced the number of M. hapla eggs up to 95.6% in comparison to untreated controls. Pochonia chlamydosporia as blastospore suspension (5·108 blastospores per 600 ml soil) reduced the number of M. hapla eggs by up to 75.5%. Additionally, tomato plants grown for 50 days in substrates previously planted with P. tanacetifolia seeds coated with P. chlamydosporia showed a significantly lower gall index than plants grown in untreated pots. In conclusion, biological enhancement of P. tanacetifolia by seed coating with P. chlamydosporia successfully reduced M. hapla and thus provides an additional tool in the management of this nematode. The method still has potential for further improvement such as increasing blastospore viability within the seed coating by optimized formulation technology.

Transcriptome-Based Comparative Expression Profiling of Sweet Potato during a Compatible Response with Root-Knot Nematode Meloidogyne incognita Infection.

M. incognita, a root-knot nematode (RKN), infects the roots of several important food crops, including sweet potato (Ipomoea batatas Lam.), and severely reduces yields. However, the molecular mechanisms underlying infection remain unclear. Previously, we investigated differential responses to RKN invasion in susceptible and resistant sweet potato cultivars through RNA-seq-based transcriptome analysis. In this study, gene expression similarities and differences were examined in RKN-susceptible sweet potato cultivars during the compatible response to RKN infection. Three susceptible cultivars investigated in previous research were used: Dahomi (DHM), Shinhwangmi (SHM), and Yulmi (YM). Of the three cultivars, YM had the highest number of genes with altered expression in response to infection. YM was also the cultivar with the highest susceptibility to RKN. Comparisons among cultivars identified genes that were regulated in more than one cultivar upon infection. Pairwise comparisons revealed that YM and DHM shared the most regulated genes, whereas YM and SHM shared the lowest number of regulated genes. Five genes were up-regulated, and two were down-regulated, in all three cultivars. Among these, four genes were highly up-regulated in all cultivars: germin-like protein, anthranilate synthase α subunit, isocitrate lyase, and uncharacterized protein. Genes were also identified that were uniquely regulated in each cultivar in response to infection, suggesting that susceptible cultivars respond to infection through shared and cultivar-specific pathways. Our findings expand the understanding of the compatible response to RKN invasion in sweet potato roots and provide useful information for further research on RKN defense mechanisms.

Characterizing microbial communities associated with northern root-knot nematode (Meloidogyne hapla) occurrence and soil health.

The northern root-knot nematode (Meloidogyne hapla) causes extensive damage to agricultural crops globally. In addition, M. hapla populations with no known genetic or morphological differences exhibit parasitic variability (PV) or reproductive potential based on soil type. However, why M. hapla populations from mineral soil with degraded soil health conditions have a higher PV than populations from muck soil is unknown. To improve our understanding of soil bio-physicochemical conditions in the environment where M. hapla populations exhibited PV, this study characterized the soil microbial community and core- and indicator-species structure associated with M. hapla occurrence and soil health conditions in 15 Michigan mineral and muck vegetable production fields. Bacterial and fungal communities in soils from where nematodes were isolated were characterized with high throughput sequencing of 16S and internal transcribed spacer (ITS) rDNA. Our results showed that M. hapla-infested, as well as disturbed and degraded muck fields, had lower bacterial diversity (observed richness and Shannon) compared to corresponding mineral soil fields or non-infested mineral fields. Bacterial and fungal community abundance varied by soil group, soil health conditions, and/or M. hapla occurrence. A core microbial community was found to consist of 39 bacterial and 44 fungal sub-operational taxonomic units (OTUs) across all fields. In addition, 25 bacteria were resolved as indicator OTUs associated with M. hapla presence or absence, and 1,065 bacteria as indicator OTUs associated with soil health conditions. Out of the 1,065 bacterial OTUs, 73.9% indicated stable soil health, 8.4% disturbed, and 0.4% degraded condition; no indicators were common to the three categories. Collectively, these results provide a foundation for an in-depth understanding of the environment where M. hapla exists and conditions associated with parasitic variability.

Expression analysis of sweet potato patatin-like protein (PLP) genes in response to infection with the root knot nematode Meloidogyne incognita

Expression analysis of sweet potato patatin-like protein (PLP) genes in response to infection with the root knot nematode Meloidogyne incognita

"Revealing the genetic arsenal of Bacillus firmus TNAU1: Unleashing nematicidal and plant growth promotion traits"

Bacillus firmus is a promising nematicidal bacterium that also confers plant growth promotion, nutrient acquisition and antimicrobial activities. In the present study, attempts were made for whole genome sequencing of B. firmus TNAU1 isolated from the rhizosphere region of cucumber. The results confirmed that the isolate was B. firmus which contained a single circular genome of 5,370,919 bp (5.3 Mb) in length with an average GC content of 41.16 %. Annotation was performed using PATRIC tool to explore the subsystem analysis, specialty genes, Enzyme Commission (EC) numbers, Gene Ontology (GO) mappings, KEGG pathways of B. firmus TNAU1. A total of 5804 coding sequence (CDS) genes that encode proteins were predicted based on the KEGG and clusters of orthologous groups (COGs) database. Comparative genomic analysis was performed to discover the unique features and their relationship with other available B. firmus strains. Blastp analysis revealed that TNAU 1 genome assemblies had 26 homologs corresponding to nematode-virulent proteases and various genes responsible for plant growth promotion which includes indole acetic acid (IAA) production, nitrate transport, phosphorus and potassium solubilization. Four secondary metabolite biosynthetic clusters encoding antibiotics and siderophore production were confirmed through comparative genomics. B. firmus TNAU1 was evaluated for its antagonistic activity against root-knot nematode Meloidogyne incognita of tomato. The results exhibited that B. firmus inhibited the egg hatching and mortality of juveniles by 96% over control under in vitro conditions and greenhouse experiments confirmed that the TNAU1 strain not only had the potential to suppress the soil and root population of M. incognita (70% reduction over control), but also triggered the plant growth parameters of tomato.

Secondary Metabolites from the Nematode-Trapping Fungus Dactylellina haptotyla YMF1.03409.

As a representative nematode-trapping fungus, Dactylellina haptotyla can capture and kill nematodes by producing traps, known as adhesive knobs. In this paper, the strain of D. haptotyla YMF1.03409 was studied by means of medium screening, fermentation, and purification and identification of crude extracts. Eighteen compounds were obtained from D. haptotyla YMF1.03409, including two new metabolites, nosporins C (1) and D (2). The known metabolites were identified to be 3-chloro-4-methoxybenzaldehyde (3), 3-chloro-4-methoxybenzoic acid (4), 2-chloro-1-methoxy-4-(methoxymethyl)benzene (5), 3-hydroxy-3-methyloxindole (6), nicotinic acid (7), succinic acid (8), 3,4-dihydroxybutanoic acid (9), 5'-O-methyladenosine (10), uridine (11), 2'-deoxyuridine (12), thymidine (13), 3-(phenylmethyl)-2,5-morpholinedione (14), methyl-β-D-glucopyranoside (15), 1,2-benzenedicarboxylic acid bis(2-methyl heptyl) ester (16), β-sitosterol (17), and 3β,6α-diol-stigmastane (18). The bioactive assay showed that these compounds had no obvious nematicidal activity against the nematodes Meloidogyne incognita and Panagrellus redivivus.

A novel chorismate mutase effector secreted from root-knot nematode Meloidogyne enterolobii manipulates plant immunity to promote parasitism1

Meloidogyne spp. is an economically important plant-parasitic nematode distributed worldwide. To fight with host immune system for successful parasitism, plant parasitic nematodes secrete effectors to promote infection. In this study, we identified one chorismate mutase (CM) effector from M. enterolobii, named Me-CM. Spatial and temporal expression assays exhibited Me-cm is expressed in esophageal glands and up-regulated at parasitic-stage juveniles. Me-CM affects the pathogenicity of M. enterolobii based on the reduced infection rate, number of galls, egg masses, eggs per mass and multiplication rate collected from RNA silencing experiments. We showed that Me-CM localized in the cytoplasm and nucleus of plant cells and decreased the expression level of the marker gene PR1 of salicylic acid (SA) pathway. Besides, constitutive expression of Me-cm in Arabidopsis thaliana significantly reduced salicylic acid concentration. These results suggested that M. enterolobii may secrete effector Me-CM to fight with plant immune systems via regulating SA signaling pathway when interacting with host plants, ultimately facilitating parasitism.

Solarized IPM Module for Biocontrol of Root-knot Nematode on Tomato at Nursery Level in District G.B Nagar, Uttar Pradesh

Background: The role of soil solarization in suppression of soil borne pathogens and weeds has been established by several researchers around the globe It involves capturing solar radiations when the soil receives the maximum sunlight in May-June using a polythene mulch. Its effectiveness depends on ambient temperature, duration of the treatments and soil moisture. This not only acts as a soil disinfectant but also as soil decontamination. It includes various changes in the soil like physical, chemical and biological properties. Methods: The field to lab and vice-versal based investigations were carried during 2021-2022 at Amity Centre for Biocontrol and Plant Disease Management, Amity University, Uttar Pradesh, Noida and identified tomato nurseries of district G B Nagar where heavy infestation (10-12 J2/cc soil) of root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood was recorded. The treatments comprised of sustainable components viz. deoiled seed cake of neem, a Arbuscular Mycorrhizal fungus Glomus intraradices and indigenous fungal strain of Trichoderma harzianum, (Th7) alone and together applied for evolving IPM module at solarized and unsolarized sets. Under microplot trials, the entire solarized treatments were carried out measuring 3 × 1 sq. meter each in which one set of all the treatments including control covered with clear transparent polythene sheet (400 ì gauge) for solarization. The treatments were replicated thrice in randomized block design. Result: The observations of solarized and unsolarized treatments clearly revealed that the soil solarization in treatments where the sun radiant energy was trapped by 400 µ transparent polysheets significantly reduced the root knot nematode Meloidogyne incognita population both in root and soil in comparison to unsolarized treatments where no solar energy trapping was done. The combined application of locally isolated Trichoderma harzianum (Th7) and VA mycorrhiza, Glomus intraredices enhanced germination and plant growth in nurseries. In the present investigation, the solarized IPM module- 4 comprising of other sustainable components viz. neem oil-seed cake, T. harzianum (Th-7) and Arbuscular Mycorrhizal (AM) fungus G. intraredices is proved to be an ideal one in root-knot nematode pest management in tomato nurseries.

Race Composition of Root Knot Nematode (Meloidogyne ) Species Infecting Cucurbitaceous Crops in Terai region of West Bengal

Race Composition of Root Knot Nematode (Meloidogyne ) Species Infecting Cucurbitaceous Crops in Terai region of West Bengal

Antagonist effect of native bacteria of the genus Bacillus on the root-knot nematode (Meloidogyne spp.) in tomato germplasm

Antagonist effect of native bacteria of the genus Bacillus on the root-knot nematode (Meloidogyne spp.) in tomato germplasm

Nematicidal Effect of Certain Agrochemicals, Nutritional Compounds and Bio-Agents on The Population of Root-Knot Nematode (Meloidogyne Spp.) Infecting Potato

Nematicidal Effect of Certain Agrochemicals, Nutritional Compounds and Bio-Agents on The Population of Root-Knot Nematode (Meloidogyne Spp.) Infecting Potato

Metarhizium carneum Formulations: A Promising New Biological Control to Be Incorporated in the Integrated Management of Meloidogyne enterolobii on Tomato Plants.

The increase in the populations of root-knot nematode Meloidogyne enterolobii in various vegetables such as tomatoes grown under greenhouse conditions as well as increasing restrictions on the use of certain chemical nematicides have led to the search for new, effective management strategies, preferably ones that are sustainable biological alternatives. In this work, two formulations of the nematophagous fungus Metarhizium carneum, one concentrated suspension and one wettable powder, were evaluated under greenhouse conditions to reduce the M. enterolobii infestation in tomato plants. In addition, the effectiveness of the liquid formulation of M. carneum was compared with two biological and three chemical commercial nematicides. The results show that the two M. carneum formulations reduced the M. enterolobii population density by 78 and 66% in relation to the control treatment. In comparison, the liquid formulation of M. carneum and Purpureocillium lilacinum treatments reduced nematode population density by 72 and 43%, respectively, while for metam sodium preplanting applications followed by M. carneum applications during the tomato growth stage, the reduction was 96%. The alternate use of some chemical compounds plus the application of M. carneum as a biocontrol is a good starting strategy for managing M. enterolobii populations. These results confirm that M. carneum is a serious candidate for the short-term commercialization of an environmentally friendly biological nematicide.