Biocontrol of wilt disease complex of pea using Pseudomonas fluorescens and Rhizobium sp.

Biocontrol of wilt disease complex of pea caused by the root-knot nematode Meloidogyne incognita and Fusarium oxysporum f. sp. pisi was studied on pea (Pisum sativum L.) using plant growth-promoting rhizobacterium Pseudomonas fluorescens and root nodule bacterium Rhizobium sp. Inoculation of M. incognita and F.oxysporum alone caused significant reductions in plant growth over un-inoculated control. Reduction in plant growth caused by M. incognita was statistically equal to that caused by F. oxysporum. Inoculation of M. incognita plus F. oxysporum together caused a greater reduction in plant growth than the sum of damage caused by these pathogens singly. Inoculation of P. fluorescens and Rhizobium sp. individually or both together increased plant growth in pathogen inoculated and un-inoculated plants. Inoculation of P. fluorescens to pathogen-inoculated plants caused a greater increase in plant growth than caused by Rhizobium sp. Application of Rhizobium plus P. fluorescens caused a greater increase in plant growth than caused by each of them singly. Inoculation of P.fluorescens caused higher reduction in galling and nematode multiplication than caused by Rhizobium sp. Use of Rhizobium plus P. fluorescens caused higher reduction in galling and nematode multiplication than their individual inoculation. Plants inoculated with both pathogens plus Rhizobium showed less nodulation than plants inoculated with single pathogen plus Rhizobium. Inoculation of Rhizobium plus P. fluorescens resulted in higher root-nodulation than inoculated only with Rhizobium. Wilting indices were 4 and 5, respectively, when plants were inoculated with F. oxysporum and F. oxysporum plus M. incognita. Wilting indices were reduced maximum to 1 and 2, respectively, when plants inoculated with F.oxysporum and plants with both pathogens were treated with P. fluorescens plus Rhizobium.     

Interactive effect of root-knot nematode,Meloidogyne incognita and root-rot fungus,Rhizoctonia solani,on okra [Abelmoschus esculentus L.]

The individual, concomitant and sequential inoculation of second stage juveniles (at 2000 J₂/kg soil) of Meloidogyne incognita and Rhizoctonia solani (at 2 g mycelial mat/kg soil) showed significant reduction in plant growth parameters viz. plant length, fresh weight and dry weight as compared to control. The greatest reduction in plant growth parameters was recorded in the plants simultaneously inoculated with M. incognita and R. solani followed by sequential and individual inoculation. In sequential inoculation, plant inoculated with M. incognita 15 days prior to R. solani shows more reduction in comparison to plant inoculated with R. solani 15 days prior to M. incognita. Moreover, the multiplication of nematode and number of galls/root system were significantly reduced in concomitant and sequential inoculation as compared to individual inoculation, whereas the intensity of root-rot/root system caused by R. solani was increased in the presence of root-knot nematode M. incognita as compared to when R. solani was inoculated individually.     

Studies on interaction of Meloidogyne incognita (Kofoid and White) Chitwood and Fusarium solani (Mart.) Sacc forming a disease complex in lentil (Lens culinaris Medik.)

Abstract

An experiment was conducted to study the effects of interaction between Meloidogyne incognita and Fusarium solani on plant length, fresh and dry weights, number of pods, chlorophyll, carotenoid, nitrogen and phosphorus contents and nitrate reductase activity in lentil plants. The results reveal a maximum damage occurring in all the plant growth, biochemical and nutrient parameters, in plants inoculated with M. incognita 10 days prior to F. solani (Mi?→?Fs). This was followed by simultaneous (Mi?+?Fs) inoculations, fungus inoculation 10 days prior to nematode (Fs?→?Mi), M. incognita alone and F. solani alone treatments. Nematode reproduction factor and root galling were highest in individual inoculation of M. incognita, while root rotting percentage was highest when nematode was inoculated 10 days prior to fungus followed by simultaneous inoculation with both nematode and fungus.     

Der Besatz von Beta-Rüubensaatgut rait Wurzelbranderregern und der Einfluß von Umweltfaktoren auf das Auftreten des samenbüurtigen Wurzelbrandes

The root knot nematode Meloidogyne incognita was controlled more effectively when P. lilacinus and G. mosseae were applied together in a pot experiment than either was applied alone. Inoculation of tomato plant with G. mosseae did not markedly increase the growth of plant infected with M. incognita. Inoculation of plant with G. mosseae and P. lilacinus together or alone resulted in a similar shoot and plant height. The highest root development was achieved when mycorrhizal plant were inoculated with P. lilacinus to combat root knot nematode. Inoculation of tomato plant with P. lilacinus suppressed galls/root system and eggs/egg masses, compared to seedling inoculated with M. incognita alone. The mycorrhizal colonization was not affected by inoculation of P. lilacinus.     

Pectolytic Bacteria Associated with Soft Rot of Calla Lily (Zantedeschia spp.) Tubers

Soft rot is the most important disease on calla lily in Poland. The isolation of the presumptive pathogen from symptomatic tubers on nutrient agar yielded bacteria with different colony morphology. Of 41 isolates collected, 10 showed pectolytic activity on crystal violet pectate medium and caused soft rot on potato slices. All pectolytic bacteria appeared to be Gram‐negative rods producing typical soft rot on inoculated leaf petioles of calla lily. Bacteria with colonies which morphologically resembled those used for inoculation were re‐isolated from diseased petioles. Their identification was based on phenotypic characters and sequence of the gene fragment coding 16S rRNA. It was found that, in addition to Pectobacterium carotovorum subsp. carotovorum, soft rot of calla lily can be caused by Pectobacterium carotovorum subsp. atrosepticum, Pseudomonas marginalis, Pseudomonas veronii and Chryseobacterium indologenes. The latter two are described for the first time as plant pathogens. The pectolytic activity of all identified bacteria, except that of P. carotovorum subsp. atrosepticum, was lower than that of P. carotovorum subsp. carotovorum, but strains of P. veronii showed a higher activity than P. marginalisand C. indologenes species.     

Interaction between Pseudomonas fluorescens and Meloidogyne incognita on tomato plant as influenced by the different levels of phosphorus

A pot experiment was conducted on tomato (Solanum lycopersicum cv. Pusa Ruby) to assess the effect of different phosphorus (P) levels (0, 125, 250 and 500 mg/pot) and the plant growth promoting rhizobacterium, Pseudomonas fluorescens, on the growth of tomato and on the reproduction of Meloidogyne incognita. Maximum growth of tomato occurred at P rates of 125 mg/kg soil, irrespective of whether plants were uninoculated or inoculated with P. fluorescens or M. incognita or inoculated with both the agents. Nematodes per gram of roots, egg masses per root, eggs per egg mass and galls per root significantly increased by increasing levels of P. P. fluorescens performed better than other treatments and different P levels in improving tomato growth and reducing galling and multiplication of M. incognita.     

Biocontrol of <Emphasis Type="Italic">Meloidogyne javanica</Emphasis> by <Emphasis Type="Italic">Rhizobium</Emphasis> and plant growth-promoting rhizobacteria on lentil

Biocontrol of the root-knot nematode Meloidogyne javanica was studied on lentil using plant growth-promoting rhizobacteria (PGPR) namely Pseudomonas putida, P. alcaligenes, Paenibacillus polymyxa and Bacillus pumilus and root nodule bacterium Rhizobium sp. Pseudomonas putida caused greater inhibitory effect on the hatching and penetration of M. javanica followed by P. alcaligenes, P. polymyxa and B. pumilus. Inoculation of any PGPR species alone or together with Rhizobium increased plant growth both in M. javanica-inoculated and -uninoculated plants. Inoculation of Rhizobum caused greater increase in plant growth than caused by any species of plant growth-promoting rhizobacteria in nematode-inoculated plants. Among PGPR, P. putida caused greater increase in plant growth and higher reduction in galling and nematode multiplication followed by P. alcaligenes, P. polymyxa and B. pumilus. Combined use of Rhizobium with any species of PGPR caused higher reduction in galling and nematode multiplication than their individual inoculation. Use of Rhizobium plus P. putida caused maximum reduction in galling and nematode multiplication followed by Rhizobium plus P. alcaligens. Pseudomonas putida caused greater root colonization and siderophore production followed by P. alcaligenes, P. polymyxa and B. pumilus. Analysis of the protein bands of these four species by SDS-PAGE revealed that P. putida had a different protein band profile compared to the protein profiles of P. alcaligenes, P. polymyxa and B. pumilus. However, the protein profiles of P. acaligenes, P. polymyxa and B. pumilus were similar.     

The Relation of Different Crop Roots Exudates to the Survival and Suppressive Effect of Stenotrophomonas maltophilia (PD4560), Biocontrol Agent of Bacterial Wilt of Potato

Experiments were performed under greenhouse conditions to control bacterial wilt of potato (potato brown rot), caused by Ralstonia solanacearum race 3 biovar 2, Phylotype II, sequevar 1 using various biocontrol strategies. These strategies involved the use of the bacterial biocontrol agent Stenotrophomonas maltophilia (PD4560), in clay or sandy soils, planted with cowpea, maize or tomato which was grown separately in different pots in the inoculated soils. After harvest, the soil derived from each cultivated crop was inoculated with a mixture of three virulent R. solanacearum strains (K3, K10 and K16) to achieve a final concentration of 5 × 10⁸ cfu/g dry soil and used in pots under greenhouse conditions to cultivate potato seed tubers. The highest survival of S. maltophilia in soil (more than 160 days) coincided with a remarkable suppressing effect on disease incidence caused by R. solanacearum that expressed by wilt severity (up to 100% reduction), area under disease progress curve (AUDPC) (up to 99% reduction) and counts of the pathogen in soil (up to 75% reduction), rhizosphere (up to 80% reduction) and plant tissue (up to 97% reduction) of potato plants. The amino acid analysis of root exudates of crops under investigation revealed high percentages of asparagines (15.5–21%), glutamine (16–20%) and sulphur‐containing methionine (7–9%) in both of the cowpea and maize, respectively. In tomato root exudates, high percentages of arginine (around 26%) and lysine (around 23%) were detected. Methionine is known to favour the growth of S. maltophilia suggesting that especially cowpea and maize are suitable for crop rotation with potato and will enhance the sustainability of the biocontrol agent S. maltophilia.     

Effect of plant growth promoting rhizobacteria,nematode parasitic fungi and root-nodule bacterium on root-knot nematodes Meloidogyne javanica and growth of chickpea

Effects of plant growth promoting rhizobacteria (Pseudomonas putida MTCC No. 3604 and Pseudomonas alcaligenes MTCC No. 493) and parasitic fungi (Pochonia chlamydosporia KIA and Paecilomyces lilacinus KIA) were studied, alone and together with Rhizobium sp. (charcoal commercial culture) on the growth of chickpea and multiplication of Meloidogyne javanica. Individually, P. putida 3604, P. alcaligenes 493 and Rhizobium caused a significant increase in the growth of chickpea in both nematode inoculated and uninoculated plants. Inoculation of Rhizobium with a parasitic fungus or with plant growth promoting rhizobaterium caused a greater increase in the growth of plants inoculated with nematodes than caused by either of them singly. Individually, P. lilacinus KIA caused a greater increase in the growth of nematode inoculated plants than caused by P. putida 3604 or P. alcaligenes 493. P. lilacinus KIA caused a greater reduction in galling and nematode multiplication followed by P. chlamydosporia KIA, P. putida 3604 and P. alcaligenes 493. Combined use of P. lilacinus KIA with Rhizobium was better in reducing galling and nematode multiplication than any other treatment. P. putida 3604 caused a greater colonization of root than P. alcaligenes 493 while P. lilacinus KIA was isolated from more nematodes than P. chlamydosporia KIA.     

Effects of dual inoculation of mycorrhiza and endophytic,rhizospheric or parasitic bacteria on the root-knot nematode disease of tomato

The effects of mycorrhisation and inoculation with soil bacteria on the disease caused by Meloidogyne incognita on tomato were studied in pots under greenhouse conditions. Efficacy in promoting plant growth and reducing disease severity and final nematode densities were evaluated for two arbuscular mycorrhizal fungi (AMF; Funneliformis mosseae and Rhizophagus irregularis), three soil bacteria with different living strategies (the endophyte Bacillus megaterium, a rhizospheric Pseudomonas putida and the hyperparasite of nematodes Pasteuria penetrans) and combinations of the fungi and bacteria. In M. incognita-infested plants, F. mosseae increased tomato growth more than R. irregularis, and plants inoculated with B. megaterium presented higher shoot fresh weight than with P. putida or P. penetrans, but dual inoculation did not improve tomato growth more than single inoculations. Disease severity and final nematode densities were reduced by F. mosseae compared to non-mycorrhizal plants. B. megaterium and P. penetrans reduced both the root galling and the final nematode densities compared to treatments without bacteria. P. penetrans reduced final nematode densities more than B. megaterium or P. putida. Dual inoculation of AMF and P. penetrans showed the highest efficacy in reducing the final nematode densities in tomato.     

Polarographische Bestimmung von Chlorat-Rückständen im Boden und in der Pflanze

An increase in the inoculum level of root‐knot nematode, Meloidogyne incognita and the reniform nematode, Rotylenchulus reniformis resulted in a relative decrease in plant growth parameters of chickpea. Consequently water absorption capability of roots was impaired. M. incognita caused greater reduction than R. reniformis at the same inoculum level. In concomitant inoculation of M. incognita and R. reniformis there was greater suppression in plant growth of chickpea. The suppression in concomitant inoculations was less than the sum of the suppression caused by the same levels of inoculations of the individual species. The multiplication rate of the nematodes decreased as the inoculum level increased. The results also suggest competition for feeding sites between the two nematode species. The multiplication rate of one species progressively decrease with the increase in the inoculum levels of the other nematode.     

Management of Root-Knot Nematode,Meloidogyne Incognita,by integration of Paecilomyces Lilacinus with organic materials in Chilli

Studies were made to determine the efficacy of Paecilomyces lilacinus in management of root-knot nematode (Meloidogyne incognita) in soil amended with various organic matters. The soil amendments with organic additives except gram and rice husks significantly reduced the multiplication of M. incognita and the root galling caused by root-knot nematode which consequently increased the plant growth. The greatest improvement in plant growth and reduced reproduction factor and root galling was recorded in soil amendment with leaves of Calotropis procera while the least was in kail saw dust. The best protection against M. incognita was observed on the integration of organic additives with P. lilacinus, which resulted increased plant growth and reduced population build-up of nematodes and root gallings. The leaves of C. procera with P. lilacinus were most effective than all other organic materials used among the different integrated approaches. The organic amendments also increased the parasitism of P. lilacinus on M. incognita.     

Modification of Resistance Expression of Phaseolus vulgaris to Meloidogyne incognita by Elevated Soil Temperatures

The effect of temperature on the reaction of susceptible (Canario Divex) and resistant (A 211) bean pure lines to Meloidogyne incognita was studied with soil temperature tanks housed in a growth chamber at 22 or 24 C. Soil temperature remained constant at 16, 22, 24, 26, 30, or 32 C in several trials. Bean line A 211 was resistant at 16 and 22 C but was susceptible at 24 C and above. Resistance to root-knot nematode reproduction was affected by a lower temperature (24 C) than was resistance to root galling (26 C) in A 211. Incubation of A 211 at 30 C for 3 and 16 days after inoculation with M. incognita resulted in a significant increase in nematode reproduction and root galling, respectively. The resistant reactions of A 211 to nematode reproduction and root galling were retained when inoculated plants were incubated at 21 C for a minimum of 16 and 23 days, respectively, prior to high temperature treatment.     

Host-induced gene silencing of Pectobacterium carotovorum quorum sensing gene enhances soft rot disease resistance in potato plants

Quorum sensing is a regulatory mechanism of gene expression in bacteria which regulated many physiological processes such as production of virulence factors in Pectobacterium carotovorum. In this research, the plant expression vector, pBI121, harbouring the anti-quorum sensing gene, aiiA, was transformed into Potato (Solanum tuberosum cv. Agria) explants by Agrobacterium mediated transformation procedure and putative transformants containing pBI121/aiiA were obtained. The results of bioassay test revealed that the expression of aiiA gene in potato plant induces the resistance to the early stage of bacterium pathogenesis. The soft rot symptoms such as wilting, yellowing and tissue maceration were not observed until 48?hr after inoculation of transgenic potatoes with P. carotovorum. Although in non-transgenic plants, the disease symptoms were appeared after 24?hr of plants infection. Hence, this study proves that the heterologous expression of aiiA gene enhances the resistance against potato soft rot disease.     

The use of fluorescent reporter protein tagging to study the interaction between Root‐Knot Nematodes and Soft Rot Enterobacteriaceae

The study of plant parasitic nematodes such as Meloidogyne spp. and their interactions with phytopathogenic bacteria remains underexplored. One of the challenges towards establishing such interactions is the dependence on symptom development as a measure of interaction. In this study, mCherry was employed as a reporter protein to investigate the interaction between the soft rot Enterobacteriaceae (SRE) Pectobacterium carotovorum subsp. brasiliensis (Pcb) and root‐knot nematode (M. incognita). Pectobacterium carotovorum subsp. brasiliensis was transformed with pMP7604 generating Pcb_mCherry strain. This strain was shown to attach to the surface coat of M.incognita J2 at the optimum temperature of 28°C. This suggests that RKN juveniles may play a role in disseminating Pcb in soils that are heavily infested with Pcb. The presence of RKN juveniles was shown to play a role in introducing Pcb_mCherry into potato tubers potentially acting as a source of latent tuber infections.

Significance and Impact of the Study

This study uses fluorescent reporter protein tagging as a tool to demonstrate the interaction between root‐knot nematode (Meloidogyne incognita) and the soft rot Enterobacteriacea (Pectobacterium carotovorum subsp. brasiliensis). Introduction of Pectobacterium through wounds generated by second‐stage juveniles (J2) into potato tubers was demonstrated. These results suggest that RKN juveniles can facilitate latent infection of potato tubers in the soil. These findings have important implications in the management of RKN and SRE in seed potato production. Furthermore, this tool can be used to study other nematode–bacteria interactions that have not been previously studied.     

Characterization of Iranian Pectobacterium carotovorum Strains from Sugar Beet by Phenotypic Tests and Whole-cell Proteins Profile

Thirty isolates of Pectobacterium carotovorum from soft rot‐affected sugar beet plants in the Fars province of Iran were characterized phenotypically and by analysis of whole‐cell protein electrophoresis patterns. The isolates were found to be heterogeneous based on the results of physiological and biochemical tests and protein profiles. The results of numerical analysis of phenotypic characteristics and protein patterns showed that only 27% of the collected isolates (phenon 4) could be identified as P. betavasculorum when compared with reference strains. Strains of the first, second, third and fifth phenon shared similar characters with those of P. carotovorum subsp. carotovorum, P. betavasculorum and P. carotovorum subsp. odoriferum, but were distinct from these subspecies. Inoculation of phenon 4 isolates into wounded sugar beet petioles led to black streaking, root rot and vascular necrosis. Other isolates were incapable of causing systemic symptoms in inoculated plants.     

Biocontrol of root-knot nematode Meloidogyne incognita by the isolates of Pseudomonas on tomato

Biocontrol of root-knot nematode Meloidogyne incognita was studied on tomato using 15 isolates of fluorescent Pseudomonads isolated from pathogen suppressive soils. Pseudomonas aeruginosa (isolates Pa8, Pa9 and Pa3) caused greater inhibitory effect on hatching of M. incognita than other isolates. In addition, isolates Pa8, Pa9 and Pa3 caused greater colonisation of tomato roots and also caused a greater increase in the growth of tomato seedlings. These isolates also caused a greater increase in growth of tomato and higher reduction in galling and nematode multiplication in a green house test than is caused by other isolates. Isolates Pf1, Pf5, Pf6 and Pa13 were unable to increase growth of tomato and caused less reduction in galling and nematode multiplication compared to other isolates. Only 10 isolates produced siderophores on chromo-azurol sulfonate (CAS) agar medium and isolate Pa12 showed greater production of siderophore followed by Pa11, Pa9, Pf10, Pa3 and Pf5. Similarly, isolates Pa14, Pa12, Pf10, Pa9, Pa8, Pa7 and Pa6 produced greater amount of HCN than the other isolates tested. Isolates Pa8 and Pa9 showed greater production of IAA than the other 13 isolates tested. This study suggests that P. aeruginosa isolates Pa8 and Pa9 may be used for the biocontrol of M. incognita on tomato.     

Simultaneous detection of major blackleg and soft rot bacterial pathogens in potato by multiplex polymerase chain reaction

A multiplex polymerase chain reaction (PCR) assay for simultaneous, fast and reliable detection of the main soft rot and blackleg potato pathogens in Europe has been developed. It utilises three pairs of primers and enables detection of three groups of pectinolytic bacteria frequently found in potato, namely: Pectobacterium atrosepticum, Pectobacterium carotovorum subsp. carotovorum together with Pectobacterium wasabiae and Dickeya spp. in a multiplex PCR assay. In studies with axenic cultures of bacteria, the multiplex assay was specific as it gave positive results only with strains of the target species and negative results with 18 non‐target species of bacteria that can possibly coexist with pectinolytic bacteria in a potato ecosystem. The developed assay could detect as little as 0.01 ng µL^–1 of Dickeya sp. genomic DNA, and down to 0.1 ng µL^–1 of P. atrosepticum and P. carotovorum subsp. carotovorum genomic DNA in vitro. In the presence of competitor genomic DNA, isolated from Pseudomonas fluorescens cells, the sensitivity of the multiplex PCR decreased tenfold for P. atrosepticum and Dickeya sp., while no change was observed for P. carotovorum subsp. carotovorum and P. wasabiae. In spiked potato haulm and tuber samples, the threshold level for target bacteria was 10¹ cfu mL^–1 plant extract (10² cfu g^–1 plant tissue), 10² cfu mL^–1 plant extract (10³ cfu g^–1 plant tissue), 10³ cfu mL^–1 plant extract (10⁴ cfu g^–1 plant tissue), for Dickeya spp., P. atrosepticum and P. carotovorum subsp. carotovorum/P. wasabiae, respectively. Most of all, this assay allowed reliable detection and identification of soft rot and blackleg pathogens in naturally infected symptomatic and asymptomatic potato stem and progeny tuber samples collected from potato fields all over Poland.     

Biological control of root-knot nematode,Meloidogyne incognita infesting tomato

Talc based formulations of two antagonistic fungi, Acremonium strictum W. Gams and Aspergillus terreus Thom were tested separately and together for their ability to suppress the development of root-knot disease of tomato caused by the root-knot nematode, Meloidogyne incognita Kofoid & White in two consecutive trials (2007–08). Tomato seedlings were each inoculated with M. incognita at 2 infective second stage juveniles /g of soil. M. incognita caused up to 48% reduction in plant growth parameters compared to un-inoculated control. Control efficacy achieved by combined soil application of both fungi, in terms of galls/root system and soil population/50 ml of soil, was 66 and 69% respectively at 60 days of inoculation compared to control. Soil application by individual fungus did not achieve as much effectiveness as the biocontrol agents applied together. The combined treatment was found to have antagonistic effect on M. incognita development and increased plant vigor. Incorporation of fine powder of chickpea pod waste with talc powder was beneficial in providing additional nutrients to both plant and biocontrol agents and increased the activity of the nematophagous fungi in soil. A. strictum and A. terreus were successfully established in the rhizosphere of tomato plants up to the termination of the experiment.     

Comparison of concomitant and sequential inoculation of Steinernema sp. in the management of root-knot (Meloidogyne incognita) nematode infecting eggplant (Solanum melongena)

Culture of Steinernema sp. was maintained on Corcyra cephalonica larvae. Steinernema sp. (at 50, 500, 1000, 2500, 5000, 10,000 and 20,000 ij’s /500?g soil) was concomitantly inoculated with 500 J₂ of Meloidogyne incognita/500?g soil to the eggplant seedlings in the pots filled with 4?kg sterilised soil. The simultaneous inoculation of M. incognita with either of the inoculum levels (1000, 2500, 5000 and 10,000 J₃/500?g soil) of Steinernema sp. significantly reduced the damage caused by M. incognita in terms of plant growth parameters, viz. plant length, dry weight, number of flowers and weight of fruits. Moreover, the highest improvement in plant growth parameters, viz. plant length, dry weight, number of flowers and weight of fruits, was recorded in plants inoculated with 5000 J₃ of Steinernema sp./500?g soil followed by 2500, 1000 and 10,000 J₃/500?g soil. The highest reduction in the reproduction factor and number of galls/root system was recorded in the plants treated with 5000 J₃ Steinernema sp./500?g soil followed by 2500, 1000 and 10,000 J₃/500?g soil. Comparison of concomitant and sequential inoculations showed that the sequential inoculation (both prior and after) of Steinernema sp. at different inoculum levels (1000, 2500, 5000, 10,000 and 20,000 ij’s/500?g soil) was more effective in the management of root-knot nematode than the concomitant inoculation. Therefore, the application of Steinernema sp. might be useful for suppression of nematode pest on eggplant and may be used as an alternative for chemicals.