Rice Root-knot Nematode Research Articles

Prevalence and Distribution of Rice Root Knot Nematode in Rice Nurseries in Chitwan and Lamjung Districts of Nepal

To determine the natural infection of the rice root-knot nematode (Meloidogyne graminicola Golden & Brichfield) in rice nurseries, a survey was carried out in Chitwan and Lamjung in June and July of 2022. Rice nurseries were randomly selected based on geographical location, agro-ecological region, land type, cropping practice, and soil type. Forty rice nurseries were surveyed i.e. twenty from each district and 100 seedlings from each nursery as the sample for the study using the simple random method of sampling were evaluated. Field survey revealed that M. graminicola was widely distributed in most rice growing areas of Chitwan and Lamjung districts. Most of the rice nurseries in Lamjung district were found to be infested with M. graminicola as compared to that of the Chitwan district. Disease severity was reported up to 23.26% in Lamjung and 20.2% in Chitwan district. Additionally, the study showed that dry bed conditions were more likely to be affected by rice root-knot disease than wet bed conditions. The majority of farmers planted seedlings on upland (dry) soil, where second-stage juvenile (J2) populations and rice root-knot disease were more common. Most farmers (87.5%) have limited knowledge about rice root knot nematodes and their control methods. This suggested a significant loss in rice output and a high danger of nematode multiplication. This information will provide knowledge about the prevalence of nematode and enabling rice growers in this region to design and implement an appropriate control strategy for managing M. graminicola.

Phylogenetic analyses and pathogenic diversity of Meloidogyne graminicola of rice (cv. BRRI Dhan28) from different agro-ecological zones of Bangladesh

Rice root-knot caused by Meloidogyne graminicola is a major yield-limiting factor in all rice growing countries around the world, which is often ignored in Bangladesh due to its subtle and obscure above ground symptoms. The current study proposes a comprehensive diagnosis of rice root-knot nematode at the molecular level and analyzes the pathogenic diversity of M. graminicola population of different AEZs. Rice seedlings of a popular variety (BRRI Dhan28) showing galls in the roots were collected from thirty Agro-Ecological-Zones (AEZs) of Bangladesh. For molecular identification, nuclear DNA was collected from single second-stage juvenile and internal transcribed spacer (ITS) was used as a universal primer. Molecular identification and phylogenetic analyses revealed that all nematode populations of galled rice seedlings from different locations belong to M. graminicola. The nematode populations constitute six phylogenetic clades. Nematode population of phylogenetic clade II showed the highest no. of galls (178 ± 1.67), although galling index was higher and similar in clade I, clade-II, clade-III and clade-VI. The highest percent reduction in both vegetative and yield-contributing traits were recorded in clade-II. A negative correlation was found in galling incidence and all growth and yield parameters. Comparative hatching of M. graminicola from different locations reveals that the pathogenicity of M. graminicola depends on the genetic variability of the nematode population, but not on the hatched juveniles. It might be concluded that the rice root-knot nematodes (M. graminicola) are prevalent in all agro-ecological zones of Bangladesh, despite the most pathogenic groups being frequent in AEZ- 1, 6, 7, 10, 18, 19, 21 and appropriate management initiatives are therefore crucial for maximizing rice yield.

Identification of a Promising Novel Genetic Source for Rice Root-Knot Nematode Resistance through Markers Associated with Trait-Specific Quantitative Trait Loci.

Direct-seeded rice (DSR) is gaining popularity among farmers due to its environmentally safe and resource-efficient production system. However, managing the rice root-knot nematode (RRKN), Meloidogyne graminicola, remains a major challenge in DSR cultivation. Developing genetic resistance is a pragmatic and effective approach compared to using hazardous pesticides. Pusa Basmati 1121 (PB1121) is the most popular Basmati rice variety, but it is highly susceptible to RRKN. In contrast, Phule Radha (PR) has shown highly resistant reaction to RRKN, as reported in our earlier study. We generated an F2:3 population from the cross of PB1121/PR and evaluated it for RRKN resistance-related traits under artificial inoculation conditions. The distribution pattern of traits in the F2:3 population indicated that resistance may be governed by a few major-effect genes and many minor-effect genes. The molecular markers reported to be associated with QTLs governing RRKN resistance traits were used to test in the current population. Although the simple linear regression identified significant associations between the markers and RRKN resistance-associated traits, these associations were spurious as the LOD score was below the threshold limit. This indicates that PR possesses novel genomic regions for resistance to RRKN as it does not possess any of the earlier reported QTLs.

Nematicidal Activity of Volatiles against the Rice Root-Knot Nematode and Environmental Safety in Comparison to Traditional Nematicides.

The rice root-knot nematode (RRKN), Meloidogyne graminicola Golden and Birchfield 1965, is a dangerous crop pest that affects rice production on a global scale. The largest rice-producing countries struggle with the impacts of RRKN infestation, namely, underdeveloped plants and a reduction in rice grain that can reach up to 70% of crop yield. In addition, the shift to strategies of sustainable pest management is leading to a withdrawal of some of the most effective pesticides, given the dangers they pose to the environment and human health. Volatile metabolites produced by plants can offer safer alternatives. The present study characterized the nematicidal activity of volatile phytochemicals against the RRKN and compared the most active with commercial nematicides concerning their safety to the environment and human health. Rice plants were used to grow large numbers of RRKNs for direct-contact bioassays. Mortality induced by the volatiles was followed for four days on RRKN second-stage juveniles. Of the 18 volatiles tested, carvacrol, eugenol, geraniol, and methyl salicylate showed the highest mortalities (100%) and were compared to traditional nematicides using (eco)toxicological parameters reported on freely available databases. While methyl salicylate had a faster activity, carvacrol had more lasting effects. When compared to synthetic nematicides, these volatile phytochemicals were reported to have higher thresholds of toxicity and beneficial ecotoxicological parameters. Ultimately, finding safer alternatives to traditional pesticides can lower the use of damaging chemicals in farming and leverage the transition to agricultural practices with a lower impact on biodiversity.

Survey for Alternate Weed Hosts of Rice Root-Knot Nematode, Meloidogyne graminicola Associated with Rice Crops in Haryana, India

Rice root-knot nematode, Meloidogyne graminicola is one of the most serious nematode pest associated with rice throughout the world. With other species of root-knot nematode, M. graminicola can also infect wide range of weed flora which is commonly grown in or near the rice field. To study the alternate weed hosts of M. graminicola a survey was conducted in the major rice growing blocks of Fatehabad and Sirsa districts of Haryana during Kharif season 2022. A total of 726 samples were collected from rice fields, both from transplanted (TR) and direct seeded rice (DSR) from Phoolan, Bharpur, Ratta Khera, and Jandwala Sotter villages of Fatehabad and Bahauddin and Sikanderpur, Dhottar, Ding and Chopta villages of Sirsa. Out of which 353 samples were found free from nematode infestation while 373 samples (209 from DSR and 164 from TR)were found infested. The juveniles and galls were recorded ranging from 4-190 on the roots of different weed plants. Hence, it is concluded from the present investigation, that nematodes favor more DSR and its weed flora than TR for infection and survival.

Evaluation of nematophagous and biocontrol efficacy of Dactylellina phymatopaga against Meloidogyne graminicola on rice (Oryza sativa L.)

Dactylellina phymatopaga is a nematode-trapping fungus which traps, kills and parasitizes nematodes. The rice root-knot nematode, Meloidogyne graminicola, is an important plant-parasitic nematode that threatens rice production worldwide. Therefore, it is most important to find new substitute for chemical control of M. graminicola. The present study aimed to investigate the in vitro trapping, germination and nematophagous ability in soil and fungus efficacy to reduce the number and biomass of developing stages of M. graminicola in rice roots. Isolates of D. phymatopaga were found to produced sessile adhesive knobs on growing hypahe to trap and paralyze M. graminicola J2 up to 98.8 % within 120 h of inoculation, in in-vitro conditions. Test for germination and nematophagous activities in various soils showed that spores of D. phymatopaga frequently germinate in soil with formation of adhesive sessile knobs on their germ lings, capturing and parasitizing nearby free living nematodes. Application of D. phymatopaga in M. graminicola-infested soil at the time and prior to rice sowing showed significant reduction in the number of root galls, number and biomass of developing stages of M. graminicola in rice roots (62.65–80.73 %) increasing plant health as compared to plants grown in nematode infested soil. Application of D. phymatopaga 7 days before sowing showed the highest biocontrol ability by decreasing in the nematode biomass in the associated rice roots per plant and the expended nematode-to-root biomass ratio (NB:RB). The results showed that the nematode-trapping behavior of D. phymatopaga yields a bio-management potential in reducing the number of developing stages of M. graminicola and their biomass in rice roots.

Optimization of DNA extraction methods for genomic analysis of rice root-knot nematode (Meloidogyne graminicola) using PCR (polymerase chain reaction) and sanger sequencing

Optimization of DNA extraction methods for genomic analysis of rice root-knot nematode (Meloidogyne graminicola) using PCR (polymerase chain reaction) and sanger sequencing

Evaluation of root-gall associated fungal endophytes for the control of Meloidogyne graminicola infecting rice

In the rice-producing regions of India, the infection of the rice root-knot nematode Meloidogyne graminicola represents a significant biotic constraint that leads to substantial yield reduction. Traditional nematode management practices are neither cost-effective nor environmentally friendly. Consequently, there is an urgent need to identify potential biocontrol agents for effectively managing this destructive pest. M. graminicola infestation in rice incites the formation of terminal root galls, which serve as multinucleated food sinks inhabited by nematodes and other endophytic microorganisms. In our study, we isolated and screened fungal endophytes associated with healthy and galled rice roots to identify potential biocontrol agents against the nematode. Among the isolated fungi, a gall-associated endophytic fungus identified as Aspergillus niger isolate F4 exhibited 100% juvenile (J2) mortality under in vitro conditions at 50% culture filtrate concentration, within 24 h of inoculation, with an LC50 of 10.85%. Additionally, it demonstrated ovicidal properties by inhibiting egg hatching by 96.96% compared to the control. Furthermore, the attraction assay revealed a significantly lower number of M. graminicola J2s attracted to rice roots treated with F4 culture filtrate compared to untreated roots. In an in vivo pot experiment, root dipping with F4 culture filtrate reduced the galling index, the number of J2s penetrating the root, and the reproduction factor. Besides the direct effects, inoculation of the fungus also triggered plant defence responses, potentially providing indirect protection against nematode infection. Overall, our study, to the best of our knowledge, is the first to demonstrate that M. graminicola root galls harbour specific endophytic fungi with potent biocontrol properties. The available evidence clearly establishes the potential of Aspergillus niger F4 as an important biological control agent against M. graminicola, offering a novel management approach for this significant rice pest.

Detection of Meloidogyne graminicola (RRKN) in Kumaon region of the Indian Himalayas

Rice root-knot nematode (RRKN), Meloidogyne graminicola is a serious pest of rice (Oryza sativa L.) reported globally. In India, RRKN has been reported from various parts of the rice growing region and causing 17–30% yield loss. In the present study, RRKN population infesting rice growing region of Kumaon hills of Uttarakhand, Indian Himalayan region was isolated during 2019–20, characterized using integrative taxonomy by combining molecular analysis using ITS, morphology of male, juveniles, adult female and morphometry measurements of different stages. The data presented in the comparative analysis of morphometry parameters for Meloidogyne graminicola isolate from the Kumaon region of the Indian Himalayas, as compared to the original description by Golden and Birchfield (1965) from Louisiana, USA, reveals some differences in the morphological characteristics of adult females, adult males, and 2nd stage juveniles (J2) of M. graminicola. The ITS sequence from the present study appeared as a single clade between the Fujian isolate (KM111531.1) and the Brazilian M. graminicola isolate (KY962651). To our knowledge, this is the first authentic characterization and report of RRKN from the Hilly region of Uttarakhand state. The detection of M. graminicola in the mid Indian Himalayan region provides valuable information for further studies on the natural population dynamics and distribution patterns of this nematode species. The findings highlight the need for regular monitoring and surveillance of nematode populations in the region to better understand their distribution and potential impact on rice production.

In vitro Screening of Different Rhizobacterial Strains against Egg Hatching of Rice Root-Knot Nematode, Meloidogyne graminicola

Meloidogyne graminicola is an economic yield loss causing major pest of rice globally. For managing this pest, biological control practices act as an alternate strategy, as it is the most effective and economic. Plant growth promoting rhizospheric bacteria (PGPR) are most significant because they benefit plants both directly and indirectly by enhancing plant growth and provides long lasting antagonistic effects against plant parasitic nematodes. Considering this an in vitro efficacy research experiment of nematoxicity of native rhizobacterial strains was conducted, against egg hatching of M. graminicola at S/2 and S/4 concentration levels of intact bacterial culture and cell free culture filtrates (CFCs). The hatching behavior of rice root-knot nematode eggs was observed on alternate days for ten days which resulted in inhibition of egg hatching by all bacterial cultures at both concentration levels. When compared to the untreated control, Bacillus spp. showed the most egg inhibition in the S/2 concentration of both culture filtrates i.e,86.8% and 84.8%. Similarly, in the S/4 level of concentration, most egg hating such as 83.7% and 79.8% was recorded in Bacillus spp. culture filtrates. The rate of hatching was inversely proportional to the concentration of strains at exposure time, decreasing as the concentration increased. The results of the experiment revealed the potential of rhizospheric bacteria which makes it more feasible and environmentally safe approach for the management of Meloidogyne graminicola.

MG1 interacts with a protease inhibitor and confers resistance to rice root-knot nematode

The rice root-knot nematode (Meloidogyne graminicola) is one of the most destructive pests threatening rice (Oryza sativa L.) production in Asia; however, no rice resistance genes have been cloned. Here, we demonstrate that M. GRAMINICOLA-RESISTANCE GENE 1 (MG1), an R gene highly expressed at the site of nematode invasion, determines resistance against the nematode in several rice varieties. Introgressing MG1 into susceptible varieties increases resistance comparable to resistant varieties, for which the leucine-rich repeat domain is critical for recognizing root-knot nematode invasion. We also report transcriptome and cytological changes that are correlated with a rapid and robust response during the incompatible interaction that occurs in resistant rice upon nematode invasion. Furthermore, we identified a putative protease inhibitor that directly interacts with MG1 during MG1-mediated resistance. Our findings provide insight into the molecular basis of nematode resistance as well as valuable resources for developing rice varieties with improved nematode resistance.

CRISPR/Cas9-mediated mutagenesis of the susceptibility gene OsHPP04 in rice confers enhanced resistance to rice root-knot nematode.

CRISPR crops carrying a mutation in susceptibility (S) genes provide an effective strategy for controlling plant disease, because they could be 'transgene-free' and commonly have more broad-spectrum and durable type of resistance. Despite their importance, CRISPR/Cas9-mediated editing of S genes for engineering resistance to plant-parasitic nematode (PPN) disease has not been reported. In this study, we employed the CRISPR/Cas9 system to specifically induce targeted mutagenesis of the S gene rice copper metallochaperone heavy metal-associated plant protein 04 (OsHPP04), and successfully obtained genetically stable homozygous rice mutants with or without transgenic elements. These mutants confer enhanced resistance to the rice root-knot nematode (Meloidogyne graminicola), a major plant pathogenic nematode in rice agriculture. Moreover, the plant immune responses triggered by flg22, including reactive oxygen species burst, defence-related genes expression and callose deposition, were enhanced in the 'transgene-free' homozygous mutants. Analysis of rice growth and agronomic traits of two independent mutants showed that there are no obvious differences between wild-type plants and mutants. These findings suggest that OsHPP04 may be an S gene as a negative regulator of host immunity and genetic modification of S genes through the CRISPR/Cas9 technology can be used as a powerful tool to generate PPN resistant plant varieties.

Population dynamics of Meloidogyne graminicola in soil in different types of direct-seeded rice agroecosystems in Hunan Province, China.

The rice root-knot nematode Meloidogyne graminicola is increasingly widely distributed in China and has had a severe incidence in Hunan Province. It is thus necessary to investigate its population dynamics in paddy fields. This study was conducted to ascertain the effect of direct-seeded rice agroecosystems on the population dynamics of M. graminicola and root gall development in rice. The results indicated that the population density of M. graminicola in soil was markedly influenced by the agroecosystem, rainfall and temperature. The population density of M. graminicola J2, and eggs in the soil and root galls, were significantly larger in the dry aerobic rice agroecosystem and in the rain-fed upland agroecosystem than in the lowland double-rice cropping sequence agroecosystem. As it can affect soil moisture rainfall was the key factor affecting the density of nematodes in both the rain-fed upland agroecosystem and the dry aerobic rice agroecosystem. Field flooding was still an effective way to reduce the population density of M. graminicola. In addition, we observed that M. graminicola can lay eggs outside rice roots under laboratory conditions. Therefore, we propose a hypothesis that M. graminicola lays egg masses within roots when the soil moisture is high, but lays eggs outside when the soil moisture is suitable. By clarifying the population dynamics of M. graminicola in different types of direct-seeded rice agroecosystems, this study is conducive to controlling rice root-knot nematodes.

Deciphering the nematostatic biomolecules from Bacillus cereus against potential protein targets of rice root-knot nematode, Meloidogyne graminicola through molecular docking approaches

Deciphering the nematostatic biomolecules from Bacillus cereus against potential protein targets of rice root-knot nematode, Meloidogyne graminicola through molecular docking approaches

Comparative Root Morpho-Anatomical Studies On Meloidogyne Graminicola Resistant And Susceptible Rice Genotypes

The work characterizes root morpho-anatomical changes in rice due to infestation of rice root-knot nematode, Meloidogyne graminicola. The susceptible rice genotype, Satabdi (IET-4786) and resistant rice genotypes Marichsal and Lakshmansal were inoculated with three different geographic isolates of M. graminicola viz., Mg1 (Ashui, West Medinipur), Mg2 (Sumitrapur, West Medinipur) and Mg3 (Gayeshpur, Nadia). The results of demonstrated that, transverse section of morpho-anatomical structure of Mg1 isolate inoculated root at 25 DAI to susceptible and resistant rice genotypes viz., Satabdi and Marichsal showed presence of adult females and egg-mass in the cortex which symbolized a successful host parasitic relationship. Organization of cellular architecture of adventitious root of rice genotypes Satabdi and Marichsal when inoculated with Mg2 isolate then nematode infestation led to drastic changes as evidenced by the disorganization of cortical cells along with dissolution of epidermal, exodermal and sclerenchymatous cells at 10 DAI. The rice genotype, Lakshmansal did not reveal any changes in the root morpho-anatomy when inoculated with Mg2 isolate at 10 DAI. The cross section of the roots of Satabdi and Marichsal revealed complete obliteration of root anatomical structures along with formation of multinucleate giant cells, cavities in the stele owing to nematode injury along with females and egg-masses at 10 and 25 DAI of Mg3 isolate. The rice genotype Lakshmansal, was characterized as resistant against all three isolates of Mg as confirmed by histological study of roots. Cortical thickness of uninfected rice roots was comparatively lesser than infected ones, while maximum stele diameter was recorded with Marichsal when inoculated with Mg1 isolate i.e. 523.01 µm at 25 DAI. Outer portion of the root was also less than infected ones. Giant cell diameter of Satabdi and Marichsal ranged from 43.45-107.46 µm and 30.68-102.67 µm, respectively, indicating successful establishment of host-nematode interaction.

Integrated approaches for the management of rice root-knot nematode, Meloidogyne graminicola in rice

Integrated approaches for the management of rice root-knot nematode, Meloidogyne graminicola in rice

Evaluation of Total Phenol Content of some Common Paddy Cultivars of Odisha with the Application of Biofertilizer in Assessing Resistance to Meloidogyne graminicola

The total phenol content of four common paddy cultivars of Odisha namely Abhisek (R), Manik (MR), Bas-12 (S) and Lalat (HS) were studied under pot culture condition in the net house following CRD design under different treatments using biofertilizer Azospirillum. brasilense alone or in combinations against rice root-knot nematode Meloidogyne graminicola. The objective of the work was to study the quantitative changes in phenolic compounds content and the effect of A.brasilense in the induction of phenolic compounds on the test nematode. It was observed that there was a significant increase in total phenol content in both resistant and moderately resistant paddy cultivars Abhisek and Manik in treatment T2 (Azospirillum brasilense @ 12kg/ha at 15DAT + M. graminicola @ 1000J2 after 7days of Azospirillum inoculation) were seen higher than the susceptible variety Bas-12 and highly susceptible variety Lalat as compared to control T5 with increase percentage of 38.77%, 36.58%, 35.02% and 39.28% respectively in shoots. Similarly the trend was continued in roots containing total phenol content of 0.25mg/g in Abhisek, 0.18mg/g in Manik, 0.21mg/g in Bas-12 and 0.19mg/g in Lalat as compared to other treatments. There were increase in percentage of change (p≤0.05) in roots under treatment T3 (A alone) in all the four varieties followed by T2 (A→N), and T1 (N→A) with respect to control T5. Basically, shoots of control plants in all four cultivars were observed more content of phenolic compounds than their roots. But after M. graminicola invasion and the action of A. brasilense the amount increased in both the roots and shoots of all the cultivars. The T4 (N alone) treatment in all the R, MR, S and HS varieties were recorded higher as compare to T5 but less than the treatments T3, T2, and T1 in both roots and shoots against the test nematode, which could exacerbating for eco-friendly RKN management approach.

Reaction of different Oryza species against rice root-knot nematode, Meloidogyne graminicola

Rice (Oryza sativa) is an important cereal crop and staple food for more than half of the world population. The sedentary endoparasitic nematode Meloidogyne graminicola is one of the major biotic stress factors that limit rice production globally irrespective of the agro-ecosystem. To tackle this, the host plant resistance is given prime importance due to global awareness towards ecologically stable and environmentally safe management options. However, the availability of resistant source within O. sativa against M. graminicola is limited and hence the search was extended to its wild relatives globally. In line with that, about 24 germplasms of different Oryza species collected from the gene bank of NRRI, Cuttack were evaluated against M. graminicola under artificial inoculation condition. Among them O. eichingeri and O. grandiglumis belonging to O. officinalis species complex and O. brachyantha were found to be resistant to M. graminicola with the lowest gall index (2.0-2.3 galls /root system). Oyza rufipogon, O. officinalis and O. alta were found tolerant to the nematode while all other species exhibited susceptible to highly susceptible reaction to the nematode. A more comprehensive study is necessary to shed light on the consistency of resistance within each Oryza species and also suggest the utilization of molecular tools to decipher the resistance mechanism govern in the reported accessions against rice root-knot nematode.

Response of rice genotypes to rice root‐knot nematode (Meloidogyne graminicola) infection under varying temperature regimes

AbstractThe rice root‐knot nematode (RRKN), Meloidogyne graminicola, is one of the major pests of the rice–wheat cropping system. Resistance against M. graminicola in rice could be most valuable in alleviating this problem. The host response of 75 Oryza genotypes was examined at three day/night temperature regimes, 29/26°C, 34/31°C and 38/35°C, in Pluronic gel as well as in soil. Out of the 75 selected rice genotypes, only Zhenshan 97 B exhibited high resistance to this set of temperature regimes, with the least number of galls/root system. At 34/31°C, more second‐stage juveniles (J2s) were hatched and J2 population densities in roots of the susceptible rice genotypes increased significantly compared with those of plants grown at the 29/26°C. In resistant genotypes, only a few J2s penetrated roots and developed into mature females. The histopathological studies revealed that in susceptible rice genotypes at high‐temperature regimes, the multinucleate giant cells were well developed. The results presented in this study revealed that an increase in temperature had a significant effect on the resistance of rice genotypes and resistance appeared more pronounced in genotype Zhenshan 97 B. This resistant genotype can be used in marker‐assisted selection to develop resistant elite cultivars.

Bio-management of rice root-knot nematode, M. graminicola by using various organic amendments and bio-control agents on rice nursery

A screen house experiment was conducted during kharif season, 2020-21 to know the effect of organic amendments and bio-agents (alone and in combination) in comparison with chemical on the population of rice root-knot nematode (Meloidogyne graminicola) in rice. Nursery was grown in 5 kg soil capacity earthen pan filled with infested soil having initial nematode population 285 J2/200 cc soil. Seeds of the rice (Variety- Pusa 1121) were soaked in tap water for 24 h and the sprouted seeds were sown in pots. Hundred seeds of rice were sown in each pot and each treatment was replicated four times. Organic amendments (neem cake and FYM) and bio-agents (Pseudomonas fluorescens, Purpureocillium lilacinum and Trichoderma viride) were added 10 days before sowing. Weighted amount of bio-agents was mixed in neem cake and FYM for enrichment with 7-10 days waiting period. Carbofuran (Furadan 3G) was added at time of sowing. The earthen pots without organic amendments, bio-agents and chemical were treated as control. Observations on plant growth parameters (seedling length in cm fresh and dry seedling weight in g) and nematode multiplication (number of galls/20 seedling, number of eggs/20 seedling and final nematode population in the soil/200 cc soil) were made at transplanting time. The plant parameters were maximum and significantly highest in treated nursery (neem cake @ 50 g/pot + Pseudomonas fluorescens @ 50 g/pot) under screen house conditions. Nematode reproduction and multiplication parameters such as number of galls/seedling, number of eggs/seedling and final nematode population were significantly reduced in neem cake @ 50 g/pot + Pseudomonas fluorescens @ 50 g/pot.