Effects of Pseudomonas fluorescens and fertilizers on the reproduction of Meloidogyne incognita and growth of tomato

A 60-day glasshouse experiment was conducted to assess the influence of two strains of Pseudomonas fluorescens (GRP3 and PRS9), organic manure, and inorganic fertilizers (urea, diammonium phosphate (DAP), muriate of potash and monocalcium phosphate) alone and in combination on the multiplication of Meloidogyne incognita and growth of tomato. Pseudomonas fluorescens GRP3 was better at improving tomato growth and reducing galling and nematode multiplication than PRS9. Organic manuring resulted in less galling and nematode multiplication than occurred with DAP. However, DAP was found better in reducing nematode multiplication and improving plant growth than urea. Muriate of potash was the inorganic fertilizer least effective in reducing galling and nematode multiplication. Pseudomonas fluorescens GRP3 with organic manure was the best combination for the management of M. incognita on tomato but improved management of M. incognita can also be obtained if DAP is used with the GRP3 strain of P. fluorescens.     

Pre-inoculation with arbuscular mycorrhizal fungi suppresses root knot nematode (<Emphasis Type="Italic">Meloidogyne incognita</Emphasis>) on cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis>)

A pot experiment was conducted to evaluate the influence of pre-inoculation of cucumber plants with each of the three arbuscular mycorrhizal (AM) fungi Glomus intraradices, Glomus mosseae, and Glomus versiforme on reproduction of the root knot nematode Meloidogyne incognita. All three AM fungi tested significantly reduced the root galling index, which is the percentage of total roots forming galls. Numbers of galls per root system were significantly reduced only in the G. intraradices + M. incognita treatment. The number of eggs per root system was significantly decreased by AM fungus inoculation, no significant difference among the three AM fungal isolates. AM inoculation substantially decreased the number of females, the number of eggs g⁻¹ root and of the number of eggs per egg mass. The number of egg masses g⁻¹ root was greatly reduced by inoculation with G. mosseae or G. versiforme. By considering plant growth, nutrient uptake, and the suppression of M. incognita together, G. mosseae and G. versiforme were more effective than G. intraradices.     

Effects of interaction of Meloidogyne incognita,Alternaria dauci and Rhizoctonia solani on the growth,chlorophyll, carotenoid and proline contents of carrot in three types of soil

Disease complex of carrot (Daucus carota L.) involving root knot nematode Meloidogyne incognita and two fungi Alternaria dauci and Rhizoctonia solani were studied in three soil types. More plant growth, chlorophyll, carotenoid and proline contents were found in carrot grown in fly ash mix soil than plants grown in sand mix soil and loamy soil. Inoculation of M. incognita, R. solani, and A. dauci reduced plant growth, chlorophyll and carotenoid but increased proline contents. Inoculation of M. incognita 20 days prior to a fungal pathogen caused a greater reduction in plant growth, chlorophyll and carotenoid than fungal pathogen was inoculated prior. Inoculation of A. dauci prior to R. solani or vice versa had a similar effect on plant growth, chlorophyll, and carotenoid. Nematode multiplication and galling was higher in plants grown in sand mix soil followed by loamy soil and fly ash mix soil. Both fungi had adverse effects on galling and nematode multiplication. Blight disease index caused by A. dauci was 3 and crown rot index by R. solani was also recorded 3. These disease indices were 5 when pathogens were inoculated in combinations.     

Effect of Inoculation with the Arbuscular Mycorrhizal Fungus Glomus Intraradices on the Root-Knot Nematode Meloidogyne Incognita in Cucumber

ABSTRACT

A pot experiment was carried out to investigate the tolerance of cucumber plants (Cucumis sativus L.) to root-knot nematode after inoculation with Glomus intraradices. Plants were inoculated with G. intraradices for four weeks and then transplanted in soil treated with Meloidogyne incognita for a further five weeks. The low phosphorus (P) loamy soil was amended with 50 and 100 mg P kg^?1 soil. Mycorrhizal colonization increased shoot dry weight, shoot length, leaf numbers, root fresh weight and shoot P concentration, whereas nematode penetration and reproduction were significantly decreased. Similarly, P fertilization usually increased shoot growth and significantly decreased the number of galls and the number of egg masses and eggs per g root. Our results indicate that inoculation with G. intraradices and P fertilizer confer tolerance of cucumber plants to M. incognita by enhancing plant growth and by suppressing reproduction and/or galling of nematodes during the early stages of plant growth.     

Glycosidation of apigenin results in a loss of its activity on different growth parameters of arbuscular mycorrhizal fungi from the genus Glomus and Gigaspora

The effect of different concentrations (0.5, 2 and 8 μM) of apigenin and its glycosidated form 5,7,4′-hydroxy flavone glycoside on arbuscular mycorrhizal (AM) fungal spore germination, hyphal growth, hyphal branching, the formation of entry points and root colonization of Gigaspora. rosea, Gi. margarita, Glomus mosseae and G. intraradices was tested. The lowest apigenin concentration (0.5 μM) nearly doubled hyphal branching, the formation of entry points and root colonization of all four tested fungi, whereas higher concentrations (2 and 8 μM) nearly doubled the hyphal growth of Gi. margarita, G. mosseae and G. intraradices. In none of the treatments with the apigenin-glycoside any effect on AM fungi could be observed. Our data show that apigenin exhibits an AM fungal genus and even species activity and we provide strong evidence that glycosidation results in a loss of its activity towards AM fungi.     

Influence of different mulch treatments on growth rate and activity of the earthworm Eudrilus eugeniae (Kinberg)

Growth characteristics of the earthworm Eudrilus eugeniae and the impac of its activity on soil properties were studied in soil culture. The highest growth rate, fecundity and total weight increase were recorded in cassava mulch, compared with cocoyam mulch, grass and plantain pseudo trunk mulch treatments. With animal manure treatments, growth rate was highest in poultry manure compared with cow and goat manures although total weight increases were highest in poultry and goat manures and lowest in cow manure. The worm activity expressed as percentage reduction of soil bulk density was greatest in cassava mulch followed by grass mulch, cocoyam mulch and plantain pseudo trunk mulch in that order. Various animal manures did not differ in this aspect. Total soil N and soil organic matter increased significantly in cassava and grass mulch treatmens while in plantain pseudo trunk mulch these factors decreased. Soil pH increased in cocoyam and plantain mulch treatments and decreased in cassava and grass mulch treatments.     

ARBUSCULAR MYCORRHIZAL FUNGI AND PIRIFORMOSPORA INDICA INDIVIDUALLY AND IN COMBINATION WITH RHIZOBIUM ON GREEN GRAM

Three species of AM fungi, Glomus mosseae, Glomus microcarpum, Gigaspora margarita and a fungus that mimics the properties of AM fungi, Piriformospora indica, were tested on green gram [Phaseolus aureus Roxb. (= Vigna radiata var. radiata)] individually and in combination with Rhizobium for their influence on growth and seed yield. The growth parameters analyzed were dry biomass, total leaf area, total chlorophyll,% root colonization, nodulation, and nitrogen, phosphorus, and potassium (NPK) content of leaf tissues using standard methodologies. Glomus microcarpum was found to be more effective in promoting biomass and seed yield when applied alone. But in combination with Rhizobium, G. mosseae enabled highest production of biomass. The tissue nitrogen content was high in G. microcarpum—Rhizobium dual inoculated plants. Many other characteristics were high in dual inoculation, while tissue P was high in individual treatment of G. mosseae. Piriformospora indica was not found to be a good synergist on green gram.     

The influence of the root-knot nematode Meloidogyne incognita, the nematicide aldicarb and the nematophagous fungus Pochonia chlamydosporia on heterotrophic bacteria in soil and the rhizosphere

Plant‐pathogenic nematodes are a major cause of crop damage worldwide, the current chemical nematicides cause environmental damage, but alternatives such as biological control are less effective, so further understanding of the relationship between nematodes, nematicides, biological control agents and soil and rhizosphere microorganisms is needed. Microbial populations from roots of cabbage and tomato plants infested with the root‐knot nematode Meloidogyne incognita were compared with those from plants where the nematode was controlled by the nematicide aldicarb, or a nematophagous fungus with biological control potential, Pochonia chlamydosporia. The total numbers of culturable bacteria and fungi in rhizosphere soil were similar in all three treatments for both plants, around 100‐fold more than in control soil in which there were no plants. However, there were clear differences in the catabolic diversity, assessed by Biolog EcoPlate? carbon substrate utilization assays, between microbial populations from unplanted soil and the rhizosphere. In cabbage, a poor host for M. incognita, the rhizosphere population from P. chlamydosporia‐treated plants was distinct from the population from untreated and aldicarb‐treated plants. In tomato, a host susceptible to the nematode, the catabolic diversity of populations from aldicarb‐ and P. chlamydosporia‐treated plants was similar and differed from the untreated, nematode‐infested plants. The genetic diversity of the fast‐growing heterotrophic bacteria in the tomato rhizosphere, indicated by PCR fingerprinting with ERIC primers, was very different in the infested roots, whereas the profiles of isolates from both aldicarb‐ and P. chlamydosporia‐treated roots were similar. Evidently, nematodes have a greater impact on the rhizosphere population of a susceptible host, tomato, than a poor one, cabbage, and nematode‐infested roots are colonized by a different subpopulation of soil microbes from that on plants where infection is controlled, illustrating differences in root morphology and physiology.     

Biocontrol potential of native Trichoderma isolates against root-knot nematodes in West African vegetable production systems

Seventeen isolates of the free-living soil fungus Trichoderma spp., collected from Meloidogyne spp. infested vegetable fields and infected roots in Benin, were screened for their rhizosphere competence and antagonistic potential against root-knot nematodes, Meloidogyne incognita, in greenhouse pot experiments on tomato. The five isolates expressing greatest reproductive ability and nematode suppression in pots were further assessed in a typical double-cropping system of tomato and carrot in the field in Benin. All seventeen isolates were re-isolated from both soil and roots at eight weeks after application, with no apparent crop growth penalty. In pots, a number of isolates provided significant nematode control compared with untreated controls. Field assessment demonstrated significant inhibition of nematode reproduction, suppression of root galling and an increase of tomato yield compared with the non-fungal control treatments. Trichoderma asperellum T-16 suppressed second stage juvenile (J₂) densities in roots by up to 80%; Trichoderma brevicompactum T-3 suppressed egg production by as much as 86%. Tomato yields were improved by over 30% following the application of these biocontrol agents, especially T. asperellum T-16. Although no significant effects were observed on carrot galling and yield, soil J₂ densities were suppressed in treated plots, by as much as 94% (T. asperellum T-12), compared with the non-fungal controls. This study provides the first information on the potential of West-African Trichoderma spp. isolates for use against root-knot nematodes in vegetable production systems. The results are highly encouraging, demonstrating their strong potential as an alternative and complementary crop protection component.     

Mycorrhizal phosphorus enhancement of plants in undisturbed soil differs from phosphorus uptake stimulation by arbuscular mycorrhizae over non-mycorrhizal controls

Previous greenhouse and field studies have shown arbuscular mycorrhizal (AM) plants usually have greater P uptake and growth when raised in undisturbed soil compared to soil disturbed between plantings, such as by tillage. We report here for the first time that AM fungi able to stimulate shoot P uptake in experimental comparisons to non-mycorrhizal plants differ in their ability to bring about similar responses in undisturbed soil compared to disturbed soil. This outcome indicates a difference in functional character between the two stimulation processes. Three isolates of AM fungi were tested for growth promotion of maize (Zea mays L.) in pots in a soil disturbance experiment that included non-mycorrhizal controls. All three fungi colonized roots well and promoted shoot P uptake compared to non-inoculated controls, but only Glomus mosseae was able to stimulate growth in undisturbed soil compared to disturbed soil. This effect was seen when Glomus mosseae was alone or in combination with Gigaspora margarita. However, the presence of Glomus aggregatum in combination with Glomus mosseae prevented any stimulation, presumably due to domination by Glomus aggregatum. The ability of AM fungi to be beneficial to plants in comparison to non-mycorrhizal situations likely relates to the spread of mycelium in the soil and the capacity for nutrient transfer to the root. The ability of an AM fungus to promote growth in undisturbed soil appears to be related to these features and, in addition, a capacity for persistence and retention of functional capacity of the extraradical mycelium from one plant generation to the next.     

Stability analysis of aggregates in relation to the hydrophobicity of organic manure for Sri Lankan Red Yellow Podzolic soils

Aggregate slaking is linked with rapid pressure buildup within aggregates. Soil water repellency may help hamper the pressure buildup within aggregates by reducing their wetting rates. We examined the effects of animal manure in improving aggregate stability, the hydrophobic effects of green manure, and the possibility of using organic manure mixtures to increase the aggregate stability for Sri Lankan red yellow podzolic soils using model aggregates. Almost all the cow dung (CD) added samples showed extremely low percentages of water stable aggregates (%WSA) demonstrating rapid destruction of aggregates. Although the addition of ≥ 10% goat dung (GD) improved the %WSA, aggregate floating occurred, showing the risk of aggregate floating with runoff water. Addition of 5% GD would be an acceptable solution if the %WSA can be improved. Casuarina equisetifolia L. leaves (CE) was found to be a hydrophobic green manure. Although addition of ≥ 5% CE increased the %WSA up to about 90%, aggregate floating occurred. The possibility of improving %WSA using 1–2% hydrophobic green manure in organic manures mixtures was tested. Samples with 5% GD + 2% CE manure mixture showed the highest and the most stable %WSA without showing aggregate floating. Additions of compost and poultry litter were found not to be effective in improving aggregate stability with or without CE. Strong or higher water repellency was not observed in any of the samples with manure mixtures, showing that the addition of 1–2% hydrophobic CE would not induce detrimental effects of water repellency. There was no clear correlation between %WSA and the hydrophobicity of soils. However, the %WSA can be considered to show a tendency to increase with increasing hydrophobicity, because the %WSA was very high in samples with hydrophobic CE, the %WSA increased when mixed with 1–2% CE, and samples with highest water drop penetration time (WDPT) among all the manure mixtures showed the highest %WSA.     

牛粪水酸化贮存过程中氮形态转化的特性研究

近年来,随着畜禽养殖规模化的快速发展,养殖粪水的处理和利用已成为养殖业健康发展的难点和热点,粪水酸化技术是通过向粪水中添加酸化剂以降低氨气排放,减少粪水贮存中氮素损失的技术,目前此技术已经在丹麦等国推广应用,但中国对此技术的研究尚未起步,为探究粪水酸化固持氮素的效果,该研究以硫酸和明矾为粪水酸化剂,以固液分离前后奶牛粪水为处理对象,通过向粪水中添加酸化剂降低粪水pH值至6.0,分析粪水贮存中氨气排放、氮素转化以及粪大肠菌群数等指标,探索粪水酸化贮存过程氮形态转化机理。研究表明:向养殖粪水中添加酸化剂可降低6.3%~11.1%的总氮损失,能够降低粪水贮存初期中氨气的排放,同时有效抑制了奶牛粪水中粪大肠菌群的活性,使其更易达到无害化处理。酸化剂的加入一方面抑制粪水中微生物作用下的有机氮向无机氮素的转化,提高粪水贮存中有机氮的含量,减少铵态氮的产生量,另一方面酸化剂与粪水中的铵态氮结合生成稳定的铵盐,抑制了粪水中铵态氮向氨气转化的化学平衡,降低了粪水中因氨气排放导致的总氮损失,从而达到减少粪水贮存中氮素损失。     

Amelioration of Acidic Soil and Production Performance of Cowpea by the Application of Different Organic Manures in Eastern Himalayan Region,India

Acidic soils are limiting the production potential of the crops because of low availability of basic ions and excess of hydrogen (H⁺), aluminium (Al³⁺), and manganese (Mn²⁺) in exchangeable forms. Therefore, a field study was conducted to know the ameliorating effect of organic manures on acidic soils and production performance of cowpea (Vigna unguiculata L., Walp.) by using different locally available organic manures. Growth and yield attributes were observed to be significantly greater with vermicompost (VC) followed by poultry manure (PM). Porosity, maximum water-holding capacity (MWHC), and organic carbon were greater with farmyard manure (FYM) and cow dung manure (CDM). However, water retention at field capacity (FC), permanent wilting point (PWP), bulk density (BD), pH, and availability of nitrogen (N), phosphorus (P), and potassium (K) were greater with VC. However, physical and chemical properties were deteriorated in control plots.     

Effect of the arbuscular mycorrhizal fungus <Emphasis Type="BoldItalic">Glomus intraradices</Emphasis> on the false root-knot nematode <Emphasis Type="BoldItalic">Nacobbus aberrans</Emphasis> in tomato plants

Information about the interaction between arbuscular mycorrhizal fungi (AMF) and the false root-knot nematode Nacobbus aberrans (Thorne, 1935) Thorne & Allen, 1944 is scarce. The effect of Glomus intraradices Schenk & Smith on tomato (Lycopersicon esculentum L.) cv. Platense inoculated with nematode juveniles from Lisandro Olmos (Argentina) was studied under greenhouse conditions. Six treatments with five replications were performed. After 80 days, nematode reproduction and percentage of AMF colonization in roots were estimated. Some plant growth parameters were also measured. In general, plants with AMF and AMF plus nematodes grew as well as the control without AMF and without nematodes. Furthermore, G. intraradices was beneficial in reducing nematode-induced damage in roots (lower number of galls) as well as in having a suppressive effect on parasite reproduction. This is the first study on the use of G. intraradices as a possible strategy in the control of N. aberrans in tomato.     

Control of tomato bacterial wilt and root-knot diseases by Bacillus thuringiensis CR-371 and Streptomyces avermectinius NBRC14893

Ralstonia solanacearum and Meloidogyne incognita are two soilborne pathogens that cause serious damage and great losses in the production of tomato. For this purpose, a bacterial isolate, Bacillus thuringiensis CR-371, and an actinomyces isolate, Streptomyces avermectinius NBRC14893, were examined for their ability to protect tomato from root-knot nematode and bacterial wilt diseases under glasshouse conditions. Treatment of tomato roots with B. thuringiensis CR-371 and S. avermectinius NBRC14893 followed by challenge inoculation with R. solanacearum and M. incognita significantly decreased disease severity of bacterial wilt alone, root-knot nematode alone, or mixed infection by both pathogens compared to the control. Furthermore, pretreatment of tomato roots with B. thuringiensis CR-371 and S. avermectinius NBRC14893 significantly reduced bacterial proliferation of R. solanacearum both in pathogen alone inoculated plants and in plants co-inoculated with R. solanacearum and M. incognita. In conclusion, our results suggest that the treatment of tomato roots with B. thuringiensis CR-371 and S. avermectinius NBRC14893 simultaneously suppresses bacterial wilt and root-knot nematode diseases. Therefore, B. thuringiensis CR-371 and S. avermectinius NBRC14893 could provide new options for integrated pest management strategies against plant diseases, especially against bacterial-nematode disease complexes that cause synergistic yield losses.     

Synergistic effect of arbuscular mycorrhizal fungi and Bacillus subtilis on the biomass and essential oil yield of rose-scented geranium (Pelargonium graveolens)

Four different arbuscular mycorrhizal (AM) fungi, Glomus aggregatum, Glomus fasciculatum, Glomus intraradices and Glomus mosseae, were used alone and in combinations with Bacillus subtilis to evaluate their capability to increase the productivity of geranium. Mycorrhizal treatment increased the growth and total biomass invariably over non-mycorrhizal control plants. In AM alone treatment, the best result was obtained for G. mosseae treatment, where 380.9 and 335.3 g fresh herb yield per pot was recorded in 2005–2006 and 2006–2007, respectively, an increase of 75.3 and 85.9% over controls. Plants inoculated with B. subtilis alone yielded 287.8 and 252.3 g fresh herb, an increase of 32.4 and 39.9% over uninoculated controls. However, B. subtilis in combination with G. mosseae produced the highest herb yield, i.e. 410.8 and 347.8 g herbs pot^?1, an increase of 89.4 and 92.9% over untreated controls. The field experimental data validated the results of the pot experiment. Treatment with G. mosseae alone increased herb yield by 49.4%, whereas in combination with B. subtilis, it increased herb yield by 59.5%. Treatment with AM fungi and B. subtilis did not affect the essential oil content of the plant, but total oil yield was significantly increased because of the increase in biomass production.     

Mycorrhiza inoculation effects on seedling establishment,survival and morphological properties of Ziziphora clinopodioides Lam.

In this paper, the establishment and growth of medicinal species Ziziphora clinopodioides Lam. were studied through inoculation with two mycorrhizal fungi species, Glomus mosseae and Glomus intraradices, in arid/semi-arid Bahar-Kish rangelands, Iran in 2012 and 2013. The root colonization percentage of Ziziphora, as well as their establishment and growth were enhanced in 2013 using G. mosseae. In this year, less rainfall and higher temperature decreased the survival, growth and morphological traits of the studied plants. Growth and establishment of the inoculated plants using G. intraradices improved in 2013, while inoculation with G. mosseae showed more beneficial effects in 2012. In both years, the strain, the growth and establishment percentage of seedlings in inoculated treatments with mycorrhizal species were significantly improved. According to the results, G. intraradices mycorrhizal fungi is recommended as a biological fertilizer in increasing the forage production and the initial establishment of Ziziphora in arid and semi-arid rangelands.     

AM fungi inoculation and addition of microbially‐treated dry olive cake‐enhanced afforestation of a desertified Mediterranean site

A field experiment was carried out to compare the effectiveness of inoculation with three arbuscular mycorrhizal (AM) fungi, namely Glomus intraradices Schenck & Smith, Glomus deserticola (Trappe, Bloss. & Menge) and Glomus mosseae (Nicol & Gerd.) Gerd. & Trappe, and the addition of Aspergillus niger‐treated dry olive cake (DOC) in the presence of rock phosphate, in increasing root nitrate reductase (NR) and acid phosphatase activities, mycorrhizal colonization, plant growth and nutrient uptake in Dorycnium pentaphyllum L. seedlings afforested in a semiarid degraded soil. Three months after planting, both the addition of fermented DOC and the mycorrhizal inoculation treatments had increased root NR activity significantly, particularly the inoculation with G. deserticola (by 75 per cent with respect to non‐inoculated plants), but they had no effect on root acid phosphatase. Mycorrhizal inoculation treatments with G. deserticola or G. mosseae on their own were even more effective than the addition of fermented DOC alone in improving the growth and (NPK) foliar nutrients of D. pentaphyllum plants. The combined treatment involving the application of microbially‐treated agrowastes and mycorrhizal inoculation with AM fungi, particularly with G. mosseae, can be proposed as a successful revegetation strategy for D. pentaphyllum in P‐deficient soils under semiarid Mediterranean conditions. Copyright © 2004 John Wiley & Sons, Ltd.     

Effects of Arbuscular Mycorrhizal Fungi on Growth and Yield of Cucumber Plants

Abstract

In two pot experiments, cucumber (Cucumis sativus L. cv. Jinlu No. 3) seedlings were each inoculated with one of three arbuscular mycorrhizal fungi (AMF), Glomus mosseae, Glomus intraradices, or Glomus versiforme, or uninoculated. Seedling growth and weight of single fruit were investigated. The results indicated that growth of seedlings was significantly enhanced by G. mosseae, inhibited by G. versiforme, and not significantly influenced by G. intraradices. The dry weight of seedlings inoculated with G. mosseae was 1.2 times its counterparts. The concentrations of nitrogen (N) and phosphorus (P) in roots and magnesium (Mg), copper (Cu), and zinc (Zn) concentration in shoots were increased by inoculating the three AMF, and potassium (K) and iron (Fe) concentrations in shoots decreased significantly. The weights of single fruit of plants preinoculated with G. mosseae and G. versiforme were about 1.4 and 1.3 times higher than those from the uninoculated treatment, respectively.     

Role of effective microorganisms in efficacy of Nemarioc-AG phytonematicide on suppression of Meloidogyne incognita and growth of tomato plants

The release of active ingredient chemicals in conventional organic amendments is primarily through microbial degradation, whereas in granular phytonematicides, leaching through irrigation water had been implied as a probable mechanism. The objective of this study was to determine the role of effective microorganisms (EM) on the efficacy of Nemarioc-AG (NAG; G?=?granular formulation) phytonematicide on suppression of root-knot (Meloidogyne species) nematodes and growth of tomato (Solanum lycopersicum) plants. A 5?×?6 factorial experiment, with EM at 0%, 0.14%, 0.17%, 0.20% and 0.25% and phytonematicide at 0, 3, 6, 9, 12 and 15?g per plant, was conducted under microplot conditions. Each plant was inoculated with 11,000 eggs and second-stage juveniles (J2) of Meloidogyne incognita. Seventy days after initiating the treatments, the interactions were not significant (P?≥?.05) on all variables, but the main factors were highly significant. Regression of nematode population densities, root gall and dry shoot mass over increasing phytonematicide concentration exhibited quadratic relations, which were explained by 93%, 97% and 99%, respectively. In contrast, stem diameter and phytonematicide concentration had a positive linear relation, which was explained by 98%. Nematode numbers over increasing EM concentration exhibited quadratic relation, which was explained by 97%. All plant variables and EM had no significant relations. In conclusion, the efficacy of NAG phytonematicide on nematode suppression and plant growth was independent of EM activities, suggesting that irrigation water played a major role in the efficacy of the product in granular formulation.