Evaluation of biocontrol potential of Arthrobotrys oligospora against Meloidogyne graminicola and Rhizoctonia solani in Rice (Oryza sativa L.)

The nematode trapping and mycoparasitic potential of Arthrobotrys oligospora was tested in vitro against Meloidogyne graminicola and Rhizoctonia solani, respectively. Five isolates of A. oligospora were isolated from different locations of India. Diversity of the trapping structures is large and highly dependent on the environmental condition and nature of the fungus. In A. oligospora, a three-dimensional adhesive net (in response to nematode) and hyphal coils developed around the hyphae of R. solani. In vitro trap formation and predacity were tested against second-stage juveniles of M. graminicola (J₂) and the interactions between A. oligospora and R. solani were recorded. Under field conditions, we demonstrated the biocontrol potential of A. oligospora against R. solani causing sheath blight of rice (Oryza sativa) for the first time. All the isolates of A. oligospora parasitized and killed M. graminicola and R. solani. Application of A. oligospora, isolate VNS-1, in soil infested with M. graminicola and R. solani reduced the number of root knot by 57.58–62.02%, sheath blight incidence by 55.68–59.32% and lesion length by 54.91–66.66% under green house and miniplot (field) conditions. Applications of A. oligospora to the soil increased plant growth: shoot length by 56.4–68.8%, root length by 44.0–54.55%, fresh weight of shoot and root by 62.91–65.4% and 38.9–44.19%, respectively, as compared to the plants grown in nematode infested soil.     

Interrelationships of Rotylenchulus reniformis with Rhizoctonia solani on Cotton

The interrelationships between reniform nematode (Rotylenchulus reniformis) and the cotton (Gossypium hirsutum) seedling blight fungus (Rhizoctonia solani) were studied using three isolates of R. solani, two populations of R. reniformis at multiple inoculum levels, and the cotton cultivars Dehapine 90 (DP 90) and Dehapine 41 (DP 41). Colonization of cotton hypocotyl tissue by R. solani resulted in increases (P ≤ 0.05) in nematode population densities in soil and in eggs recovered from the root systems in both 40- and 90-day-duration experiments. Increases in soil population densities resulted mainly from increases in juveniles. Enhanced reproduction of R. reniformis in the presence of R. solani was consistent across isolates (1, 2, and 3) of R. solani and populations (1 and 2) and inoculum levels (0.5, 2, 4, and 8 individuals/g of soil) of R. reniformis, regardless of cotton cultivar (DP 90 or DP 41). Severity of seedling blight was not influenced by the nematode. Rhizoctonia solani caused reductions (P ≤ 0.05) in cotton growth in 40- and 90-day periods. Rotylenchulus reniformis reduced cotton growth at 90 days. The relationship between nematode inoculum levels and plant growth reductions was linear. At 90 days, the combined effects of these pathogens were antagonistic to plant growth.     

Pathogenicity of root knot nematode Meloidogyne incognita on okra and its management through botanicals

An investigation was carried out to study the pathogenicity of root knot nematode Meloidogyne incognita on okra and its management through various organic amendments. The inoculum level of 1000 juveniles per plant showed significant reduction in various plant growth parameters, which reveals that M. incognita is a potential pathogen of okra. With the increase in inoculums level of M. incognita (J₂), there was a progressive decrease in various plant growth parameters. The maximum reduction in plant growth parameters was observed at an inoculum level of 4000 juveniles per plant. The efficacy of five organic amendments viz. groundnut cake, castor cake, sunflower cake, linseed cake and sawdust was tested against root knot nematode M. incognita. Amending the soil with different oil cakes was found to be effective in reducing the nematode soil population, number of females, number of egg masses as well as root gall formation in okra. The highest increase in plant growth (13%) and maximum reduction in number of galls (54%), number of females (57%) and number of egg masses (55%) was recorded on application of groundnut cake.     

Ralstonia solanacearum colonization of tomato roots infected by Meloidogyne incognita

Bacterial wilt, caused by Ralstonia solanacearum, is one of the most serious diseases of tomato (Solanum lycopersicum). Concomitant infection of R. solanacearum and root‐knot nematode Meloidogyne incognita increases the severity of bacterial wilt in tomato, but the role of this nematode in disease complexes involving bacterial pathogens is not completely elucidated. Although root wounding by root‐knot nematode infection seems to play an important role, it might not entirely explain the increased susceptibility of plants to R. solanacearum. In the present study, green fluorescent protein (GFP)‐labelled R. solanacearum distribution was observed in the root systems of the tomato cultivar Momotaro preinoculated with root‐knot nematode or mock‐inoculated with tap water. Fluorescence microscopy revealed that GFP‐labelled R. solanacearum mainly colonized root‐knot nematode galls, and little or no green fluorescence was observed in nematode‐uninfected roots. These results suggest that the gall induced by the nematode is a suitable location for the growth of R. solanacearum. Thus, it is crucial to control both R. solanacearum and root‐knot nematode in tomato production fields to reduce bacterial wilt disease incidence and effects.     

The Rhizoctonia-Meloidogyne Disease Complex in Flue-cured Tobacco

If Meloidogyne incognita preceded Rhizoctonia solani by 10 days or 21 days in roots of greenhouse-grown tobacco plants, root rot was more extensive than when the nematode and fungus were introduced either simultaneously or separately or when R. solani was added after artificial wounding. Histological examination of galled roots 72 days after inoculation with R. solani revealed extensive fungal colonization in the root-knot susceptible cultivar ''Dixie Bright 101'' when M. incognita preceded R. solani by 21 days. R. solani, normally nonpathogenic on mature tobacco roots, may cause severe losses when present with well-established root-knot nematode infections.     

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.     

Manipulation of Rhizosphere Bacterial Communities to Induce Suppressive Soils

Naturally occurring disease-suppressive soils have been documented in a variety of cropping systems, and in many instances the biological attributes contributing to suppressiveness have been identified. While these studies have often yielded an understanding of operative mechanisms leading to the suppressive state, significant difficulty has been realized in the transfer of this knowledge into achieving effective field-level disease control. Early efforts focused on the inundative application of individual or mixtures of microbial strains recovered from these systems and known to function in specific soil suppressiveness. However, the introduction of biological agents into non-native soil ecosystems typically yielded inconsistent levels of disease control. Of late, greater emphasis has been placed on manipulation of the cropping system to manage resident beneficial rhizosphere microorganisms as a means to suppress soilborne plant pathogens. One such strategy is the cropping of specific plant species or genotypes or the application of soil amendments with the goal of selectively enhancing disease-suppressive rhizobacteria communities. This approach has been utilized in a system attempting to employ biological elements resident to orchard ecosystems as a means to control the biologically complex phenomenon termed apple replant disease. Cropping of wheat in apple orchard soils prior to re-planting the site to apple provided control of the fungal pathogen Rhizoctonia solani AG-5. Disease control was elicited in a wheat cultivar-specific manner and functioned through transformation of the fluorescent pseudomonad population colonizing the rhizosphere of apple. Wheat cultivars that induced disease suppression enhanced populations of specific fluorescent pseudomonad genotypes with antagonistic activity toward R. solani AG-5, but cultivars that did not elicit a disease-suppressive soil did not modify the antagonistic capacity of this bacterial community. Alternatively, brassicaceae seed meal amendments were utilized to develop soil suppressiveness toward R. solani. Suppression of Rhizoctonia root rot in response to seed meal amendment required the activity of the resident soil microbiota and was associated with elevated populations of Streptomyces spp. recovered from the apple rhizosphere. Application of individual Streptomyces spp. to soil systems provided control of R. solani to a level and in a manner equivalent to that obtained with the seed meal amendment. These and other examples suggest that management of resident plant-beneficial rhizobacteria may be a viable method for control of specific soilborne plant pathogens.     

Influence of Rhizoctonia solani on Egg Hatching and Infectivity of Rotylenchulus reniformis

The effects of culture filtrates of Rhizoctonia solani and root exudates of R. solani-infected cotton (Gossypium hirsutum) seedlings on hatching of eggs and infectivity of females of Rotylenchulus reniformis were evaluated in an attempt to account for the enhanced nematode reproduction observed in the presence of this fungus. Crude filtrates of R. solani cultures growing over sterile, deionized distilled water did not affect egg hatching. Exudates from roots of cotton seedlings increased hatching of R. reniformis eggs over that observed in water controls. Exudates from cotton seedling roots not infected or infected with R. solani did not differ in their effect on egg hatching. However, infection of cotton seedlings by reniform females was increased in the presence of R. solani, resulting in the augmented egg production and juvenile population densities in soil observed in greenhouse studies.     

Suppression of the root rot–root knot disease complex by Pseudomonas aeruginosa in tomato: The influence of inoculum density,nematode populations,moisture and other plant-associated bacteria

The influence of different application rates of the plant growth-promoting rhizobacterium, Pseudomonas aeruginosa, population densities of the root-knot nematode, Meloidogyne javanica, moisture and other plant-associated bacteria in the suppression of root rot–root knot disease complex of tomato are described. The impact of these factors on bacterial rhizosphere and inner root and shoot establishment are also presented. The highest inoculum level of P. aeruginosa (7.4 × 10⁸ cfu ml^–1) in the presence of the lowest population density of M. javanica (500 J2/plant) caused the greatest reduction in gall formation due to M. javanica. The number of root–knot nematodes recovered from soil and roots treated with P. aeruginosa were also significantly reduced. Root infection caused by the soilborne root-infecting fungi Fusarium oxysporum, F. solani and Rhizoctonia solani was also effectively suppressed following application of P. aeruginosa. A P. aeruginosa-Bacillus subtilis treatment was the most effective in the suppression of root-rot disease complex with enhancement of plant growth. Biocontrol and growth promoting potential of the bacterium was enhanced when soil was kept at 50% or 75% moisture holding capacity, whereas a 25% MHC reduced bacterial efficacy. Rhizosphere population of P. aeruginosa declined drastically in P. aeruginosa-Bradyrhizobium japonicum treatments. Rhizosphere colonisation by P. aeruginosa seems to be governed by two factors: Initial inoculum size of the bacterium and severity of the root-knot disease. Endoroot and endoshoot colonisation of the bacterium was dependent on degree of root-colonisation by Fusarium oxysporum. An inoculum level 2.5 × 10⁸ cfu/ml of P. aeruginosa was optimal for the enhancement of plant growth, whereas inoculum below this level reduced plant growth.     

Pseudomonas induces salinity tolerance in cotton (Gossypium hirsutum) and resistance to Fusarium root rot through the modulation of indole-3-acetic acid

Abiotic stresses cause changes in the balance of phytohormones in plants and result in inhibited root growth and an increase in the susceptibility of plants to root rot disease. The aim of this work was to ascertain whether microbial indole-3-acetic acid (IAA) plays a role in the regulation of root growth and microbially mediated control of root rot of cotton caused by Fusarium solani. Seed germination and seedling growth were improved by both NaCl and Mg₂SO₄ (100 mM) solutions when treated with root-associated bacterial strains Pseudomonas putida R4 and Pseudomonas chlororaphis R5, which are able to produce IAA. These bacterial strains were also able to reduce the infection rate of cotton root rot (from 70 to 39%) caused by F. solani under gnotobiotic conditions. The application of a low concentration of IAA (0.01 and 0.001 μg/ml) stimulated plant growth and reduced disease incidence caused by F. solani (from 70 to 41–56%, respectively). Shoot and root growth and dry matter increased significantly and disease incidence was reduced by bacterial inoculants in natural saline soil. These results suggest that bacterial IAA plays a major role in salt stress tolerance and may be involved in induced resistance against root rot disease of cotton.     

Suppression of Root Rotting Fungi and Root Knot Nematode of Chili by Seaweed and Pseudomonas aeruginosa

Solvent fractions (i.e. n -hexane, chloroform and methanol) of the ethanol extracts of the seaweeds Codium iyengarii , Jania capillacea , Stokeyia indica and Solieria robusta caused more than 50% mortality of Meloidogyne javanica juveniles within 24 h at 10 mg/ml. Nematode mortality increased with an increase in fraction concentration or exposure time. The n -hexane fractions from S. indica , J . capillacea and C . iyengarii and the chloroform fraction from S . robusta also resulted in more than 50% mortality within 48 h at 1.0 mg/ml. In a screen-house experiment application of S . indica and S . robusta as soil amendments alone or with Pseudomonas aeruginosa , a plant growth promoting rhizobacterium (PGPR), significantly suppressed infection of chili roots by root-infecting fungi Macrophomina phaseolina , Rhizoctonia solani , Fusarium solani and the root knot nematode Meloidogyne javanica . Seaweed alone or with PGPR also increased plant growth. Suppressive effect on root pathogens and growth enhancement potential of seaweeds and P . aeruginosa were also effective in field plots.     

Systemic Resistance in Tomato Induced by Biocontrol Bacteria Against the Root-Knot Nematode, Meloidogyne javanica is Independent of Salicylic Acid Production

Salicylic acid (SA)‐mediated induction of systemic resistance by Pseudomonas aeruginosa strain 7NSK2 and P. fluorescens strain CHA0 against soil‐borne fungi and viruses have been reported. The role of SA biosynthesis in the enhancement of defence mechanism against plant‐parasitic nematodes by these bacterial strains in tomato is not known. To better understand the importance of SA in rhizobacteria‐mediated suppression of root‐knot nematodes, biocontrol potential of SA‐negative or SA‐overproducing mutants against Meloidogyne javanica was evaluated with their respective wild type counter parts. Culture supernatant of 7NSK2, CHA0 and their respective mutants caused significant mortality of M. javanica juveniles in vitro. SA deletion in 7NSK2 and SA overproduction in CHA0 did not influence bacterial efficacy to cause nematode deaths. Similarly, culture supernatants resulting from King's B liquid medium amended with FeCl₃ did not influence nematicidal activity of the bacterial strains. Strain CHA0 induced juvenile deaths more than 7NSK2 did. In pot experiments, the bacterial strains applied in unsterilized sandy loam soil markedly reduced final nematode population densities in roots and subsequent root‐knot infection in tomato seedlings. SA‐negative or overproducing derivatives prevented tomato roots in kinetics similar to those with their respective wild types. When soil iron concentration was lowered by the addition of ethylenediamine di(o‐hydroxyphenylacetic acid), nematode biocontrol by the bacterial strains (both wild type and mutants) remained unaltered. To understand the mechanism involved in rhizobacteria‐mediated suppression of root‐knot nematode in tomato, bacterial performance was assessed in a split root trial in which one‐half of the root system was treated with bacterium while the other inoculated with nematode. Compared with the controls, application of the bacterial cell suspension to one‐half of the root system lowered the populations of root‐knot nematode in non‐bacterized nematode‐treated sections indicating enhanced defence in the non‐bacterized half. With respect to nematode infection, mutants induced systemic resistance to a similar extent as that caused by the wild types in both wild type tomato and NahG tomato plants. It is concluded that fluorescent pseudomonads induce systemic resistance against root‐knot nematode via a signal transduction pathway, which is independent of SA accumulation in roots.     

Interactions Between Rhizoctonia Root Rot and the Foliar Common Bean Diseases Anthracnose and Rust

The effects of co‐inoculation of Rhizoctonia solani and Colletotrichum lindemuthianum or Uromyces appendiculatus at different inoculum levels were studied on the disease dynamics and on the growth of bean plants under greenhouse conditions. Bean seeds were sown in R. solani‐infested soil. Additional experiments in which seedlings were transplanted to infested soil were also carried out. Conidial suspensions of C. lindemuthianum or uredospores of U. appendiculatus were inoculated onto leaves at plant developmental stages V2 and V3, respectively. Interactions between root rot and the aerial diseases were observed depending on the inoculum levels and on the timing of R. solani inoculation. Anthracnose severity tended to be higher on R. solani‐infected plants. Conversely, R. solani infection significantly reduced diameter of pustules and rust severity. When seedlings were transplanted to soil infested with low levels of R. solani, root rot severity and density of R. solani in the soil were magnified at high levels of C. lindemuthianum or U. appendiculatus. In these experiments, a synergistic interaction between root rot and anthracnose was observed to affect the plant dry weight. Antagonistic effects on the plant dry weight were found for the combination root rot/rust only when seeds were sown in infested soil.     

Pathogenicity and life cycle of Meloidogyne javanica on broccoli

A pathogenicity trial conducted against root-knot nematode, Meloidogyne javanica on broccoli indicated that a gradual increase in the nematode inoculum from 500 to 8000 juveniles/kg soil was associated with a progressive decline in all the plant growth parameters and reproduction factor of the nematode. Although 8000 juveniles/kg soil showed maximum plant growth reduction and root knot index, statistical analysis of the data revealed that the population of 1000 juveniles/kg soil was associated with a significant decline in plant growth. Hence, this level was indicative of being the pathogenic level. The significant reduction in seedling emergence was recorded at and above 2000 juveniles/kg soil and it decreased further with increasing inoculum levels. Meloidogyne javanica required 27 days to complete the life cycle on broccoli at a temperature range of 28–35°C.     

Eggs of Tylenchulus semipenetrans Inhibit Growth of Phytophthora nicotianae and Fusarium solani in vitro

In previous greenhouse and laboratory studies, citrus seedlings infested with the citrus nematode Tylenchulus semipenetrans and later inoculated with the fungus Phylophthora nicotianae grew larger and contained less fungal protein in root tissues than plants infected by only the fungus, demonstrating antagonism of the nematode to the fungus. In this study, we determined whether eggs of the citrus nematode T. semipenetrans and root-knot nematode Meloidogyne arenaria affected mycelial growth of P. nicotianae and Fusarium solani in vitro. Approximately 35,000 live or heat-killed (60°C, 10 minutes) eggs of each nematode species were surface-sterilized with cupric sulfate, mercuric chloride, and streptomycin sulfate and placed in 5-pl drops onto the center of nutrient agar plates. Nutrient agar plugs from actively growing colonies of P. nicotianae or F. solani were placed on top of the eggs for 48 hours after which fungal colony growth was determined. Live citrus nematode eggs suppressed mycelial growth of P. nicotianae and F. solani (P ≤ 0.05) compared to heat-killed eggs and water controls. Reaction of the fungi to heat-killed eggs was variable. Root-knot nematode eggs had no effect on either P. nicotianae or F. solani mycelial growth. The experiment demonstrated a species-specific, direct effect of the eggs of the citrus nematode on P, nicotianae and F. solani.     

Effects of Meloidogyne spp. and Rhizoctonia solani on the Growth of Grapevine Rootings

A disease complex involving Meloidogyne incognita and Rhizoctonia solani was associated with stunting of grapevines in a field nursery. Nematode reproduction was occurring on both susceptible and resistant cultivars, and pot experiments were conducted to determine the virulence of this M. incognita population, and of M. javanica and M. hapla populations, to V. vinifera cv. Colombard (susceptible) and to V. champinii cv. Ramsey (regarded locally as highly resistant). The virulence of R. solani isolates obtained from roots of diseased grapevines also was determined both alone and in combination with M. incognita. Ramsey was susceptible to M. incognita (reproduction ratio 9.8 to 18.4 in a shadehouse and heated glasshouse, respectively) but was resistant to M. javanica and M. hapla. Colombard was susceptible to M. incognita (reproduction ratio 24.3 and 41.3, respectively) and M. javanica. Shoot growth was suppressed (by 35%) by M. incognita and, to a lesser extent, by M. hapla. Colombard roots were more severely galled than Ramsey roots by all three species, and nematode reproduction was higher on Colombard. Isolates of R. solani assigned to putative anastomosis groups 2-1 and 4, and an unidentified isolate, colonized and induced rotting of grapevine roots. Ramsey was more susceptible to root rotting than Colombard. Shoot growth was inhibited by up to 15% by several AG 4 isolates and by 20% by the AG 2-1 isolate. AG 4 isolates varied in their virulence. Root rotting was higher when grapevines were inoculated with both M. incognita and R. solani and was highest when nematode inoculation preceded the fungus. Shoot weights were lower when vines were inoculated with the nematode 13 days before the fungus compared with inoculation with both the nematode and the fungus on the same day. It was concluded that both the M. incognita population and some R. solani isolates were virulent against both Colombard and Ramsey, and that measures to prevent spread in nursery stock were therefore important.     

Biological Control of Soil Pests by Mixed Application of Entomopathogenic and Fungivorous Nematodes

In greenhouse experiments, massive application of the fungivorous nematode, Aphelenchus avenae, in summer at 26-33 C (1 x l0⁵ nematodes/500 cm³ autoclaved soil) or in autumn at 18-23 C (5 x 10⁴ nematodes/500 cm³ autoclaved soil) suppressed pre-emergence damping-off of cucumber seedlings due to Rhizoctonia solani AG-4 by 67% or 87%, respectively. Application of 2 x l0⁵ A. avenae to sterilized soil infested with R. solani caused leafminer-like symptom on the cotyledons, which did not occur in mixed inoculations with the entomopathogenic nematode, Steinernema carpocapsae. When 1 x 10⁶ A. avenae were applied 3 days before inoculation with 100 Meloidogyne incognita juveniles, gall numbers on tomato roots were reduced to 50% of controls. Gall numbers also were suppressed by S. carpocapsae (str. All). Reduction in gall numbers was no greater with mixed application of A. avenae and S. carpocapsae than with application of single species, even though twice the number of nematodes were added in the former case. These nematodes were positively attracted to tomato root tips. Aphelenchus avenae suppressed infection of the turnip moth, Agrotis segetum, but not the common cutworm, Spodoptera litura, by S. carpocapsae.     

Effects of Soil Texture on the Interaction Between Rhizoctonia solani and Meloidogyne incognita on Cotton Seedlings

Soils containing 60, 75, and 90% coarse particles (sand plus coarse silt) were prepared by dilution of a field soil with 246μm (60-mesh) silica sand. As the coarse-particle content of the soils increased, the synergistic interaction between Meloidogyne incognita and Rhizoctonia solani on cotton seedlings increased. Increasing the coarse-particle content of the soil also increased damage from the nematode alone and slightly increased soreshin damage from R. solani alone.     

Identification and evaluation of a potential biocontrol agent,Bacillus subtilis,against Fusarium sp. in apple seedlings

To find a potential biocontrol agent against Fusarium sp. in apple seedlings, an endophytic bacterium strain was isolated from apple tree tissues. The inhibitive efficiency of the isolated strain against the hyphal growth of Fusarium sp. and Rhizoctonia solani was tested. Strain Y-1 showed significant inhibitory effects against Fusarium oxysporum, F. moniliforme, F. proliferatum, F. solani and R. solani. Its antifungal activity against F. oxysporum was the highest, reaching up to 64.90 %. In vivo tests indicated that strain Y-1 effectively protects apple from F. oxysporum infections. The control effect reached 92.26 % when bacterial inoculation was performed 3 days prior to pathogen inoculation. Strain Y-1 could colonize the rhizosphere and tissues within 30 days. It was also able to induce systemic resistance in apple seedlings as shown by the activities of SOD and POD. Strain Y-1 significantly increased the root length, root wet and dry weights, and plant height of the apple seedlings compared with the control group. The homology analysis of the 16S rRNA sequence, together with morphological, physical, and biochemical analyses, revealed that strain Y-1 is Bacillus subtilis.     

Fungal endophytes of turmeric (<Emphasis Type="Italic">Curcuma longa</Emphasis> L.) and their biocontrol potential against pathogens <Emphasis Type="Italic">Pythium aphanidermatum</Emphasis> and <Emphasis Type="Italic">Rhizoctonia solani</Emphasis>

Endophytic fungi have been isolated from the healthy turmeric (Curcuma longa L.) rhizomes from South India. Thirty-one endophytes were identified based on morphological and ITS–rDNA sequence analysis. The isolated endophytes were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric respectively. Results revealed that only six endophytes showed >?70% suppression of test pathogens in antagonistic dual culture assays. The endophyte T. harzianum TharDOB-31 showed significant in vitro mycelial growth inhibition of P. aphanidermatum (76.0%) and R. solani (76.9%) when tested by dual culture method. The SEM studies of interaction zone showed morphological abnormalities like parasitism, shriveling, breakage and lysis of hyphae of the pathogens by endophyte TharDOB-31. Selected endophytic isolates recorded multiple plant growth promoting traits in in vitro studies. The rhizome bacterization followed by soil application of endophyte TharDOB-31 showed lowest Percent Disease Incidence of rhizome rot and leaf blight, 13.8 and 11.6% respectively. The treatment of TharDOB-31 exhibited significant increase in plant height (85 cm) and fresh rhizome yield/plant (425 g) in comparison with untreated control under greenhouse condition. The confocal microscopy validates the colonization of the TharDOB-31 in turmeric rhizomes. The secondary metabolites in ethyl acetate extract of TharDOB-31 were found to contain higher number of antifungal compounds by high resolution liquid chromatograph mass spectrometer analysis. Thereby, endophyte T. harzianum isolate can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.