Root Rot Disease Incidence Research Articles

EFFECT OF SOWING DATES AND PHOSPHORUS FERTILIZER ON ROOT ROT AND QUALITY OF SOME SUGAR BEET VARIETIES

The present investigation was carried out at the experimental farm of Malawi Agricultural Research Station, El-Minia Governorate, Egypt during 2009/2010 and 2010/2011 seasons to investigate the effect of sowing dates (15th October, 30th October and 15th November) and phosphorus fertilizer (0, 15 and 30) kg P2O5 /fed on root rot disease incidence, yield and its quality of three sugar beet varieties i.e. Farida, Kawemira and Montibianco. A split-split plot design with three replications was used, sowing dates were allocated in the main plots, phosphorus fertilizer was assigned in the sub plots while, sugar beet varieties were distributed in the sub- sub plots. The results revealed that sowing date15th October significantly reduced root rot disease incidence and increased all quality parameters, i.e. sucrose ,sex, Na, K, alpha amino N,SLM and extractability percentages except purity % as well as productivity traits (top and root yields ) in the two growing seasons. The above varieties of sugar beet significantly differed in all studies traits in the two growing seasons. Phosphorus fertilizer significantly effected on all studies traits in both seasons, except sugar yield and (root yield and root fresh weight ) in the first season only. Planting Kawemira sugar beet variety when received 30 kg P2O5 / fed in 15th October significantly increased yields of root and top (ton/fed) in the second season.

Effects of different irrigation methods on pepper yield and soilborne diseases incidence

In this study, the effect of different irrigation strategies and irrigation methods on yields and the incidence of wilt (Fusarium oxysporum) and root rot (Fusarium solani and Macrophomina phaseolina) diseases causing significant yield losses on field grown processing red pepper is determined. Experiments were carried out at Topcu Station of the Soil and Water Resources Research Institute of Tarsus in 2010 and 2011. Karaisali processing pepper (Capsicum annuum L.) was used in the experiments. Three furrows and five drip irrigation treatments were used in the study. The disease incidence rates were found 8.0-18.2% in furrow irrigation plots and 4.5-10.0% in drip irrigation plots in 2010, while it was 3.4-9.7% in furrow irrigation plots and 2.2-4.5% in drip irrigation plots in 2011. Pepper yields ranged from 3 416 to 4 417 kg da-1 and 3 376 to 4 779 kg da-1 in drip irrigated plots in 2010 and 2011, respectively. However, yields varied between 3 172-3 559 kg da-1 and 2 932-4 150 kg da-1 in furrow irrigated plots in 2010 and 2011 growing seasons.

Field application of bio-control agents for controlling fungal root rot and root-knot nematode in potato

Six bio-control agents (BCAs) named Stanes sting® [Bacillus subtilis at 109 bacterial cells/ml], Bio-Nematon® [Paecilomyces lilacinus at 108 unit/cm3], Trichoderma hamatum, Trichoderma album, Stanes symbion vam plus® (Glomus fasciculatum and Gigaspora sp.) and Rhizo-N® [B. subtilis, 25 million bacterial cells/g] were applied in commercial potato field for controlling for root-rot disease caused by Fusarium solani and Rhizoctonia solani and nematode root-knot caused by Meloidogyne arenaria, compared to chemical nematicide of Nemacur (fenamiphos) [3-methyl-4-(methylthio) phenyl (1-methylethyl) phosphoramidate]. The BCAs highly increased the frequency of Aspergillus spp., followed by A. niger, compared to Penicillium spp., and Trichoderma spp., compared to the control. The BCAs significantly reduced the frequency of F. solani and R. solani, as well as the percentages of disease incidence of root rot in the rhizospheres of treated potato plants, compared to Nemacur® as well as the untreated plants. After two months of treatment, reduction of number of juveniles (J2) caused by BCAs in soil was in the range of 33.1–76.9%, compared to 16.9% with Nemacur®. After four months of treatment, the percentages of reduction of the total juveniles in soil and roots was in the range of 1.1–86.1%, compared to 24.5% with Nemacur®. Effect of BCAs on averages of plant height, number stems/pit and leaves per plant were determined after two months of planting, while their effect on yield parameters such as the average of tubers weight/pit, number of tubers per pit and average of tuber weight were determined at harvest.

Ecological management of tropical sugar beet (TSB) root rot (Sclerotium rolfsii (Sacc.) by rhizosphere Trichoderma species

Trichoderma species are collected from different location of sugarbeet growing areas of Tamil Nadu and it is effective against Sclerotium rolfsii pathogen caused by sugarbeet ecosystems. Out of thirty-one isolates of Trichoderma viride and four isolates of Trichoderma harzianum collected and tested for their antagonistic activity against S. rolfsii by dual culture technique, one isolate was found to be effective T. viride (TVB1) that recorded the maximum (73.03%) inhibition on the mycelial growth recording only 2.40 cm growth as against 8.90 cm in the control. The isolates of T. harzianum THB-1 recorded 71.19% mycelial growth reduction over control. The colonisation behaviour of T. viride (TVB1) revealed that it completely over grew on pathogen within 48 h after interaction with the pathogen, and speed of growth on pathogen was also high and it possesses a higher level of competitive saprophytic ability. The best four isolates of TVB1, TVB-2, TVB-3 and TVB31 and two isolates of T. harzianum THB-1 and THB-2 were compared with other species of Trichoderma longibrachiatum, Trichoderma reesei, Trichoderma koningii and Chaetomium globosum and tested under in vitro condition. BA of neem cake at 150 kg ha−1 + T. viride isolate (TVB1) at 2.5 kg/ha recorded least root rot disease incidence of 17.05% which accounted for 75.37% disease reduction over control and highest recorded maximum root yield 65.73 t ha−1 and increasing sugar content.

Formulations of Bacillus Spp. and Pseudomonas Fluorescens for Biocontrol of Cantaloupe Root Rot Caused by Fusarium Solani

Abstract The aim of this study was to evaluate the different carrier formulations of antagonistic bacteria on incidence of root rot disease of cantaloupe. Twenty-seven isolates of bacteria isolated from rizosphere cantaloupe plants (collected from different localities of the Assiut Governorate, Egypt) were tested in vitro against the growth of Fusarium solani. The tested isolates exhibited varied percentages of mycelial inhibition of F. solani. The highly antagonistic bacteria isolates were identified as Bacillus subtilis, Bacillus cereus, and Pseudomonas fluorescens. The effect of talc based powder and wood flour as various carrier formulations of antagonistic bacteria were tested on incidence of cantaloupe root rot disease in greenhouse and field experiments. All tested carrier formulations of antagonistic bacteria significantly decreased the disease index percentage (p > 0.05) of root rot disease compared with the control, in greenhouse or in field experiments. Application of the wood flour formulation to the infested soil at the time of planting, gave the lowest disease (21.75%) index percentage compared to an application fifteen days before planting (26.83%). The reverse effect occurred in the case of the talc based powder formulation application. In field experiments, during the two growing seasons of 2009 and 2010, wood flour formulation gave the same effect in the reduction of the disease index when added before planting or at the time of planting to soil infested with the pathogen. However, application of the talc formulation at the time of planting showed the least disease index compared to when it was applied fifteen days before planting. In general, wood flour formulation significantly decreased the disease index when compared with the talc formulation. In all the formulations, a number of viable colonies of bioagents were decreased gradually by prolonging the storage time at 4°C. Storage time was prolonged up to five months. But in the case of B. subtilis on talc and B. cereus on wood flour formulations, storage time needed to be prolonged up to seven months

Induction of Resistance in Tomato Plants against Fusarium Crown and Root Rot Disease by Trichoderma harzianum and Chitosan

Phenolic compounds in addition to activity of polyphenol oxidase (PPO) and peroxidase (POD) were significantly increased in tomato plants in response to Fusarium oxysporum f.sp. radicislycopersici (FORL) infection, whereas chitinase and β-1,3 glucanase activities were significantly inhibited when compared with the healthy plant. Trichoderma harzianum and chitosan reflected many components of defence signals which leading to the activation of power defence system in tomato against pathogen attack. The reduction in disease incidence and severity was accompanied with remarkable increases in phenolic content and activity of polyphenol oxidase, peroxidase and glucanase in infected plant treated with T. harzianum and chitosan. On the other hand, chitinase activity showed insignificant increase under the application of T. harzianum and chitosan when compared with the infected untreated control. T. harzianum and chitosan treatment as root dipping in combination with chitosan foliar spray was the most effective treatment against Fusarium crown and root rot disease (FCRR) incidence and severity, through induction of physiological host defence mechanisms. Induction of systemic resistance against FORL is one of the main mechanisms by which T. harzianum and chitosan contribute to tomato plants protection.

Effects of manure composts on soil biota and root-rot disease incidence of ginseng (Panax ginseng)

Some saprophytic fungi are pathogenic to ginseng, and input of organic materials may influence these pathogens. The objective of this study was to investigate the application effects of manure composts on soil-borne pathogenic fungi and the responses of soil organisms in relation to root rot disease. Manure composts from 3 different organisms, namely, chicken, cow, and pig, were applied at 20Mgha−1. We compared these effects between paddy-converted fields and upland fields. Despite the input of manure composts, the root yield did not increase because of root loss and growth disorder caused by root rot disease. We isolated Cylindrocarpon destructans and Fusarium solani from the diseased roots, which suggested that these 2 fungi were the main causal pathogens. Hyphal growth of the 2 fungi increased in soils of both fields treated with manure composts, but the promoting effect was high in paddy-converted fields. These findings suggest that the application of manure composts may accelerate root rot disease by promoting pathogenic fungi. Microflora was estimated by analysing phospholipid fatty acids, and non-metric multidimensional scaling analysis showed that the responses of microflora were different between the two fields. Aerobic bacterial PLFAs were greatly increased in the upland field, which indicated that influences of manure compost might differ according to soil type. Fungal PLFAs showed correlations with fungivorous nematodes but not with abundance of Collembola and Oribatida. It seemed that the suppressive effect of fungivorous fauna promoted by manure compost is minor and restricted to some organisms. Our study suggests that increased substrates in the soil might promote the growth of C. destructans and F. solani, and suppression of these pathogenic fungi is required in relation to the application of manure composts.

Effect of mycorrhiza and biofertilisers on reducing the incidence of Fusarium root and pod rot diseases of peanut

Pathogenicity tests of twenty-six fungal isolates were tested on peanut plants (Giza 5 cv.) and the results revealed that, Fusarium oxysporum isolate (No. I) followed by F. solani (No. II) then F. moniliforme (No III) significantly caused highest incidence of root rot disease. Also, F. moniliforme (No III) followed by F. solani (No II) then F. oxysporum (No I) gave the highest incidence of pod rot disease. The effectiveness of vescular arbuscular-mycorrhiza (VAM) at different application rates on the incidence of root rot, pod rot diseases and plant growth parameters of peanut was studied. All soil treatments with each rate of VAM significantly reduced root and pod rot diseases compared with control (rate 0%). The best reduction in the severity of both diseases with VAM was found at the rate of 3%. Application of rhizobacterin, microbin and cerialin biofertilisers at the different concentrations decreased the severity of both root rot and pod rot severity diseases compared with non-treated seeds. The greatest reduction in both diseases was achieved at a concentration of 8/100 g seeds. The highest number of pods and fresh weight (g) was achieved in seed supplemented with each biofertiliser at concentration of 8/100 g seed.

EFFCT OF CERTAIN MICROELEMENTS AND SOWING DATE ON INCIDENCE OF SAFFLOWER ROOT ROT AND WILT DISEASES

EFFCT OF CERTAIN MICROELEMENTS AND SOWING DATE ON INCIDENCE OF SAFFLOWER ROOT ROT AND WILT DISEASES

THE PREVENTIVE CONTROL OF WHITE ROOT ROT DISEASE IN SMALL HOLDER RUBBER PLANTATION USING BOTANICAL, BIOLOGICAL AND CHEMICAL AGENTS

The preventive control of white root rot disease in small holder plantation using botanical, biological, and chemical agents. A field and laboratory experiment were conducted from June 2008 to December 2009 in Panumangan, Tulang Bawang - Lampung. The field experiment was intended to evaluate the effect of botanical plants (Alpinia galanga, Sansiviera auranthii, and Marantha arundinacea), biological agents (organic matter and Trichoderma spp.), and chemical agents (lime and natural sulphur) on the incidence of white root rot disease and population of some soil microbes. The laboratory experiment was conducted to observe the mechanism of botanical agents in controlling white root rot disease. In the field experiment, the treatments were applied in the experimental plot with cassava plant infection as the indicator. The variables examined were the incidence of white root rot and population of soil microbes. In the laboratory experiment, culture of R. microporus was grown in PDA containing root exudate of the antagonistic plant (botanical agent). The variable examined was colony diameter of R. microporus growing in the PDA plates. The results of the field experiment showed that planting of the botanical agents, and application of Trichoderma spp., as well as natural sulphur, decreased the incidence of white root rot disease. The effectiveness of M. arundinacea and Trichoderma spp. was comparable to natural sulphur. The laboratory experiment showed only root exudate of A. galanga and S. auranthii that were significantly inhibit the growth of R. microporus.

Occurrence and Distribution of Chickpea Diseases in Central and Southern Parts of India

A survey was conducted in 2010-2011 rabi cropping season to obtain information on the distribution and incidence of chickpea diseases in respect to soil type, cultivar used, seed treatment in central and southern parts of India. Local cultivars predominated in most farmers’ fields (25% - 48%). 63% of the farmers were practices seed treatment with fungicide. Dry root rot and collar rot diseases were found at all of the sites and incidence ranged from 8.9% - 10.3% and 7.1% - 10.5% respectively irrespective of cultivar type and locations. Incidence of wilt and black root rot disease ranged from 9.7% - 13.8% and 6.6% - 7.4% respectively. Black root rot disease was found in Andhra Pradesh and Karnataka states only. The result indicated that dry root rot and collar rot is currently highly distributed in all surveyed chickpea growing areas of central and southern parts of India. Therefore, possible management options are vital to alleviate the problem.

Bioagents and Commercial Algae Products as Integrated Biocide Treatments for Controlling Root Rot Diseases of Some Vegetables under Protected Cultivation System

Integrated commercial blue-green algae extracts and bioagents treatments against vegetables root rot incidence when used as soil drench under greenhouse and plastic house conditions were evaluated. All applied treatments reduced significantly root rot incidence at both pre- and postemergence growth stages of cucumber, cantaloupe, tomato, and pepper plants compared with untreated check control. In pot experiment, the obtained results showed that treatments ofTrichoderma harzianumorBacillus subtiliseither alone or combined with commercial algae extracts were significantly superior for reducing root rot disease for two tested vegetable plants compared with the other tested treatments as well as control. It is also observed that rising concentrations of either algae products, Oligo-X or Weed-Max, were reflected in more disease reduction. Promising treatments for controlling root rot disease incidence were applied under plastic houses conditions. As for field trails carried out under plastic houses conditions at different locations, the obtained results revealed that the applied combined treatments significantly reduced root rot incidence compared with fungicide and check control treatments. At all locations it was observed that Weed-Max (2 g/L) +Bacillus subtilissignificantly reduced disease incidence of grown vegetables compared with Oligo-X (2 mL/L) +Trichoderma harzianumtreatments. An obvious yield increase in all treatments was significantly higher than in the control. Also, the harvested yield in applied combined treatments at all locations was significantly higher than that in the fungicide and control treatments.

English

The incidence of root rot diseases partly contribute to the currently observed low percentage increase in the yield of cassava. We estimated gene diversities and identified putative hybridizing parents for root rot resistance using 18 simple sequence repeats loci in 43 improved genotypes of cassava. Root rot was measured over 2 years as the percentage proportion of rotten roots to the total number of roots harvested at 12 month after planting. Estimated rot ranged from 1.2 to 21.2% with a mean of 5.7±0.5. Rank-sum analysis generated 8 rot classes and identified TMS 96/1089A as best genotype resistant to root rot. Gene diversity analysis revealed expected heterozygosity that ranged from 0.701 for very highly susceptible genotypes to 0.781 for moderately resistant and susceptible. Genetic differentiation ranged from -0.0178 (resistant and susceptible) to 0.0523 (very highly resistant and highly resistant genotypes). A total heterozygosity of 0.764 was estimated and was largely due to within class diversity (0.755). DNA analysis representatives for window (DARwin) identified 10 hybridizing groups with a dissimilarity coefficient that ranged from 0.18 to 0.81 on a mean of 0.60. The results obtained from the present study are useful for the genetic improvement of cassava against root rot disease. Key words: Cassava genotypes, gene diversity, heterozygosity, resistant genotypes, root rot disease.

Economic Performance of Ginger (Zingiber officinale Rose.) Cultivation in Some Selected Locations of Bangladesh

The study was conducted in two ginger growing districts, namely Nilphamari and Khagrachari of Bangladesh during the period of 2009-10 to estimate the technical efficiency of ginger growers. The study revealed that ginger production was profitable and the average benefit cost ratio (BCR) was found 2.17. The estimated results showed that the average level of technical efficiency among the sample farmers was 85. This implies that given the existing technology and level of inputs, the output could be increased by 15 percent. In inefficiency model, the coefficient of farmer’s education and experience in ginger cultivation was negative and significant. Sixty eight percent farmers produced outputs to the maximum frontier output level (81-95%). Farmers in the study area also mentioned some problems like incidence of root rot disease, high price of seed, insect infestation etc to its production. DOI: http://dx.doi.org/10.3329/bjar.v37i1.11182 Bangladesh J. Agril. Res. 37(1): 109-120, March 2012

Effectiveness of Rhizosphere Bacteria for Control of Root Rot Disease and Improving Plant Growth of Wheat (<i>Triticum </i><i>a</i><i>estivum</i> L)

Pathogenic fungus Rhizoctonia solani causes root rot disease in wheat leading to collapsing of the aerial part of the plant. To characterize antagonistic bacteria, one hundred and thirty bacterial isolates were obtained from the rhizosphere soil of wheat and these rhizobacterial isolates alongwith 72 reference strains were screened for their antagonistic interactions against R. solani under cultural conditions. Sixteen bacterial isolates inhibited the growth of R. solani and growth inhibition zone varied from 6-15 mm by different rhizobacterial isolates. Two isolates WPS3 and WPS90 caused maximum growth inhibition of the fungi. Growth inhibiton of the pathogenic fungi was also observed using culture filterates of antagonistic rhizobacterial isolates. The protein estimation of the culture filterates showed that the amount of protein excreted by different rhizobacterial isolates varied from 3.6 to 33.0 mg ml -1 of the supernatant. The loss of antagonistic activity after treatment with proteinase K and high temperature treatment indicated that excreted proteins are responsible for the antagonism. Pot house studies showed that inoculation of R. solani in wheat caused 85-90% root rot disease incidence at 60 to 90 days of plant growth. The single inoculation of rhizobacterial isolate WPS3 resulted in 131% increase of plant dry weight as compared to uninoculated control plants. The coinoculation of isolate WPS3 with R. solani enhanced 115% plant dry weight whereas coinoculation of Pseudomonas isolate WPS90 caused 98% increase in plant dry weight in comparison to control uninoculated plants at 90 days of plant growth. Coinoculation of Pseudomonas isolates WPS3 and WPS90 with R. solani also caused 88.9 and 66.7% disease control, respectively at 90 days of plant growth. Thus, Pseudomonas isolate WPS3 could be further ex- ploited for plant growth improvement under field conditions.

Evaluation of vermicompost doses for management of root-rot disease complex in Coleus forskohlii under organic field conditions

Organic field experiments were conducted (2007–09) for the medicinal plant Coleus forskohlii with different doses of vermicompost to minimize the root-rot disease incidence and increase the growth and yield. The use of vermicompost significantly increased the growth parameters in general but the maximum plant height, plant spread and number of branches increased with the application of 5 t ha−1 of vermicompost. Root-rot/wilt, a complex disease of C. forskohlii involving Fusarium chlamydosporum and Ralstonia solanacearum, was significantly (P < 0.05) reduced in terms of percent wilt incidence (PWI) and severity of root-rot as measured by percent disease index (PDI) with different doses of vermicompost. The highest levels of biomass (root and shoot; 48 % and 71 %, respectively) and forskolin yield (46 %) and disease suppression (PWI and PDI; 73 % and 82 %, respectively) were found at the top level of vermicompost (5 t ha−1). Nutrient (NPK) uptake was significantly elevated in plots supplemented with vermicompost compared to control plots.

Influence of some biotic and abiotic inducers on root rot disease incidence of sweet basil

Influence of some biotic and abiotic inducers on root rot disease incidence of sweet basil

Soil Suppressiveness to Fusarium Disease Following Organic Amendments and Solarization.

Soil suppressiveness to soilborne pathogens can evolve following the incorporation of plant residues in the soil and solarization. We studied its occurrence by assessing disease incidence and severity in sandy soil which was infested after the disinfestation treatment. Disease incidence and severity of crown and root rot in cucumber plants inoculated with Fusarium oxysporum f. sp. radicis-cucumerinum macroconidia were reduced by 20 to 80% when seedlings were planted in the tested soils 2 to 34 months after soil amendment. Residues of Diplotaxis tenuifolia (wild rocket [WR]), Artemisia dracunculus (tarragon), Salvia officinalis (sage), and Brassica oleracea var. italica (broccoli) were most effective for inducing soil suppressiveness. Effective soil suppressiveness continued to be evident after repeated inoculations and plantings in the same soil without additional treatment between inoculations. Moreover, residues of WR induced soil suppressiveness in two additional tested soils differing in their physical and chemical properties. Residues of Rosmarinus officinalis (rosemary), Coriandrum sativum (coriander), Mentha piperita (peppermint), and B. oleraceae var. botrytis (cauliflower) induced disease suppression at the first inoculated planting but not upon repeated inoculation and planting. The contribution of soil solarization to the evolution of soil suppressiveness, albeit evident, was inconsistent. Soil suppressiveness to Fusarium crown and root rot was also observed when cucumber seed were sown in soils which were initially amended with WR residues and later infested with F. oxysporum f. sp. radicis-cucumerinum chlamydospores. There is a potential for the use of plant residues for inducing soil suppressiveness and further contributing to the control of diseases caused by soilborne pathogens.

Combining Pseudomonas, Bacillus and Trichoderma strains with organic amendments and micronutrient to enhance suppression of collar and root rot disease in physic nut

The fungal and bacterial biocontrol agents were tested individually and in combinations with oil cakes, organic manures and micronutrients for their efficacy against collar and root rot pathogen, Lasiodiplodia theobromae under in vitro, glasshouse and field conditions. Among the fungal ( Trichoderma) and bacterial ( Pseudomonas and Bacillus) antagonists screened against L. theobromae under in vitro conditions, Trichoderma viride (Tv1), Pseudomonas fluorescens (Pf1) and Bacillus subtilis (Bs16) isolates exhibited maximum inhibition compared to other isolates. Among the oil cakes, organic manures and micronutrients tested in vitro against the pathogen, neem cake, farmyard manure (FYM) and zinc sulphate were most effective in reducing the growth of the pathogen. The compatibility studies revealed the isolate of T. viride (Tv1), P. fluorescens (Pf1) and B. subtilis (Bs16) were compatible with other and also with neem cake and zinc sulphate. Of the biocontrol agents tested individually as well as in mixtures with neem cake, FYM and zinc sulphate against L. theobromae, combination of Pf1 + Tv1 + Bs16 + neem cake + FYM + zinc sulphate showed maximum inhibition in mycelial growth of the pathogen. In glasshouse and field experiments also, the mixture of Pf1 + Tv1 + Bs16 + neem cake + FYM + zinc sulphate was found to be superior in reducing the collar and root rot disease incidence compared to other treatments.

Direct effect of biocontrol agents on wilt and root-rot diseases of sesame

In Egypt, sesame cultivation is subject to attack by wilt and root-rot diseases caused by Fusarium oxysporum f.sp. sesami (Zap) Cast. and Macrophomina phaseolina (Maubl) Ashby causing losses in quality and quantity of sesame seed yield. Bacillus subtilis and Trichoderma viride isolates which were isolated from sesame rhizosphere were the most effective to antagonise fungal pathogens, causing high reduction of hyphal fungal growth. Trichoderma viride was found to be mycoparasitic on Fusarium oxysporum f.sp. sesami and M. phaseolina causing morphological atternation of fungal cells and sclerotial formation. In general, Bacillus subtilis, T. viride, avirulent Fusarium oxysporum isolate and Glomus spp. (Amycorrhizae) significantly reduced wilt and root-rot incidence of sesame plants at artificially infested potted soil by each one or two pathogens. Data obtained indicate that Glomus spp significantly reduced wilt and disease severity development on sesame plants followed by T. viride. Meanwhile, avirulent Fusarium oxysporum isolate followed by Glomus spp. were effective against root-rot disease incidence caused by M. phaseolina. Glomus spp. followed by B. subtilis significantly reduced wilt and root-rot disease of sesame plants. All biotic agents significantly reduced F. oxysporum f.sp. sesami and M. phaseolina counts in sesame rhizosphere at the lowest level. Glomus spp. and the avirulent isolate of F. oxysporum eliminated M. phaseolina in sesame rhizosphere. Meanwhile T. viride was the best agent at reducing F. oxysporum at a lower level than other treatments. Application of VA mycorrhizae (Glomus spp.) in fields naturally infested by pathogens significantly reduced wilt and root-rot incidence and it significantly colonised sesame root systems and rhizospheres compared to untreated sesame transplantings.