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resolving tylenchid evolutionary relationships through multiple gene analysis derived from est data.sequence-based phylogenetic analyses typically are based on a small number of character sets and report gene trees which may not reflect the true species tree. we employed an est mining strategy to suppress such incongruencies, and recovered the most robust phylogeny for five species of plant-parasitic nematode (meloidogyne arenaria, m. chitwoodi, m. hapla, m. incognita, and m. javanica), three closely related tylenchid taxa (heterodera glycines, globodera pallida, and g. rostochiensis) and a di ...200515876542
isolation and characterization of another cdna encoding a chorismate mutase from the phytoparasitic nematode meloidogyne arenaria.a new cdna, named ma-cm-2, encoding a chorismate mutase (cm), has been isolated from meloidogyne arenaria. the full-length cdna, carrying the trans-spliced sl1 leader sequence, was 753-bp long with an open reading frame of 576 bp. the deduced protein ma-cm-2 including amino-terminal signal peptide shows significant similarity to cms of meloidogyne incognita, meloidogyne javanica, and also bacteria. secondary structure prediction of ma-cm-2 indicates the presence of the three conserved alpha-heli ...200616458297
observations on the suppression of root-knot nematode (meloidogyne arenaria) on tomato by incorporation of cyanobacterial powder (oscillatoria chlorina) into potting field soil.experiments were carried out to investigate the nematicidal potential of a cyanobacterium, oscillatoria chlorina, against the root-knot nematode, meloidogyne arenaria on tomato plants grown in pots filled with 500 cm3 of field soil infested with 12-s stage juveniles (j2)/cm3 soil. incorporation of freeze-dried cyanobacterial powder into potted field soil at the rate of 0.2%, 0.4%, 0.6%, 0.8% and 1.0% (w/w) 5 days prior to tomato planting, reduced root galling, final population of m. arenaria and ...200716458501
survey of crop losses in response to phytoparasitic nematodes in the united states for 1994.previous reports of crop losses to plant-parasitic nematodes have relied on published results of survey data based on certain commodities, including tobacco, peanuts, cotton, and soybean. reports on crop-loss assessment by land-grant universities and many commodity groups generally are no longer available, with the exception of the university of georgia, the beltwide cotton conference, and selected groups concerned with soybean. the society of nematologists extension committee contacted extensio ...199919270925
morphological variability and molecular phylogeny of the nematophagous fungus monacrosporium drechsleri.an isolate of the nematode-trapping fungus monacrosporium drechsleri was collected from cultures of the root-knot nematode meloidogyne arenaria that had been maintained on tomato roots in greenhouse pots in beltsville, maryland. the plant-parasitic nematodes heterodera glycines, meloidogyne incognita and pratylenchus zeae and the free-living nematodes caenorhabditis elegans and panagrellus redivivus were placed on colonies of m. drechsleri grown in petri dishes to study ability of the isolate to ...200516396348
nematicidal activity and chemical component of poria cocos.poria cocos, a famous traditional chinese medicine, was found to have nematicidal activity in experiments searching for nematicidal fungi. the experiment showed it could kill 94.9% of the saprophytic nematode, panagrellus redivivue, 92.6% of the root-knot nematode, meloidogyne arenaria, and 93.5% of the pine nematode, bursaphelenchus xylophilus, on pda plate within 12 hours. according to the nematicidal activity, three new compounds, 2, 4, 6-triacetylenic octane diacid, 2, 4, 5, 6-tetrahydroxyhe ...200515765052
location of independent root-knot nematode resistance genes in plum and peach.prunus species express different ranges and levels of resistance to the root-knot nematodes (rkn) meloidogyne spp. in myrobalan plum ( prunus cerasifera), the dominant ma gene confers a high-level and wide-spectrum resistance to the predominant rkn, meloidogyne arenaria, meloidogyne incognita, meloidogyne javanica and the isolate meloidogyne sp. florida which overcomes the resistance of the amygdalus sources. in japanese plum ( prunus salicina), a similar wide-spectrum dominant resistance gene, ...200414569426
protein variability in meloidogyne spp. (nematoda:meloidogynidae) revealed by two-dimensional gel electrophoresis and mass spectrometry.total protein variation as revealed by two-dimensional electrophoresis (2d-e) was studied in 18 isolates from populations of meloidogyne arenaria (six isolates), meloidogyne incognita (10 isolates), and meloidogyne javanica (one isolate) plus an unclassified isolate. gels (80 x 60 x 0.75 mm) were silverstained and digitized in order to compare their protein patterns. optical density and position of protein patterns were measured using statistical cluster analysis and computer-assisted image anal ...200212645913
antibodies from chicken eggs as probes for antigens from pasteuria penetrans endospores.the bacteria pasteuria spp. have been identified as among the most promising of several microbial organisms currently under investigation as biological control agents of plant-parasitic nematodes. as part of our goal to develop methods to discriminate isolates of pasteuria penetrans with different host preferences, we investigated the potential of developing antibody probes to identify endospores of different isolates of p. penetrans. polyclonal igy antibodies were raised in chickens against end ...199719274158
genetic diversity of root-knot nematodes from brazil and development of scar markers specific for the coffee-damaging species.rapd markers were used to characterize the genetic diversity and relationships of root-knot nematodes (rkn) (meloidogyne spp.) in brazil. a high level of infraspecific polymorphism was detected in meloidogyne arenaria, meloidogyne exigua, and meloidogyne hapla compared with the other species tested. phylogenetic analyses showed that m. hapla and m. exigua are more closely related to one another than they are to the other species, and illustrated the early divergence of these meiotically reproduc ...200212416618
molecular cloning and characterisation of a venom allergen ag5-like cdna from meloidogyne incognita.rna fingerprinting was used to identify rnas that were expressed in parasitic second-stage juveniles of meloidogyne incognita, but absent from or reduced in preparasitic second-stage juveniles. a cdna encoding a putative secretory protein was cloned from a m. incognita second-stage juvenile cdna library by probing with a 0.5kb fragment derived from fingerprinting that was more strongly expressed in parasitic second-stage juveniles. the cdna, named mi-msp-1, contained an open reading frame encodi ...200010675748
metabolism of plant sterols by nematodes.parasitic nematodes do not biosynthesize sterols de novo and therefore possess a nutritional requirement for sterol, which must be obtained from their hosts. consequently, the metabolism of phytosterols by plant-parasitic nematodes is an important process with potential for selective exploitation. the sterol compositions of several species of plant-parasitic nematodes were determined by capillary gas chromatography-mass spectrometry and compared with the sterol compositions of their hosts. satur ...19911779708
response of meloidogyne spp., heterodera glycines, and radopholus similis to tannic acid.tannins, which are water-soluble polyphenols, are toxic to numerous fungi, bacteria, and yeasts. our objectives were to study the efficacy of tannic acid in control of meloidogyne arenaria on tomato and its effects on the behavior of m. arenaria, m. incognita, heterodera glycines, and radopholus similis. three concentrations of tannic acid, 0.1, 1.0, and 10 g/500 cm(3) of soil, were applied preplant (powder) and at-plant (powder and drench) into soil infested with m. arenaria. tannic acid at the ...199719274278
population dynamics of meloidogyne incognita, m. arenaria,and other nematodes and crop yields in rotations of cotton, peanut, and wheat under minimum tillage.wheat, cotton, and peanut were arranged in three cropping sequences to determine the effects of fenamiphos (6.7 kg a.i./ha) and cropping sequence on nematode population densities and crop yields under conservation tillage and irrigation for 6 years. the cropping sequences included a wheat winter cover crop each year and summer crops of cotton every year, peanut every year, or cotton rotated every other year with peanut. the population densities of meloidogyne spp. and helicotylenchus dihystera w ...200019270949
fosthiazate controls meloidogyne arenaria and m. incognita in flue-cured tobacco.the nematicide fosthiazate was evaluated over a 3-year period for management of meloidogyne incognita race 3 (site 1) and m. arenaria race 2 (site 2) in flue-cured tobacco. fosthiazate was applied broadcast and incorporated at rates ranging from 22 to 88 g a.i./100 m(2), and compared with the nematicides fenamiphos (67 g a.i./100 m(2)), 1,3-d (56.1 l/ha, 670 ml/100-m row), and an untreated control. root-gall indices and leaf yields were averaged over the 3-year period. root galling was negativel ...199919270938
greenhouse studies on the effect of marigolds (tagetes spp.) on four meloidogyne species.the effects of preplanted marigold on tomato root galling and multiplication of meloidogyne incognita, m. javanica, m. arenaria, and m. hapla were studied. marigold cultivars of tagetes patula, t. erecta, t. signata, and a tagetes hybrid all reduced galling and numbers of second-stage juveniles in subsequent tomato compared to the tomato-tomato control. all four meloidogyne spp. reproduced on t. signata 'tangerine gem'. several cultivars of t. patula and t. erecta suppressed galling and reproduc ...199919270876
pasteuria spp.: systematics and phylogeny of these bacterial parasites of phytopathogenic nematodes.pasteuria spp. include endospore-forming bacterial pathogens of cladoceran crustaceans and plant-parasitic nematodes. propagation of these nematode pathogens requires attachment of soilborne endospores to nematode hosts, infection, growth, sporulation, and release of endospores to repeat the cycle of infection and propagation. the ability of these bacteria to suppress the levels of plant-parasitic nematodes in the field has made them particularly promising candidates for biocontrol of nematode d ...200319265995
host suitability of the olive cultivars arbequina and picual for plant-parasitic nematodes.host suitability of olive cultivars arbequina and picual to several plant-parasitic nematodes was studied under controlled conditions. arbequina and picual were not suitable hosts for the root-lesion nematodes pratylenchus fallax, p. thornei, and zygotylenchus guevarai. however, the ring nematode mesocriconema xenoplax and the spiral nematodes helicotylenchus digonicus and h. pseudorobustus reproduced on both olive cultivars. the potential of meloidogyne arenaria race 2, m. incognita race 1, and ...200319265971
responses of some common cruciferae to root-knot nematodes.ten cultivated plants of the family cruciferae were evaluated for susceptibility to meloidogyne arenaria race 1, m. incognita races 1 and 3, and m. javanica in a series of four separate greenhouse tests. after 62-64 days, or 1,032-1,072 degree days (10 c base), several of the crops evaluated showed moderate to severe levels of galling (> 3.0 on 0-5 scale) and moderate numbers of egg masses (>2.0 on 0-5 scale) in response to each of the nematode species and races. among the plants tested, collard ...199519277321
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. ...200219265943
effects of switchgrass (panicum virgatum) rotations with peanut (arachis hypogaea l.) on nematode populations and soil microflora.a 3-year field rotation study was conducted to assess the potential of switchgrass (panicum virgatum) to suppress root-knot nematodes (meloidogyne arenaria), southern blight (sclerotium rolfsii), and aflatoxigenic fungi (aspergillus sp.) in peanut (arachis hypogaea l.) and to assess shifts in microbial populations following crop rotation. switchgrass did not support populations of root-knot nematodes but supported high populations of nonparasitic nematodes. peanut with no nematicide applied and ...200219265915
meloidogyne incognita and m. arenaria reproduction on dwarf hollies and lantana.meloidogyne incognita and m. arenaria reproduction and host plant tolerance were assessed in field and greenhouse experiments on seven holly cultivars including ilex glabra 'shamrock', i. vomitoria 'schelling's dwarf', i. cornuta 'carissa', red holly hybrid (ilex little red), and i. crenata 'compacta', 'green luster', and 'helleri' as well as japanese boxwood (buxus microphylla) and two lantana cultivars (lantana camara 'miss huff' and 'new gold'). boxwood had the highest m. arenaria and m. inco ...200119265898
analysis of 1,3-dichloropropene for control of meloidogyne spp. in a tobacco pest management system.1,3-dichloropropene (1,3-d) and nonfumigant nematicides were evaluated for control of meloidogyne spp. and soil and foliar insects in a tobacco pest management system. in a field with a high meloidogyne spp. population density (root gall index 4.0 to 4.5 on a 0 to 10 scale in untreated controls), tobacco yields and crop values increased (482 kg/ha and $1,784/ha for 1, 3-d; 326 kg/ha and $1,206/ha for fenamiphos; 252 kg/ha and $933/ha for ethoprop) with nematicide application over an untreated co ...200119265897
effects of chicken-excrement amendments on meloidogyne arenaria.the effects of chicken litter on meloidogyne arenaria in tomato plants cv. rutgers were determined in the greenhouse. tomato seedlings were transplanted into a sandy soil amended with five rates of chicken litter and inoculated with 2,000 m. arenaria eggs. after 10 days, total numbers of nematodes in the roots decreased with increasing rates of chicken litter. after 46 days, egg numbers also decreased with increasing litter rates. in another experiment, soil was amended with two litter types, n- ...199319279745
crop rotation and nematicides for management of mixed populations of meloidogyne spp. on tobacco.the effects of crop rotation and the nematicides 1,3-dichloropropene (1,3-d), ethoprop, and fenamiphos on the relative frequency of meloidogyne incognita race 3, m. arenaria race 2, and m. javanica and tobacco yields on a sandy loam soil were determined. cropping sequences altered the species composition and population densities of meloidogyne spp. meloidogyne arenaria and m. incognita predominated when cotton, corn, sorghum, or rye-fallow preceded tobacco. meloidogyne javanica and m. arenaria p ...200119265896
distribution and downward movement of pasteuria penetrans in field soil.endospores of pasteuria penetrans were evaluated for their vertical distribution in field soil and their downward movement through soil in the laboratory. in the field trial, the number of endospores attached to second-stage juveniles (j2) of meloidogyne arenaria race 1 varied greatly in different soil depths. there were higher percentages of j2 with endospores attached in former weed fallow plots during the first 3 years of growing peanut than in former bahiagrass and rhizomal peanut plots (p < ...200519262855
persistence and suppressiveness of pasteuria penetrans to meloidogyne arenaria race.the long-term persistence and suppressiveness of pasteuria penetrans against meloidogyne arenaria race 1 were investigated in a formerly root-knot nematode suppressive site following 9 years of continuous cultivation of three treatments and 4 years of continuous peanut. the three treatments were two m. arenaria race 1 nonhost crops, bahiagrass (paspalum notatum cv. pensacola var. tifton 9), rhizomal peanut (arachis glabrata cv. florigraze), and weed fallow. two root-knot nematode susceptible wee ...200419262836
morphological and molecular characterization of meloidogyne mayaguensis isolates from florida.the discovery of meloidogyne mayaguensis is confirmed in florida; this is the first report for the continental united states. meloidogyne mayaguensis is a virulent species that can reproduce on host cultivars bred for nematode resistance. the perineal patterns of m. mayaguensis isolates from florida show morphological variability and often are similar to m. incognita. useful morphological characters for the separation of m. mayaguensis from m. incognita from florida are the male stylet length va ...200419262811
life cycle, ultrastructure, and host specificity of the north american isolate of pasteuria that parasitizes the soybean cyst nematode, heterodera glycines.light and transmission electron microscopy were used to investigate the life cycle and ultrastructure of an undescribed isolate of pasteuria that parasitizes the soybean cyst nematode, heterodera glycines. studies also were conducted to determine the host specificity of pasteuria. the endospores that attached to the cuticle of second-stage juveniles (j2) of h. glycines in soil did not germinate until the encumbered nematodes invaded soybean roots. thereafter, the bacterium developed and complete ...200419262804
relationship between meloidogyne arenaria and aflatoxin contamination in peanut.damaged and developing kernels of peanut (arachis hypogaea) are susceptible to colonization by fungi in the aspergillus flavus group which, under certain conditions, produces aflatoxins prior to harvest. our objective was to determine whether infection of peanut roots and pods by meloidogyne arenaria increases aflatoxin contamination of the kernels when peanut is subjected to drought stress. the experiment was a completely randomized 2-x-2 factorial with 6 replicates/treatment. the treatment fac ...200419262803
temporal formation and immunolocalization of an endospore surface epitope during pasteuria penetrans sporogenesis.the synthesis and localization of an endospore surface epitope associated with the development of pasteuria penetrans was determined using a monoclonal antibody (mab) as a probe. nematodes, uninfected or infected with p. penetrans, were harvested at 12, 16, 24, and 38 days after inoculation (dai) and then examined to determine the developmental stage of the bacterium. vegetative growth of p. penetrans was observed only in infected nematodes harvested at 12 and 16 dai, whereas cells at different ...200319262762
effect of temperature on attachment, development, and interactions of pasteuria penetrans on meloidogyne incognita.the effect of temperature (10, 20, 25, 30, and 35 c) on attachment and development of pasteuria penetrans on meloidogyne arenaria race 1 was elevated in growth chambers. the greatest attachment rate of endospores of p. penetrans occurred on second-stage juveniles at 30 c. the bacterium developed more quickly within its host at 30 and 35 c than at 25 c or below. the development of the bacterium within the nematode female was divided into nine recognizable life stages, which ranged from early vege ...199219283029
the role of microbes associated with chicken litter in the suppression of meloidogyne arenaria.the role of microbes associated with chicken litter in the suppression of meloidogyne arenaria in amended soil was investigated. amended soil treatments were prepared, including combinations of sterile and nonsterile chicken litter and soil. microbial biomass in different treatments was compared by measuring carbon dioxide evolution. there was less co evolved in sterile litter than in nonsterile litter treatments. tomato seedlings cv. rutgers were transplanted into soil mixtures and inoculated w ...199219283030
root vs pod infection by root-knot nematodes on aflatoxin contamination of peanut.aflatoxins are potent carcinogens produced by some aspergillus spp. infection of peanut (arachis hypogaea) by root-knot nematodes (meloidogyne arenaria) can lead to an increase in aflatoxin contamination of kernels when the plants are subjected to drought stress during pod maturation. it is not clear whether the increased aflatoxin contamination is primarily due to greater invasion of the galled pods by toxigenic aspergillus spp. or whether root galling is also involved. our objective was to det ...200718399500
the ever-expanding neuropeptide gene families in the nematode caenorhabditis elegans.neuropeptides act as chemical signals in the nervous system to modulate behaviour. with the ongoing est projects and dna sequence determination of different genomes, the identification of neuropeptide genes has been made easier. despite the relatively 'simple' repertoire of behaviours in the nematode caenorhabditis elegans, this worm contains a surprisingly large and diverse set of neuropeptide genes. at least 109 genes encoding over 250 potential neuropeptides have been identified in c. elegans ...200516569285
extraction and purification of pasteuria spp. endospores.pasteuria penetrans is an endospore-forming bacterial parasite of root-knot nematodes that has potential as a biological control agent. biochemical investigations of p. penetrans are limited because of difficulty in obtaining large quantities of endospores free of plant debris and contaminating microorganisms. our objective was to develop a technique for extraction and purification of p. penetrans endospores from root-knot nematodes. tomato roots infected with meloidogyne arenaria that was paras ...200019270952
suppression mechanisms of meloidogyne arenaria race 1 by pasteuria penetrans.the biological control of meloidogyne arenaria on peanut (arachis hypogaea) by pasteuria penetrans was evaluated using a six x six factorial experiment in field microplots over 2 years. the main factors were six inoculum levels of second-stage juveniles (j2) of m. arenaria race 1 (0, 40, 200, 1,000, 5,000, and 25,000 j2/microplot, except that the highest level was 20,000 j2/microplot in 1995) and six infestation levels of p. penetrans as percentages of j2 with endospores attached (0, 20, 40, 60, ...199719274127
temperature-dependent development of pasteuria penetrans in meloidogyne arenaria.pasteuria penetrans is a promising biological control agent of plant-parasitic nematodes. this study was conducted to determine effects of temperature on the bacterium's development in meloidogyne arenaria. developmental stages of p. penetrans were viewed with a compound microscope and verified with scanning electron microscopy within each nematode at 100 accumulated degree-day intervals by tracking accumulated degree-days at three temperatures (21, 28, and 35 degrees c). five predominant develo ...199719274154
differential response to root-knot nematodes in prunus species and correlative genetic implications.responses of 17 prunus rootstocks or accessions (11 from the subgenus amygdalus and 6 from the subgenus prunophora) were evaluated against 11 isolates of meloidogyne spp. including one m. arenaria, four m. incognita, four m. javanica, one m. hispanica, and an unclassified population from florida. characterization of plant response to root-knot nematodes was based on a gall index rating. numbers of females and juveniles plus eggs in the roots were determined for 10 of the rootstocks evaluated aga ...199719274170
temperature effects on the attachment of pasteuria penetrans endospores to meloidogyne arenaria race 1.pasteuria penetrans is a gram positive bacterium that prevents meloidogyne spp. from reproducing and diminishes their ability to penetrate roots. the attachment of the endospores to the cuticle of the nematodes is the first step in the life cycle of the bacterium and is essential for its reproduction. as a preliminary study to a field solarization test, the effects of temperature on the attachment of p. penetrans on meloidogyne arenaria race 1 were investigated. preexposing second-stage juvenile ...199719274192
damage potential and reproduction of meloidogyne incognita race 3 and m. arenaria race 1 on kenaf.the effects of meloidogyne incognita race 3 and m. arenaria race 1 on growth of kenaf cv. everglades 41 was determined under greenhouse conditions. seedlings of kenaf were inoculated with initial population densities (pi) of 0, 625, 1,250, 2,500, 5,000, and 10,000 eggs/plant and placed on greenhouse benches in a randomized complete block design. plant growth and nematode reproduction were assessed 6 and 12 weeks after inoculation. growth suppression of kenaf in response to increasing pi was obse ...199619277193
infection, reproduction potential, and root galling by root-knot nematode species and concomitant populations on peanut and tobacco.single populations of meloidogyne arenaria races 1 (ma1) and 2 (ma2) and m. hapla (mh), and mixed populations of ma1 + ma2 and ma1 + mh with four inoculum levels of eggs were tested on peanut cv. 'florigiant' and m. incognita-resistant tobacco cv. 'mcnair 373' in a greenhouse experiment. root infection, female development, and reproduction of ma2 on peanut and ma1 on resistant tobacco were limited at 2 and 6 weeks. ma1, mh, and ma1 + mh on peanut had similar root infection (total parasitic forms ...199519277277
effects of peanut-tobacco rotations on population dynamics of meloidogyne arenaria in mixed race populations.a 3-year microplot study was initiated to characterize the population dynamics, reproduction potential, and survivorship of single or mixed populations of meloidogyne arenaria race 1 (ma1) and race 2 (ma2), as affected by crop rotations of peanut 'florigiant' and m. incognita races 1 and 3-resistant 'mcnair 373' and susceptible 'coker 371-gold' tobacco. infection, reproduction, and root damage by ma2 on peanut and by ma1 on resistant tobacco were limited in the first year. infection, reproductio ...199519277278
temporal efficacy of selected nematicides on meloidogyne species on tobacco.aldicarb, ethoprop, and fenamiphos were evaluated for their efficacy in controlling various species of root-knot nematodes on flue-cured tobacco and for their residual activity, as determined through periodic sampling and bioassays of soil taken from field plots. field experiments were conducted at five locations over 2 years with flue-cured tobacco. soil in plots treated with nematicides were formed into high, wide beds before transplanting with 'coker 371-gold' or 'k 326' tobacco. residual con ...199519277289
effect of cutting age on the resistance of prunus cerasifera (myrobalan plum) to meloidogyne arenaria.the response of softwood cuttings of myrobalan plum infested after 50 and 105 days with 3,000 second-stage juveniles (j2) of meloidogyne arenaria was compared to 15-month-old hardwood cuttings in 13 genotypes ranging from highly resistant to susceptible. gall index and number of galls were recorded 30 days after infestation. fifty-day-old cuttings rooted in perlite developed many rootlets, but had only incipient galls after infestation. in sand, rooting of 50-day-old cuttings not treated with in ...199519277333
quantification of endospore concentrations of pasteuria penetrans in tomato root material.six methods for quantification of the endospore concentrations of pasteuria penetrans from tomato roots are described. mortar disruption and machine disruption methods gave the highest estimations (endospores per gram of root material) of 83.7 and 79.0 million, respectively. these methods were significantly superior to incubation bioassay (47.7 million), enzymatic disruption (32.1 million), and enzymatic disruption + flotation (25.8 million) methods. a centrifugation bioassay method gave the low ...199619277345
additive effects of meloidogyne arenaria and sclerotinin rolfsii on peanut.field observations have suggested that infection of peanut by meloidogyne arenaria increases the incidence of southern blight caused by sclerotium rolfsii. three factorial experiments in microplots were conducted to determine if interactions between m. arenaria and s. rolfsii influenced final nematode population densities, incidence of southern blight, or pod yield. treatments included four or five initial population densities of m. arenaria and three inoculum rates of s. rolfsii. final nematode ...199619277351
penetration rates by second-stage juveniles of meloidogyne spp. and heterodera glycines into soybean roots.the rates of soybean root penetration by freshly hatched second-stage juveniles (j2) of meloidogyne arenaria, m. hapla, m. incognita, m. javanica, and heterodera glycines races 1 and 5 were examined over a period of 1 to 240 hours. heterodera glycines entered roots more quickly than meloidogyne spp. penetration by most nematodes was accomplished within 48 hours. the increases in penetration after 48 hours were insufficient to warrant further assessments. penetration of j2 into roots of soybean s ...199319279739
soybean response to a planting-time application of ethylene dibromide in a soil infested with meloidogyne incognita, m. arenaria, and heterodera glycines.a field study was conducted to evaluate one susceptible and six nematode-resistant soybean cultivars for their effects on seed yield, nematode populations, and response to a fumigant nematicide, ethylene dibromide. the soil was a sandy loam, and the field was infested with a mixture of meloidogyne incognita, m. arenaria, and heterodera glycines. soybean cultivars significantly affected yield and juvenile numbers of meloidogyne spp. but did not affect the h. glycinesjuvenile population. fumigatio ...198719290278
effects of aldicarb on nematodes, early season insect pests, and yield of soybean.the effects of aldicarb on soybean cyst (heterodera glycines) and root-knot (meloidogyne incognita and m. arenaria) nematode populations, early season insect pests and soybean (glycine max) yield were evaluated in five field experiments in northern and southern alabama. aldicarb significantly (p = 0.05) reduced nematode populations in only two cases: m. arenaria in centennial soybean in the wiregrass site and m. incognita in bedford soybean in a tennessee valley site. no significant difference ( ...198719290282
differential sensitivity of meloidogyne spp. and heterodera glycines to selected nematicides.differential sensitivity of meloidogyne arenaria, m. hapla, m. incognita, m. javanica, and heterodera glycines races 1 and 5 to the nonfumigant nematicides aldicarb, ethoprop, and fenamiphos was evaluated using a 48-hour root-penetration bioassay. generally, h. glycines was more tolerant of the nematicides, especially ethoprop, than were the meloidogyne species. among meloidogyne species, m. incognita was most sensitive to aldicarb and fenamiphos, but its reaction to ethoprop was similar to the ...199319279834
a centrifugation method for attaching endospores of pasteuria spp. to nematodes.attachment of relatively low numbers of endospores from two isolates of pasteuria spp. to several species of nematodes was consistently achieved in 2-5 minutes with a centrifugation technique. the rate of attachment of pasteuria penetrans at 10 endospores/0.1 ml/tube to second-stage juveniles (j2) of meloidogyne javanica, m. incognita race 1, m. incognita race 3, and m. arenaria races 1 and 2 in two tests averaged 4.4, 5.2, 0.1, 0.3, and 0 endospores per j2, respectively. the rate of attachment ...199319279840
weed hosts of meloidogyne arenaria and m. incognita common in tobacco fields in south carolina.thirty-two weed species common in south carolina and one cultivar of tobacco were evaluated as hosts of meloidogyne arenaria race 2 and m. incognita race 3 in the greenhouse. egg mass production and galling differed (p < 0.05) among weed species. chenopodium album, euphorbia maculata, and vicia villosa were good hosts of m. arenaria. amaranthus palmeri, rumex crispus, amaranthus hybridus, ambrosia artemisiifolia, lpomoea hederacea var. integriuscula, setaria lutescens, sida spinosa, portulaca ol ...198819290313
effect of crop rotation on soybean in a field infested with meloidogyne arenaria and heterodera glycines.the effect of previous crops--soybean (glycine max) or corn (zea mays)--and aldicarb (2.2 kg a.i./ha) on yield and nematode numbers at harvest for soybean cultivars with various combinations of nematode resistance was determined in a sandy loam soil infested with meloidogyne arenaria race 2 and heterodera glycines races 3 and 4 at elberta, alabama, in 1987. cultivars had an effect on yield and nematode numbers (p = 0.01), as did the interaction of previous crop and cultivar. the nematicide treat ...198819290314
bahiagrass for the management of meloidogyne arenaria in peanut.bahiagrass (paspalum notatum) cultivars argentine, pensacola, and tifton-9 were non-hosts for meloidogyne arenaria, m. incognita, and heterodera glycines in a greenhouse experiment using field soil infested with these nematodes. the effect of pensacola bahiagrass in rotation with peanut (arachis hypogaea) on m. arenaria was studied in 1986 and 1987 in a field at the wiregrass substation near headland, alabama. each year soil densities of second-stage juveniles of m. arenaria, determined near pea ...198819290315
potential of crops uncommon to alabama for management of root-knot and soybean cyst nematodes.vigna unguiculata, cassia fasiculata, and sesamum indicum did not support meloidogyne arenaria, m. incognita, or heterodera glycines race 4 in greenhouse studies with soils from peanut and soybean fields. fagopyron eseulentum, cyamopsis tetragonoloba, and cucurbita pepo were hosts to the two meloidogyne spp. but were nonhosts to h. glycines. meloidogyne arenaria and m. incognita galled but reproduced poorly in the roots of three types of amaranthus cruentus, and low densities of these two meloid ...198819290317
morphological comparisons of host races 1 and 2 of meloidogyne arenaria from florida.morphometric comparisons of two populations each of races 1 and 2 of meloidogyne arenaria from tobacco, peanut, and soybean in different localities in florida showed no significant differences in any characters measured by light microscopy. thirteen morphometric characters of females, 22 of males, and 21 of infective second-stage juveniles were measured for each population. the stylet length in each population and in each life stage was the least variable character. proposed character additions ...198519294095
velvetbean in rotation with soybean for management of heterodera glycines and meloidogyne arenaria.the effect of previous crops - soybean (glycine max) or velvetbean (mucuna deeringiana) - and aldicarb on yield and nematode numbers for selected soybean cultivars was studied in a field infested with a mixture of meloidogyne arenaria and heterodera glycines. soybean following velvetbean yielded 959 kg/ha more than soybean following soybean. nematicide treatment resulted in increased yield, and there was no interaction between nematicide treatment and previous crop. cultivars interacted signific ...199319279845
plant-parasitic nematode distributions in an alfalfa field.a 7-ha alfalfa field (medicago saliva l. cv mesa sirsa) was sampled systematically on a 6 x 6-m grid by removing individual cores (2.54 cm diam) to a depth of 45 cm from each of the 1,936 grid intersections. the soil was mainly coarse-textured with a fine-textured streak running centrally, north to south. nematodes were extracted by a semiautomatic elutriator and sugar flotation-sieving technique. five plant-parasitic species were consistently present: meloidogyne arenaria, pratylenchus minyus, ...198019300685
rotations with coastal bermudagrass, cotton, and bahiagrass for management of meloidogyne arenaria and southern blight in peanut.the efficacy of coastal bermudagrass (cynodon dactylon) as a rotation crop for controt of root-knot nematode (meloidogyne arenaria) in 'florunner' peanut (arachis hypogoea) was evaluated in a 3-year field trial. coastal bermudagrass-peanut rotation (cbp) was compared with peanut monoculture without nematicide (p - ) and peanut monoculture with aldicarb (p + ). the performance of cbp was also compared with 'pensacola' bahiagrass (paspalum notatum)-peanut (bp), and 'deltapine 90' cotton (gossypium ...199419279945
sample optimization for five plant-parasitic nematodes in an alfalfa field.a data base representing nematode counts and soil weight from 1,936 individual soil cores taken from a 7-ha alfalfa field was used to investigate sample optimization for five plant-parasitic nematodes: meloidogyne arenaria, pratylenchus minyus, merlinius brevidens, helicotylenchus digonicus, and paratrichodorus minor. sample plans were evaluated by the accuracy and reliability of their estimation of the population and by the cost of collecting, processing, and counting the samples. interactive f ...198119300768
peroxidase isozymes from meloidogyne spp. and their origin.two peroxidase isozymes (ef 0.43 and 0.53) were detected by electrophoretic analysis in homogenates of meloidogyne arenaria, m. hapla, m. javanica, and m. incognita females reared on tomato. no peroxidase isozymes were detected electrophoretically in homogenates of adult males, preparasitic larvae, or eggs. peroxidase isozymes from females reared on bean, eggplant, or tobacco differed from those from females reared on tomato. bean and eggplant populations had a single peroxidase isozyme each, re ...197919305520
evaluation of fosthiazate for management of meloidogyne javanica in florida flue-cured tobacco.one grower trial and two experiment station tests were conducted to evaluate a new nematicide, fosthiazate, for management of meloidogyne javanica in florida flue-cured tobacco. fosthiazate was applied broadcast and incorporated at rates ranging from 21 to 84 g/100 m(2) and compared with 1,3-dichloropropene at 240 and 460 ml/100 m(2) and fenamiphos at 67 g/100 m(2). all fosthiazate treatments increased tobacco yields and reduced root galling. application of 1,3-d provided the highest tobacco yie ...199419279951
influence of concomitant pratylenchus brachyurus and meloidogyne spp. on root penetration and population dynamics.populations of pratylenchus brachyurus on cotton were increased significantly in the presence of either meloidogyne incognita or m. arenaria.this occurred with either simultaneous inoculation or prior invasion by m. incognita. p. brachyurus penetrated cotton roots previously invaded by, or simultaneously inoculated with, m. incognita, as well as, or better than, in the absence of m. incognita. prior invasion by m. incognita, however, suppressed p. brachyurus populations on tomato, while it had n ...197319319334
nematodes parasitic on forest trees: iii. reproduction on selected hardwoods.the host-parasite relationships of 13 species of plant parasitic nematodes and five species of hardwoods native to the southeastern united states were tested on greenhouse-grown tree seedlings for 6-10 months. criteria for parasitism were completion o f life cycle and population increase of nematodes. belonolaimus longicaudatus, helicotylenchus dihystera, scutellonema brachyurum and tylenchorhynchus claytoni parasitized and reproduced on three or more of the species tested. hoplolaimus galeatus ...197119322363
response of some common annual bedding plants to three species of meloidogyne.twelve ornamental bedding plant cultivars were grown in soil infested with isolates of meloidogyne incognita race 1, m. javanica, or m. arenaria race 1 in a series of tests in containers in a growth room. root galling (0-5 scale) and eggs/plant were evaluated 8-10 weeks after soil infestation and seedling transplantation. snapdragon, antirrhinum majus cv. first ladies, was extensively galled and highly susceptible (mean gall rating >/=4.2 and >/=14,500 eggs/plant), and celosia argentea cv. centu ...199419279963
susceptibility of several common subtropical weeds to meloidogyne arenaria, m. incognita, and m. javanica.experiments were conducted in the greenhouse to assess root galling and egg production of three root-knot nematode species, meloidogyne arenaria, m. incognita, and m. javanica, on several weeds common to florida agricultural land. weeds evaluated were amaranthus retroflexus (redroot pigweed), cyperus esculentus (yellow nutsedge), eleusine indica (goosegrass), portulaca oleracea (common purslane), and solanum americanum (american black nightshade). additionally, although it is recommended as a co ...201223482324
variability among populations of meloidogyne arenaria.variability in reproduction and pathogenicity of 12 populations of meloidogyne arenaria race 1 was evaluated on florunner peanut, centennial soybean, rutgers tomato, g70, k326, and mc944 tobacco, and carolina cayenne, mississippi nemaheart, and santanka pepper. differences among m. arenaria populations in rates of egg production 45 days after inoculation were observed for all cultivars except santanka pepper. differences among populations in dry top weights or fresh root weights were recorded on ...199219283016
crop rotation studies with velvetbean (mucuna deeringiana) for the management of meloidogyne spp.results from a greenhouse experiment at cabrils, spain, with two velvetbean (mucuna deeringiana) accessions (florida and mozambique) growing in sterilized sandy loam and inoculated with meloidogyne arenaria race 2, m. incognita race 1, and m. javanica revealed that the legume was not a host for these nematodes. in contrast, roots of 'clemson spineless' okra (hibiscus esculentum), 'summer crookneck' squash (cucurbita pepo), and 'davis' soybean (glycine max) were galled by all three root-knot nema ...199219283043
population development of pasteuria penetrans on meloidogyne arenaria.a microplot study on the influence of cropping sequences with peanut in summer and bare fallowed or cover crops of rye or vetch in winter on the population development of pasteuria penetrans was initiated in the spring of 1987. the number of spores of p. penetrans attached per second-stage juvenile of meloidogyne arenaria race 1 increased from 0.11 in the fall of 1987 to 7.6, 8.6, and 3.6 in the fall of 1989 in the rye, vetch, and fallowed plots, respectively. higher (p </= 0.05) levels of p. pe ...199119283094
penetration of susceptible and resistant tobacco cultivars by meloidogyne juveniles.rates of penetration of meloidogyne incognita, m. arenaria, and m. javanica into tobacco cultivars nc2326 (susceptible to all three species) and k399 (resistant to m. incognita) and a breeding line that had been selected for resistance to m. incognita were compared. meloidogyne incognita penetrated nc2326 rapidly during the first 24 hours after inoculation. numbers of m. incognita continued to increase gradually through the 14-day experiment. higher numbers of m. incognita were observed in the r ...199119283116
resistance in soybean cultivars from maturity groups v-viii to soybean cyst and root-knot nematodes.one hundred thirty-nine cultivars of soybean (glycine max) in maturity groups v, vi, vii, and viii were evaluated in a greenhouse for resistance to heterodera glycines races 3 and 14 and meloidogyne incognita, m. arenaria, and m. javanica. of the cultivars tested, 37% had resistance to h. glycines race 3 alone, 12% had resistance to both races 3 and 14, and 69% exhibited a moderate or high level of resistance to one or more of the meloidogyne spp. however, 24% were susceptible to each race of h. ...199119283166
resistance to root-knot, reniform, and soybean cyst nematodes in selected soybean breeding lines.soybean breeding lines and reported sources of nematode resistance were evaluated in repeated greenhouse tests for resistance to north carolina populations of the soybean cyst nematode heterodera glycines, reniform nematode rotylenchulus reniformis, and the root-knot nematode species meloidogyne incognita, m. arenaria, and m. arenaria. lines from the soybean breeding program in missouri that had 'hartwig' soybean as a parent were the most resistant to races 1-4 of the soybean cyst nematode and t ...199819274243
suppression of meloidogyne arenaria race 1 by soil application of endospores of pasteuria penetrans.the potential of pasteuria penetrans for suppressing meloidogyne arenaria race 1 on peanut (arachis hypogaea) was tested over a 2-year period in a field microplot experiment. endospores of p. penetrans were mass-produced on m. arenaria race 1 infecting tomato plants. endospores were inoculated in the first year only at rates of 0, 1,000, 3,000, 10,000, and 100,000 endospores/g of soil, respectively, into the top 20 cm of microplots that were previously infested with m. arenaria race 1. one peanu ...199619277131
pasteuria sp. parasitizing trophonema okamotoi in florida.two populations of trophonema okamotoi parasitized by pasteuria sp. were found on liquidambar styraciflua (sweetgum) and on an unidentified tropical grass in north-central florida. endospores of this pasteuria sp. attached to motile vermiform second-stage juveniles (j2) and males of t. okamotoi, but not to other developmental stages. sporangia and new endospores were produced only inside the bodies of swollen and sedentary third- and fourth-stage juveniles and females that developed in the host ...199219283199
separation and characterization of heterodera glycines acetylcholinesterase molecular forms.the composition and biochemical properties of acetylcholinesterases isolated from heterodera glycines were determined. heterodera glycines contains three separable ache molecular forms that can be grouped into two classes corresponding to classes a and c found in some other nematode species. the apparent lack of class b ache is unusual and may have significant behavioral ramifications. the class c enzyme isolated from h. glycines is similar to that from meloidogyne arenaria and m. incognita but ...199219283216
long-term effect of crop rotation on soybean in a field infested with meloidogyne arenaria and heterodera glycines.previous cropping sequence (corn-soybean vs. soybean-soybean) and aldicarb effects on soybean yield and nematode numbers at harvest for soybean cultivars with various combinations of nematode resistance were determined in 1988 in a sandy loam soil infested with meloidogyne arenaria race 2 and heterodera glycines races 3 and 4 at elberta, alabama. yield and nematode numbers differed among cultivars with 'leflore' having the highest yield. aldicarb treatment resulted in increased soybean yield but ...198919287680
plant-parasitic nematode acetylcholinesterase inhibition by carbamate and organophosphate nematicides.the sensitivity of acetylcholinesterases (ache) isolated from the plant-parasitic nematodes meloidogyne arenaria, m. incognita, and heterodera glycines and the free-living nematode caenorhabditis elegans to carbamate and organophosphate nematicides was examined. the ache from plant-parasitic nematode species were more sensitive to carbamate inhibitors than was ache from c. elegans, but response to the organophosphates was approximately equivalent. the sulfur-containing phosphate nematicides were ...199019287747
host range and ecology of isolates of pasteuria spp. from the southeastern united states.isolates of pasteuria penetrans were evaluated for ecological characteristics that are important in determining their potential as biological control agents. isolate p-20 survived without loss of its ability to attach to its host nematode in dry, moist, and wet soil and in soil wetted and dried repeatedly for 6 weeks. some spores moved 6.4 cm (the maximum distance tested) downward in soil within 3 days with percolating water. the isolates varied greatly in their attachment to different nematode ...199019287753
spring or fall fumigation for control of meloidogyne spp. on tobacco.tests were conducted in 1987-88 to compare the efficacy of spring or fall fumigant nematicide applications for control ofmeloidogyne arenaria and m. incognita on tobacco. chloropicrin, 1,3-d, methyl isothiocyanate, and a methyl isothiocyanate-l,3-d mixture were applied as row treatments. fenamiphos, fenamiphos + fensulfothion, or ethoprop were applied in the spring as nonfumigant nematicide standards. fumigant nematicides increased yields and reduced galling (p = 0.01) in all four tests. spring ...199019287773
peanut-cotton rotations for the management of meloidogyne arenaria.the efficacy of 'deltapine 90' cotton (gossypium hirsutum) in rotation with 'florunner' peanut (arachis hypogaea) for the management of meloidogyne arenaria was studied for 2 years in a field in southeastern alabama. in 1985, m. arenaria juvenile populations in plots with cotton were 98% lower than in plots with peanut. peanut and cotton yields were increased by treatment with aldicarb (3.3 kg a.i./ha in a 20-cm-band) in 1985 but not in 1986. in 1986, peanut yields were highest and m. arenaria j ...198719290174
soybean response to ethylene dibromide in a soil infested with meloidogyne arenaria and heterodera glycines.one susceptible and six nematode-resistant soybean cultivars were evaluated in the field for their effects on seed yield, nematode populations, and response to the fumigant nematicide, ethylene dibromide. the soil was a loamy sand infested with meloidogyne arenaria and heterodera glycines. cultivars significantly affected yield and numbers of h. glycines but did not affect m. arenaria numbers. fumigation increased yield and reduced m. arenaria numbers but did not affect numbers of h. glycines. t ...198719290285
host suitability of grain sorghum cultivars to meloidogyne spp.grain sorghum cultivars (funk g-499gbr, funk g-611, funk g-522a, funk g-522dr, coker 7723, coker 7675, coker 7623, pioneer b815, pioneer 8222, pioneer 8272) were evaluated in the greenhouse for resistance to populations of meloidogyne incognita race 3, m. arenaria race 2, and m. javanica from south carolina, and m. arenaria race 1 from georgia. all the sorghum cultivars were poor hosts or nonhosts of meloidogyne spp. with fewer than 1 or 2 egg masses per root system in all cultivar x nematode co ...198819290305
histopathology of selected cultivars of tobacco infected with meloidogyne species.rates of nematode penetration and the histopathology of root infections in fluecured tobacco cultivars 'mcnair-944,' 'speight g-28,' and 'nc-89' with either meloidogyne arenaria, m. incognita, m. hapla, or m. javanica were investigated. penetration of root tips by juveniles of all species into the m. incognita-resistant nc-89 and g-28 was much less than that on the susceptible mcnair-944. few juveniles of m. incognita were detected in resistant cultivars 7 and 14 days after inoculation. infectio ...198319295823
comparative studies on root invasion, root galling, and fecundity of three meloidogyne spp. on a susceptible tobacco cultivar.root invasion, root galling, and fecundity of meloidogyne javanica, m. arenaria, and m. incognita on tobacco was compared in greenhouse and controlled environment experiments. significantly more m. javanica than m. arenaria or m. incognita larvae were found in tobacco roots at 2, 4, and 6 d after inoculation. eight days after inoculation there were significantly more m. arenaria and m. javanica than m. incognita larvae. ten days after inoculation no significant differences were found among the t ...198119300745
japanese hollies: intolerant hosts of meloidogyne arenaria in microplots.japanese hollies were itttolerant of meloidogyne arenaria in field microplot experiments. ilex crenata var. rotundifolia was relatively more tolerant than i. crenata var. convexa or i. crenata var. helleri. when m. arenaria was added at various itfitial population densities to soil containing plants of "helleri," "convexa," and "rotundifolia," respectively, 91, 75, and 25% were killed by the end of the third growing season. no control plants died during the same period. initial numbers of m. are ...197719305618
detection of pasteuria penetrans infection in meloidogyne arenaria race 1 in planta by polymerase chain reaction.we report on the development of a pcr-based assay to detect pasteuria penetrans infection of meloidogyne arenaria in planta using specific primers for recently sequenced sige, spoiiab and atpf genes of p. penetrans biotype p20. amplification of these genes in crude dna extracts of ground tomato root galls using real-time kinetic pcr distinguished infected from uninfected m. arenaria race 1 by analysis of consensus thresholds for single copy genes. fluorescent in situ hybridization (fish) using t ...200419712314
characterization of a root-knot nematode population of meloidogyne arenaria from tupungato (mendoza, argentina).root-knot nematodes (meloidogyne spp.) are polyphagous plant parasites of global importance. successful host infection depends on the particular interaction between a specific nematode species and race and a specific plant species and cultivar. accurate diagnosis of nematode species is relevant to effective agricultural management; and benefits further from understanding the variability within a single nematode species. here, we described a population of m. arenaria race 2 from mendoza (argentin ...201223481918
evaluation of an antibiotic-producing strain of pseudomonas fluorescens for suppression of plant-parasitic nematodes.the antibiotic 2,4-diacetylphloroglucinol (dapg), produced by some strains of pseudomonas spp., is involved in suppression of several fungal root pathogens as well as plant-parasitic nematodes. the primary objective of this study was to determine whether wood1r, a d-genotype strain of dapg-producing p. fluorescens, suppresses numbers of both sedentary and migratory plant-parasitic nematodes. an experiment was conducted in steam-heated soil and included two seed treatments (with wood1r and a cont ...200922736820
root transcriptome analysis of wild peanut reveals candidate genes for nematode resistance.wild peanut relatives (arachis spp.) are genetically diverse and were adapted to a range of environments during the evolution course, constituting an important source of allele diversity for resistance to biotic and abiotic stresses. the wild diploid a. stenosperma harbors high levels of resistance to a variety of pathogens, including the root-knot nematode (rkn) meloidogyne arenaria, through the onset of the hypersensitive response (hr). in order to identify genes and regulators triggering this ...201526488731
immunolocalization of a putative cuticular collagen protein in several developmental stages of meloidogyne arenaria, globodera pallida and g. rostochiensis.the monoclonal antibody iacr-ccnj.3d has previously been used to isolate a gene (gp-col-8) with strong similarity to cuticular collagen from a mixed stage globodera pallida cdna expression library. the antibody has also been shown to label specifically the amphidial canal of pre-parasitic second stage juveniles (j2) of several plant nematode species without any reactivity on the cuticular surface, indicating that this protein is either not present or is inaccessible on the cuticular surface. thi ...200212018190
problems and strategies associated with long-term use of nematode resistant cultivars.plant-parasitic nematodes are obligate parasites, and planting cultivars that are highly resistant to these organisms places extensive selection pressure on the target species and affects nontarget nematodes as well. problems encountered with long-term planting of cultivars resistant to nematodes include shifts in nematode races or species and the occurrence of multiple species of nematodes within the same field. these problems can be alleviated to some extent when crop management is used to les ...199219282988
sensitive pcr detection of meloidogyne arenaria, m. incognita, and m. javanica extracted from soil.we have developed a simple pcr assay protocol for detection of the root-knot nematode (rkn) species meloidogyne arenaria, m. incognita, and m. javanica extracted from soil. nematodes are extracted from soil using baermann funnels and centrifugal flotation. the nematode-containing fraction is then digested with proteinase k, and a pcr assay is carried out with primers specific for this group of rkn and with universal primers spanning the its of rrna genes. the presence of rkn j2 can be detected a ...200619259460
preliminary study of the green algae chlorella (chlorella vulgaris) for control on the root-knot nematode (meloidogyne arenaria) in tomato plants and ectoparasite xiphinema indexin grape seedlings.the alternative ecological methods require investigation of many organo-biological means for plant protection against dangerous root parasites such as root-knot nematode meloidogyne arenaria and some ectoparasites (xiphinema index). the bulgarian organic product - dry extract of green alga chlorella vulgaris ("the golden apple"-plamen barakov) is the latest product, which in comparative aspect gives the best results. series of laboratory and pot experiments are carried out with tomato (cv. bele ...200516628939
seed treatment as a means of preventing nematode damage to crop plants.a procedure for treating crop seeds with aqueous solutions of the systemic nematicide oxamyl is described. seedlings from treated seeds were more resistant to attack by parasitic nematodes. leachate from treated seeds reduced the number of free-living nematodes in the surrounding soil.197719305617
cotton as a rotation crop for the management of meloidogyne arenaria and sclerotium rolfsii in peanut.the value of cotton (gossypium hirsutum cv. deltapine 90) in rotation with peanut (arachis hypogaea cv. florunner) for the management of root-knot nematode (meloidogyne arenaria) and southern blight (sclerotium rolfsii) was studied for 6 years in a field at the wiregrass substation in southeast alabama. peanut yields following either 1 or 2 years of cotton (c-p and c-c-p, respectively) were higher than those of peanut monoculture without nematicide [p(-)]. at-plant application of aldicarb to con ...199119283179
rotations of bahiagrass and castorbean with peanut for the management of meloidogyne arenaria.the relative value of 'hale' castorbean (ricinus communis) and 'pensacola' bahiagrass (paspalum notatum) as rotational crops for the management of meloidogyne arenaria and southern blight (sclerotium rolfsii) in 'florunner' peanut (arachis hypogaea) production was studied for 3 years in a field experiment in southeast alabama. peanut following 2 years of castorbean (c-c-p) yielded 43% higher than monocultured peanut without nematicide. at-plant application of aldicarb (30.5 g a.i./100 m row in a ...199119283180
rotations of soybean with tropical corn and sorghum for the management of nematodes.the relative efficacy of rotations of soybean with sorghum and tropical corn for nematode management was studied for 2 years in a field infested with root-knot (meloidogyne arenaria) and soybean cyst (heterodera glycines, race 14) nematodes. corn, sorghum, and soybean cv. kirby were planted in 1989, and in 1990 the same areas were planted with seven soybean cultivars with and without at-plant application ofaldicarb. corn and sorghum did not support h. glycines, but significant juvenile populatio ...199119283181
specific gravity of spores of pasteuria penetrans and extraction of spore-filled nematodes from soil.the specific gravity of spores of pasteuria penetrans collected from meloidogyne arenaria was found to be around 1.28. increasing the sucrose concentration used for the extraction of pratylenchus scribneri from a specific gravity of 1.14 to 1.26 led to the recovery of higher numbers of specimens filled with spores of pasteuria sp. (p </= 0.05). the numbers of spore-filled specimens of hoplolaimus galeatus recovered from field soil were not affected by the concentration of the sucrose solutions. ...199119283193
evaluation of steam and soil solarization for meloidogyne arenaria control in florida floriculture crops.steam and soil solarization were investigated for control of the root-knot nematode meloidogyne arenaria in 2 yr of field trials on a commercial flower farm in florida. the objective was to determine if preplant steam treatments in combination with solarization, or solarization alone effectively controlled nematodes compared to methyl bromide (mebr). trials were conducted in a field with naturally occurring populations of m. arenaria. treatments were solarization alone, steam treatment after sol ...201627765992
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