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effects of nematicides and herbicides alone or combined on meloidogyne incognita egg hatch and development.the effects of nematicides carbofuran (c) and fenamiphos (f) and herbicides metribuzin (m) and trifluralin (t), alone and in combination, on hatching, penetration, development, and reproduction of meloidogyne incognita race 3 were determined under laboratory conditions. to study hatching, entire egg masses were exposed to nematicides (6 mug/ml), herbicides (0.5 mug/ml), and their combinations over a period of 16 days; the hatched juveniles were extracted and counted every 48 hours. second-stage ...198719290279
evaluation of soybean cultivars for production in meloidogyne incognita-infested soil.significant (p < 0.05) differences among galling and yields of 41 soybean cultivars and breeding lines were found when they were produced at a site infested with meloidogyne incognita during 3 years of investigation. over a period of 6 years of testing, 13 cultivars were identified as having a suitably low susceptibility to warrant their production in m. incognita infested soil.198719290271
production and partial characterization of stylet exudate from adult females of meloidogyne incognita.adult females of meloidogyne incognita were excised from tomato roots and incubated in 0.04 m phosphate buffered saline, ph 7.4 for 18-72 hours to allow accumulation of stylet exudate. twenty-four percent of the females produced exudate during the initial 18-hour incubation period; 70% of those females producing exudate initially produced additional exudate during the subsequent 54-hour incubation period. analysis of exudate by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed t ...198719290172
control of root-knot nematodes on tomato by lectins.significant control of tomato root knot was achieved by applications of the lectins concanavalin a (con a) and limax flavus agglutinin in greenhouse, growth chamber, and microplot trials. four consecutive weekly applications at lower concentrations of con a yielded better control than single applications at a higher total concentration. the present state of knowledge on binding of con a to soil nematodes and the in vitro effect of this lectin in chemotactic behavior are discussed. the mode of ac ...198719290152
effect of meloidogyne incognita on plant nutrient concentration and its influence on the physiology of beans.phaseolus vulgaris plants, 3, 8, 11, and 13 days old, were inoculated with 0, 2,000, 4,000, or 8,000 second-stage meloidogyne incognita larvae and maintained under controlled conditions. the photosynthetic rate and the shoot and root concentration of k, ca, mn, fe, cu, and zn were determined by destructive assay at 1-27-day intervals and by nondestructive assay of leaves, stems, and roots at 27 or 28 days after inoculation. in the destructive assay, the concentration of the elements in the plant ...198719290151
comparison of compatible and incompatible response of potato to meloidogyne incognita.one susceptible (d6) and two resistant (e2 and n4) clones of solanum sparsipilum x (s. phureja x haploid of s. tuberosum) were used to study the responses of potato roots and tubers to race 1 of meloidogyne incognita (kofoid &white) chitwood. the compatible response was characterized by rapid penetration of large numbers of second-stage juveniles (j2) into roots, cessation of root growth, and occasional curving of root tips. the life cycle of m. incognita in the susceptible clone was completed i ...198719290132
water absorbent polymer aids in the infestation of field sites with meloidogyne eggs. 198719290118
root-knot nematode management and yield of soybean as affected by winter cover crops, tillage systems, and nematicides.management of meloidogyne incognita on soybean as affected by winter small grain crops or fallow, two tillage systems, and nematicides was studied. numbers of m. incognita did not differ in plots planted to wheat and rye. yields of soybean planted after these crops also did not differ. numbers of m. incognita were greater in fallow than in rye plots, but soybean yield was not affected by the two treatments. soybean yields were greater in subsoil-plant than in moldboard plowed plots. ethylene dib ...198719290104
relationship between morphology and parasitism in two populations of meloidogyne incognita.the reliability of morphological characters and host differential plants for distinguishing between two populations of meloidogyne incognita was studied. population a (originally from north carolina) had incognita-type perineal patterns. a single egg mass subpopulation of population a had a mixture of incognita and acrita perineal patterns with 33% of the patterns atypical for either species. population b (from georgia) had predominantly acrita-type patterns with only about 5% atypical patterns. ...198719290101
nicotine content of tobacco roots and toxicity to meloidogyne incognita.the motility of meloidogyne incognita second-stage juveniles (j2) and their ability to induce root galls in tomato were progressively decreased upon exposure to nicotine at concentrations of 1-100 mug/ml. ec values ranged from 14.5 to 22.3 mug/ml, but j2 motility and root-gall induction were not eliminated at 100 mug/ml nicotine. nicotine in both resistant nc 89 and susceptible nc 2326 tobacco roots was increased significantly 4 days after exposure to m. incognita. the increase was greater in re ...198719290102
biological control of meloidogyne incognita by paecilomyces lilacinus and pasteuria penetrans.the root-knot nematode meloidogyne incognita was controlled more effectively and yields of host plants were greater when paecilomyces lilacinus and pasteuria penetrans were applied together in field microplots than when either was applied alone. yields of winter vetch from microplots inoculated with the nematode and with both organisms were not statistically different from yields from uninoculated control plots.198719290133
interaction between meloidogyne incognita and hoplolaimus columbus on davis soybean.greenhouse and laboratory experiments were performed to determine if an interaction exists between meloidogyne incognita and hoplolaimus columbus on davis soybean. greenhouse tests were performed with three population levels of m. incognita and h. columbus (0, 1,500, 6,000/1.5-liter pot) separately and in all combinations. dry root weight (drt) declined nonlinearly and dry shoot weight (dst) declined linearly with respect to increasing initial populations of m. incognita and h. columbus. when th ...198719290154
selective migration and root penetration by meloidogyne incognita and hoplolaimus columbus on soybean roots in vitro. 198719290161
geographical distributions of rotylenchulus reniformis, meloidogyne incognita, and tylenchulus semipenetrans in the lower rio grande valley as related to soil texture and land use.a survey was conducted over a 22-year period to evaluate the influence of soil texture and land use on the geographical distributions of rotylenchulus reniformis, meloidogyne incognita, and tylenchulus semipenetrans in the lower rio grande valley. the distributions of r. reniformis and m. incognita were related to soil texture, whereas t. semipenetrans occurred wherever host plants were present regardless of soil texture. the incidence of m. incognita was greatest in elevated sandy loams and mod ...198719290268
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
effect of combining soil solarization with certain nematicides on target and nontarget organisms and plant growth.field experiments compared pesticidal and plant growth effects of soil solarization, alone and in combination, with overall applications of several nematicides. nematodes, including meloidogyne incognita j2, that were targeted for control were significantly reduced (p < 0.05) by solarization, 1,3-dichloropropene (44 and 132 liter/ha), ethoprop (13.5 kg/ha), metham sodium (64 liter/ha), formaldehyde (111 liter/ha), and by solarization-nematicide combinations. control of pythium ultimum also was o ...198719290287
nematode response to cool season annual graminaceous species and cultivars.the response of 29 rye, oat, triticale, and wheat cultivars to selected nematode species was determined in the greenhouse. variability in nematode root galling and final nematode population densities in root and soil in response to cool season annual graminaceous crops occurred for spiral (helicotylenchus dihystera), stubby root (paratrichodorus minor), and root-knot (meloidogyne incognita) nematodes. although none of the graminaceous crops supported m. incognita at levels as high as the suscept ...198719290289
effective use of marine algal products in the management of plant-parasitic nematodes.algal extracts were ineffective against meloidogyne spp., panagrellus redivivus, and neoaplectana carpocapsae at 1.0% aqueous concentrations, with the exception of spatoglossum schroederi. s. schroederi killed meloidogyne incognita, m. javanica, m. acrita, and hoplolaimus galeatus at concentrations of 1.0, 0.75, and 0.50%. extracts from s. schroederi at a concentration of 1.0% were ineffective against hirschmanniella caudacrena and belonolaimus longicaudatus. spatoglossum schroederi, botryocladi ...198719290129
usefulness of egg assays in nematode population-density determinations. 198719290117
response of cowpea breeding lines and cultivars to meloidogyne incognita and m. arenaria.twenty-four cowpea breeding lines and four cultivars were tested for resistance to meloidogyne incognita in the greenhouse. gall and egg mass ratings indicated a range of responses from susceptible to highly resistant. five breeding lines - vs84-2, vs84-8, vs84-12, vs84-14, and vs84-22 - and the cultivar erectset had gall and egg mass ratings comparable to the m. incognita-resistant cultivar mississippi silver. all of these were also resistant to m. arenaria. significantly fewer m. incognita juv ...198719290274
host suitability of commercial corn hybrids to meloidogyne arenaria and m. incognita.the host suitability of 64 commercial corn hybrids for a meloidogyne arenaria race 2 population and a m. incognita race 4 population was determined in greenhouse experiments. 'northrup king 508' and 'pioneer brand 3147' maintained m. arenaria below and at the initial population level, respectively, indicating that these hybrids are relatively poor hosts for this species. rf values (final egg number/initial egg number) of the hybrids for m. arenaria ranged from 0.8 for northrup king 508 to 42.3 f ...198719290266
sterol composition and ecdysteroid content of eggs of the root-knot nematodes meloidogyne incognita and m. arenaria.free and esterified sterols of eggs of the root-knot nematodes meloidogyne incognita races 2 and 3 and m. arenaria race 1 were isolated and identified by gas-liquid chromatography-mass spectrometry. the major sterols of eggs of each race were 24-ethylcholesterol (33.4-38.8% of total sterol), 24-ethylcholestanol (18.3-25.3%), 24-methylcholesterol (8.6-11.7%), 24-methylcholestanol (7.7-12.5%), and cholesterol (4.6-11.6%). consequently, the major metabolic transformation performed by meloidogyne fe ...198719290155
effects of several phytoparasitic nematodes on the growth of basil, ocimum basilicum.greenhouse experiments were conducted in 15-cm-d pots of steamed myakka fine sand to determine the host status and tolerance of common basil (ocimum basilicum) to several important phytoparasitic nematodes in florida. populations of meloidogyne incognita, belonolaimus longicaudatus, and pratylenchus scribneri increased and caused significant suppression of foliage and root growth during a 10-month period. the population of paratrichodorus christiei increased and caused a significant reduction in ...198819290296
nematode population densities and yield of sweet potato and onion as affected by nematicides and time of application.nematode population densities and yield of sweet potato and onion as affected by nematicides and time of application were determined in a 3-year test. population densities of meloidogyne incognita race 1 in untreated plots of sweet potato increased each year, but helicotylenchus dihystera and criconemella ornata did not. ethoprop (6.8 kg a.i./ha) incorporated broadcast in the top 15-cm soil layer each spring before planting sweet potato reduced population densities of nematodes in the soil and i ...198819290295
transport of the nematicide oxamyl in roots transformed with agrobacterium rhizogenes.infection of roots transformed with agrobacterium rhizogenes by meloidogyne incognita and heterodera schachtii second-stage juveniles was established in bicompartmental petri dishes. one compartment contained the murashige and skoog agar medium and the nematicide oxamyl, and the other compartment contained water agar. transformed roots of carrot, tomato, alfalfa, cowpea, rape, and sugarbeet were placed in the nutrient compartment and grew over the barrier that divided the petri dishes and into t ...198819290298
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
resistance in commercial soybean cultivars to six races of heterodera glycines and to meloidogyne incognita.soybean cultivars grown in pots in the greenhouse were tested for resistance by inoculation with meloidogyne incognita or one of six races of heterodera glycines. selected cultivars were tested against each nematode isolate. the numbers of cultivars tested against each h. glycines race and the numbers resistant and (or) moderately resistant were as follows: race 2 - 114 tested, 1 resistant and 9 moderately resistant; race 3 - 170 tested, 56 resistant and 17 moderately resistant; race 4 - 89 test ...198819290307
response of cotton to infection by hoplolaimus columbus.three field experiments were established in 1987 to determine the reaction of five cotton cultivars to infection by hoplolaimus columbus and the efficacy of selected nematicides against this nematode. at two sites in calhoun county, south carolina, early season plant growth and subsequent yields were greater in plots treated with aldicarb, fenamiphos, and 1,3-dichloropropene. hoplolaimus columbus suppressed yields approximately 10% at site 1 and 25% at site 2; however, greater yield suppression ...198819290310
tillage and multiple cropping systems and population dynamics of phytoparasitic nematodes.the effect of two cropping and tillage systems on the population dynamics of four nematode species was evaluated on a loamy sand. hairy vetch succeeded by corn or grain sorghum was seeded in split plots randomized within whole plots of no-tillage versus conventional tillage over four growing seasons (1980-83). the vetch-corn cropping system increased the density of meloidogyne incognita 2.9 x more than the vetch-grain sorghum cropping system. in contrast, the vetch-grain sorghum cropping system ...198819290311
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
interactions between meloidogyne incognita and pratylenchus brachyurus on soybean.interactions among meloidogyne incognita, pratylenchus brachyurus, and soybean genotype on plant growth and nematode reproduction were studied in a greenhouse. coker 317 (susceptible to both nematodes) and gordon (resistant to m. incognita, susceptible to p. brachyurus) were inoculated with increasing initial population densities (pi) of both nematodes individually and combined. m. incognita and p. brachyurus individually usually suppressed shoot growth of both cultivars, but only root growth on ...198819290187
histology of the interactions of paecilomyces lilacinus with meloidogyne incognita on tomato.excised tomato roots were examined histologically for interactions of the fungus paecilomyces lilacinus and meloidogyne incognita race 1. root galling and giant-cell formation were absent in tomato roots inoculated with nematode eggs infected with p. lilacinus. few to no galls and no giant-cell formation were found in roots dipped in a spore suspension of p. lilacinus and inoculated with m. incognita. numerous large galls and giant cells were present in roots inoculated only with m. incognita. p ...198819290224
effect of meloidogyne incognita and m. javanica on leaf water potential and water use of tobacco.greenhouse lysimeter and field microplot tests were conducted to evaluate the effects of meloidogyne incognita and m. javanica on plant water relations and growth performance of nc 2326 flue-cured tobacco. in the greenhouse, afternoon leaf water potential values at 8-11 weeks after transplanting were lower by as much as 0.22 mpa in plants infected with either nematode than in the control plants. from 11 to 22 weeks, leaf water potential values were similar in all treatments. over the course of t ...198819290249
pasteuria thornei sp. nov. and pasteuria penetrans sensu stricto emend., mycelial and endospore-forming bacteria parasitic, respectively, on plant-parasitic nematodes of the genera pratylenchus and meloidogyne.descriptions are presented of two members of the pasteuria penetrans group of mycelial and endospore-forming bacteria, parasitic on plant-parasitic nematodes. in one case, the epithet p. penetrans sensu stricto emend. has now been limited to members of this group with cup-shaped sporangia and ellipsoidal endospores, parasitic primarily on the root-knot nematode meloidogyne incognita. the second organism, with rhomboidal sporangia and nearly spherical endospores, which is parasitic primarily on t ...19883382544
screening of a granular chelate of metham-zinc for nematicidal activity using citrus and root-knot nematodes.a granular formulation of a chelate of metham-zinc (cmz) which liberates the biocidal methyl isothiocyanate was tested for nematicidal activity on tylenchulus semipenetrans in a jar soil screening and on meloidogyne javanica (greenhouse test) and m. incognita (field test) infecting tomato. comparisons were made with 1,3-d in the jar and pot experiments. the cmz caused only 3.9% mortality of citrus nematode juveniles at 1.0 mug a.i./g soil, but 95.4% mortality at 10.0 mug a.i./g and 100.0% at 100 ...198819290294
characterization of carbohydrates on the surface of second-stage juveniles of meloidogyne spp.fluorescent conjugates of the lectins soybean agglutinin (sba), concanavalin a (con a), wheat germ agglutinin (wga), lotus tetragonolobus agglutinin (lot), and limulus polyphemus agglutinin (lpa) bound primarily to amphidial openings and amphidial secretions of viable, preinfective second-stage juveniles (j2) of meloidogyne incognita races 1 and 3 (mil, mi3) and m. javanica (mj). no substantial difference in fluorescent lectin binding was observed among the populations examined. binding of only ...198819290262
extremely sensitive thermotaxis of the nematode meloidogyne incognita.eggs of the root-knot nematode meloidogyne incognita were acclimated to 23 c. newly hatched second-stage juveniles migrated toward higher temperatures when placed in shallow thermal gradients averaging 23 c. the threshold gradient for this response was below 0.001 c/cm, with a best estimate of 4 x 10 c/cm. calculations of physical limitations on thermotaxis indicate that this sensitivity is well within the limits of what is physically possible.198819290261
growth and energy demand of meloidogyne incognita on susceptible and resistant vitis vinifera cultivars.food (energy) consumption rates ofmeloidogyne incognita were calculated on vitis vinifera cv. french colombard (highly susceptible) and cv. thompson seedless (moderately resistant). one-month-old grape seedlings in styrofoam cups were inoculated with 2,000 or 8,000 m. incognita second-stage juveniles (j2) and maintained at 17.5 degree days (dd - base 10 c)/day until maximum adult female growth and (or) the end of oviposition. at 70 dd intervals, nematode fresh biomass was calculated on the basis ...198819290253
relationship between egg viability and population densities of meloidogyne incognita on cotton.cotton seedlings were inoculated with a range of initial populations (pi) of meloidogyne incognita in greenhouse experiments to test the relationship between nematode population densities and egg viability. in two of three experiments, a significant (p < 0.05) negative linear relationship was detected between percentage of hatch of first generation eggs and log pi. a similar relationship between hatch and root-gall index was observed. in two experiments numbers of eggs judged to be nonviable bas ...198819290248
meloidogyne incognita and tomato response to thiamine, ascorbic acid, l-arginine, and l-glutamic acid.the influence of solutions of ascorbic acid, thiamine, l-arginine, and l-gtutamic acid on egg hatch, juvenile survival, and development and reproduction of meloidogyne incognita in susceptible and resistant tomatoes was studied. maximum inhibition of egg hatch occurred at 2,000, 4,000, and 2,000 ppm for ascorbic acid, l-arginine, and l-glutamic acid, respectively. larval survival was significantly reduced by concentrations of 2,000 ppm ascorbic acid and 1,000 ppm of l-arginine. maximum inhibitio ...198819290237
behavioral responses of meloidogyne incognita to small temperature changes.small, rapid temperature changes were generated by incandescent radiation, and behavioral responses of meloidogyne incognita juveniles were recorded with high time resolution by computer tracking. temperature changes away from the preferred temperature resulted in decreases in the rate of movement and increases in the rate of change of direction, whether the changes were toward warmer or cooler temperatures. these behavioral changes lasted about 30 seconds. temperature changes toward the preferr ...198819290222
α-tomatine and resistance of tomato cultivars toward the nematode,meloidogyne incognita.susceptible and resistant tomato cultivars were assayed for root tomatine concentrations at different developmental times. no correlation between high tomatine levels and resistance towardmeloidogyne incognita was apparent. in plants infected with nematodes, tomatine in the roots was the same as in uninfected controls. tomatine concentration, as measured by bulk analysis, does not appear to play an important role in resistance toward the nematode studied.198824276208
lectin binding sites on the amphidial exudates of meloidogyne.lectin binding sites on the surface of meloidogyne incognita races 1, 2, 3, and 4; m. javanica; m. arenaria races 1 and 2; and m. hapla races a and b were determined with lectins conjugated to fluorescein isothiocyanate or colloidal gold. the amphidial exudate, which was demonstrated histochemically to contain carbohydrate, was the principal binding site. some lectins also bound to the external cuticular surface. species and race specific binding patterns were observed for both amphidial and cut ...198819290216
ultrastructural cytochemistry of secretory granules of esophageal glands of meloidogyne incognita.ultrastructural cytochemical tests for several enzymes, proteins, carbohydrates, and nucleic acids were conducted on secretory granules o pound dorsal and subventral esophageal glands of preparasitic second-stage juveniles and the dorsal gland of adult females of meloidogyne incognita. secretory granules in the subventral glands of juveniles stained positive for acid phosphatase. peroxidase, dnase, rnase, cellulase, and nucleic acids were not detected in these granules. secretory granules in the ...198819290195
winter survival of meloidogyne incognita in six soil types.winter survival of meloidogyne incognita in six soil types (fuquay sand, norfolk loamy sand, portsmouth loamy sand, muck, cecil sandy clay loam, and cecil sandy clay) was determined in microplots at one location from november 1981 to may 1982 and from november 1982 to march 1983. survival, based on second-stage juveniles (j2) of m. incognita, from november 1981 until may 1982 ranged from 1% in the muck soil to 6% in a cecil sandy clay loam, but survival rates were much higher the next year follo ...198819290193
histopathology of root-knot nematode (meloidogyne incognita) infection on white yam (dioscorea rotundata) tubers.white yam tissues naturally and artificially infected with root-knot nematodes were fixed, sectioned, and examined with a microscope. infective second-stage juveniles of meloidogyne incognita penetrated and moved intercellularly within the tuber. feeding sites were always in the ground tissue layer where the vascular tissues are distributed in the tubers. giant cells were always associated with xylem tissue. they were thin walled with dense cytoplasm and multinucleated. the nuclei of the giant c ...198819290181
encapsulation of meloidogyne incognita eggs in carrageenan. 198919287650
drip irrigation as a delivery system for infestation of field plots with nematodes.a drip irrigation delivery system was used to infest field sites with the plant-parasitic root-knot nematodes, meloidogyne incognita. juvenile or egg inocula passed through the system without blockage of emitters or harm to the nematodes. field sites so infested were available for experimentation. delivery of approximately 5 x 10 to 10 juveniles or 10 to 3 x 10 eggs per emitter through the drip system resulted in heavy root galling of tomatoes planted next to the drip emitters. nematodes feeding ...198919287648
neoplastic growths in preparasitic juveniles of meloidogyne incognita. 198919287632
endoparasitic nematodes in maize roots in the western transvaal as related to soil texture and rainfall.eight endoparasitic nematode species were recovered from 170 maize root samples in western transvaal, republic of south africa. pratylenchus zeae had the highest average population density (17,454/5 g roots), followed by p. neglectus (5,827/5 g roots), p. penetrans (5,617/5 g roots), p. brachyurus (3,060/5 g roots), meloidogyne incognita plus m. javanica (301 juveniles/5 g roots), p. crenatus (130/5 g roots), and rotylenchutus parvus (64/5 g roots). the 17 reasonably homogeneous farming areas (r ...198919287620
influence of environmental factors on the hatch and survival of meloidogyne incognita.the influence of soil temperature and moisture on meloidogyne incognita (kofoid and white) chitwood was examined in relation to hatching and survival of second-stage juveniles (j2). nematodes were cultured on cotton (gossypium hirsutum l. cv. acala sj2) under field conditions to provide populations similar to those found in the field in late autumn. egg masses were placed in a temperature range (9-12 c and 21 c), and hatch was measured over a period equivalent to 20 degree days > 10 c (dd10). ha ...198919287616
progression of root-knot nematode symptoms and infection on resistant and susceptible cottons.progressive development in cotton root morphology of resistant a623 and susceptible m-8 cotton (gossypium hirsutum l.) lines following infection by the root-knot nematode meloidogyne incognita was studied in glass front boxes. symptom development and radicle growth were observed; degree of galling, gall and egg mass diameter, and number of eggs per egg mass were recorded; and root segments were examined histologically. small cracks caused by m. incognita appeared in the root epidermis and cortex ...198919287602
root tissue response of two related soybean cultivars to infection by lectin-treated meloidogyne spp.treatment of second-stage juveniles (j2) of meloidogyne incognita race 1 and m. javanica with soybean agglutinin, concanavalin a, wheat germ agglutinin, lotus tetragonolobus agglutinin, or limax flavus agglutinin or the corresponding competitive sugars for each of these lectins did not alter normal root tissue response of soybean cultivars centennial and pickett 71 to infection by m. incognita race 1 or m. javanica. giant cells were frequently induced in centennial and pickett 71 roots 5 and 20 ...198919287600
structure-activity studies on nematicidal activity of dialkyl carbamates and thiocarbamates.in laboratory tests, 129 dialkyl carbamates of types roc(o)nhr', rsc(o)nhr', and roc(s)nhr' were tested in a screening bioassay against panagrellus redivivus. the 10 most active were lethal at concentrations from 5 ppm down to ca. 1 ppm. eight of these (the only ones active below 2.5 ppm) were thiolcarbamates (rsc(o)nhr'). decyl n-methyhhiolcarbamate was also lethal to meloidogyne incognita at approximately 1 ppm in direct contact tests.198919287593
in situ observations of root-gall formation using nuclear magnetic resonance imaging. 198919287587
preferred temperature of meloidogyne incognita.in laboratory thermal gradients, newly hatched infective juveniles of the plant-parasitic root-knot nematode meloidogyne incognita migrated toward a preferred temperature that was several degrees above the temperature to which they were acclimated. after shifting egg masses to a new temperature, the preferred temperature was reset in less than a day. possible functions of this type of thermotaxis are discussed, including the use of thermal gradients around plant roots to locate hosts and to main ...198919287582
overwintering stages of meloidogyne incognita in vitis vinifera.the overwintering of meloidogyne incognita in and around vitis vinifera cv. french colombard roots was studied in a naturally infested vineyard at the kearney agricultural center, in a growth chamber, in inoculated vines in microplots at the university of california, davis, and in a greenhouse. infected roots were sampled at intervals from onset of vine dormancy until plants accumulated about 800 degree days (dd - base 10 c). embryogenesis within eggs, classified as less than or more than 16 cel ...198919287581
impact of meloidogyne incognita on physiological efficiency of vitis vinifera.four-week-old french colombard plants rooted from green cuttings were inoculated with 0, 1,000, 2,000, 4,000, or 8,000 meloidogyne incognita second-stage juveniles and maintained at 25 c night and 30 c day. leaf area and dry weight and the rates of photosynthesis, stomatal conductance, and internal leaf co concentration were measured at intervals up to 59 days after inoculation. nematode stress dosage, measured as the product of cumulative number of juveniles and females and their total energy ( ...198919287578
influence of glomus intraradices and soil phosphorus on meloidogyne incognita infecting cucumis melo.the interaction among glomus intraradices, meloidogyne incognita, and cantaloupe was studied at three soil phosphorus (p) levels in a greenhouse. all plants grew poorly in soil not amended with p, regardless of mycorrhizal or nematode status. in soil amended with 50 mug p /g soil, m. incognita suppressed the growth of nonmycorrhizal plants by 84%. in contrast, growth of mycorrhizal plants inoculated with m. incognita was retarded by only 21%. a similar trend occurred in plants grown in soil with ...198919287577
resistance to meloidogyne spp. in allohexaploid wheat derived from triticum turgidum and aegilops squarrosa.expression of resistance to meloidogyne incognita and m. javanica from aegilops squarrosa was studied in a synthetic allohexaploid produced from triticum turgidum var. durum cv. produra and ae. squarrosa g 3489. the reproductive rate of different races of m. incognita and m. javanica, expressed in eggs per gram of fresh root, was low (p < 0.05) on the synthetic allohexaploid and the resistant parent, ae. squarrosa g 3489, compared with different bread and durum wheat cultivars. reproduction of r ...198919287575
impact of paecilomyces lilacinus inoculum level and application time on control of meloidogyne incognita on tomato.microplot experiments were conducted to evaluate the effects of inoculum level and time of application of paecilomyces lilacinus on the protection of tomato against meioidogyne incognita. the best protection against m. incognita was attained with 10 and 20 g of fungus-infested wheat kernels per microplot which resulted in a threefold and fourfold increase in tomato yield, respectively, compared with tomato plants treated with this nematode alone. greatest protection against this pathogen was att ...198919287585
survival of paecilomyces lilacinus in selected carriers and related effects on meloidogyne incognita on tomato.laboratory and microplot experiments were conducted to determine the influence of carrier and storage of paecilomyces lilacinus on its survival and related protection of tomato against meloidogyne incognita. spores of p. lilacinus were prepared in five formulations: alginate pellets (pellets), diatomaceous earth granules (granules), wheat grain, soil, and soil plus chitin. fungal viability was high in wheat and granules, intermediate in pellets, and low in soil and chitin-amended soil stored at ...198919287586
growth of isolates of paecilomyces lilacinus and their efficacy in biocontrol of meloidogyne incognita on tomato.the potential of 13 paecilomyces lilacinus isolates from various geographic regions as biocontrol agents against meloidogyne incognita, the effects of temperature on their growth, and the characterization of the impact of soil temperature on their efficacy for controlling this nematode were investigated. maximum fungal growth, as determined by dry weight of the mycelium, occurred from 24 to 30 c; least growth was at 12 and 36 c. the best control of m. incognita was provided by an isolate from pe ...198919287594
influence of four nematodes on root and shoot growth parameters in grape.two grape cultivars, susceptible french colombard and tolerant rubired, and four nematodes, meloidogyne incognita, pratylenchus vulnus, tylenchulus semipenetrans, and xiphinema index, were used to quantify the equilibrium between root (r) and shoot (s) growth. root and shoot growth of french colombard was retarded by m. incognita, p. vulnus, and x. index but not by t. semipenetrans. although the root growth of rubired was limited by all the nematodes, the shoot growth was limited only by x. inde ...198919287609
accelerated movement of nematodes from soil in baermann funnels with temperature gradients.baermann funnels were modified to eliminate or reverse the small temperature gradient (1-2 c/cm) across the soil layer that normally results from water evaporation. effects of modifications on extraction efficiency were examined at various ambient temperatures and after overnight adaptation of three nematode species at 20 and 30 c. extraction of meloidogyne incognita from sandy loam, tylenchulus semipenetrans from sandy clay loam, and rotylenchulus reniformis from silt was greatly accelerated si ...198919287622
monoclonal antibodies to secretory granules in esophageal glands of meloidogyne species.monoclonal antibodies to secretory granules in the dorsal or subventral esophageal glands were generated by injecting balb/c mice with immunogens from preparasitic second-stage juveniles (j2) of meloidogyne incognita. antibodies specific for secretory granules in the j2 subventral esophageal glands or the dorsal gland were identified by indirect immunofluorescence microscopy. only antibodies that reacted with granules in the j2 dorsal gland reacted with the esophageal gland lobe ofm. incognita a ...198919287625
effects and dynamics of a nematode community on maize.relationships between nematode density and yield and between final and preplant population levels were examined in small maize plots on sandy soils in north-central florida. plant-parasitic nematodes present in the community included belonolaimus longicaudatus, criconemella sphaerocephala, meloidogyne incognita, paratrichodorus minor, pratylenchus brachyurus, and a xiphinema sp. plant growth--including stand count, grain yield, stalk weight, and size of young plants--often was inversely correlat ...198919287639
effects and dynamics of a nematode community on soybean.the relationships between densities of all members of a plant-parasitic nematode community and yield of 'davis' soybean and between final and preplant population levels were examined in small plots on sandy soils in north-central florida. plant-parasitic nematodes present in the community included belonolaimus longicaudatus, criconemella sphaerocephala, meloidogyne incognita, paratrichodorus minor, pratylenchus brachyurus, and xiphinema sp. plant growth, including stand count, soybean yield (kg/ ...198919287643
managing root-knot on tobacco in the southeastern united states.root-knot nematodes suppress yields of flue-cured tobacco an estimated 0.1 to 4.8% annually in the southeastern united states, even though nematode management practices have been widely adopted. although meloidogyne incognita races 1 and 3 have predominated, m. arenaria, m. javanica, and m. incognita races 2 and 4 are increasingly important. seventy-five percent of the flue-cured tobacco hectarage in north carolina and virginia is rotated on 2-year or 3-year intervals. over half of the hectarage ...198919287655
dna complexity of the root-knot nematode (meloidogyne spp.) genome.cot curves derived from renaturation kinetics of sheared denatured dna indicated that the genome of six populations representing the four most common root-knot nematode species (meloidogyne incognita, m. arenaria, m. javanica, and m. hapla) is composed of 20% repetitive and 80% nonrepetitive sequences of dna. cot curves were almost identical, indicating that all populations had a haploid genome of approximately the same size. calculations from an average cot curve gave an estimate of 0.51 x 108 ...198919287606
host suitability of soybean cultivars for meloidogyne incognita and m. arenaria.the suitability of five maturity group (mg) iii and five mg iv soybean, glycine max, cultivars as hosts for meloidogyne incognita and m. arenaria was evaluated in a greenhouse. 'forrest', a mg v cultivar, was used as the standard of comparison for m. incognita resistance. with m. incognita, root-gall and egg-mass indices and reproductive factors for 'asgrow 3307', 'ffr 398', and 'pioneer 9442' were comparable with those found on forrest. meloidogyne arenaria reproduction was lower (p </= 0.05) o ...198919287669
suitability of small grains as hosts of meloidogyne species.seven cultivars of wheat, five of oat, one of rye, and four of barley were tested as hosts for meloidogyne incognita, m. javanica, or m. arenaria under greenhouse conditions where soil temperature ranged from 21 to 34 c. reproduction rates of all nematode species were high on all cultivars, except m. javanica and m. arenaria on 'brooks' and 'florida 501' oat. meloidogyne incognita and m. javanica produced more eggs on roots of 'rutgers' tomato than on cultivars of wheat, oat, rye, or barley.198919287666
effect of carbamate, organophosphate, and avermectin nematicides on oxygen consumption by three meloidogyne spp.second-stage juveniles (i2) of meloidogyne arenaria consumed more oxygen (p </= 0.05) than m. incognita j2, which in turn consumed more than m. javanica j2 (4,820, 4,530, and 3,970 mul per hour per g nematode dryweight, respectively). decrease in oxygen consumption depended on the nematicide used. except for aldicarb, there was no differential sensitivity among the three nematode species. meloidogyne javanica had a greater percentage decrease (p </= 0.05) in oxygen uptake when treated with aldic ...198919287640
resistance in lycopersicon peruvianum to isolates of mi gene-compatible meloidogyne populations.root-knot nematode resistance of f progeny of an intraspecific hybrid (lycopersicon peruvianum var. glandulosum acc. no. 126443 x l. peruvianum acc. no. 270435), l. esculentum cv. piersol (possessing resistance gene mi), and l. esculentum cv. st. pierre (susceptible) was compared. resistance to 1) isolates of two meloidogyne incognita populations artificially selected for parasitism on tomato plants possessing the mi gene, 2) the wild type parent populations, 3) four naturally occurring resistan ...199019287762
development, distribution, and host studies of the fungus macrobiotophthoira vermicola (entomophthorales).the life cycle and host range of macrobiotophthora vermicola were studied. secondary spores produced from forcibly ejected primary spores adhered to the cuticle of cruznema tripartitum, germinated, and penetrated the cuticle within 30 minutes. new primary spores were produced within 24 hours of initial spore adhesion. in a host range study, species of rhabditidae, diplogasteridae, and aphelenchoidea were hosts, but not species of bunonematidae, tripylidae, cephalobida, or tylenchina. numbers of ...199019287687
effects of soil fumigants and aldicarb on nematodes, tuber quality, and yield in potato.efficacy of the fumigants ethylene dibromide (edb), edb + chloropicrin, and 1,3-dichloropropene (1,3-d) applied with one or three chisels per row, singly or in combination with aldicarb, was evaluated in 1982 and 1983 on potato (solanum tuberosum) cultivars atlantic and sebago for control of several nematodes, including belonolaimus longicaudatus, meloidogyne incognita, and trichodorids. generally, nematode populations were lowest following application of fumigants with three chisels per row, fo ...199019287794
control of nematodes and soil-borne diseases in florida potatoes with aldicarb and 1,3-d.yields of u.s. size a potato tubers were increased by 1,3-dichloropropene (1,3-d) (56 liters/ha) and 1,3-d (56 liters/ha) + aldicarb (3.4 kg/ha) in 1982 and 1983 and by aldicarb (3.4 kg/ha) in 1982. treatments that included aldicarb provided the best control of corky ringspot disease, whereas those including 1,3-d were more effective against bacterial wilt. the most effective nematode control (nematodes included meloidogyne incognita, belonolaimus longicaudatus, trichodorids, criconemella ornata ...199019287795
vertical distribution of plant-parasitic nematodes in sandy soil under soybean.vertical distribution of five plant-parasitic nematodes was examined in two north florida soybean fields in 1987 and 1988. soil samples were collected from 0-15 cm, 15-30 cm, and 30-45 cm deep at each site. soil at the three depths consisted of approximately 96% sand. more than 50% of belonolaimus longicaudatus population densities occurred in the upper 15-cm soil layer at planting, but the species became more evenly distributed through the other depths as the season progressed. criconemella sph ...199019287693
meloidogyne incognita survival in soil infested with paecilomyces lilacinus and verticillium chlamydosporium.meloidogyne incognita-infected tomato seedlings were transplanted into sterilized soil or unsterilized soil collected from 20 california tomato fields to measure suppression caused by paecilomyces lilacinus, verticillium chlamydosporium, and other naturally occurring antagonists. unsterilized soils q, a, and h contained 35, 39, and 55% fewer m. incognita second-stage juveniles (j2) than did sterilized soil 1 month after infected tomato seedlings were transplanted to these soils and placed in a g ...199019287707
association of verticillium chlamydosporium and paecilomyces lilacinus with root-knot nematode infested soil.population densities of meloidogyne incognita and the nematophagous fungi, paecilomyces lilacinus and verticillium chlamydosporium, were determined in 20 northern california tomato fields over two growing seasons. paecilomyces lilacinus was isolated from three fields, v. chlamydosporium was isolated from one field, and both fungi were isolated from 12 fields. verticillium chlamydosporium numbers were positively correlated with numbers of m. incognita and p. lilacinus. paecilomyces lilacinus numb ...199019287711
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
reproduction of meloidogyne incognita on open-pollinated maize varieties.forty-three open-pollinated maize varieties were tested for resistance to the southern root-knot nematode, meloidogyne incognita race 4, in greenhouse tests. an experiment repeated on five different planting dates assessed nematode reproduction 60 days after inoculation with 3,000 eggs per plant. tebeau and old raccoon showed consistently high levels of resistance in all plantings, with the lowest reproduction factor (rf) values (0.2 and 0.4) and low numbers of eggs per gram of fresh root (222 a ...199019287774
interaction of three plant-parasitic nematodes on corn and soybean.interaction of belonolaimus longicaudatus, meloidogyne incognita, and pratylenchus brachyurus on corn and b. longicaudatus, m. incognita, and heterodera glycines on soybean was investigated in micropiots during two seasons for corn and one season for soybean. changes in population densities and effects on plant growth of each nematode on corn or soybean alone and in mixed culture were compared. no interactions occurred on corn in 1987. in 1988, midseason population densities of b. longicaudatus ...199019287797
identification of single meloidogyne juveniles by polymerase chain reaction amplification of mitochondrial dna.polymerase chain reaction (pcr) was used to amplify a specific 1.8-kb sequence of mitochondrial dna from single juveniles and eggs from 17 populations of meloidogyne incognita, m. hapla, m. javanica, and m. arenaria. approximately 2 mug amplified product were produced per reaction. restriction digestion of the amplified product with hinfi permitted discrimination of clonal lineages of the four species. meloidogyne javanica, however, could not be separated from m. hapla by the enzymes used in the ...199019287752
effects of planting date, small grain crop destruction, fallow, and soil temperature on the management of meloidogyne incognita.the effects of planting date, rye (secale cereale cv. wren abruzzi) and wheat (triticura aestivum cv. coker 797), crop destruction, fallow, and soil temperature on managing meloidogyne incognita race 1 were determined in a 2-year study. more m. incognita juveniles (j2) and egg-producing adults were found in roots of rye planted 1 october than in roots of rye planted 1 november and wheat planted 1 november and 1 december. numbers of m. incognita adults with and without egg masses were near or bel ...199019287731
strong repellency of the root knot nematode,meloidogyne incognita by specific inorganic ions.simple inorganic salts of the ions k(+), nh 4 (+) , cs(+), no 3 (-) , and cl(-) are strongly repellent to infective second-stage larvae of the root knot nematode,meloidogyne incognita. some of these salts are known to be beneficial to plant growth. the results suggest a new means of plant protection.199024263720
response of resistant soybean plant introductions to meloidogyne incognita in field microplots.the response of two soybean plant introductions, pi 96354 and pi 417444, highly resistant to meloidogyne incognita, to increasing initial soil population densities (pi) (0, 31, 125, and 500 eggs/100 cm(3) soil) of m. incognita was studied in field microplots for 2 years. the plant introductions were compared to the cultivars forrest, moderately resistant, and bossier, susceptible to m. incognita. averaged across years, the yield suppressions of bossier, forrest, pi 417444, and pi 96354 were 97, ...199019287716
physiological response of resistant and susceptible vitis vinifiera cultivars to meloidogyne incognita.the effect of meloidogyne incognita on growth, general physiological response, and the concentration of reducing and nonreducing sugars at the nematode feeding sites of french colombard (susceptible) and thompson seedless (moderately resistant) vitis vinifiera cultivars was studied up to 2,100 degree-days (dd-base 10 c). nematode stress dosage, measured as the product of cumulative number of juveniles and females and their total energy (calories) demand, accounted for up to 15 and 10% of the ene ...199019287714
effects of cowpea and maize root leachates on meloidogyne incognita egg hatch. 199019287701
invasion of tomato roots and reproduction of meloidogyne incognita as affected by raw sewage sludge.the antagonistic effects of raw sewage sludge on infection of tomato by meloidogyne incognita were tested in greenhouse pot experiments. sludge was mixed with the soil or added on its surface before and after inoculation of tomato plants with nematode eggs. juvenile penetration was determined 1 and 10 days after inoculation, and 6 weeks later root systems were assessed for nematode reproduction. fewer juveniles penetrated roots in pots with sludge added to the soil than in unamended control pots ...199119283192
nematode population changes and forage yields of six corn and sorghum cultivars.two temperate corn (zea mays) hybrids (pioneer 3320 and northrup king 508), two tropical corn cultivars (pioneer x304c hybrid and florida syn-1 experimental open pollinated cultivar), the sorghum (sorghum bicolor) x sudangrass (sorghum sudanense) hybrid dekalb sx-17, and the sorghum hybrid dekalb fs25e were compared for effect on nematode densities and forage yield in three plantings (one single-crop and one double-crop system) in florida. final population densities of meloidogyne incognita in t ...199119283183
nematode densities associated with corn and sorghum cropping systems in florida.final densities (pf) of meloidogyne incognita and pratylenchus spp. increased more than ten-fold over initial densities (pi) on corn (zea mays) cultivars grown at three sites in north florida. the pf of m. incognita following sorghum (sorghum bicolor) were much lower (p </=0.001) than pf following corn at the two sites in which sorghum was grown. at one of these sites, pf of m. incognita was </= 5/100 cm(3) soil, and at the other site pf < pi. at one site, population densities of criconemella sp ...199119283182
response of tomato cultigens to meloidogyne javanica and races of meloidogyne incognita.thirty-six cultigens of tomato were evaluated for resistance against meloidogyne javanica and four races of m. incognita with standards and parameters adopted by the international meloidogyne project. most cultigens were susceptible to the nematodes, including some that were previously reported to be resistant to these nematodes. ten accessions, namely pusa-120, calmart vfn, panjab 6.nr-7, ec173898 (72t6), ec173897 (cal-mart), ec173896 (kewalo), cln363bcf-167-1-0, cln363bcf-190-1-0, cln363bcf-34 ...199119283169
reaction of trifolium repens cultivars and germplasms to meloidogyne incognita.ten cultivars and 13 germplasms of white clover (trifolium repens) were evaluated in the greenhouse for resistance to the southern root-knot nematode, meloidogyne incognita race 4. one hundred plants of each cultivar or germplasm were rated for percentage of the root system galled (prsg) at 60 days after inoculation with root-knot nematode eggs. tillman (9%) and srvr (19%) had the highest percentage of resistant plants (prsg = 0 or 1 on a scale of 0-5 ) for the cultivars and germplasms, respecti ...199119283168
interaction of meloidogyne incognita and water stress in two cotton cultivars.a series of controlled-environment experiments were conducted to elucidate the effects of meloidogyne incognita on host physiology and plant-water relations of two cotton (gossypium hirsutum) cultivars that differed in their susceptibility to nematode infection. inoculation of m. incognita-resistant cultivar auburn 634 did not affect growth, stomatal resistance, or components of plant-water potential relative to uninoculated controls. however, nematode infection of the susceptible cultivar stone ...199119283156
infection of cultured thin cell layer roots of lycopersicon esculentum by meloidogyne incognita.a new aseptic culture system for studying interactions between tomato (lycopersicon esculentum) and meloidogyne incognita is described. epidermal thin cell layer explants from peduncles of tomato produced up to 20 adventitious roots per culture in 4-9 days on murashige &scoog medium plus kinetin and indole acetic acid. rooted cultures were transferred to gamborg's b-5 medium and inoculated with infective second-stage juveniles. gall formation was apparent 5 days after inoculation and egg product ...199119283152
evidence against amplification of four genes in giant cells induced by meloidogyne incognita.giant-cell dna was isolated from pea (pisum sativum) inoculated with meloidogyne incognita and used in slot blots to test for selective sequence amplification. four sequences representing low (ribulose 1,5-bisphosphate carboxylase and actin), mid-level (histone 3), and highly repetitive (large ribosomal repeat) sequence dna were used as probes. known amounts of root-tip dna and giant-cell dna were blotted onto hybridization membranes and probed. the signal strength on autoradiographs containing ...199119283148
plant protection with inorganic ions.gradients of salts of the specific ion repellents for meloidogyne incognita -- nh, k, cl, and no -- have been demonstrated to shield tomato roots from infestation in soil. the strategy of these greenhouse experiments was to interpose a salt barrier in a soil column between the plant roots and the nematodes. the relative effectiveness of the salts as a barrier to infective second-stage juveniles in a sandy loam was nhno, nhcl > kno > kcl. some of these ions are beneficial to plant growth, and the ...199119283146
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