| 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 ... | 1997 | 19274170 |
| relationship between meloidogyne incognita and rotylenchulus reniformis as influenced by soybean genotype. | the effect of soybean genotype on competition between meloidogyne incognita race 2 (mi) and rotylenchulus reniformis (rr) was evaluated in greenhouse and microplot replacement series experiments. soil in pots containing seedlings of 'davis' (susceptible to mi) or 'buckshot 66' (resistant to mi) was infested with 1,000 vermiform individuals in the following mi:rr ratios: 0:0, 100:0, 75:25, 50:50, 25:75, or 0:100. after 91 days, the relative nematode yields (number of nematodes in mixed culture di ... | 1997 | 19274173 |
| 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 ... | 1997 | 19274192 |
| effects of monoclonal antibodies, cationized ferritin, and other organic molecules on adhesion of pasteuria penetrans endospores to meloidogyne incognita. | the incidence of adhesion of pasteuria penetrans endospores to meloidogyne incognita second-stage juveniles (j2) was studied after pretreatment of the latter with monoclonal antibodies (mab), cationized ferritin, and other organic molecules in replicated trials. monoclonal antibodies developed to a cuticular epitope of m. incognita second-stage juveniles gave significant reductions in attachment of p. penetrans endospores to treated nematodes. mab bound to the entire length of j2 except for the ... | 1997 | 19274193 |
| pathogenicity of pratylenchus penetrans, heterodera glycines, and meloidogyne incognita on soybean genotypes. | the pathogenicity of heterodera glycines, meloidogyne incognita, and pratylenchus penetrans on h. glycines-resistant 'bryan,' tolerant-susceptible 'g88-20092,' and intolerant-susceptible 'tracy m' soybean cultivars was tested using plants grown in 800 cm(3) of soil in 15-cm-diam. clay pots in three greenhouse experiments. plants were inoculated with 0, 1,000, 3,000, or 9,000 h. glycines race 3 or m. incognita eggs, or vermiform stages of p. penetrans/pot. forty days after inoculation, nmnbers of ... | 1998 | 19274203 |
| peanut-cotton-rye rotations and soil chemical treatment for managing nematodes and thrips. | in the southeastern united states, a cotton-peanut rotation is attractive because of the high value and extensive planting of both crops in the region. the objective of this experiment was to determine the effects of cotton-peanut rotations, rye, and soil chemical treatments on management of plant-parasitic nematodes, thrips, and soilborne fungal diseases and on crop yield. peanut-cotton-rye rotations were conducted from 1988 to 1994 on tifton loamy sand (plinthic kandiudult) infested primarily ... | 1998 | 19274213 |
| review of pasteuria penetrans: biology, ecology, and biological control potential. | pasteuria penetrans is a mycelial, endospore-forming, bacterial parasite that has shown great potential as a biological control agent of root-knot nematodes. considerable progress has been made during the last 10 years in understanding its biology and importance as an agent capable of effectively suppressing root-knot nematodes in field soil. the objective of this review is to summarize the current knowledge of the biology, ecology, and biological control potential of p. penetrans and other past ... | 1998 | 19274225 |
| crop yields and nematode population densities in triticale-cotton and triticale-soybean rotations. | triticale cv. beagle 82, cotton cv. mcnair 235, and soybean cv. twiggs were arranged in three cropping sequences to determine the effects of fenamiphos and cropping sequence on nematode population densities and crop yields under conservation tillage for 4 years. the cropping sequences were triticale (t)-cotton (c)-t-c, t-soybean (s)-t-s, and t-c-t-s. numbers of meloidogyne incognita second-stage juveniles declined on trificale but increased on cotton and soybean each year. root-gall indices of c ... | 1998 | 19274228 |
| 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 ... | 1998 | 19274243 |
| velvetbean and bahiagrass as rotation crops for management of meloidogyne spp. and heterodera glycines in soybean. | soybean (glycine max) yield often is limited by the phytoparasitic nematodes meloidogyne spp. and heterodera glycines in the southeastern united states. we studied the effects of rotation with bahiagrass (paspalum notatum), velvetbean (mucuna pruiens), or continuous soybean, aldicarb, and soybean cultivar on yield and population densities in two fields infested with a mixture of meloidogyne spp. and h. glycines. velvetbean and bahiagrass reduced population levels of both nematode species to near ... | 1998 | 19274247 |
| minimal growth temperature of pasteuria penetrans. | pasteuria penetrans is an obligate, mycelial, and endospore-forming bacterial parasite of meloidogyne spp. with promise for the management of root-knot nematodes. our objective was to use regression analysis of developmental time (days) to various temperatures to determine the minimal temperature for growth and development of p. penetrans in meloidogyne spp. the data set for regression originated from a previously published report. the data fit well to hyperbolic equations. for various developme ... | 1997 | 19274263 |
| host range and distribution of the clover root-knot nematode, meloidogyne trifoliophila. | the ability of meloidogyne trifoliophila to gall 230 species and cultivars of plants was determined in a greenhouse. all clovers (trifolium spp.) were severely galled regardless of species or cultivar. most soybean cultivars were moderately to severely galled. among other legumes, broad bean, garden pea, korean lespedeza, sweetclover, and common vetch were good hosts, but alfalfa, bird's-foot trefoil, peanut, and pole bean were poor or nonhosts. among other plant families, most apiaceae (umbelli ... | 1997 | 19274266 |
| evaluation of 15 trifolium spp. and of medicago sativa as hosts of four meloidogyne spp. found in new zealand. | the predominant root-knot nematode in new zealand pastures is meloidogyne trifoliophila, identified until recently as m. hapla. clarification was needed on the host range of these two species on legumes found in new zealand pastures and on clover species closely related to trifolium repens. in a greenhouse test, 15 trifolium spp. and medicago sativa were inoculated with eggs of m. trifoliophila, m. hapla, m. incognita, or m. javanica. all legumes tested were hosts to some degree to each of the r ... | 1997 | 19274267 |
| nematicidal activity of fatty acid esters on soybean cyst and root-knot nematodes. | researchers have indicated that the c fatty acid, pelargonic acid (nonanoic acid), has considerable nematicidal activity that could be increased by derivitization and improved emulsification. microemulsions of methyl and ethylene glycol esters of pelargonic acid developed by mycogen corporation (san diego, ca) were tested for nematicidal activity against root-knot and soybean cyst nematodes. all treamaents were compared to a deionized water control and a microemulsion "blank" (minus active ingre ... | 1997 | 19274268 |
| coastal bermudagrass rotation and fallow for management of nematodes and soilborne fungi on vegetable crops. | the efficacy of clean fallow, bermudagrass (cynodon dactylon) as a rotational crop, and fenamiphos for control of root-knot nematode (meloidogyne incognita race 1) and soilborne fungi in okra (hibiscus esculentus), snapbean (phaseolus vulgaris), and pepper (capsicum annuum) production was evaluated in field tests from 1993 to 1995. numbers of m. incognita in the soil and root-gall indices were greater on okra than on snapbean or pepper. application of fenamiphos at 6.7 kg a.i./ha did not suppres ... | 1997 | 19274273 |
| 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 ... | 1997 | 19274278 |
| resistance to meloidogyne incognita race 3 and rotylenchulus reniformis in wild accessions of gossypium hirsutum and g. barbadense from mexico. | forty-six accessions of g. hirsutum and two of g. barbadense were examined for resistance to meloidogyne incognita race 3 and rotylenchulus reniformis in environmental growth chamber experiments, with the objective of finding new sources of resistance. only the g. barbadense accessions, tx-1347 and tx-1348, supported significantly less reproduction by r. reniformis than the susceptible control, deltapine 16 (usda accession sa-1186). however, they were highly susceptible to m. incognita race 3. t ... | 1997 | 19274280 |
| 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 ... | 1996 | 19277131 |
| meloidogyne paranaensis n. sp. (nemata: meloidogynidae), a root-knot nematode parasitizing coffee in brazil. | a root-knot nematode parasitizing coffee in paran state, brazil, is described as meloidogyne paranaensis n. sp. the suggested common name is paraná coffee root-knot nematode. the perineal pattern is similar to that of m. incognita; the labial disc and medial lips of the female are fused and asymmetric and rectangular; the lateral lips are small, triangular, and fused laterally with the head region. the female stylet is 15.0-17.5 mum long, with broad, distinctly set-off knobs; the distance from t ... | 1996 | 19277133 |
| attachment of pasteuria penetrans endospores to the surface of meloidogyne javanica second-stage juveniles. | pasteuria penetrans spore adhesion to meloidogyne javanica second-stage juveniles (j2) was examined following several different pretreatments of the latter. the detergents sodium dodecyl sulfate and triton x-100, the carbohydrates fucose and alpha-methyl-d-mannoside, and the lectins concanavalin a and wheat germ agglutinin reduced spore attachment. spores exposed to m. javanica surface coat (sc) extract exhibited decreased adherence to the j2 surface. second-stage juveniles that had been treated ... | 1996 | 19277150 |
| meloidogyne incognita infested soil amended with chicken litter. | the effects of chicken litter on meloidogyne incognita in cotton, gossypium hirsutum cv. dpl50 were determined in field microplots. litters (manure and pine-shaving bedding) from a research facility and a commercial broiler house were used. treatments consisted of 0.25%, 0.5%, and 1% litter by dry weight of soil for each kind of litter. three control treatments consisted of soil not amended with litter, with and without nematodes, and one treatment to which mineral fertilizer was added at a nitr ... | 1996 | 19277155 |
| glucuronidase expression in transgenic tobacco roots with a parasponia promoter on infection with meloidogyne javanica. | the expression of a g-us reporter gene linked to a parasponia andersonii hemoglobin promoter has been studied in transgenic tobacco plants after infection by meloidogyne javanica. transgenic roots were harvested at different times after nematode inoculation, and stained histochemically for expression of the gus gene. during the early stages of infection (0-2 weeks) there was little expression in giant cells, in contrast to other cells of the root. in later stages of infection (3-6 weeks) there w ... | 1996 | 19277159 |
| impact of soil texture on the reproductive and damage potentials of rotylenchulus reniformis and meloidogyne incognita on cotton. | the effects of soil type and initial inoculum density (pi) on the reproductive and damage potentials of meloidogyne incognita and rotylenchulus reniformis on cotton were evaluated in microplot experiments from 1991 to 1993. the equilibrium nematode population density for r. reniformis on cotton was much greater than that of m. incognita, indicating that cotton is a better host for r. reniformis than m. incognita. reproduction of m. incognita was greater in coarse-textured soils than in fine-text ... | 1996 | 19277171 |
| greenhouse evaluation of selected soybean germplasm for resistance to north carolina populations of heterodera glycines, rotylenchulus reniformis, and meloidogyne species. | selected soybean genotypes were evaluated for resistance to north carolina populations of the soybean cyst nematode heterodera glycines, the root-knot nematodes meloidogyne incognita races 3 and 4, m. arenaria races 1 and 2, m. javanica, and the reniform nematode rotylenchulus reniformis in two greenhouse tests. populations of cyst nematode used in the first test were cultures from field samples originally classified as races 1-5, and those used in the second test included inbred cyst lines that ... | 1996 | 19277179 |
| prunus rootstock evaluation to root-knot and lesion nematodes in spain. | two screening and one resistance verification trial involving 20 prunus rootstocks were conducted under greenhouse conditions against meloidogyne spp. and pratylenchus vulnus. most of the rootstocks were experimental genotypes or new commercial peach and plums of spanish and french origin. nearly all are interspecific hybrid rootstocks. in the first trial, the rootstocks bruce, cadaman, mirac, g x n no. 15, cachirulo x (g x n no. 9), and p. myra x peach were immune or resistant to a mixture of s ... | 1996 | 19277184 |
| 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 ... | 1996 | 19277193 |
| embryogenesis and postinfection development of meloidogyne konaensis. | the effects of temperature on embryogenesis and postinfection development in meloidogyne konaensis were examined. embryogenesis was evaluated at 5, 8, 10, 13, 16, 20, 22, 24, 26, 28, 30, 35, and 40 c. no embryonic development occurred at 5 c. some development, although incomplete, occurred at 8 and 10 c. the rate of embryogenesis was linear from 13 to 30 c, but decreased at 35 c. the lowest egg mortality occurred at 24 c, whereas all eggs died within 24 hours at 40 c. postinfection development w ... | 1995 | 19277267 |
| spatial-temporal patterns of meloidogyne konaensis on coffee in hawaii. | population densities ofmeloidogyne konaensis were determined in march and july of 1991 and 1992 on coffee cultivars guatemalan and 502, and on four rootstocks (purpuree, congensis, deweveri, and kaffe) with guatemalan or 502 as a scion. three-dimensional spatial patterns were characterized on roots of guatemalan and deweveri. population densities differed among rootstocks (p < 0.05) and times (p < 0.01). the greatest number of second-stage juveniles (j2) occurred on guatemalan and fewest j2 on p ... | 1995 | 19277268 |
| the surface coat of plant-parasitic nematodes: chemical composition, origin, and biological role-a review. | chemical composition, origin, and biological role of the surface coat (sc) of plant-parasitic nematodes are described and compared with those of animal-parasitic and free-living nematodes. the sc of the plant-parasitic nematodes is 5-30 nm thick and is characterized by a net negative charge. it consists, at least in part, of glycoproteins and proteins with various molecular weights, depending upon the nematode species. the lability of its components and the binding of human red blood cells to th ... | 1995 | 19277272 |
| 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 ... | 1995 | 19277277 |
| atomic force microscopy of plant-parasitic nematodes. | a simple method for atomic force microscopy (afm) of nematode cuticle was developed to visualize the external topography of helicotylenchus lobus, meloidogyne javanica, m. incognita, and xiphinema diversicaudatum. endospores of two isolates of the nematode parasite, pasteuria penetrans, adhering to m. incognita and x. diversicaudatum were also visualized and measured by this technique. scanning procedures were applied to specimens killed and dehydrated in air or dehydrated and stored in glycerol ... | 1995 | 19277280 |
| 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 ... | 1995 | 19277289 |
| enzymes of the phenylpropanoid pathway in soybean infected with meloidogyne incognita or heterodera glycines. | transcription of genes encoding several enzymes and the activity of some of these enzymes of the phenylpropanoid pathway leading to synthesis of chemical and physical barriers for defense of plants against root pathogens was estimated in susceptible and resistant soybean infected with heterodera glycines race 3 or with meloidogyne incognita race 3. transcription of genes encoding phenylalanine ammonia lyase (pal) and the activity of this enzyme increased in resistant, but not susceptible, soybea ... | 1995 | 19277292 |
| occurrence of pasteuria-like organisms on selected plant-pamsitic nematodes of pineapple in the hawaiian islands. | soils from 320 sites representing diverse undisturbed habitats from five hawaiian islands were assessed for occurrence of pasteuria-like organisms. mean annual rainfall at sites ranged from 125-350 cm, elevation from 69-2,286 m, and annual mean temperature from 12-24 c. seven different natural communities were represented: wet lowland, mesic lowland, wet montane, mesk montane, dry montane, mesic subalpine, and dry alpine. pasteuria spp. in a soil sample was detected by baiting with infective sta ... | 1995 | 19277305 |
| rotations with coastal bermudagrass and fallow for management of meloidogyne incognita and soilborne fungi on vegetable crops. | the efficacy of fallow and coastal bermudagrass (cynodon dactylon) as a rotation crop for control of root-knot nematode (meloidogyne incognita race 1) and soilborne fungi in okra (hibiscus esculentus cv. emerald), squash (cucurbita pepo cv. dixie hybrid), and sweet corn (zea mays cv. merit) was evaluated in a 3-year field trial. numbers of m. incognita in the soil and root-gall indices were greater on okra and squash than sweet corn and declined over the years on vegetable crops following fallow ... | 1995 | 19277312 |
| 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 ... | 1995 | 19277321 |
| mixtures of olive pomace with different nitrogen sources for the control of meloidogyne spp. on tomato. | the efficacy of mixtures of dry olive (olea europea) pomace with biuret, guanidine, and melamine for control of root-knot nematodes (meloidogyne spp.) on tomato (lycopersicon esculentum) was studied in greenhouse experiments. olive pomace (op) applied pre-plant at 10 g/kg soil was phytotoxic. mixtures of op (10 g/kg soil) with biuret or guanidine at 200-300 mg/kg soil reduced or eliminated the phytotoxic effect, controlled root-knot nematodes, and increased soil esterase activity indicative of m ... | 1995 | 19277325 |
| comparison of crop rotation and fallow for management of heterodera glycines and meloidogyne spp. in soybean. | the effects of cropping systems (fallow, rotation with sorghum-sudangrass hybrid [sorghum bicolor x s. sudanense], and continuous soybean [glycine max]), nematicide (aldicarb) treatment, and soybean cultivar on yield and nematode population densities were studied in a field infested with a mixture of meloidogyne spp. and heterodera glycines. soybean following sorghum-sudangrass yielded 111 kg/ha more than soybean following fallow and 600 kg/ha more than continuous soybean. aldicarb treatment inc ... | 1995 | 19277326 |
| 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 ... | 1995 | 19277333 |
| co-infection of wilt-resistant chickpeas by fusarium oxysporum f. sp. ciceri and meloidogyne javanica. | fusarium oxysporum f. sp. ciceri and meloidogyne javanica are important pathogens of chickpea. interrelationships between fusarium oxysporum f. sp. ciceri and m. javanica were investigated on 53 fusarium wilt-resistant chickpea genotypes in pot experiments. all of the genotypes were susceptible to m. javanica. fusarium wilt resistance in one genotype (icc 12275) was ineffective in the presence of m. javanica, and all the plants completely wilted. resistance in four genotypes (iccs 11319, 11322, ... | 1995 | 19277336 |
| suppression of meloidogyne incognita and m. javanica by pasteuria penetrans in field soil. | the role of pasteuria penetrans in suppressing numbers of root-knot nematodes was investigated in a 7-year monocuhure of tobacco in a field naturally infested with a mixed population of meloidogyne incognita race 1 and m. javanica. the suppressiveness of the soil was tested using four treatments: autoclaving (ac), microwaving (mw), air drying (dr), and untreated. the treated soil bioassays consisted of tobacco cv. northrup king 326 (resistant to m. incognita but susceptible to m. javanica) and c ... | 1996 | 19277344 |
| 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 ... | 1996 | 19277345 |
| 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 ... | 1996 | 19277351 |
| 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- ... | 1993 | 19279745 |
| the future of nematology: integration of new and improved management strategies. | the potential for managing plant-parasitic nenlatodes by combining two or more control strategies in an integrated program is examined. advantages of this approach include the use of partially effective strategies and protection of highly effective ones vulnerable from nematode adaptation or environmental risk. strategies can be combined sequentially from season to season or applied simultaneously. programs that have several strategies available but that are limited in the true integration of co ... | 1993 | 19279784 |
| 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 ... | 1993 | 19279834 |
| 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 ... | 1993 | 19279840 |
| 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 ... | 1993 | 19279845 |
| resistance to meloidogyne javanica and rotylenchulus reniformis in wild relatives of pigeonpea. | meloidogyne javanica and rotylenchulus reniformis are important nematode pests of pigeonpea. greenhouse evaluation of 66 accessions of 25 species of cajanus, rhynchosia, and flemingia for resistance to m. javanica based on number and size of galls, galled area of root, and number of egg masses showed resistance to be available in these wild relatives of pigeonpea. thirty-five accessions had </= 10 galls. five accessions of c. scarabaeoides (icpw 92, 101, 103, 128, and 133) had very small or no g ... | 1993 | 19279848 |
| reproductive and damage potentials of two populations of rotylenchulus reniformis on sweetpotato and related comparisons with meloidogyne javanica on tomato. | two rotylenchulus reniformis populations (north carolina and georgia) were compared on sweetpotato and tomato. 'beauregard' sweetpotato and 'better boy' and 'marion' tomato were excellent hosts for both r. reniformis populations. on beauregard sweetpotato, the two populations did not differ in fecundity; however, on both tomato cultivars, the georgia population reproduced at a higher rate than the north carolina population (p </= 0.05). meloidogyne javanica reproduction was higher (p </= 0.05) o ... | 1993 | 19279849 |
| meloidogyne incognita and rotylenchulus reniformis and associated soil textures from some cotton production areas of texas. | the incidence of meloidogyne incognita and rotylenchulus reniformis on cotton was determined in 1989-92 from 1,089 soil samples collected from 31 counties that account for nearly 60% of the 2.2 million hectares planted to cotton in texas. meloidogyne incognita was commonly found in the southern high plains and brazos river valley regions of texas (57% and 34%, respectively, of samples) but was found in less than 8% of samples from the central blacklands, coastal bend, low plains, or the upper gu ... | 1993 | 19279860 |
| description of the kona coffee root-knot nematode, meloidogyne konaensis n. sp. | meloidogyne konaensis n. sp. is described from coffee from kona on the island of hawaii. the perineal pattern of the female is variable in morphology, the medial lips of the female are divided into distinct lip pairs, and the excretory pore is 2-3 stylet lengths from the base of the stylet. mean stylet length is 16.0 mum, and the knobs gradually merge with the shaft. the knobs are indented anteriorly and rounded posteriorly and the dorsal esophageal gland orifice (dego) is long, 3.5-7 mum. the m ... | 1994 | 19279905 |
| methods for the study of verticillium chlamydosporium in the rhizosphere. | methods for screening isolates of the nematophagous fungus, v. chlamydosporium, for their ability to colonize the surface of plant roots are described. significant differences in the extent of colonization were observed in sterile conditions and in soil; plant species and cultivars also differed in their ability to support a selected isolate of the fungus. although fungal density could be estimated using a semi-selective medium, it was not possible to separate differences in vegetative growth fr ... | 1994 | 19279929 |
| occurrence of pasteuria spp. in florida. | two years of data collected from the florida nematode assay laboratory of the florida cooperative extension service and 4 years of data from the florida department of agriculture and consumer services, division of plant industry, were compiled to find out the distribution of pasteuria spp. on nematodes in florida soils. information recorded came from 335 samples and included nematode genera with pasteuria endospores attached, host plants associated with the samples, and the origins of the sample ... | 1994 | 19279936 |
| response of meloidogyne spp. to pasteuria penetrans, fungi, and cultural practices in tobacco. | the response of a mixed population of meloidogyne incognita and m. javanica to three cultural practices, tobacco cultivars (two cultivars, differing in resistance to m. incognita), cover treatments (three treatments), and inorganic nitrogen fertilizer (two treatments), pasteuria penetrans, and soil-borne fungi was investigated in a tobacco field in 1991. on all sampling dates, higher densities of root-knot nematodes were observed on tobacco cv. coker 371 gold than on k-326. initially, forage sor ... | 1994 | 19279937 |
| reaction of pigeonpea cultivars and germplasm accessions to the root-knot nematode, meloidogyne javanica. | meloidogyne javanica is an important nematode pest of pigeonpea. thirty-four pigeonpea cultivars and 227 germplasm accessions were evaluated for resistance to m. javanica based on number of galls, egg masses, size of galls, and area of root covered with galls. galls were not formed on 75% of the cultivars, and no egg masses were observed on the roots of four cultivars (upas 120, pant a3, co 1, and bdn 2); however, shoot mass of 64% of the cultivars was reduced by m. javanica. pant a3, anm 504, a ... | 1994 | 19279941 |
| 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 ... | 1994 | 19279945 |
| 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 ... | 1994 | 19279951 |
| host response of ornamental palms to rotylenchulus reniformis. | the responses of 20 species of ornamental palms and one cycad (cycas revoluta) to two populations of the reniform nematode, rotylenchulus reniformis, from southern florida were studied in two greenhouse experiments conducted in 1989-1991 and 1991-92. ornamental palms in pots were exposed to initial population densities of 400 and 1,500 r. reniformis/l00 cm(3) soil for 16 and 15 months, respectively. nematode reproduction occurred on acoelorrhaphe wrightii and washingtonia robusta, but not on the ... | 1994 | 19279956 |
| host status of 32 plant species to meloidogyne konaensis. | a host suitability study of 32 plant species to meloidogyne konaensis included 54 vegetable cultivars, 12 field crop cultivars, one gardenia sp., and two weed species. host suitability was classified according to a m. konaensis reproductive factor: final population density (pf) (eggs + j2) / initial population density (pi) (eggs). the number of eggs per gram dry root, and a galling index was also included. reproductive factor ranges and percentages of plants in the ranges were as follows: pf/pi ... | 1994 | 19279957 |
| raphanus sativus, sinapis alba, and fagopyrum esculentum as hosts to meloidogyne incognita, meloidogyne javanica, and plasmodiophora brassicae. | cultivars of oilseed radish (raphanus sativus var. oleifera cv. adagio, nemex, pegletta, renova, siletina, siletta nova, and ultimo), white mustard (sinapis alba cv. albatross, emergo, maxi, martigena, metex, and serval), buckwheat (fagopyrum esculentum cv. prego, tardo), and phacelia (phacelia tanacetifolia cv. angelia) were tested for susceptibility to meloidogyne incognita race 3 and meloidogyne javanica. experiments were conducted in growth chambers at 25 c and 16 hours light for 42 days aft ... | 1994 | 19279960 |
| plant-parasitic nematodes associated with cherry rootstocks in michigan. | in two field trials, 10-year-old sweet and tart cherry rooted on 'mazzard', 'mahaleb', 'mxm 2', 'mxm 14', 'mxm 39', 'mxm 60', 'mxm 97', and 'colt' showed 10-203 pratylenchus penetrans per g fresh root from all tart rootstocks, and up to 46 pratylenchus, criconemella, and xiphinema spp. per 100 cm(3) soil. infestation of soil containing 1-year-old mazzard, mahaleb, mxm 60, 'gi148-1', and 'g1148-8' with 625/100 cm(3) soil of either p. penetrans or c. xenoplax resulting in final nematode population ... | 1994 | 19279962 |
| 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 ... | 1994 | 19279963 |
| molecular transfer of nematode resistance genes. | recombinant dna techniques have been used to introduce agronomically valuable traits, including resistance to viruses, herbicides, and insects, into crop plants. introduction of these genes into plants frequently involves agrobacterium-mediated gene transfer. the potential exists for applying this technology to nematode control by introducing genes conferring resistance to nematodes. transferred genes could include those encoding products detrimental to nematode development or reproduction as we ... | 1992 | 19282989 |
| predisposition of broadleaf tobacco to fusarium wilt by early infection with globodera tabacum tabacum or meloidogyne hapla. | in greenhouse experiments, broadleaf tobacco plants were inoculated with tobacco cyst (globodera tabacum tabacum) or root-knot (meloidogyne hapla) nematodes 3, 2, or 1 week before or at the same time as fusarium oxysporum. plants infected with nematodes prior to fungal inoculation had greater fusarium wilt incidence and severity than those simultaneously inoculated. g. t. tabacum increased wilt incidence and severity more than did m. hapla. mechanical root wounding within 1 week of f. oxysporum ... | 1992 | 19283018 |
| 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 ... | 1992 | 19283029 |
| chemigation for control of black shank-root-knot complex and weeds in tobacco. | tank mixes of a fungicide (metalaxyl) and a nematicide (fenamiphos) with herbicides (isopropalin or pendimethalin) and an insecticide (chlorpyrifos) were applied by soil incorporation or irrigation to control the black shank-root knot complex and weeds on four tobacco cultivars. the disease complex was more severe on cultivars mcnair 944, nc-2326, and k-326 than on speight g-70. the disease complex was reduced (p </= 0.05) on all cultivars with the pesticide combinations containing metalaxyl + f ... | 1992 | 19283041 |
| 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 ... | 1992 | 19283043 |
| reproduction of four races of meloidogyne incognita on hibiscus cannabinus. | the feasibility of cultivation of kenaf (hibiscus cannabinus) in the united states is receiving a multifaceted evaluation. among the factors being evaluated is kenafs susceptibility to nematodes. in this investigation, four races of meloidogyne incognita reproduced extensively on each of the several kenaf genotypes examined in greenhouse tests. some genotypes of kenaf, however, demonstrated limited resistance to certain races of m. incognita. | 1992 | 19283051 |
| 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 ... | 1991 | 19283094 |
| 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 ... | 1991 | 19283116 |
| a collagenolytic fungus, cunninghamella elegans, for biological control of plant-parasitic nematodes. | the root-galling index of tomatoes inoculated with meloidogyne javanica was decreased 70% when collagen was used as a soil amendment (0.1% w/w) and 90% when the amendment was supplemented with the collagenolytic fungus cunninghamella elegans. the root-galling index was reduced 80% when the fungus was homogenized in collagen culture medium and added to soil without collagen supplement. culture filtrates of the fungus c. elegans, grown on collagen as a single source of carbon and nitrogen, immobil ... | 1991 | 19283126 |
| 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. ... | 1991 | 19283166 |
| 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 ... | 1991 | 19283179 |
| 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 ... | 1991 | 19283180 |
| 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 ... | 1991 | 19283181 |
| 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 ... | 1989 | 19287585 |
| 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 ... | 1989 | 19287586 |
| efficacy of oxamyl coated on alfalfa seed with a polymer sticker in pratylenchus and meloidogyne infested soils. | a polymer sticker was used as a coating in which oxamyl was applied to seeds of alfalfa cultivar saranac for the control of pratylenchus penetrans and meloidogyne hapla. the sticker, diluted 1:1 (sticker:water) to 1:5, delayed seedling emergence during the first 4 days after planting. by day 13, however, emergence from all sticker treatments was comparable to the control. shoot growth of seedlings at day 21 was less than that of the control only from seeds coated with a 1:1 dilution; root growth ... | 1989 | 19287603 |
| 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 ... | 1989 | 19287625 |
| further details and sem observations on meloidogyne marylandi (nematoda: meloidogynidae). | specimens of meloidogyne marylandi from bermuda grass and a population from zoysia grass were examined and compared morphologically by light and electron microscopy. the populations probably are conspecific and the differences noted in the zoysia population, mainly those of second-stage juveniles (j2) with shorter tails, are considered normal variations rather than representing another form. scanning electron microscope observations provided additional details of the perineal pattern and head of ... | 1989 | 19287638 |
| 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 ... | 1989 | 19287639 |
| 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/ ... | 1989 | 19287643 |
| yield relationships and population dynamics of meloidogyne spp. on flue-cured tobacco. | the complex nature of nematode-induced diseases of tobacco, the relationships between nematode levels and damage, the methods of determining these relationships, and the evolving nematode communities on tobacco in eastern north carolina are described. crop damage associated with these pathogens varies with nematode race and species, crop cultivar, microflora, and environmental conditions. root-gall indices as well as initial and mid-season numbers of meloidogyne spp, in soil are useful for estim ... | 1989 | 19287654 |
| 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 ... | 1989 | 19287655 |
| 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 ... | 1989 | 19287680 |
| 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 ... | 1990 | 19287693 |
| 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 ... | 1990 | 19287711 |
| meloidogyne morocciensis n. sp. (meloidogyninae), a root-knot nematode from morocco. | meloidogyne morocciensis n. sp. is described from specimens parasitic on peach rootstock from morocco. this species exhibits a combination of morphological characters similar to m. arenaria, m. incognita, and m. javanica. the perineal pattern of females is oval to squarish with a moderately high to high dorsal arch, and widely spaced, smooth striae; lateral lines are absent. the stylet, 16.5 mum long, has transversely ovoid, set-off knobs. males have a set-off, annulated head region. the large, ... | 1990 | 19287722 |
| 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 ... | 1990 | 19287753 |
| repeated sampling to determine the precision of estimating nematode population densities. | the first phase of this study involved repeated samplings of five fields using composite samples of 10, 20, 40, and 80 soil cores, to determine the precision of nematode assays. the second phase focused on randomly selecting two and four 2-ha subunits (data on meloidogyne spp.) of 24 fields ranging from 6 to 40 ha and computing the precision of estimated means for these numbers ofsubunits versus the general field mean (based on all 2-ha subunits). average numbers of nematodes from most samples c ... | 1990 | 19287757 |
| 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 ... | 1990 | 19287773 |
| plant-parasitic nematodes and fungi associated with root rot of peas on prince edward island. | eight commercial pea fields on prince edward island were sampled in june and july over a 2-year period (1986-87) to determine soil population densities and the incidence of nematodes and fungi associated with root rot of peas. root lesion nematodes (pratylenchus spp.) were the dominant endoparasitic nematodes recovered from roots and soil. low populations of the northern root-knot nematode (meloidogyne hapla) were also present. tylenchorhynchus spp. and paratylenchus spp. were recovered frequent ... | 1990 | 19287779 |
| 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 ... | 1987 | 19290102 |
| evaluation of cultivars, experimental lines and plant introduction collection of sainfoin for resistance to meloidogyne hapla chitwood. | stands of several cultivars and experimental lines of sainfoin (onobrychis viciifolia) were severely reduced (92% average loss) in a field naturally infested with meloidogyne hapla. stands of two alfalfa cultivars included in the test were unaffected. in studies conducted in the greenhouse with plants inoculated at the time of seeding, average mortality was 55% for sainfoin entries and 7% for ladak alfalfa. little mortality occurred when plants were inoculated after establishment. three months a ... | 1987 | 19290103 |
| a semi-selective medium for the isolation of paecilomyces lilacinus from soil. | | 1987 | 19290138 |
| 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 ... | 1987 | 19290154 |
| selective migration and root penetration by meloidogyne incognita and hoplolaimus columbus on soybean roots in vitro. | | 1987 | 19290161 |
| control of pratylenchus penetrans and meloidogyne hapla and yield response of alfalfa due to oxamyl seed treatments. | alfalfa (medicago sativa l. cv. saranac) seed were soaked for 20 minutes in water, acetone, or methanol containing 10 or 50 mg/ml of oxamyl (vydate l) or coated with a 2% aqueous cellulose solution containing the same amounts of oxamyl. seed were analyzed for oxamyl by hplc immediately after treatment and after 9 and 26 months of storage. oxamyl content of alfalfa seed did not decline after 26 months of storage. the effects of seed treatment on growth of alfalfa and nematode control were examine ... | 1987 | 19290170 |
| meloidogyne mayaguensis n. sp. (meloidogynidae), a root-knot nematode from puerto rico. | meloidogyne mayaguensis n. sp. is described and illustrated from specimens obtained from galled roots of eggplant, solanum melongena l., from puerto rico. the perineal pattern of females is round to ovoid with fine, widely spaced striae. it has occasional breaks of striation laterally and a circular tail tip area lacking striae. the stylet, 15.8 mum long, has reniform knobs that merge gradually with the stylet shaft. males have a high, rectangular, smooth head region, not set off from the body c ... | 1988 | 19290185 |