Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| 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 |
| root-knot nematode--directed expression of a plant root--specific gene. | root-knot nematodes are obligate plant parasites that induce development of an elaborate feeding site during root infection. feeding-site formation results from a complex interaction between the pathogen and the host plant in which the nematode alters patterns of plant gene expression within the cells destined to become the feeding site. expression of tobrb7, a gene expressed only in tobacco roots, is induced during feeding site development. the cis-acting sequences that mediate induction by the ... | 1994 | 17839183 |
| meloidogyne javanica parasitic on peanut. | peanut fields in four governorates of egypt were surveyed to identify species of meloidogyne present. fourteen populations obtained from peanut roots were all identified as m. javanica based on perineal patterns, stylet and body lengths of second-stage juveniles, esterase phenotypes, and restriction fragment length polymorphisms of mtdna. three of 14 populations, all from contiguous fields in the behara governorate, had individuals with a unique two-isozyme esterase phenotype. all populations of ... | 1994 | 19279913 |
| response of resistant soybean plant introductions to meloidogyne arenaria races 1 and 2. | resistant plant introductions, pi 230977 and pi 200538, and partially resistant jackson and susceptible cns were evaluated for seed yield in response to races 1 and 2 of meloidogyne arenaria. initial soil population densities (pi) of the nematode were 0, 31, 125, and 500 eggs/100 cm(3) soil. at the highest pi, yield suppressions of cns, jackson, pi 230977, and pi 200538 were 55, 28, 31, and 29%, and 99, 86, 66, and 58% for races 1 and 2 compared with uninfested controls. numbers of second-stage ... | 1994 | 19279881 |
| low, but strongly structured mitochondrial dna diversity in root knot nematodes (meloidogyne). | root-knot nematodes (genus meloidogyne) have been the subject of recent and numerous studies of genetic variation because of the need to develop molecular diagnostics for the four globally distributed, parthenogenetic species that are significant agricultural pests. our analysis of meloidogyne mtdna improves on previous studies: (i) by examining restriction site polymorphism among a large number of isolates also characterized for standard morphological, host range and allozyme phenotypes; (ii) b ... | 1994 | 7911772 |
| the structure of syncytia induced by the phytoparasitic nematode nacobbus aberrans in tomato roots, and the possible role of plasmodesmata in their nutrition. | the structure of syncytia induced within galls in tomato roots by the false root-knot nematode nacobbus aberrans has been examined by light and electron microscopy. a syncytium develops by breakdown or individual cell walls, which allows movement of cytoplasmic contents between transformed cells. the wall breakdown takes place at pit fields, where the plasmodesmata may be protected from digestion until the surrounding wall is removed. numerous sieve elements differentiate in the cells outside th ... | 1994 | 197113 |
| resistance of diploid triticeae species and accessions to the columbia root-knot nematode, meloidogyne chitwoodi. | the columbia root-knot nematode, meloidogyne chitwoodi race 2, is associated with several plant species, including members of the tribe triticeae. we evaluated 15 diploid species for m. chitwoodi gall and reproductive indices from the following genera: agropyron, pseudoroegneria, hordeum, psathyrostachys, and thinopyrum. species from the genus thinopyrum (thinopyrum bessarabicum; j genome) and psathyrostachys (psathyrostachys fragilis, p. juncea, p. stoloniformis; n genome) expressed more resist ... | 1994 | 19279939 |
| competition between the plant-parasitic nematodes pratylenchus neglectus and meloidogyne chitwoodi. | in experiments on competition between pratylenchus neglectus and meloidogyne chitwoodi in barley, the species that parasitized the roots first inhibited penetration by the latter species. prior presence of p. neglectus impeded the development of m. chitwoodi. pratylenchus neglectus reduced egg production, final population levels, and reproductive index of m. chitwoodi. the reduction was linearly related to initial population densities of p. neglectus. initial population densities of m. chitwoodi ... | 1994 | 19279894 |
| survey of meloidogyne spp. in tomato production fields of baix llobregat county, spain. | a survey was conducted to determine the frequency and abundance of meloidogyne spp. in tomato production sites located in baix llobregat county, barcelona, spain. forty-five sites were sampled before planting and at harvest from february to october, 1991. meloidogyne spp. occurred in 49% of the sites sampled. preplant population densities ranged from 10 to 220 (x = 110)juveniles/ 250 cm(3) soil, and final population densities ranged from 20 to 1,530 (x = 410)juveniles/250 cm(3) soil. final popul ... | 1994 | 19279955 |
| efficacy of fenamiphos formulations applied through irrigation for control of meloidogyne incognita on squash. | management ofmeloidogyne incognita by chemigation with fenamiphos was studied in an infested field planted to m. incognita-suscepfible yellow summer squash cv. dixie hybrid. fenamiphos (vl 73.1% a.i. manufacturing concentrate in propylene glycol) was mixed with unitol dsr-90 or used as fenamiphos 3 sc (spray concentrate). both formulations, applied with 63.5 kl irrigation water per hectare, decreased numbers of m. incognita second-stage juveniles in the soil and root-gall indices, and increased ... | 1994 | 19279950 |
| efficacy and compatibility for fenamiphos and eptc applied in irrigation water for nematode and weed control in snapbean production. | a nematicide (fenamiphos) and a herbicide (eptc) were injected into a sprinkler irrigation system separately and as tank mixtures and applied in 25.4 kl water/ha for nematode and weed control on snapbean. there were no differences (p = 0.05) between methods of injection of fenamiphos + eptc on efficacy or crop response. the root-gall indices of cultivars eagle and gv 50 were lower in fenamiphos-treated plots than those treated with eptc alone and untreated plots. the yield and crop value were gr ... | 1994 | 19279949 |
| influence of 1,3-dichloropropene, fenamiphos, and carbofuran on meloidogyne incognita populations and yield of chile peppers. | field trials were conducted during 1986, 1988, 1989, and 1991 to compare the effects of 1,3-dichloropropene, fenamiphos, and carbofuran on yield and quality of chile peppers (capsicum annuum) in soil infested with meloidogyne incognita. when compared with untreated plots, numbers of m. incognita juveniles recovered from soil 60 and(or) 90 days after chile pepper emergence were reduced (p = 0.05) following 1,3-d treatment every year except 1986. nematode numbers were also reduced (p = 0.05) by fe ... | 1994 | 19279948 |
| reaction of ten cultivars of watermelon (citrullus lanatus) to a puerto rican population of meloidogyne incognita. | ten cultivars of watermelon were evaluated for their response to a puerto rican population of meloidogyne incognita under greenhouse conditions in a 2-year study (1989 and 1990). ten-day-old seedlings were planted in steam-sterilized soil in 15-cm-d plastic pots. the nematode inoculum consisted of 10,000 eggs and (or) second-stage juveniles (j2)/plant. the cultivars were sugar baby, charleston gray, seedless, prince charles, charleston 76, jubilee, florida giant, royal charleston, royal sweet, a ... | 1994 | 19279940 |
| optimal levels of meloidogyne incognita inoculum for infection of tomato and peach in vitro. | penetration of second-stage juveniles (j2) of meloidogyne incognita into tomato root explants and in vitro propagated peach plantlet roots were compared. five inoculum levels were used: 25, 50, 75, 100, and 200 j2 for tomato; and 50, 100, 200, 500, and 1,000j2 for peach. the greatest root penetration into tomato was 30% at the 75 j2 level, but the maximum penetration into peach roots was only 8% at the 200 j2 level. the difference (p = 0.05) in penetration of m. incognita at all inoculum levels ... | 1994 | 19279926 |
| partial characterization of cytosolic superoxide dismutase activity in the interaction of meloidogyne incognita with two cultivars of glycine max. | the closely related soybean (glycine max) cultivars centennial and pickett 71 were confirmed to be resistant and susceptible, respectively, to the root-knot nematode meloidogryne incognita. increases in superoxide dismutase (sod) activity were detected in roots of both soybean cultivars 48 hours following inoculation. superoxide dismutase activity increased in roots of the susceptible cultivar overall, but declined after 96 hours in roots of the resistant cultivar. the isoelectric points of sod ... | 1994 | 19279911 |
| low-temperature scanning electron microscope observations of the meloidogyne incognita egg mass: the gelatinous matrix and embryo development. | the root-knot nematode meloidogyne incognita was cultured monoxenically on excised tomato roots. galls and egg masses were observed daily using a light microscope. two phases were distinguished in the gelatinous matrix of the egg mass: a translucent, amorphous material on the surface of the egg mass and a denser, layered phase in which nematode eggs were deposited. egg masses were also cryofixed, fractured, and observed as frozen, hydrated specimens on a cold stage in a scanning electron microsc ... | 1994 | 19279909 |
| reproduction of virulent isolates of meloidogyne incognita on susceptible and mi-resistant tomato. | the reproductive potential of natural and laboratory-selected meloidogyne incognita isolates virulent against the tomato mi resistance gene, all derived from a single egg-mass, were compared when the nematodes were inoculated on susceptible and resistant tomato. fewer second-stage juveniles (p = 0.01) of the two virulent populations selected under laboratory conditions matured to females on the resistant tomato compared to the susceptible cultivar. in contrast, no differences were found between ... | 1994 | 19279899 |
| distribution and regulation of meloidogyne nataliei. | between 1978 and 1990, eight surveys were conducted in southwest michigan to document the occurrence of meloidogyne nataliei, the michigan grape root-knot nematode. the known distribution of m. nataliei is limited to a total of six sections in antwerp and porter townships in van buren county, michigan. in 1984, a m. nataliei regulatory program was initiated by the michigan department of agriculture, u. s. department of agriculture animal and plant health inspection service, and michigan state un ... | 1994 | 19279954 |
| host status of crotalaria juncea, sesamum indicum, dolichos lablab, and elymus glaucus to meloidogyne javanica. | reproduction of meloidogyne javanica on crotalaria juncea pi 207657 and cv. tropic sun, sesamum indicum, dolichos lablab, and elymus glaucus was assessed using a root-gall index, a reproductive index obtained by dividing the final population of juveniles (j2) in soil by the initial j2 population (pf/pi), and the number of j2 per gram of root recovered from roots by mist chamber extraction. lycopersicon esculentum (cv. uc 204 c) was included as a susceptible host. the root-gall index and soil rep ... | 1994 | 19279920 |
| genetic polymorphism between and within meloidogyne species detected with rapd markers. | genetic analyses were conducted on root-knot nematode populations belonging to the four major species of the genus meloidogyne and originating from many countries throughout the world. discrete genetic markers used in this study were random genomic dna sequences amplified by the polymerase chain reaction (rapd). primers of 17-30 nucleotides with 30-55% g + c content were tested. five of them generated a total of 74 scorable markers that provided reliable polymorphisms both between and within spe ... | 1994 | 7828838 |
| penetration of crotalaria juncea, dolichos lablab, and sesamum indicum roots by meloidogyne javanica. | penetration of crotalaria juncea (pi 207657 and cv. tropic sun) dolichos lablab cv. highworth, and sesamum indicum by juveniles (j2) of meloidogyne javanica was assessed to investigate the mechanism by which these plants may reduce nematode numbers in the field. growth chamber experiments were conducted at 25 c, with vials containing 90 g sand infested with 450 j2; tomato (uc 204 c) was included as a susceptible host. fifteen days after inoculation, roots were stained and the nematodes within st ... | 1994 | 19279887 |
| influence of inoculum density, host, and low-temperature period on delayed hatch of meloidogyne javanica eggs. | most eggs of m. javanica hatch within several days when incubated in water. those that do not are said to show delayed hatching. several experiments were conducted to determine the effect of specific conditions on the percentage of eggs with delayed hatch. six initial inoculum densities ranging from 100 to 20,000 eggs per pot did not influence egg hatch within a 45-day incubation period. in a 60-day test, the percentage of eggs hatching after more than 20 days was low for egg masses removed from ... | 1994 | 19279871 |
| a pcr-based marker tightly linked to the nematode resistance gene, mi, in tomato. | a pcr-based codominant marker has been developed which is tightly linked to mi, a dominant genetic locus in tomato that confers resistance to several species of root-knot nematode. dna from tomato lines differing in nematode resistance was screened for random amplified polymorphic dna markers linked to mi using decamer primers. several markers were identified. one amplified product, rex-1, obtained using a pair of decamer primers, was present as a dominant marker in all nematode-resistant tomato ... | 1994 | 24190460 |
| control of plant-parasitic nematodes by a nematicidal strain ofaspergillus niger. | an isolate ofaspergillus niger (designated pd-42) was evaluated in laboratory, greenhouse, and field trials for efficacy in controlling plant-parasitic nematodes. in greenhouse experiments, pd-42 drenches containing spores of pd-42 on oatmeal significantly reduced galling on tomato due to root-knot nematode as compared to untreated controls. in a one-half acre field experiment, pd-42 incorporated in seed coats was associated with significantly increased yield and decreased root-knot galling on p ... | 1994 | 24241697 |
| plant-cyst nematode and plant-root-knot nematode interactions. | root-knot nematodes and cyst nematodes are obligate plant parasites that cause extensive damage to the agriculture of both temperate and tropical countries. in this review, andreas niebel, godelieve gheysen and marc van montagu describe how, in the past decade, the use of molecular techniques has provided new insights in the complex interactions between these sedentary plant-parasitic nematodes and their infected host plants. they give an account of the progress in our understanding of both the ... | 1994 | 15275524 |
| influence of temperature on the virulence of two races of meloidogyne chitwoodi on wheat and barley. | races of the columbia root-knot nematode, meloidogyne chitzooodi, from idaho (r1) and utah (r2) suppressed (p < 0.05) tillering of dusty winter wheat, fielder spring wheat, luther winter barley, and steptoe spring barley at 15-30 c. nematode inoculum density was negatively correlated with tillering (r = -0.79). inoculum densities of both nematode races were negatively correlated with heads per plant (r = -0.83), head length (r = -0.87), and head dry weight (r = 0.73) of fielder spring wheat and ... | 1993 | 19279794 |
| suppression of meloidogyne chitwoodi with sudangrass cultivars as green manure. | meloidogyne chitwoodi race 1 reproduced on piper sudangrass (sorghum bicolor (l.) moench), 332 (sudangrass hybrid), and p855f and p877f (sorghum-sudangrass hybrids), but failed to reproduce efficiently on trudan 8, trudex 9 (sudangrass hybrids), and sordan 79, ss-222, and bravo ii (sorghum-sudangrass hybrids). meloidogyne chitwoodi race 2 behaved similarly and reproduced more efficiently on piper, p855f, and p877f than on trudan 8, trudex 9, or sordan 79. the mean reproductive factor for m. chit ... | 1993 | 19279773 |
| summer cropping effects on the abundance of meloidogyne arenaria race 2 and subsequent soybean yield. | a summer-planted crop of alyceelover significantly (p < 0.05) increased the soil abundance of meloidogyne arenaria race 2 juveniles by 3.7-fold when measured in the following spring. maize, sorghum, and soybean had no significant effects on residual nematode numbers over the same period. summer plantings of aeschynomene, cotton, hairy indigo, tespedeza, millet, peanut, and sorghum-sudangrass were as efficient as fallow in reducing root-knot nematode population levels. soybean yields (averaging 2 ... | 1993 | 19279844 |
| morphometric evaluation of hypotriploid and triploid populations of meloidogyne arenaria. | a morphometric comparison of seven hypotriploid populations with five pooled triploid populations of meloidogyne arenaria was made using standard descriptive statistics, stepwise discriminant analysis (sda), and cluster analysis. six morphometric characters of females, 14 of second-stage juveniles (j2), and 18 of males were measured for each population. useful differentiating characters included: body length in j2; stylet length in females and j2; stylet-knob dimensions in females and males; dor ... | 1993 | 19279751 |
| morphological comparison of seven hypotriploid populations of meloidogyne arenaria with the typical triploid populations. | a morphological comparison of seven hypotriploid populations of meloidogyne arenaria was made to clarify their taxonomic status, using light and scanning electron microscopy. all populations differed from each other and from the typical triploid m. arenaria by certain features. differences were not regarded as sufficient to justify recognition of the variants as distinct species. morphological divergence of populations from the typical m. arenaria was gradual. the most useful characters were sty ... | 1993 | 19279750 |
| parasitism of heterodera schachtii and meloidogyne javanica by hirsutella rhossiliensis in microplots over two growing seasons. | numbers of cyst and root-knot nematodes and percentage parasitism by the nematophagous fungus hirsutella rhossiliensis were quantified in microplots over 2 years. the microplots contained either sugarbeets in loam infested with heterodera schachtii or tomatoes in sand infested with meloidogyne javanica. the fungus was added to half of the microplots for each crop. although h. rhossiliensis established in both microplot soils, the percentage of nematodes parasitized did not increase with nematode ... | 1993 | 19279790 |
| induction patterns of an extensin gene in tobacco upon nematode infection. | when sedentary endoparasitic nematodes infect plants, they induce complex feeding sites within the root tissues of their host. to characterize cell wall changes induced within these structures at a molecular level, we studied the expression of an extensin gene (coding for a major structural cell wall protein) in nematode-infected tobacco roots. extensin gene expression was observed to be induced very early upon infection. this induction was weak, transient, and probably due to wounding during pe ... | 1993 | 12271052 |
| 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 |
| enzymatic digestion of roots for recovery of root-knot nematode developmental stages. | developmental stages of meloidogyne javanica were successfully released from roots by treatment with commercially available cellulase and pectinase. the average percentage recovery of nematode developmental stages from dolichos lablab, elymus glaucus, and lycopersicon esculentum were as follows: eggs = 526%, j2 = 272%, j3 = 783%, j4 = 549%, adult females = 285%, and total = 425%, expressed as percentages of the counts obtained from stained roots spread on glass plates. root digestion was more ac ... | 1993 | 19279814 |
| glycoprotein characterization of the gelatinous matrix in the root-knot nematode meloidogyne javanica. | proteinaceous components of freshly formed gelatinous matrix (gm) of the root-knot nematode metoidogyne javanica were analyzed. under reducing conditions, the prominent protein fragments had molecular weights of 26 to 66 kda and 150 to >200 kda, and most were glycosylated. most of the fragments were digested by proteinase k, and fewer by trypsin. the lectins soybean agglutinin (sba), ulex europaeus agglutinin, and wheat germ agglutinin labeled the higher molecular weight bands (i.e., >200 kda). ... | 1993 | 19279813 |
| long-range physical maps of two loci (aps-1 and gp79) flanking the root-knot nematode resistance gene (mi) near the centromere of tomato chromosome 6. | the root knot nematode resistance gene mi in tomato has been mapped in the pericentromeric region of chromosome 6. with the objective of isolating mi through a map-based cloning approach, we have previously identified and ordered into a high-resolution genetic linkage map a variety of tightly linked molecular markers. using pulsed-field gelelectrophoresis and various rarely cutting restriction enzymes in single, double and partial digestions, we now report long-range physical maps of the two clo ... | 1993 | 8106010 |
| colonization of greenhouse nematode cultures by nematophagous mites and fungi. | unproductive > 7-year-old greenhouse cultures of citrus nematode (tylenchulus semipenetrans) had a well-developed soil invertebrate fauna that included nematophagous mite species characteristic of florida citrus groves. nematophagous mite densities in box cultures were 285 +/- 42 mites/liter, 2.5 to 25 times higher than densities in citrus nematode-infested groves. vigorous root-knot nematode (meloidogyne incognita) cultures grown in steam-pasteurized soil had few nematophagous mites until more ... | 1993 | 19279841 |
| effects of 1,3-dicliloropropene for meloidogyne incognita management on cotton produced under furrow irrigation. | field trials were conducted during 1990 to evaluate the effects of preplant soil fumigation with 1,3-dichloropropene (1,3-d) on yield and fiber quality of furrow-irrigated cotton cultivars subjected to high population densities of meloidogyne incognita. we measured the responses of eight upland cotton cultivars with different levels of root-knot nematode resistance and compared the responses of upland and pima cottons. reductions in lint weight ranged from 10 to 52% among cultivars grown in soil ... | 1993 | 19279835 |
| spatial and temporal interactions of meloidogyne incognita and soybean. | the spatial and temporal dynamics of meloidogyne incognita, relative to soybean shoot and root growth in field microplots, were determined at 11 sampling dates during a growing season. the population dynamics of m. incognita on soybean were dependent on initial population (pi), soil moisture, and root spatial distribution. final egg and juvenile population densities were greatest in plots with higher pi. the population densities of juveniles and eggs were highest from mid- to late-season and wer ... | 1993 | 19279833 |
| dynamics of concomitant populations of meloidogyne incognita and criconemella xenoplax on peach. | the interaction between meloidogyne incognita and criconemella xenoplax on nematode reproduction and growth of lovell peach was studied in field microlots and the greenhouse. meloidogyne incognita suppressed reproduction of c. xenoplax in both field and greenhouse experiments. tree growth, as measured by trunk diameter, was reduced (p </= 0.05) in the presence of m. incognita as compared with c. xenoplax of the uninoculated control trees 26 months following inoculation. a similar response regard ... | 1993 | 19279823 |
| response of peach scion cultivars and rootstocks to meloidogyne incognitain vitro and in microplots. | the response of the peach scion cultivars, jerseyqueen, redhaven, compact redhaven, and rio oso gem and rootstocks 'lovely and 'nemaguard' to inoculation with meloidogyne incognita was compared in vitro and in microplots. one or more parameters monitored in vitro correlated with at least one parameter monitored in microplots, 4 years after tree planting (1989). a range of responses was observed from highlysusceptible in lovell to resistant in nemaguard. in vitro and microplot data suggest high a ... | 1993 | 19279797 |
| dynamics of the nuclear complement of giant cells induced by meloidogyne incognita. | the total numbers of nuclei in giant cells induced by meloidogyne incognita in pea, lettuce, tomato, and broad bean were determined. mature giant cells from pea had the most nuclei per giant cell with a mean of 59 +/- 23, lettuce had the fewest with 26 +/- 16, and tomato and broad bean were intermediate. the rate of increase in numbers of nuclei for all plant species was greatest during the first 7 days after inoculation. no mitotic activity was observed in giant cells associated with adult nema ... | 1993 | 19279788 |
| energetics of meloidogyne incognita on resistant and susceptible alyceclover genotypes. | to determine the energy cost of a population of meloidogyne incognita on the roots of alyceclover, nematode biomass was estimated and equations in the literature were used to calculate energy budgets. amounts of energy consumed, respired, or used in production of nematode biomass were calculated. results suggested that severe infestations of root-knot nematodes can remove significant quantities of energy from their hosts. over a 36-day period, a population of 2.6 females of m. incognita per root ... | 1993 | 19279766 |
| an in vitro test for temperature sensitivity and resistance to meloidogyne incognita in tomato. | an in vitro root explant tissue culture technique is described for determining susceptibility of tomato (lycopersicon esculentum mill.) breeding lines and cultivars to the root-knot nematode meloidogyne incognita. root explants were taken from 2-day-old seedlings cultured for 30 days at 28 c on gamborg's b-5 medium with or without nematode inoculum. the remaining portion of the root and stem from the excised root explants was transferred to soil in pots and grown to maturity in the greenhouse. i ... | 1993 | 19279747 |
| use of nematodes as biomonitors of nonfumigant nematicide movement through field soil. | three field experiments were established in a loamy sand soil in the coastal plain of north carolina to determine downward movement of aldicarb and fenamiphos with a nematode bioassay. penetration of bioassay plant roots by meloidogyne incognita was measured at 1, 3, 7, 14, 21, and 28 days after treatment in the greenhouse as a means of determining nematicide effectiveness. chemical movement was similar in planted and fallow soil. nematicidal activity was greater in soil collected from the 0 to ... | 1993 | 19279744 |
| population development of meloidogyne incognita on soybean defoliated by pseudoplusia includens. | greenhouse studies examined population densities of meloidogyne incognita race 4 on soybean (glycine max 'davis') defoliated by larvae of soybean looper (pseudoplusia indudens (walker)). plants were defoliated over a 2-week period beginning 5 weeks after seedlings were transplanted. four groups of plants were infested with nematodes (5,000 eggs/pot) at 2-week intervals to allow harvesting of plants at 0, 2, 4, and 6 weeks postdefoliation (wpd). plants in each group were harvested 4 weeks after n ... | 1993 | 19279741 |
| inheritance of heat-stable resistance to meloidogyne incognita in lycopersicon peruvianum and its relationship to the mi gene. | the inheritance of heat-stable resistance to the root-knot nematode, meloidogyne incognita (kofoid and white) chitwood, was studied in crosses between different accessions and clones of lycopersicon peruvianum l. f1, f2 and bc1 generations were evaluated for their index of resistance based on numbers of eggs and infective second-stage juveniles (j2) per gram of root, and the segregation ratios were determined in experiments carried out at constant soil temperatures of 25 °c and 30 °c. l. peruvia ... | 1993 | 24196050 |
| the interaction of so2 and root-knot nematode on tomato. | intermittent exposure of tomato plants (cv. pusa ruby) to so(2) at 286 microg m(-3) (3 h every heavy third day for 75 days) induced slight chlorosis of leaves. at 571 microg m(-3), considerable chlorosis with browning developed on the foliage. these symptoms were more pronounced and appeared earlier on so(2)-exposed plants infected with meloidogyne incognita race 1 (mi), especially in post- and concomitant-inoculation exposures. mi and/or so(2) significantly reduced different parameters of plant ... | 1993 | 15091816 |
| 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 |
| distribution of heterodera carotae and meloidogyne hapla in michigan carrot production. | during 1986 and 1988, selected farms in all of the major carrot-growing counties of michigan were surveyed to determine the extent of infestation by heterodera carotae and meloidogyne hapla. both species were found in all eight counties surveyed, but not on all farms. heterodera carotae was recovered from 67.4% of the fields surveyed. meloidogyne hapla was detected in 24.8% of the samples and from 69.8% of the fields. in most cases, h. carotae and m. hapla occurred in the same field. | 1992 | 19283061 |
| field evaluation of selected soybean cultivars for resistance to two races of meloidogyne arenaria. | the soybean cultivars 'braxton' and 'kirby' were less susceptible to both races 1 and 2 of meloidogyne arenaria than 'centennial' and 'young', which were highly susceptible. soybean seed yields of resistant cultivars were greater (p = 0.05) than susceptible cultivars. reproduction of m. arenaria races 1 and 2 was significantly lower on less susceptible cultivars compared to highly susceptible cultivars. root galling, caused by m. arenaria, was 5-10 times greater on centennial and young than on l ... | 1992 | 19283054 |
| field evaluation of susceptibility to meloidogyne arenaria in arachis hypogaea plant introductions. | resistance to meloidogyne arenaria race 1 is not currently available in commercial peanut cultivars. moderate levels of resistance have been identified in arachis hypogaea plant introductions (pi) in previous greenhouse studies. the purpose of this work was to evaluate the effects of resistance in peanut pi on populations dynamics of m. arenaria in field plots. the pi designated as resistant in greenhouse studies had fewer m. arenaria in roots than the most susceptible pi. at midseason and at th ... | 1992 | 19283050 |
| effects of root decay on the relationship between meloidogyne spp. gall index and egg mass number in cucumber and horned cucumber. | a greenhouse study was conducted to determine if root necrosis had an effect on the relationship between root-knot nematode gall index and egg mass number. thirty-four cultigens of cucumis (14 accessions, 12 cultivars, and six breeding lines of c. sativus, and two accessions of c. metuliferus) were evaluated against four root-knot species (meloidogyne arenaria race 2, m. incognita race 1, m. incognita race 3, and m. javanica) measuring gall index, root necrosis, and egg mass number. root necrosi ... | 1992 | 19283049 |
| a rapid and efficient method for the screening of acid phosphatase 1 in young tomato seedlings, and for the identification of root-knot nematode species using miniaturized polyacrylamide gel electrophoresis. | a relatively rapid and highly sensitive miniaturized polyacrylamide gel electrophoresis technique is described for the analysis of certain isozymes from single cotyledons of tomato seedlings and from single females of the root-know nematode (meloidogyne spp.). homogenates from single tomato cotyledons (7, 14, 21, and 28 days old) were electrophoresed and stained for acid phosphatase 1 (aps 1) activity. cotyledons from plants of all the above age groups showed good aps 1 activity. nondestructive ... | 1992 | 1382970 |
| damage functions for meloidogyne arenaria on peanut. | microplot experiments were conducted in 1989 and 1990 to determine the relationship between yield of peanut (arachis hypogaea) and inoculum density ofmeloidogyne arenaria race 1. nine inoculum densities were used, ranging from 0-200 eggs/100 cm(3) soil (1989) or from 0-100 eggs/100 cm(3) (1990), and each density was replicated 10 times. in 1989, higher final densities (mean of 1,171 juveniles [j2]/100 cm(3) soil) were obtained in plots inoculated with 0.5 to 50 eggs/100 cm(3) soil than in plots ... | 1992 | 19283223 |
| relative damage functions and reproductive potentials of meloidogyne arenaria and m. hapla on peanut. | the reproductive potential and damage functions for meloidogyne hapla and m. arenaria race 1 on virginia-type peanuts (arachis hypogaea cv. florigiant) were determined over 2 years in microplot experiments in north carolina. peanut yield suppression and damage to pods as a result of galling were greatest in response to m. arenaria (p = 0.01). damage functions for the two species were adequately described by the quadratic models: yield (g/plot) = 398 - 17.1 (log[pi + 1]) - 17.0(log[pi + 1])(2); ( ... | 1992 | 19283222 |
| a novel technique for infesting field sites with encapsulated eggs of meloidogyne spp. | eggs of meloidogyne arenaria race 1 were encapsulated in calcium alginate for use as inoculum to infest peanut field plots. some eggs within the capsules remained viable up to 10 weeks after preparation. a field site was successfully infested at peanut planting and (or) 6 weeks later. dual applications of nematode inoculum (at planting and 6 weeks later) were superior to single applications (at planting or 6 weeks after planting). field-site infestation levels at the end of the first year were r ... | 1992 | 19283221 |
| host suitability and response of asparagus cultivars to meloidogyne species and races. | the host-parasite relationships of asparagus and meloidogyne spp. were examined under greenhouse and microplot conditions. meloidogyne species and races differed greatly in their ability to reproduce on asparagus seedlings. meloidogyne hapla generally failed to reproduce, and m. javanica, m. arenaria race 1, and m. incognita race 3 reproduced poorly, with a reproduction factor (rf = final population/initial population) usually < 1.0. only m. arenaria race 2 and m. incognita races 1 and 4 reprodu ... | 1992 | 19283211 |
| resistance of lathyrus species and accessions to the northern root-knot nematode, meloidogyne hapla. | the leguminous plant genus lathyrus contains many species useful for soil conservation and reclamation. some of these species may also have vaiue in the united states for forage production. the extent of genetic variation among lathyrus populations in reaction to most disease pathogens is not known. we examined 28 usda agricultural research service plant introduction accessions representing 16 lathyrus species for their ability to tolerate attack by the northern root-knot nematode, meloidogyne h ... | 1992 | 19283053 |
| effects of cropping sequences on population densities of meloidogyne hapla and carrot yield in organic soil. | the influence of various cropping sequences on population densities of meloidogyne hapla and carrot yield was studied in organic soil under microplot-and field conditions. spinach, radish, barley, oat, and wheat were poor or nonhosts for m. hapla. population densities of m. hapla were maintained or increased on cabbage, celery, lettuce, leek, marigold, and potato. marketable percent-age and root weight of carrots were greater following spinach, oat, radish, and fallow-onion than those following ... | 1992 | 19283022 |
| occurrence of meloidogyne spp. in argentina. | a record of 84 plant species in 32 families that are hosts to the root-knot nematode species found in argentina is presented. the genus meloidogyne appears to be widely distributed in the country, with meloidogyne incognita and m. javanica the most frequently detected species. other species found in argentina include m. arenaria, m. cruciani, m. decalineata, m. hapla, and m. ottersoni. the present survey is supplemented with existing published information. | 1992 | 19283059 |
| host suitability of ixora spp. for the root-knot nematodes meloidogyne incognita race 1 and m. javanica. | eight commonly cultivated ixora species or cultivars were tested for their suitability as hosts and their level of tolerance to meloidogyne incognita race 1 and m. javanica in a greenhouse study. twenty weeks postinoculation with 5,000 eggs per pot, m. incognita race 1 and m. javanica produced galls and formed egg masses on roots of all eight ixora species or cultivars tested. however, only m. javanica-infected 'petite yellow' and 'maui' had decreases (p </= 0.05) in root wet weights, suggesting ... | 1992 | 19283052 |
| nematode numbers and crop yield in a fenamiphos-treated sweet corn-sweet potato-vetch cropping system. | nematode population densities and yield of sweet corn and sweet potato as affected by the nematicide fenamiphos, in a sweet corn-sweet potato-vetch cropping system, were determined in a 5-year test (1981-85). sweet potato was the best host of meloidogyne incognita of these three crops. fenamiphos 15g (6.7 kg a.i./ha) incorporated broadcast in the top 15 cm of the soil layer before planting of each crop increased (p </= 0.05) yields of sweet corn in 1981 and 1982 and sweet potato number 1 grade i ... | 1992 | 19283032 |
| effects of rapeseed and vetch as green manure crops and fallow on nematodes and soil-borne pathogens. | in a rapeseed-squash cropping system, meloidogyne incognita race 1 and m. javanica did not enter, feed, or reproduce in roots of seven rapeseed cultivars. both nematode species reproduced at low levels on roots of the third crop of rapeseed. reproduction of m. incognita and m. javanica was high on squash following rapeseed, hairy vetch, and fallow. the application of fenamiphos suppressed (p = 0.05) root-gall indices on squash following rapeseed, hairy vetch, and fallow; and on dwarf essex and c ... | 1992 | 19283212 |
| ethoprop depletion from soil as influenced by simulated rainfall. | two field microplot tests were conducted in sandy soil to evaluate retention of ethoprop in relation to simulated rainfall levels. ethoprop was applied at the equivalent of 13.5 kg a.i./ha, and simulated rainfall was added at rates of 2.5, 7.5, 15.0, and 22.5 cm over a 6-day period. ethoprop concentration in the soil at 5-, 10-, and 40-day intervals indicated that it was depleted rapidly with increased rainfall levels. the 2.5-cm level of simulated rainfall reduced ethoprop concentration to one- ... | 1992 | 19283040 |
| the root-knot nematode resistance gene (mi) in tomato: construction of a molecular linkage map and identification of dominant cdna markers in resistant genotypes. | a dominant allele at the mi locus on chromosome 6 of tomato (lycopersicon esculentum mill) confers resistance to three species of root-knot nematodes (meloidogyne). the resistance, which is associated with a localized necrotic response, was originally introduced into tomato from the wild species lycopersicon peruvianum. as a step towards the molecular cloning of mi, we have identified closely linked dna markers from both cdna and genomic dna libraries as restriction fragment length polymorphisms ... | 1992 | 1302643 |
| effects of incorporation method of ethoprop and addition of aldicarb on potato tuber infection by meloidogyne hapla. | the efficacy of controlling meloidogyne hapla on potato with water incorporation of ethoprop was compared to physical incorporation before planting. the standard practice of aldicarb application for insect control was also evaluated for m. hapla suppression with and without ethoprop. physical incorporation before planting by rototilling or discing reduced (p </= 0.05) tuber infection. postplant water incorporation of ethoprop was not as effective as physical incorporation of ethoprop or postplan ... | 1991 | 19283186 |
| further studies on the role of polyploidy in the evolution of meloidogyne. | two tetraploid isolates of meloidogyne hapla, 86p and e289p, with haploid chromosome numbers of 34 and 28, respectively, were studied cytogenetically and biologically in relation to the diploid populations, 86-va (n = 17) and e289-taiwan (n = 14), from which they had been originally isolated. both isolates were quite stable, converting to diploidy at the low rate of about 2.5%. the tetraploid isolate 86p maintained itself in competition with its diploid counterpart in mixed cultures, although an ... | 1991 | 19283121 |
| efficacy of ethoprop on meloidogyne hapla and m. chitwoodi and enhanced biodegradation in soil. | responses of egg masses, free eggs, and second-stage juveniles (j2) ofmeloidogyne hapla and m. chitwoodi to ethoprop were evaluated. the results indicated that j2 were the most sensitive, followed by free eggs and egg masses. in general, m. chitwoodi was more susceptible to ethoprop than m. hapla. ethoprop at 7.2 mug a.i./g soil protected tomato roots from upward migrating m. chitwoodi for 5 weeks. the zone of protection was extended to 10 and 20 cm below the root zone when 3.6 and 7.2 cm water ... | 1991 | 19283141 |
| population dynamics of meloidogyne chitwoodi on russet burbank potatoes in relation to degree-day accumulation. | population dynamics of meloidogyne chitwoodi were studied for 2 years in a commercial potato field and microplots. annual second-stage juvenile (j2) densities peaked at harvest in mid-fall, declined through the winter, and were lowest in early summer. in the field and in one microplot study, population increase displayed trimodal patterns during the 1984 and 1985 seasons. overwintering nematodes produced egg masses on roots by 600-800 degree-days base 5 c (dd) after planting. second-generation a ... | 1991 | 19283128 |
| suppression of root-knot nematode populations with selected rapeseed cultivars as green manure. | meloidogyne chitwoodi races 1 and 2 and m. hapla reproduced on 12 cultivars of brassica napus and two cultivars of b. campestris. the mean reproductive factors (rf), rf = pf at 55 days / 5,000, for the three nematodes were 8.3, 2.2, and 14.3, respectively. all three nematodes reproduced more efficiently (p < 0.05) on b. campestris than on b. napus. amending m. chitwoodi-infested soil in plastic bags with chopped shoots of jupiter rapeseed reduced the nematode population more (p < 0.05) than amen ... | 1991 | 19283108 |
| seasonal migration of meloidogyne chitwoodi and its role in potato production. | seasonal vertical migration of meloidogyne chitwoodi through soil and its impact on potato production in washington and oregon was studied. nematode eggs and second-stage juveniles (j2) were placed at various depths (0-180 cm) in tubes filled with soil and buried vertically or in holes dug in potato fields. tubes were removed at intervals over a 12-month period and soil was bioassayed on tomato roots. upward migration began in the spring after water had percolated through the tubes. nematodes we ... | 1991 | 19283107 |
| characterization of acetylcholinesterase molecular forms of the root-knot nematode, meloidogyne. | multiple molecular forms of acetylcholinesterase have been isolated and characterized from the root-knot nematodes meloidogyne arenaria and meloidogyne incognita. the forms of enzyme present in these 2 species are similar but not identical to those that occur in the free-living nematode caenorhabditis elegans. the 5 enzyme forms exhibit differential solubilities and can be classified into 3 classes, a, b, and c, based on substrate affinity, inhibitor and detergent sensitivity, and thermal inacti ... | 1991 | 1775164 |
| comparison of winter and spring soil fumigation with 1,3-d for the management of meloidogyne arenaria on peanut. | field experiments were conducted in which the fumigant 1,3-d was applied at broadcast rates of 56 and 112 liters/ha during late winter and spring to two differing soil types in north florida. no advantage was demonstrated in applying the fumigant at the higher rate for the management of meloidogyne arenaria on peanut, and there was no disadvantage to applying a standard rate of the fumigant during winter as opposed to the standard practice of a 2-week preplant treatment. at one site, where rainf ... | 1991 | 19283185 |
| meloidogyne arenaria populations on soybean. | the distribution of meloidogyne spp. was determined in the piedmont and coastal plains soybean production areas of south carolina. meloidogyne arenaria, m. incognita, and m. javanica were found in six of seven counties surveyed, with some populations consisting of two or more species. because m. arenaria populations did not reproduce on peanut (arachis hypogaea cv. florunner), they were designated as host race 2. severity of root galling, shoot and root growth, seed yield, and nematode reproduct ... | 1991 | 19283177 |
| race composition of meloidogyne incognita and m. arenaria populations in vegetable fields in uttar pradesh. | a total of 1,256 populations of meloidogyne incognita and 442 populations of m. arenaria were collected from vegetables in eight districts of uttar pradesh, india. host differentials were used to identify the host race of each population. all four host races of m. incognita were present in six of the eight districts. in the other two districts, only host races 1, 2, and 4 were found. although frequencies of occurrence of the races differed among districts, races 1 and 2 comprised 62% of all m. i ... | 1991 | 19283172 |
| resistance to root-knot nematodes in cucumber and horned cucumber. | two experiments were conducted in the greenhouse. in one experiment, cucumber (cucumis sativus) and horned cucumber (c. metuliferus) cultigens were evaluated for resistance to four root-knot nematode species (meloidogyne arenaria, m. hapla, m. incognita, and m. javanica), and, in a second experiment, a standard (12-week) test was compared with a rapid (6-week) test. in the first experiment, horned cucumber cultigens varied in response to the meloidogyne species. 'sumter' cucumber was more suscep ... | 1991 | 19283171 |
| reaction of prunus rootstocks to meloidogyne incognita and m. arenaria in spain. | prunus rootstocks were evaluated for their reaction to meloidogyne incognita and m. arenaria. most rootstocks were peach-almond hybrids of spanish origin. in one experiment three selections of garfi x nemared (g x n) and hansen-5 were highly resistant to m. incognita, but four other rootstocks were susceptible showing high galling indices and population increases. in two experiments with m. arenaria, the hybrid selections g x n nos. 1 and 9 were immune, gf-305 and hansen-5 were resistant, but ni ... | 1991 | 19283164 |
| development of meloidogyne arenaria on peanut and soybean under two temperature cycles. | florunner peanut and three soybean cultivars, centennial, gasoy 17, and wright, were inoculated with 48-hour age cohorts of meloidogyne arenari race 1 second-stage juveniles and placed in a growth chamber set to simulate early season (low temperature) and midseason (high temperature) conditions. percentages of the initial inoculum penetrating roots 4 and 8 days after inoculation were 2-3 times higher in soybean cultivars than in peanut; 25% on susceptible soybean and 9% on peanut. penetration an ... | 1991 | 19283157 |
| characterization of species and races of the genus meloidogyne by dna restriction enzyme analysis. | total dna of three species of meloidogyne spp., including four subspecific races of m. incognita, were digested separately with ecor i, cla iii, and hind iii and probed with (3)(2)p-labelled total genomic dna from m. incognita race 1 in southern hybridizations. short exposures of southern blots after hind iii digestion revealed patterns that were useful for separating the species. race differences were seen after longer exposures. the dna fragment patterns obtained were scanned with a laser dens ... | 1991 | 19283147 |
| aggressiveness and reproduction of four meloidogyne arenaria populations on soybean. | aggressiveness and reproduction differed among four geographical populations of m. arenaria on six soybean cultivars in field microplots. these differences were consistent over 3 years. the populations did not differ in virulence; i.e., population by cultivar interactions were not significant. perineal pattern morphology, the north carolina differential host test, chromosome counts of immature oocytes, and esterase phenotypes confirmed that the four populations were m. arenaria. three population ... | 1991 | 19283118 |