Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| usefulness of egg assays in nematode population-density determinations. | 1987 | 19290117 | |
| soybean yield as related to rates of 1,3-dichloropropene applied at planting for management of root-knot disease. | 1,3-dichloropropene (1,3-d) at rates of 17.2 to 51.6 liters/ha applied 3 days preplant or at planting significantly (p < 0.05) reduced the amount of galling on roots of soybean grown in sites infested with meloidogyne incognita or m. arenaria. populations of m. incognita second-stage juveniles at harvest were significantly (p < 0.05) reduced by all treatments. only the 51.6-liters/ ha treatments and a 3-day preplant 34.4-liters/ha application significantly reduced at-harvest juvenile infestation ... | 1986 | 19294212 |
| interrelationships of meloidogyne arenaria and m. incognita on tolerant soybean. | reproduction of meloidogyne arenaria race 2 was excellent on centennial, govan, and kirby soybeans, the latter two of which have tolerance to this species. the m. incognita race 1 isolate reproduced poorly on centennial, especially at the higher of two temperature regimes. numbers of galls and egg masses of m. arenaria plus m. incognita in simultaneous equivalent infestations on centennial did not differ from sequential infestations in which m. arenaria was added first and m. incognita was added ... | 1986 | 19294149 |
| genotypic differentiation of meloidogyne populations by detection of restriction fragment length difference in total dna. | detection of ecori restriction fragment length differences in repetitive dna sequences permitted the rapid diagnosis, by genotype, of randomly selected populations of meloidogyne incognita, races 1, 2, 3, and 4; m. javanica; m. arenaria, races 1 and 2; and m. hapla, races a and b. | 1986 | 19294145 |
| a comparison of techniques useful for preparing nematodes for scanning electron microscopy. | second-stage juveniles of meloidogyne incognita were prepared by several different techniques for scanning electron microscopy (sem). sequential fixation in the cold (4-8 c) was superior to rapid fixation at room temperature, glutaraldehyde and glutaraldehyde-formalin were better fixatives than formalin alone, and critical point drying with carbon dioxide or freon gave similar results that were only slightly better than air drying with freon. freeze drying sequentially fixed nematodes from 100% ... | 1986 | 19294215 |
| effects of interactions among heterodera glycines, meloidogyne incognita, and host genotype on soybean yield and nematode population densities. | the effects of host genotype and initial nematode population densities (pi) on yield of soybean and soil population densities of heterodera glycines (hg) race 3 and meloidogyne incognita (mi) race 3 were studied in a greenhouse and field microplots in 1983 and 1984. centennial (resistant to hg and mi), braxton (resistant to mi, susceptible to hg), and coker 237 (susceptible to hg and mi) were planted in soil infested with 0, 31, or 124 eggs of hg and mi, individually and in all combinations, per ... | 1986 | 19294208 |
| effects of heterodera glycines and meloidogyne incognita on early growth of soybean. | greenhouse and field microplot studies were conducted to compare soybean shoot and root growth responses to root penetration by heterodera glycines (hg) and meloidogyne incognita (mi) individually and in combination. soybean cultivars centennial (resistant to hg and mi), braxton (resistant to mi, susceptible to hg), and coker 237 (susceptible to hg and mi) were selected for study. in the greenhouse, pot size and number of plants per pot had no effect on hg or mi penetration of coker 237 roots; r ... | 1986 | 19294209 |
| effects of cyanide ion and hypoxia on the volumes of second-stage juveniles of meloidogyne incognita in polyethylene glycol solutions. | changes in the volumes of second-stage juveniles of meloidogyne incognita were monitored in aqueous solutions of polyethylene glycol supplemented with dilute balanced salts. at key points within a 48-hour cycle of fluctuating water potential, nematodes were placed under hypoxic conditions or exposed to the respiratory inhibitor, sodium cyanide, to detect any respiration-dependent process that regulates volume. aerobic respiratory arrest at -500 kpa induced pronounced water loss, lateral and dors ... | 1986 | 19294227 |
| retention of resistance to meloidogyne incognita in lycopersicon genotypes at high soil temperature. | lycopersicon glandulosum and l. peruvianum clones and l. esculentum cultivars 'vfn8' (resistant) and 'rutgers' (susceptible) were tested for their resistance to meloidogyne incognita (race l) at soil temperatures of 25 and 32 c. l. esculentum cv. vfn8 and l. peruvianum acc. no. 128657, both of which possess the mi gene, were resistant at 25 c but were susceptible at 32 c. l. glandulosum acc. no. 126443 and l. peruvianum acc. no. 270435, with combined resistance to m. hapla and m. incognita, and ... | 1986 | 19294217 |
| effect of meloidogyne incognita and importance of the inoculum on the yield of eggplant. | the relationship between population densities of race 1 of meloidogyne incognita and yield of eggplant was studied. microplots were infested with finely chopped nematode-infected pepper roots to give population densities of 0, 0.062, 0.125, 0.25, 0.50, 1, 2, 4, 8, 16, 32, 64, and 128 eggs and juveniles/cm(3) soil. both plant growth and yield were suppressed by the nematode. a tolerance limit of 0.054 eggs and juveniles/cm(3) soil and a minimum relative yield of 0.05 at four or more eggs and juve ... | 1986 | 19294216 |
| soybean and maize cropping models for the management of meloidogyne incognita in the coastal plain. | models are presented to describe the influence of rotations of meloidogyne incognita-susceptible cultivars, resistant cultivars, and maize on postharvest abundance of m. incognita juveniles in the soil. depending on initial densities of juveniles, monocultured regimes reached equilibrium densities after a few years of 287, 40, and 10 juveniles per 10 cm(3) soil for susceptible soybean, resistant soybean, and maize, respectively. yearly changes in the population density of juveniles due to rotati ... | 1986 | 19294210 |
| penetration and postinfection development of meloidogyne incognita on cotton as affected by glomus intraradices and phosphorus. | the influence of the vesicular-arbuscular mycorrhizal fungus glomus intraradices (gi) and superphosphate (p) on penetration, development, and reproduction of meloidogyne incognita (mi) was studied on the mi-susceptible cotton cultivar stoneville 213 in an environmental chamber at 28 c. plants were inoculated with mi eggs at planting or after 28 days and destructively sampled 7, 14, 21, and 28 days after nematode inoculation. mi penetration after 7 days was similar in all treatments at either ino ... | 1986 | 19294207 |
| comparison of development, reproduction, and aggressiveness of meloidogyne incognita races 3 and 4 on cotton. | 1986 | 19294201 | |
| management of root-knot nematodes by phenamiphos applied through an irrigation simulator with various amounts of water. | phenamiphos (6.7 kg a.i./ha) was applied via an irrigation simulator to squash at planting (ap) and 2 weeks after planting (pp), and to corn ap and 1 week pp to manage root-knot nematodes (meloidogyne incognita). the nematicide was applied with 0.25, 0.64, 1.27, and 1.91 cm surface water/ ha to a lakeland sand in which the soil moisture was at or near field capacity. based on efficacy and crop response, no additional benefits resulted when phenamiphos was applied in volumes of water greater than ... | 1986 | 19294192 |
| meloidogyne incognita resistance characteristics in tomato genotypes developed for processing. | nine resistant processing tomato (lycopersicon esculentum) cultivars and advanced lines were compared with four susceptible cultivars in 1,3-dichloropropene-fumigated and nontreated plots on meloidogyne incognita-infested sites over 3 years. yield of all resistant genotypes grown in nontreated and nematicide-treated plots did not differ and was greater than yield of susceptible genotypes. m. incognita initial soil population densities caused 39.3-56.5% significant (p = 0.05) yield suppressions o ... | 1986 | 19294190 |
| effects of environments, meloidogyne incognita inoculum levels, and glycine max genotype on root-knot nematode-soybean interactions in field microplots. | five soybean cultivars (braxton, gordon, jeff, bragg, and wright) resistant to meloidogyne incognita (mi) and three susceptible cultivars (coker 156, gasoy 17, and coker 237) were grown at two locations for four seasons in microplots with increasing initial soil population densities (pi) of mi. the resistant cultivars and coker 156 yielded better than gasoy 17 and coker 237 at all pi. yield response was dependent on environmental conditions and at one location was stimulated on braxton, gordon, ... | 1986 | 19294188 |
| effects of soil type on the damage potential of meloidogyne incognita on soybean. | effects of soil type on the reproduction and damage potential of meloidogyne incognita on soybean, glycine max (l.) merr., were determined at five locations in north carolina, including one site where plots with six soil types were established. m. incognita reproduced readily on a susceptible soybean cultivar in most soil types, with somewhat limited reproduction in muck soils. the relationship between initial population densities and yield varied among soil types and nematode populations. yield ... | 1986 | 19294187 |
| relative virulence of meloidogyne incognita host races on soybean. | sensitivity and host efficiency of susceptible ('lee 68', 'coker 156') and resistant ('bragg', 'centennial', 'forrest', 'lee 74') soybean (glycine max (l.) merr.) cultivars for races of meloidogyne incognita (mi) were determined in greenhouse experiments. eight mi populations collected from the southeastern united states were utilized. all mi races reproduced readily on lee 68 and lee 74 and moderately on forrest and bragg. coker 156 exhibited resistance to races 1 and 2, and some race 3 populat ... | 1986 | 19294186 |
| effects of temperature, plant age, soil texture, and meloidogyne incognita on early growth of soybean. | a digitizer-microcomputer combination was utilized to determine soybean seedling response to population densities of m. incognita (mi) under varied environmental conditions. plant age, temperature, soil texture, and initial mi inoculum (pi) influenced the pattern of shoot and root growth. effects of mi on plant top growth were evident on plants inoculated 2 days after seeding, but generally were not noticeable on those receiving mi after 4, 6, or 8 days (observations limited to 6 days after inoc ... | 1986 | 19294185 |
| cuticular collagenous proteins of second-stage juveniles and adult females of meloidogyne incognita: isolation and partial characterization. | cuticles isolated from second-stage juveniles and adult females of meloidogyne incognita were purified by treatment with 1% sodium dodecyl sulfate (sds). the juvenile cuticle was composed of three zones differing in their solubility in beta-mercaptoethanol (bme). proteins in the cortical and median zones were partially soluble in bme, whereas the basal zone was the least soluble. the bme-soluble proteins from the juvenile cuticle were separated into 12 bands by sds-polyacrylamide gel electrophor ... | 1986 | 19294181 |
| interaction of endomycorrhizal fungi, superphosphate, and meloidogyne incognita on cotton in microplot and field studies. | microplot and field experiments were conducted to determine the effects of two vesicular-arbuscular mycorrhizal (vam) fungi, glomus intraradices (gi) and gigaspora margarita (gm), and dicalcium phosphate (p) on meloidogyne incognita (mi) reproduction and seed cotton yield of the mi-susceptible cotton cultivar, stoneville 213. in 1983 population densities of mi juveniles were significantly lower 60 and 90 days after planting in microplots receiving gi. mycorrhizal fungi reduced the severity of yi ... | 1986 | 19294168 |
| distribution of field corn roots and parasitic nematodes in subsoiled and nonsubsoiled soil. | a field trial was conducted for 2 years in an arredondo fine sand containing a tillage pan at 15-20 cm deep to determine the influence of subsoiling on the distribution of corn roots and plant-parasitic nematodes. soil samples were taken at various depths and row positions at 30, 60, and 90 days after planting in field corn subsoiled under the row with two chisels and in non-subsoiled corn. at 30 and 60 days, in-row nematode population densities to 60 cm deep were not affected by subsoiling comp ... | 1986 | 19294167 |
| influence of meloidogyne incognita on resistant and susceptible sweet potato cultivars. | effects of several population densities ofmeloidogyne incognita on the sweet potato cultivars centennial (susceptible) and jasper (moderately resistant) were studied. field plots were infested with initial levels (pi) of 0, 10, 100, 1,000, 5,000, and 10,000 eggs and juveniles/500 cm(3) soil in 1980 and 0, 100, 1,000, 2,000, 3,000, 4,000, and 5,000 in 1981. m. incognita population development trends were similar on both cultivars; however, at high pi, more eggs and juveniles were recovered from c ... | 1986 | 19294141 |
| isolation of subcellular granules from second-stage juveniles of meloidogyne incognita. | subcellular granules from the second-stage (preparasitic) juveniles of root-knot nematode meloidogyne incognita were isolated by isopycnic centrifugation on percoll. the granules had an apparent density of 1.13 g/cm(3). the relative specific activity of acid phosphatase in the granule extract was 8.4. acid phosphatase activity was also detected histochemically in the subventral gland granules. electron microscopy and malate dehydrogenase activity indicated that contamination of granules by mitoc ... | 1985 | 19294128 |
| behavior of tethered meloidogyne incognita. | the tethered-nematode technique was adapted for use with second-stage juveniles of meloidogyne incognita. the data demonstrate that m. incognita exhibits the same patterns of behavior as adults of the free-living nematode, caenorhabditis elegans. the principal differences are that m. incognita is slower and less regular in its behavior than c. elegans. the frequency of normal waves is about 0.2 hz; that of reversal waves is about 0.06 hz. reversal bouts last about 1 minute. in response to a chan ... | 1985 | 19294124 |
| control of root-knot nematodes on tomato by the endoparasitic fungus meria coniospora. | the endoparasitic nematophagous fungus meria coniospora reduced root-knot nematode galling on tomatoes in greenhouse pot trials. the fungus was introduced to pots by addition of conidia at several inoculum levels directly to the soil or addition of nematodes infected with m. coniospora to the soil; both methods reduced root galling by root-knot nematodes. these studies represent a part of a recently initiated effort to evaluate the potential of endoparasitic nematophagous fungi for biocontrol of ... | 1985 | 19294101 |
| dynamics of winter survival of eggs and juveniles of meloidogyne incognita and m. arenaria. | winter survival dynamics of meloidogyne incognita and m. arenaria were studied at nine sites in texas for 2 years. population survival from october until april was variable among sites, ranging from 0.1% to 33%. a negative correlation (r = -0.86, p = 0.01) was observed between initial population, densities in october and survival percentage until the following april. total population (eggs + j2) and population of eggs declined continuously during the survival period. populations of juveniles (j2 ... | 1985 | 19294090 |
| density-dependent nematode seasonal multiplication rates and overwinter survivorship: a critical point model. | nematode multiplication rates pf/pi and overwinter survivorship (pi2/pfl) for meloidogyne incognita were both adequately described by negative exponential models, indicating density dependence in each case. density dependence of the multiplication rates is mediated by resource limitation and host damage; in survivorship rates it may be mediated by limitation of stored reserves or prevalence of antagonists. parameters of multiplication rate models were crop specific and varied with host status an ... | 1985 | 19294065 |
| population densities of meloidogyne incognita and yield of capsicum annuum. | two microplot experiments in 1981 and 1983 provided information on the effect of different population densities of meloidogyne incognita race 1 and yield of sweet pepper. microplots were square concrete pipes (30 x 30 cm and 50 cm long) filled with 40 liters of soil infested with 0, 0.062, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128, 256, and 512 eggs and juveniles/cm(3) soil. tolerance limits of 2.2 and 0.165 eggs and juveniles/cm(3) soil and minimum yields of 58% and 20% of the controls were ... | 1985 | 19294056 |
| effect of tillage system and irrigation on population densities of plant nematodes in field corn. | soil populations of plant-parasitic nematodes were monitored bimonthly for 18 months in irrigated and nonirrigated corn plantings using four production systems: conventional and minimum tillage with crop residue returned and minimum tillage with 60% or 90% of previous corn crop residue removed. populations of meloidogyne incognita, scutellonema brachyurum, pratylenchus scribneri, and paratrichodorus christiei varied among the tillage, nematicide, and irrigation treatments. meloidogyne incognita ... | 1985 | 19294053 |
| spatial pattern analysis of plant-parasitic nematodes. | spatial patterns of meloidogyne incognita, tylenchorhynchus claytoni, helicotylenchus dihystera, and criconemella ornata were analyzed using hill's two-term local quadrat variance method (ttlqv), spectral analysis, and spatial correlation. data were collected according to a systematic grid sampling plan from seven tobacco fields in north carolina. different estimates of nematode cluster size were obtained through ttlqv and spectral analysis. no relationship was observed between either estimate a ... | 1985 | 19294064 |
| root penetration by meloidogyne incognita juveniles infected with bacillus penetrans. | bacillus penetrans inhibited penetration by meloidogyne incognita second-stage juveniles (j2) into tomato roots in the laboratory and greenhouse. spores from this florida population of b. penetrans attached to j2 of m. javanica, m. incognita, and m. arenaria. a greater proportion of j2 of m. javanica were infected than were j2 of either m. incognita or m. arenaria, and a greater number of spores attached to m. incognita than to m. arenaria. | 1985 | 19294069 |
| overestimation of yield loss of tobacco caused by the aggregated spatial pattern of meloidogyne incognita. | overestimation of yield loss caused by meloidogyne incognita on tobacco was calculated as a function of the statistical frequency distribution of sample counts. sampling frequency distributions were described by a negative binomial model, with parameter k, and the resulting probability generating function was used to calculate discrete damage probabilities. negative binomial damage predictions were compared to mean-density estimates of damage. predictions based on mean density alone overestimate ... | 1985 | 19294089 |
| nematode control related to fusarium wilt in soybean and root rot and zinc deficiency in corn. | nematode and disease problems of irrigated, double-cropped soybean and corn, and zinc deficiency of corn were investigated. ethylene dibromide, phenamiphos, and aldicarb were equally effective for controlling nematodes and increasing yields of corn planted minimum-till and soybean planted in a moldboard plow prepared seedbed. the residual effects on yields of nematicides applied to the preceeding crop occurred during 3 years for soybean and 1 year for corn. fusarium wilt symptoms of soybean that ... | 1985 | 19294099 |
| interactions between six warm-season legumes and three species of root-knot nematodes. | 1985 | 19294109 | |
| pathogenicity and reproduction of hoplolaimus columbus and meloidogyne incognita on 'davis' soybean. | the effects of initial populations of hoplolaimus columbus and meloidogyne incognita on growth and yield of davis soybean were determined for 1980 and 1981 in microplots and h. columbus in field tests in 1981. m. incognita suppressed yield in microplots both years and h. columbus in 1980. maximum suppression of dry pod weight by m. incognita was 45% and by h. columbus 35%. the relationship of yield vs. nematode population at planting time was described by a declining exponential model. maximum r ... | 1984 | 19294036 |
| application of isoelectric focusing to the taxonomic identification of meloidogyne spp. | meloidogyne incognita, m. arenaria, m. hapla, and m. javanica were distinguishable from each other by isoelectric focusing (ief) of nematode egg proteins. proteins extracted from larvae and adults of hoplolaimus columbus and from eggs of heterodera glycines had distinctive profiles, also. protein profiles from eggs, preparasitic larvae and egg-laying adults of m. incognita showed differences. it was necessary to compare samples run at the same time to ensure reliability. | 1984 | 19295881 |
| reactions of grape rootstocks to pratylenchus vulnus and meloidogyne spp. | five grape rootstocks were inoculated with 0, 100, 1,000, and 10,000 pratylenchus vulnus. dogridge and saltcreek supported low average total numbers of p. vulnus, 136-705/pot, at 12 months after inoculation. growth of both rootstocks was not affected. harmony, couderc 1613, and ganzin 1 supported high average total numbers, 6-856 times the inoculum levels. numbers in harmony continued to increase at all levels but reduced root weight only at the 10,000 level after 12 months. numbers in couderc 1 ... | 1984 | 19295896 |
| variability in reproduction of four races of meloidogyne incognita on two cultivars of soybean. | variability in the reproduction of the four races ofmeloidogyne incognita on the soybean cuhivars pickett 71 and centennial was studied in growth chamber experiments. analysis of variance in the number of eggs produced by the races 6 weeks after the plants had been inoculated with 5,000 eggs of each race revealed that the nematode race by soybean cultivar interaction was highly significant (p = 0.001). races 1, 3, and 4 produced from about 5,000 to 15,000 eggs per root system on pickett 71 and o ... | 1984 | 19294039 |
| nematostatic activity of oxamyl and n,n-dimethyl-1-cyanoformamide (dmcf) on meloidogyne incognita juveniles. | the nematostatic activity of oxamyl, methyl-n',n'-dimethy]-n-hydroxy-l-thiooxamimidate (oxamyl-oxime) and n,n-dimethyl-l-cyanoformamide (dmcf) was studied by immersing 10 meloidogyne incognita second-stage juveniles into aqueous solutions of various concentrations of each chemical. at concentrations of 500 to 8,000 mug/ml, oxamyl quickly immobilized immersed juveniles. in all other concentrations studied (down to 4 mug/ml), oxamyl stopped or reduced movement of juveniles within 24 hours. dmcf al ... | 1984 | 19294031 |
| crop rotation and races of meloidogyne incognita in cotton root-knot management. | the influence o f various crop rotations and nematode inoculum levels on subsequent population densities of meloidogyne incognita races 1 and 3 were studied in microplots. ten different 3-year sequences o f cotton, corn, peanut, or soybean, all with cotton as the 3rd-year crop, were grown in microplots infested with each race. cotton monoculture, two seasons o f corn, or cotton followed by corn resulted in high race 3 population densities and severe root galling on cotton the 3rd year. peanut fo ... | 1984 | 19294030 |
| nematicides and nonconventional soil amendments in the management of root-knot nematode on cotton. | granular and liquid commercial humates, with micronutrients, and a microbial fermentation product were compared in several combinations with nematicides for their effects on cotton lint yield and root-knot nematode suppression. fumigant nematicides effectively reduced cotton root galling caused by root-knot nematodes, and cotton lint yields increased. organophosphates and carbamates were not effective. occasionally, cotton lint yields were increased or maintained with combination treatments o f ... | 1984 | 19295893 |
| triphasic locomotor response of a plant-parasitic nematode to avermectin: inhibition by the gaba antagonists bicuculline and picrotoxin. | the response of the plant parasitic nematode, meloidogyne incognita (j2 stage) to avermectin b2a-23-one is triphasic, comprising an initial loss of locomotor activity where the juveniles remain sensitive to touch, a recovery phase and a final loss of activity where the juveniles are relatively insensitive to touch. in contrast, the acetylcholinesterase inhibitor, oxamyl, causes initial hyperactivity of juveniles followed by a progressive decline in movement. the addition of bicuculline and to a ... | 1984 | 6326020 |
| root extracts of pangola digitgrass affect egg hatch and larval survival of meloidogyne incognita. | 1983 | 19295861 | |
| reproduction of two races of meloidogyne incognita in tomato plants grown at high temperature. | 1983 | 19295858 | |
| use of avermectins for the control of meloidogyne incognita on tomatoes. | the efficacy of avermectins b and b for control of meloidogyne incognita on tomato was studied in pots and field plots for two seasons. avermectins were applied as granules and liquid in furrows or by low pressure drip irrigation systems, at rates ranging from 0.093 to 0.34 kg a.i./ha, as single or multiple applications. levels of control comparable to those obtained by oxamyl and aldicarb at 3.36 kg a.i./ha were achieved by the avermectin with only 1/10 the volume of chemicals applied to the en ... | 1983 | 19295838 |
| interaction of vesicular-arbuscular mycorrhizal fungi and phosphorus with meloidogyne incognita on tomato. | the influence of two vesicular-arbuscular mycorrhizal fungi and phosphorus (p) nutrition on penetration, development, and reproduction by meloidogyne incognita on walter tomato was studied in the greenhouse. inoculation with either gigaspora margarita or glomus mosseae 2 wk prior to nematode inoculation did not alter infection by m. incognita compared with nonmycorrhizal plants, regardless of soil p level (either 3 mug [low p] or 30 mug [high p] available p/g soil). at a given soil p level, nema ... | 1983 | 19295826 |
| influence of maize rotations on the yield of soybean grown in meloidogyne incognita infested soil. | a replicated field study was conducted from 1972 to 1980 involving soybeans grown in 2-, 3-, and 4-year rotations with maize in soil infested with meloidogyne incognita. monocultured soybeans were maintained as controls. cropping regimes involved root-knot nematode susceptible and resistant soybean cultivars and soybeans treated and not treated with nematicides. yields of susceptible cultivars declined with reduced length of rotation. nematicide treatment significantly increased yields of suscep ... | 1983 | 19295824 |
| parasitic variability of meloidogyne incognita populations on susceptible and resistant cotton. | root gall induction and egg production by the four recognized host races and two cytological races of meloidogyne incognita were compared on cotton gossypium hirsutum cvs. deltapine 16 (root-knot susceptible) and auburn 634 (highly resistant). the 12 nematode populations included in the study were from various parts of the world. no population increases occurred on the highly resistant cultivar. after 45 days, populations of host races 1 and 2 induced slight root galling on both cuhivars with on ... | 1983 | 19295806 |
| validation of a model for prediction of host damage by two nematode species. | plant roots were mechanically injured or subjected to nematode parasitism to test the model of host damage by two nematode species: y = m' + (l - m')c'z(p)z(p) for y </= 1.0 and y = 1.0 for y > 1.0, where m' = m + (m - m) (1 - y)/[(1 - y) + (l - y)] and c' = (z(-t) + z(-t))/2. damage functions for greenhouse-grown radish plants (cv. cherry belle) mechanically injured with small or large steel needles were used to predict growth of plants injured by both needles. growth predictions accounted for ... | 1983 | 19295796 |
| development of meloidogyne incognita inhibited by digtaria decumbens cv. pangola. | population densities of the root-knot nematode, meloidogyne incognita, were lower after 90 days in soil planted to digitgrass (digitaria decumbens cv. pangola) than in soil left fallow or planted to tomato. roots of tomato seedlings interplanted with pangola digitgrass were less galled than were roots of tomato seedlings planted alone. fewer second stage larvae invaded roots of pangola digitgrass than tomato and those that entered the grass roots failed to develop beyond the late second stage. | 1983 | 19295772 |
| population dynamics of meloidogyne incognita and rotylenchulus reniformis alone and in combination, and their effects on sweet potato. | meloidogyne incognita (mi) and rotylenchulus reniformis (rr) interactions on sweet potato were studied in naturally and artificially infested field plots for 3 years. in a naturally infested field, early season counts of mi or rr were positively correlated with later counts of the same nematode, but negative correlations were found between early mi and subsequent rr, and early rr and subsequent mi counts. in field plots fumigated with methyl bromide and then infested with low levels of rr, mi, a ... | 1983 | 19295792 |
| effects of concomitant development on reproduction of meloidogyne incognita and rotylenchulus reniformis on sweet potato. | the influence of various factors on reproduction of concomitant meloidogyne incognita (mi) and rotylenchulus reniformis (rr) on sweet potato were studied in the greenhouse. reproduction of rr was reduced by mi at all inoculum levels and experiment durations used, while mi reproduction was not inhibited. both species failed to affect each other when inoculated simultaneously onto root systems developed in separate pots from different nodes of the same plant. reproduction of each species was not s ... | 1983 | 19295794 |
| phytoalexins and their role in the resistance of plants to nematodes. | phytoalexins are antibiotic compounds synthesized in an infected plant in response to infection. nematodes are capable of eliciting phytoalexins in resistant plants. resistant lima bean (phaseolus lunatus) infected by pratylenchus penetrans produces the phytoalexin coumestrol; soybean (glycine max) infected by meloidogyne incognita produces glyceollin; cotton (gossypium hirsuturn) infected by m. incognita produces terpenoid aldehydes. | 1982 | 19295667 |
| fine structure of the esophagus of males of sarisodera hydrophila (heteroderoidea). | the fine structure of the esophagus, including procorpus, metacorpus, isthmus, gland lobe, and esophago-intestinal junction, is examined in males of sarisodera hydrophila. a cuticle-lined lumen extends most of the length of the esophagus, broadens to form a pump chamber in the metacorpus, and posteriorly is continuous with junctional complexes among four esophago-intestinal cells. these four cells are partially enveloped by the gland lobe which basically consists of three gland cells, one dorsal ... | 1982 | 19295711 |
| the effect of arthrobotrys conoides on meloidogyne incognita population densities in corn as influenced by temperature, fungus inoculum density, and time of fungus introduction in the soil. | in greenhouse experiments, the effect of arthrobotrys conoides on meloidogyne incognita population densities as affected by soil temperature, inoculum density, and green alfalfa was determined. the effect on m. incognita population densities was greater at a soil temperature of 25 c than at 18 or 32 c. nematode control by a. conoides was most effective when the fungus was introduced into the soil 2 wk prior to nematode inoculation and planting of corn. inoculum density of a. conoides was positiv ... | 1982 | 19295692 |
| population dynamics of meloidogyne incognita on corn grown in soil in fested with arthrobotrys conoides. | microplot and greenhouse experiments were conducted to evaluate the effects of soil incorporation of the nematophagous fungus arthrobotrys conoides and green alfalfa mulch on the population dynamics of meloidogyne incognita on corn. reproduction of m. incognita and the incidence of root galling were reduced by the addition of a. conoides and/or green alfalfa in all tests. numbers of juveniles were reduced by as much as 84%, and eggs were fewest in early to mid-season soil samples from microplots ... | 1982 | 19295673 |
| sex differentiation in meloidogyne incognita and anatomical evidence of sex reversal. | sex differentiation was studied by examining the cellular structure of gonad primordia extracted from second-stage juveniles developing under different environmental conditions. in female jnveniles, divisions of the two somatic cells of the primordium occurred in mid-sccond stage and resulted in 12 cells. two of them were differentiated as cap cells, two occupied the anterior central and eight the posterior central part of the v-shaped primordium. the two germinal cells divided at the 6-8 somati ... | 1982 | 19295752 |
| genetic basis of the epidemiologic effects of resistance to meloidogyne incognita in the tomato cultivar small fry. | the genetic nature of resistance and its epidemiologic effects on two meloidogyne incognita populations were assessed in the f hybrid tomato cv. small fry. the progeny of a small fry x small fry cross segregated in a 3:1 resistant:susceptible ratio, indicating the presence of a single, completely dominant resistance gene (lmir) in small fry. in a subsequent experiment, infection frequency and the rate of development of primary infection on resistant small fry x small fry segregates were compared ... | 1982 | 19295750 |
| optimum initial inoculum levels for evaluation of resistance in tomato to meloidogyne spp. at two different soil temperatures. | the effects of meloidogyne incognita or m. javanica at five initial inoculum levels of 20, 100, 200, 1,000, and 2,000 eggs and infective juveniles per seedling on 'floradade,' 'nemarex,' 'patriot,' and 'pi 129149-2(sib)-5' tomatoes maintained at 25 or 32.5 c were studied. the number of egg masses on roots of the susceptible cultivar floradade was similar for both species of root-knot nematodes at either 2.5 or 32.5 c soil temperatures. at 25 c, very low numbers of egg masses were produced by bot ... | 1982 | 19295749 |
| estimating relative error in nematode numbers from single soil samples composed of multiple cores. | spatial distributions of several species of plant-parasitic nematodes were determined in each of three fallow vegetable fields and in smaller subunits of those fields. goodness of fit to each of several theoretical distributions was tested hy means of a x(2) test. distributions for most species showed good agreement with a negative binomial model. an exception occurred with crictmemella sp., which showed a better fit to the neyman type a distribution. for nematodes distributed according to the n ... | 1982 | 19295747 |
| simulated sampling strategies for nematodes distributed according to a negative binomial model. | a fortran computer program was developed to simulate nematode soil sampling strategies consisting of various numbers of samples per field, with each sample consisting of various numbers of soil cores. the program assumes that the nematode species involved fit a negative binomial distribution. required input data are estimates of the mean and k values, the number of samples per field and cores per sample in the strategy to be investigated, and the number of times the simulation is to be replicate ... | 1982 | 19295746 |
| effects of the temperature and duration of the initial incubation period on resistance to meloidogyne incognita in tomato. | 1982 | 19295733 | |
| influence of initial population densities of meloidogyne incognita on three chile cultivars. | the effects of meloidogyne incognita on the big jim, jalapeno, and new mexico no. 6 chile (capsicum annuum) cultivars were investigated in microplots for two growing seasons. all three cultivars were susceptible to m. incognita and reacted similarly to different initial populations of this nematode. severe stunting and yield suppressions occurred at all initial m. incognita densities tested ranging from 385 to 4,230 eggs and larvae/500 cm(3) soil. regression analysis of the microplot data from a ... | 1982 | 19295720 |
| influence of soil temperature on meloidogyne incognita resistant and susceptible cotton, gossypium hirsutum. | the degree of resistance by a cotton plant to meloidogyne incognita is affected by soil temperature, particularly in moderately resistant cultivars, the total number of nematodes in the resistant and moderately resistant rools at 35 c was equal to, or greater than, the number in susceptible roots at 20, 25, or 30 c. a shift in numbers to developing and egg-bearing forms of nematodes in the susceptible cultivar as tentperature increased indicates development was affected by temperature rather tha ... | 1982 | 19295718 |
| morphological comparison of head shape and stylet morphology of second-stage juveniles of meloidogyne species. | head shape and stylet morphology of second-stage juveniles of one population each of m. incognita, m. javanica, m. arenaria, and m. hapla were compared by light microscopy. excised stylets of each species were also compared by scanning electron microscopy (sem). differences in head morphology were observed only between m. hapla and the other three species. in sem, differences in stylet size, shape, and relative distance of the dorsal esophageal gland orifice to the base of the stylet were eviden ... | 1982 | 19295717 |
| meloidogyne cruciani n. sp. a root-knot nematode from st. croix (u.s. virgin islands) with observations on morphology of this and two other species of the genus. | meloidogyne cruciani n. sp. infecting tomato (lycopersicon esculentum mill.) in the u.s. virgin islands is described and illustrated. m. cruciani is distinguished from other species of the genus by having punctations around the anus of the female and by the second-stage juveniles possessing tri-lobed esophageal glands which are longer than most other species, with their posterier end at about 46.4% of the body length. the esophageal glands of the immature and adult females are contained in five ... | 1982 | 19295712 |
| the relationship between soil populations of meloidogyne incognita and yield reduction of soybean in the coastal plain. | in a replicated field plot experiment, the population density of meloidogyne incognita was monitored biweekly through the overwintering period (december through april) between soybean crops. the population survived as second-stage juveniles whose numbers remained stable through the winter months and did not decline until february. the yields of plots planted with a m. incognita susceptible cultivar were negatively correlated with the numbers of juveniles recovered at all preplanting sampling dat ... | 1982 | 19295691 |
| development of meloidogyne incognita in stored potato tubers. | 1982 | 19295688 | |
| nematicidal principles from two species of lamiaceae. | aqueous extracts of ocimum sanctum and o. basilicum leaves contained compounds that killed meloidogyne incognita larvae in 160 min. thin layer and gas-liquid chromatography, and infrared spectrophotometry indicated that the essential oils eugenol and linalool were the active nematicidal compounds. | 1982 | 19295684 |
| chloroplast differentiation in tomato root galls induced by the root knot nematode meloidogyne incognita. | primary roots of tomato, lycopersicon esculentum cv. marglobe, were cultured aseptically on agar containing a standard nutrient formulation with or without kinetin. when secondary roots developed, cultures were inoculated with the root-knot nematode, meloidogyne incognita. following inoculation, the cultures were divided into two groups which were incubated either in total darkness or in 16-h light-8-h dark cycles. at 24 h, 1, 2, 3, and 4 wk after incubation, roots from all cultures were process ... | 1982 | 19295678 |
| effects of management practices on meloidogyne incognita and snap bean yield. | phenamiphos applied at 6.7 kg ai/ha through a solid set or a center pivot irrigation system with 28 mm of water effectively controlled root-knot nematodes, meloidogyne incognita, and resulted in greater snap bean growth and yields irrespective of growing season, tillage method, or cover crop system. the percentage yield increases attributed to this method of m. incognita control over nontreated controls were 45% in the spring crop, and 90% and 409% in the fall crops following winter rye and fall ... | 1982 | 19295676 |
| varietal response of tomato to the interaction of salinity and meloidogyne incognita infection. | response of tomato (lycopersicon esculentum) cultivars to a range of conductivity levels was tested in the presence and absence of meloidogyne incognita. the conductivity levels were produced by appropriate adjustment of a 1:1 solution of sodium chloride and calcium chloride. the growth of m. incognita resistant ('beefmaster' and 'atkinson') and susceptible ('hunts 2580' and 'ronita') tomato plants was inversely related to soil salinity between ec(e) 0 and 5 mmhos/cm. nematode inoculation of sal ... | 1982 | 19295675 |
| localization of cuticular binding sites of concanavalin a on caenorhabditis elegans and meloidogyne incognita. | utilizing a concanavalin a (con a)-hemocyanin conjugate, the majority of cuticular con a binding sites were shown to be localized on the head region of caenorhabclitis elegans and meloidogyne incognita. secretions which apparently emanated from the amphids and inner labial papillae did not label. | 1982 | 19295672 |
| potential of tissue culture for breeding root-knot nematode resistance into vegetables. | plant protoplast technology is being investigated as a means of transferring root-knot nematode resistance factors from solanum sisymbriifolium into the susceptible s. melongena. solanum sisymbriifolium plants regenerated from callus lost resistance to meloidogyne javanica but retained resistance to m. incognita. tomato plants cloned from leaf discs of the root-knot nematode resistant 'patriot' were completely susceptible to m. incognita, while sections of stems and leaves rooted in sand in the ... | 1982 | 19295668 |
| a soil-free system for assaying nematicidal activity of chemicals. | a biological assay system for studying the nematicidal activity of chemicals has been devised using a model consisting of cucumber (cucumis sativus l. cv. long marketer) seedlings growing in the dispo(r) growth-pouch apparatus. meloidogyne incognita was used as the test organism. the response was quantified in terms of the numbers of galls produced. statistical procedures were applied to estimate the ed(50) values of currently available nematicides. this system permits accurate quantification of ... | 1981 | 19300800 |
| foliar spray effects of selected amino acids on sunflower infected with meloidogyne incognita. | 1981 | 19300787 | |
| beta-glycosidases from meloidogyne incognita and m. javanica. | 1981 | 19300785 | |
| the effect of meloidogyne incognita and tissue wounding on severity of seedling disease of cotton caused by rhizoctonia solani. | 1981 | 19300778 | |
| scanning electron microscope study of the root-knot nematode (meloidogyne incognita) on tomato root. | this study examines the types of structural information that can be gained by utilizing the scanning electron microscope (sem) and a cryofracture technique to examine the host-parasite interaction. roots of tomato, lycopersicon esculentum cv. marglobe, were cultured aseptically and inoculated with the root-knot nematode, meloidogyne incognita. twenty-four hours to four weeks after inoculation, developing galls were removed from the cultures and processed for sem observation. the cryofracture tec ... | 1981 | 19300776 |
| the development and influence of meloidogyne incognita and m. javanica on wheat. | the effects of soil temperature and initial inoculum density (pi) of meloidogyne incognito and m. javanica on growth of wheat (triticum aestivum cv. anza) and nematode reproduction were studied in controlled temperature baths in the glasshouse. nematode reproduction was directly proportional to temperature between 14 and 30 c for m. incognita and between 18 and 26 c for m. javanica. reproduction rates (pf/pi, where pf = final number of eggs) for pi's of 3,000, 9,000, and 30,000 eggs/plant were g ... | 1981 | 19300774 |
| effects of soil temperature and planting date of wheat on meloidogyne incognita reproduction, soil populations, and grain yield. | wheat cultivars anza and produra grown in winter in california were planted in meloidogyne incognita infested and noninfested sandy loam plots in october (soil temperature 21 c) and november (soil temperature 16 c) of 1979. meloidogyne incognita penetrated roots of mid-october planted ataza (427 juveniles/g root), developed into adult females by january, and produced 75 eggs/g root by harvest in april. penetration and development did not occur in late plantings. anza seedlings grown in infested ... | 1981 | 19300773 |
| effect of soil texture and the clay component on migration of meloidogyne incognita second-stage juveniles. | the vertical migration of m. incognita juveniles introduced at 20 cm from the roots was studied in five natural soils, 100% silica sand, 95% silica sand with 5% clay, 90% silica sand with 10% clay, and 95% silica sand with 5% clay as a concentrated layer. in natural soils the percentage of juveniles capable of migrating 20 cm and penetrating the roots decreased when the percentage of clay and silt increased. no migration occurred in silica sand without clay particles; when 5 or 10% of clay were ... | 1981 | 19300747 |
| applying nematicides through an overhead sprinkler irrigation system for control of nematodes. | phenamiphos, ethoprop, and carbofuran each at 6.7 kg a.i./ha were applied to squash, southern pea, and corn via injection into a sprinkler irrigation system. this method was then compared with a conventional application of phenamiphos and ethoprop granules spread on the soil surface and incorporated into the top 15 cm for control of macroposthonia ornata and meloidogyne incognita. nematode populations in the soil and root-gall indices were lower, and yields greater, in treated than in untreated ... | 1981 | 19300737 |
| influence of water and soil temperature on the concentration and efficacy of phenamiphos for control of root-knot nematodes. | field plots of tifton loamy sand were treated with phenamiphos for control of root-knot nematodes in a multiple-crop system of turnips, field corn, and southern peas. preplant applications of phenamiphos protected roots of turnips and corn from damage by root-knot nematodes. concentrations of phenamiphos at application in the 0-15-cm soil layer were near 6 mug/g on turnips and near 4 mug/g on corn and southern peas. after 30 d, concentrations were approximately 1 mug phenamiphos/g of soil for al ... | 1981 | 19300736 |
| effects of film mulch and soil pesticides on nematodes, weeds, and yields of vegetable crops. | field plots in tifton loamy sand were treated with various soil pesticides in 1973 and 1974 and either left exposed or covered with biodegradable flint mulch. test crops were cantaloup, slicing and pickling cucumber, squash, and sweet corn. overhead sprinkler irrigation was used in 1973, and trickle irrigation under the film mulch was used on sweet corn in 1974. soil was assayed for nematodes, and roots of plants were evaluated for damage by root-knot nematodes. nematode populations were reduced ... | 1981 | 19300735 |
| oogenesis and the chromosomes of the parthenogenic root-knot nematode meloidogyne incognita. | 220 populations of meloidogyne incognita and related forms from 46 countries reproduced by mitotic parthenogenesis (apomixis). determination of somatic chromosome numbers from oogonia and oocytes revealed the existence of a predominant, possibly triploid race a with 3n = 40 to 46 and a rare, diploid race b with 2n = 32 to 36 chromosomes. there is no correlation between cytological races and the four recognized host races of this species. the characteristic behavior of prophase i chromosomes of m ... | 1981 | 19300730 |
| influence of photoperiod and temperature on migrations of meloidogyne juveniles. | photoperiod influences the migration of m. incognita juveniles toward tomato roots. approximately 33% migrated vertically 20 cm in 7 days to roots when 12 h dark were alternated with 12 h light. only 7% migrated when light was constant for 24 h. vertical migration of m. incognita juveniles was studied at 14, 16, 18, 20, and 22 c. the migration of m. incognita juveniles begins at about 18 c and reaches its maximum at 22 c. the migration of m. hapla and m. incognita juveniles were compared at 14, ... | 1981 | 19300748 |
| effect of foliar application of carbofuran and a related compound on plant-parasitic nematodes under greenhouse and growth chamber conditions. | greenhouse and growth chamber studies were made to investigate the downward systemic nematicidal activity of carbofuran and its analog 2,3-dihydro-2,2-dimethyl-7-benzofuranyl [(di-n-butyl)-4-aminosulfenyl] carbamate against meloidogyne incognita, tylenchorhynchus claytoni, and pratylenchus penetrans. oxamyl was used as standard in tests with t. claytoni. both carbofuran and its analog reduced all three plant-parasitic species when plant foliage was sprayed with chemical suspension of 1,200, 2,40 ... | 1981 | 19300716 |
| dynamics of concomitant populations of hoplolaimus columbus, scutellonema brachyurum, and meloidogyne incognita on cotton. | cotton seedlings grown in a greenhouse and a growth chamber were inoculated with scutellonema brachyurum, hoplolaimus columbus, and meloidogyne incognita, singly and in all possible combinations, at two initial population (pi) levels (100 and 300/100 cm(3)). s. brachyurum alone was not pathogenic to cotton at these population levels. it fed primarily as an ectoparasite but matured and reproduced within the root when it penetrated. populations of s. brachyurum increased in the presence of h. colu ... | 1981 | 19300720 |
| influence of meloidogyne incognita on fusarium wilt of tomato at or below the minimum temperature for wilt development. | 'bonny best' tomato plants were grown at 16, 21, or 24 c for 28 d in soil infested with either of two isolates of fusarium oxysporum f. sp. lycopersici race 1 and meloidogyne incognita. significant levels of fusarium wilt occurred at all temperatures including 16 c, which has not been reported previously. one fusarium isolate resulted in the highest levels of disease incidence at 21 and 24 c in the presence of root-knot nematodes, and at 24 c when the nematodes were not present. at 16 c there wa ... | 1981 | 19300723 |
| identification of the chromosome carrying the factor for resistance to meloidogyne incognita in tobacco. | to identify the chromosome carrying the factor for resistance to meloidogyne incognita in tobacco, crosses were made between resistant tobacco 'nc95' as pollen parent and each of the 12 tobacco monosomics (a-l) representative of the tomentosae half of the nicotiana tabacum chromosome complement. of the f seedlings, 927 plants were grown for observation. from these, 223 plants were selected as possible monosomics on the basis of morphological characteristics. these plants were self-pollinated, an ... | 1981 | 19300724 |
| yield response and injury levels of meloidogyne incognita and m. javanica on the susceptible tobacco 'mcnair 944'. | the effects of meloidogyne incognita and m. javanica on a susceptible tobacco (nicotiana tabacum l.) cv. mcnair 944 were investigated in field microplots during 1978 and 1979. three initial inoculum levels-4, 16, and 64 nematode eggs and/or second-stage larvae per 100 cm(3) of soil-were used for each nematode species. data obtained from the experiments included plant yield and the amount of reproduction of the two nematode species. at comparative inoculum levels, m. javanica was more aggressive ... | 1981 | 19300744 |
| effects of one and two applications of nematicides on nematode populations and soybean yields. | yields of 'mcnair 800' soybeans, glycine max (l.) merr., were significantly increased with ethylene dibromide + chloropicrin, dbcp, phenamiphos, and aldicarb applied at-planting and with phenamiphos, aldicarb, and dbcp applied postplant to soil infested with meloidogyne incognita (kofoid and white) chitwood. yields of 'gasoy 17' were significantly increased with ethylene dibromide + chloropicrin, dbcp, phenamiphos, and aldicarb applied, preplant and with dbcp, carbofuran, phenamiphos, aldicarb, ... | 1980 | 19300706 |
| inhibition of syncytia formation and root-knot nematode development on cultures of excised tomato roots. | two different defined growth media were used to culture aseptically the root-knot nematode, meloidogyne incognita, on excised roots of tomato, lycopersicon esculentum cv 'marglobe.' one of these media, stw, was a formulation by skoog, tsui, and white and the other, ms, a formulation by murashige and skoog. from 1 through 4 weeks, inoculated tissues were fractured to observe root infection, giant-cell formation, and nematode development with the scanning electron microscope (sem). four weeks afte ... | 1980 | 19300696 |
| interaction of uromyces phaseoli and meloidogyne incognita on bean. | uromyces phaseoli, the causal agent of bean rust, suppressed shoot and root growth of three bean cultivars, reducing root weight more than shoot weight. the greatest suppression of root weight was on the cultivar that appeared most susceptible by visual ratings of shoot symptoms. meloidogyne incognita suppressed shoot and root growth of all test cultivars; root weight reductions differed among cultivars identical in susceptibility to this pathogen in root-gall rating tests. infection of plants w ... | 1980 | 19300692 |
| morphological comparison of meloidogyne males by scanning electron microscopy. | field plots of tifton loamy sand were treated with methyl bromide, dd-mencs, or ethoprop for control of root-knot nematodes, meloidogyne incognita, in a multiple cropping system of turnips, field corn, and southern peas. annual applications of methyl bromide and dd-mencs in november or december suppressed nematode numbers to very low levels through september, but numbers increased in the following october, november, and/or december. no benefit was found from ethoprop applied to dd-mencs-treated ... | 1980 | 19300667 |
| managing nematode population densities on tomato transplants using crop rotation and a nematicide. | millet, milo, soybean, crotalaria, and norman pigeon pea were used in conjunction with clean fallow and a nematicide (fensulfothion) for managing nematode populations in the production of tomato transplants (lycopersicon esculentum mill.). glean fallow was the most effective treatment in suppressing nematode numbers. after 2 years in tomato, root-knot nematodes increased in numbers to damaging levels, and fallow was no longer effective for complete control even in conjunction with fensulfothion. ... | 1980 | 19300664 |
| histological study of the compatible and incompatible interaction of soybeans and meloidogyne incognita. | 1979 | 19300654 | |
| histochemical localization and nematoxicity of terpenoid aldehydes in cotton. | in healthy cotton, except for random occasional occurrence in cortical cells, terpenoid aldehydes (ta) are localized in the epidermis and, even there, are absent from the tip 2-4 cm of the root. since constitutive ta do not occur in the endodermis and stele of the root, they cannot be effective agents against the development of the sedentary stage of the root-knot nematode, meloidogyne incognita. within 4 days after inoculation with the root-knot nematode, infection-induced ta accumulated in the ... | 1979 | 19300641 |