Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| nematocidal activity to pratylenchus penetrans by culture fluids from actinomycetes and bacteria. | 1966 | 5951708 | |
| pratylenchus penetrans (cobb) populations as influenced by microorganisms and soil amendments. | numbers of pratylenchus penetrans in sterilized soil decreased significantly 2 weeks after the addition of 1% w/w (700 ppm n) nonsterile soybean meal (sbm), or sterilized sbm in combination with selected microorganisms. sterilized sbm had no effect on nematode populations in steamed soil. bacteria and fungi in the presence of sbm were more effective than the actinomycetes tested, causing up to 96-100% reduction in nematode populations. simpler nitrogenous compounds included kno, ca(no), nhno, (n ... | 1969 | 19325687 |
| thermotactic response of some plant parasitic nematodes. | attraction of ditylenchus dipsaci and pratylenchus penetrans to a temperature gradient was tested. heating wires, infrared radiations and germinating alfalfa seeds were used to create a temperature gradient as small as 0.033 c/cm in agar. p. penetrans, d. dipsaci, and tylenchorhynchus claytoni responded to a temperature gradient of 0.033 c over a 4-cm distance from the heat source. trichodorus christiei and xiphinema arnericanum showed no response. individuals of p. penetrans oriented their head ... | 1969 | 19325653 |
| oogenesis and embryology of two plant-parasitic nematodes, pratylenchus penetrans and p. zeae. | the process of oogenesis was studied in the bisexual species, pratylenchus penetrans, and the monosexual species, p. zeae. the nucleus of the oocyte of p. penetrans underwent two divisions after sperm penetration. the chromosome number of p. penetrans observed at metaphase of the first maturation division was 2n = 10 and the reduced chromosome number observed at anaphase of the first maturation division was n = 5. two polar bodies were found within the egg, indicating that this species reproduce ... | 1969 | 19325696 |
| reproduction of pratylenchus penetrans (nematoda:tylenchida). | pratylenchus penetrans did not reproduce without males. cytological examination indicated that cross-fertilization occurred. females had a chromosome number of 2n = 12. virgin females reared in isolation laid eggs, but these failed to undergo cleavage. males reared in isolation produced sperms. | 1970 | 19322280 |
| soil temperature effects on onion seedling injury by pratylenchus penetrans. | the effect of soil temperatures 7-25 c upon injury to seedling onions by pratylenchus penetrans was investigated. at 7-13 c < 100 nematodes/g of root caused significant reduction in onion root weights by the fifth week. more than 400 nematodes/g were required to produce comparable injury at 16-25 c. | 1970 | 19322305 |
| penetration of alfalfa roots by different stages of pratylenchus penetrans (cobb). | 1970 | 19322310 | |
| the influence of environmental factors on the respiration of plant-parasitic nematodes. | respiration of selected nematode species was measured relative to co level, temperature, osmotic pressure, humidity, glucose utilization and high ionic concentrations of sodium and potassium.in general, respiration was stimulated most by the dominant environmental factors at levels near those expected in the nematode's "natural" habitat. soil-inhabiting nematodes utilized o, most rapidly with high (1-2%) co whereas a foliar nematode (aphelenchoides ritzemabosi) did so with 0.03% co, the concentr ... | 1970 | 19322313 |
| populations of pratylenchus penetrans relative to decomposing nitrogenous soil amendments. | populations of pratylenchus penetrans decreased in soil following addition of 70 and 700 ppm n in the form of nitrate, nitrite, organic nitrogen, or ammonium compounds. nitrate was less effective than other nitrogen carriers. population reduction is principally attributed to ammonification during decomposition. this hypothesis is supported by chromatographic analyses of soil atmospheres, survival of nematodes in pure co and n, inverse relationship of co, content in amended soils to nematode popu ... | 1971 | 19322339 |
| histochemical root pathology of brassica oleracea capitata l. infected by pratylenchus penetrans (cobb) filipjev and schuurmans stekhoyen (nematoda: tylenchidae). | histochemical study of cabbage roots axenically parasitized by pratylenchus penetrans revealed a five-fold increase in peroxidase activity (localized near lesions), pectic xylem plugs (resembling those caused by fusarium), and accumulation of oxidase-mediated polyphenols in the region of mechanical injury. fusarium-resistant cabbage was more susceptible to pratylenchus than the fusariunt-susceptible varieties, particularly in the formation of oxidized phenolic compounds. of 13 fluorescent compou ... | 1971 | 19322342 |
| infection of red clover seedlings by heterodera trifolii goffart and pratylenchus penetrans (cobb). | penetration of 3-day-old 'kenland' red clover seedlings by heterodera trifolii goffart and pratylenchus penetrans (cobb) was investigated in 50-mm petri dishes on 1% agat or discs of miracloth(r) (chicopee mills, inc., new york, n.y. 10018). penetration by both nematodes increased arithmetically with increased numbers in the inoculum. h. trifolii larvae slowly penetrated all root tissue but in relatively low numbers, 25-30% of inocula. swelling of larvae and formation of syncytia within roots wa ... | 1972 | 19319241 |
| histopathology of pea roots axenically infected by pratylenchus penetrans. | the histological changes in pea roots axenically infected by pratylenchus penetrans were studied and described. roots of pea seedlings growing aseptically on the surface of nutrient agar slants were inoculated with axenized nematodes. six hours after inoculation most of the nematodes introduced were probing the root epidermis, but none had completely entered though a few were observed with their anterior section already in the root. most of the nematodes penetrated the roots after 12 hr inoculat ... | 1972 | 19319243 |
| interactions of pratylenchus penetrans and meloidogyne incognita as coinhabitants in tomato. | greenhouse experiments on the interactions of pratylenchus penetrans and meloidogyne incognita showed that the population densities of both nematode species were depressed whenthey coinhabited tomato roots. fifty days after inoculation, the population level of a p. penetrans monoculture was about four times higher than when m. incognita was present. conversely, m. incognita reproduced twice as fast alone as in combination. there were no significant differences in the numbers of p. penetrans when ... | 1972 | 19319262 |
| infection of seedlings of alfalfa and red clover by concomitant populations of meloidogyne incognita and pratylenchus penetrans. | invasion of 2-day-old seedlings of 'buffalo' alfalfa and 'kenland' red clover by larvae of m. incognita and adults of p. penetrans, during 1-3 day periods of incubation at 24 c, was investigated in 50-mm petri dishes on 1% agar. penetration by both nematodes increased arithmetically with increased numbers in inocula. p. penetrans invaded alfalfa more readily than red cover, but m. incognita invaded red clover more readily than alfalfa. both nematodes inhibited root-elongation of alfalfa more tha ... | 1972 | 19319281 |
| effects of soil ph on reproduction of pratylenchus penetrans and forage yield of alfalfa. | 'vernal' alfalfa was grown for 30 weeks in nematode-free soil and in soil infested with pratylenchus penetrans. charlottetown fine sandy loam soil was used at its ph of 4.4 and at adjusted reactions of 5.2, 6.4 and 7.3. nematode reproduction was significantly greater at pit 5.2 and 6.4 and was not related to alfalfa root production over the full ph range studied. a significant nematode infestation x soil pit interaction on forage yield was recorded. nematode infestation significantly decreased f ... | 1972 | 19319283 |
| the effect of single and combined heat and co2 stimuli at different ambient temperatures on the behavior of two plant-parasitic nematodes. | pratylenchus penetrans and ditylenchus dipsaci were reared at 15-16 c, and their behavior towards single and combined heat and co stimuli was studied at ambient temperatures of 8.6 and 27.3 c. at the lower temperature, attractivity of the heat source was prevalent in both species, but co was also attractive. at the higher ambient temperature (27.3 c), the reaction to co was more positive and more rapid than to heat. in fact, at this temperature only d. dipsaci was attracted to the heat source, w ... | 1972 | 19319254 |
| ultrastructure of the feeding apparatus of pratylenchus penetrans. | the feeding apparatus of pratylenchus penetrans (cobb) chitwood and oteifa was studied by means of the electron microscope. the stomatostylet is composed of tooth, shaft, and basal knobs. the tooth and shaft are closely interlocked. the tooth forms the outer covering and the inner lining of the anterior half of the stylet, whereas the shaft extends from the basal knobs to the level of the stylet opening. it is proposed that the shaft and knobs are living tissues, whereas the tooth is the product ... | 1972 | 19319259 |
| interaction of meloidogyne naasi, pratylenchus penetrans, and tylenchorhynchus agri on creeping beentgrass. | the pathogenicity and interactions of meloidogyne naasi, pratylenchus penetrans, and tylenchorhynchus agri on 'toronto c-15' creeping bentgrass, agrostis palustris, was studied in a long-term greenhouse experiment. based on dry weights of roots and clippings, m. naasi alone and in all combinations with p. penetrans and t. agri was highly pathogenic to creeping bentgrass. p. penetrans and t. agri alone and in combination inhibited root growth but adversely affected top growth only when the two we ... | 1972 | 19319260 |
| technique for quantifying injury to seedling soybeans by pratylenchus penetrans without sacrificing the plant. | 1973 | 19319301 | |
| a simplified medium for monoxenic culture of pratylenchus penetrans and ditylenchus dipsaci. | 1973 | 19319303 | |
| extraction of eggs of pratylenchus penetrans from alfalfa callus and relationship between age of culture and yield of eggs. | 1973 | 19319305 | |
| relationship between population densities of pratylenchus penetrans and crop losses in flue-cured tobacco in ontario. | flue-cured tobacco was grown in microplots consisting of concrete drainage tries, 40-cm (i.d.), infested with 0; 666 ; 2000; 6000 or 18,000 root-lesion nematodes, pratylenchus penetrans/kg of soil. yield and grade index decreased with preplant soil population densities in excess of 2000/kg of soil. at initial densities of 6000 and 18,000/kg of soil losses in crop returns were 11.0% and 27.5%, respectively. decreases in the maturity index and in percentage dry stalk weight with increasing densiti ... | 1973 | 19319324 |
| nematode response to carbofuran. | higher populations of meloidogyne incognita larvae and pratylenchus penetrans were recovered from soil treated with carbofuran 10 and 15 days after treatment, respectively, than were recovered from untreated control soil. the number of p. penetrans, however, was lower 50 days after treatment, and symptoms developed only occasionally on the root systems of host plants. populations of tylenchorhynchus claytoni inoculated at different distances from the base of corn seedlings growing in carbofuran- ... | 1973 | 19319291 |
| phenol accumulation related to resistance in tomato to infection by root-knot and lesion nematodes. | host-parasite relationships of meloidogyne incognita acrita and pratylenchus penetrans were compared on three closely related cultivars of tomato: 'nemared', resistant to root-knot nematodes; 'hawaii 7153', moderately resistant; and 'b-5', susceptible. root-knot nematode larvae induced typical galls on the roots of b-5; larvae that entered nemared were walled-off by necrotic cells; both reactions occurred in hawaii 7153. lesion nematodes caused surface lesions which were initially similar on all ... | 1973 | 19319346 |
| effect of meloidogyne incognita on reproduction of pratylenchus penetrans in red clover and alfalfa. | roots of seedlings of red clover and alfalfa growing on 10(1) hoagland and arnon solution agar were inoculated with various combinations of meloidogyne incognita and pratylenchus penetrans. egg-laying by p. penetrans decreased as the number of nematodes, the ratio of entrant m. incognita to entrant p. penetrans, and the priority of invasion of roots by m. incognita increased. embryogeny and hatching of eggs of p. penetrans, and development of larvae of m. incognita, were not affected. in red clo ... | 1975 | 19308128 |
| effects of light intensity and quality effects on reproduction of plant-parasitic nematodes. | growing cotton in a greenhouse with 12-h of supplemental light [8,608 lux (800 ft-c) from combination of mercury and lucalux lamps] resulted in 2 x to > 3 x greater reproduction of meloidogyne incognita and belonolaimus longicaudatus as compared to natural light alone. rate of increase of hoplolaimus galeatus was affected little in this experiment. in a second experiment under controlled conditions in a phytotron, light source and intensity had greater influence on the reproduction of heterodera ... | 1975 | 19308183 |
| influence of nematodes and light sources on growth and nodulation of soybean. | the influence of nematodes on nodulation of soybean varied according to their modes of parasitism. in the greenhouse, nodule formation was stimulated by the endoparasites, meloidogyne hapla and pratylenchus penetrans, but was inhibited slightly by the ectoparasite, belonolaimus longicaudatus. in an experiment under controlled conditions in a phytotron, heterodera glycines severely inhibited nodule formation, whereas plants inoculated with b. longicaudatus and p. penetrans had more nodules per g ... | 1976 | 19308196 |
| ultrastructure of the spicules of pratylenchus penetrans. | the two spicules of pratyienchus penetrans are not morphologically identical. the outer spicule is slightly larger and longer than the inner spicule. each spicule is composed of a blade, shaft, and base. the spicules originate from the gradual thickening and invagination of the posterior walls of the spicular pouch. at the tip of each spicule are two small pores with one dendritic process associated with each pore. at the shaft portion, the spicule has a thick body which has a central core fille ... | 1976 | 19308200 |
| effects of potassium fertilization and pratylenchus penetrans on yield and potassium content of red clover and alfalfa. | red clover and alfalfa were inoculated with pratylenchus penetrans and grown in an alberry sandy loam soil to which potassium (k) was added at seeding at 0, 41.5, 83, and 166 microg/g. in one experiment with alfalfa, additional k was added after each forage cut to replace that which was removed. nematode populations were not consistently affected by k fertilization. nematode infection stunted red clover and alfalfa and resulted in lower yields at all k levels, except for alfalfa at the lowest k ... | 1976 | 19308208 |
| sex expression and tail morphology of female progenies of smooth-tail and crenate-tail females of pratylenchus penetrans. | an analysis of the offspring of single smooth- and crenate-tail females of pratylenchus penetrans indicated the existence of progenies containing only males or females. of the 80 progenies analyzed, 46 contained females with smooth and crenate tails. in general, regardless of the mother's tail type, most females possessed crenate tails, although more crenate-tail females originated from a crenate-tail female than from a smooth-tail female. twenty-three progenies contained only females with crena ... | 1976 | 19308222 |
| effects of plastic mulch on soil treatments toxic to pratylenchus penetrans. | 1976 | 19308219 | |
| morphological variation in pratylenchus penetrans. | variability of morphological characters used to separate pratylenchus penetrans from other species of the genus was studied in a population originating from a single gravid female. pronounced heteromorphism was observed and characterized. about 30% of females had a crenate-tail terminus. several shapes of stylet knobs were characterized; 50% of them were anteriorly flattened to indented. the outer margin of the cephalic framework extended into the body from one-half to two annules. the shape of ... | 1976 | 19308221 |
| efficacy of multiple applications of oxamyl and phenamiphos for control of pratylenchus penetrans in birdsfoot trefoil. | preplant soil applications of granular phenamiphos effectively reduced pratytenchus penetrans in soil during the seeding year and 1 year after, and in the roots of birdsfoot trefoil 2 years after seeding. forage yields were increased in the season following application of phenamiphos, but stands of plants/m(2) were not greater (p = 0.05) than those in the checks 1 and 2 years after treatment. additional spring applications of phenamiphos 1 and 2 years after seeding further reduced numbers of nem ... | 1976 | 19308245 |
| fine structure of the esophagus of pratylenchus penetrans. | the fine structure of the esophagus of pratylenchus penetrans is described. the gland lobe is syncytial and contains two types of nuclei: three large nuclei with little chromatin, and more numerous smaller nuclei with large amounts of chromatin. some of the smaller nuclei are associated only with glandular tissue, whereas others are part of nerve ceils within the esophagus. clusters of free ribosomes, rough endoplasmic reticulum, and numerous mitochondria occur in the lobe region where the secre ... | 1976 | 19308226 |
| relative susceptibility of selected cultivars, of potato to pratylenchus penetrans. | pratylenchus penetrans suppressed the tuber yields of potato cultivars 'katahdin', 'kennebec', and 'superior', but did not affect yields of 'russet burbank'. in comparison with noninfested controls, all initial nematode densities (p(i)) of p. penetrans (p(i) = 38, 81, 164, 211/ 100 cm(3) of soil) suppressed yields of superior; a moderate p(i) (81/100 cm(3) soil) suppressed yields of kennebec; and on katahdin, a moderate p(i) enhanced yields, but higher p(i)'s caused a marked loss. in general, yi ... | 1976 | 19308229 |
| nematicidal injection: targeted control of plant-parasitic nematodes of trees and vines. | pressurized injection of nematicidal solutions was effective for control of nematodes within trees and vines. significant (p = 0.01) control of pratylenchus vulnus on grape was attained with four nonfumigants (carbofuran, oxamyl, phenamiphos, and sulfocarb) and one fumigant nematicide (dbcp). pratylenchus penetrans was controlled (p = 0.05 and 0.1) in apples and walnuts with sulfocarh and oxamyl. this species also was controlled in apples with carbofuran and phenamiphos. the advantages of pressu ... | 1977 | 19305613 |
| interaction of plastic, hay and grass mulches, and metam-sodium on control of pratylenchus penetrans in tomatoes. | 1977 | 19305623 | |
| analysis of crop losses in tomato due to pratylenchus penetrans. | the effects of pratylenchus penetrans upon yields of 'veebrite' tomato were studied at initial soil population densities (p(i)) of 360, 2,010, 4,580, and 14,360 nematodes/kg of soil in 20-cm (i.d.) clay-tile microplots. the lowest p(i) appeared to stimulate fruit production. higher p(i)'s suppressed fruit production (total weight of marketable tomatoes and numbers of intermediate- and large-sized fruits), in comparison to control yields, the highest p(i) resulted in 38% fewer fruits which weighe ... | 1977 | 19305610 |
| suppression of pratylenchus penetrans and tylenchorhynchus dubius by trichoderma viride. | 1977 | 19305589 | |
| effects of hydroclytic enzymes on plant-parasitic nematodes. | proteases, lipase, and chitinase killed tylenchorhynchus dubius in vitro and in soil. tylenchorhynchus dubius was more susceptible to the enzymes than pratylenchus penetrans. papain was the most effective protease, and other enzymes were less effective. heating enzymes to 80 c for 10 min greatly reduced nematicidal effectiveness. scanning electron micrographs showed that papain and chitinase produced structural changes in the cuticle of t. dubius. lipase removed a thin outer layer. papain remove ... | 1977 | 19305592 |
| the influence of pratylenchus penetrans on the incidence and severity of verticillium wilt of potato. | the influence of pratylenchus penetrans on the incidence and severity of verticillium wilt was examined in the potato cultivars 'kennebec', 'katahdin', and 'abnaki'. single-stem plants were grown in soil maintained at a temperature of 22 +/- 1 c. axenically cultured nematodes were suspended in water and introduced to the soil, at a rate of ca 5,000/25.4-cm pot, through holes made around each stem. ten days after infestation with nematodes, conidial suspensions of verticillium albo-atrum were int ... | 1978 | 19305819 |
| infectivity of pratylenchus penetrans on alfalfa. | the infectivity of pratylenchus penetrans on alfalfa seedlings cv. du pulls was studied. the dense root-hair zone was the preferred zone of penetration by females, males, and third-stage larvae. a lesion initially appeared as a water-soaked area at the root surface, becoming yellow and elliptical as the nematode entered the cortex, with dark-brown cells later appearing in the centre as the nematode fed. at 20 c, females penetrated roots earlier, faster, and in greater numbers than either males o ... | 1978 | 19305861 |
| growth response of three vegetables to smooth- and crenate-tailed females of three species of pratylenchus. | the effect of morphological variants of females of pratylenchus penetrans, p. neglectus, and p. crenatus on the growth of three vegetables was studied. variants were characterized by having either a smooth or crenate tail terminus. pea was inoculated with variants of p. penetrans, one female per seedling, and grown at light intensities ranging from 1,350 to 21,600 lux in a series of five experiments. only crenate-tailed females of p. penetrans suppressed the growth of pea and only when pea was g ... | 1978 | 19305853 |
| growth reduction of apple seedlings by pratylenchus penetrans as influenced by seedling age at inoculation. | apple seedlings of different ages (1, 3, and 5 weeks) were inoculated with 6,900 pratylenchus penetrans per seedling in 10-cm-diam pots in a growth chamber. rate of growth suppression and total growth suppression of seedlings by p. penetrans were inversely proportional to seedling age at time of nematode inoculation. younger seedlings were found to contain a higher number of nematodes per gram root. | 1979 | 19305551 |
| effect of soil water potential on growth of apple trees infected with pratylenchus penetrans. | malling-merton 106 apple rootstocks inoculated with pratylenchus penetrans, or uninoculated, were grown in a growth chamber in pots of loamy sand maintained at two moisture levels, 0 to -0.4 bar or 0 to -10 bars. either inoculation or low soil moisture suppressed shoot growth and increased root necrosis. however, the nematode-soil moisture interaction was not significant. | 1979 | 19305552 |
| effects of phenamiphos, methyl bromide, and fallowing on pratylenchus penetrans, yield of medicago sativa, and fusarium infections. | a field study was made of the effects of a residual nematicide (phenamiphos), a fumigant (methyl bromide), and fallowing on the number of root lesion nematodes (pratylenchus penetrans), forage yields of alfalfa, and the occurrence of fusarium spp. in plant roots and soil. fallowing controlled nematodes initially, but by the end of the second growing season, nematode numbers were as high as in plots which had grown a nematode-susceptible crop. forage yield was greater in fallowed plots only for t ... | 1979 | 19300645 |
| response of pinus ponderosa seedlings to stylet-bearing nematodes. | of 12 stylet-bearing nematodes used for inoculations, pratylenchus penetrans, p. brachyurus, p. vulnus, ditylenchus destructor, meloidogyne incognita, m. javanica, and m. hapla reproduced on pinus ponderosa, while xiphinema index, aphelenchus avenae, paratylenehus neoamblycephalus, tylenchulus semipenetrans, and macroposthonia xenoplax did not. p. vulnus, p. brachyurus, p. penetrans, a. avenae, d. destructor, t. semipenetrans, and p. neoamblycephalus significantly suppressed both the shoot and r ... | 1979 | 19300659 |
| 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 |
| influence of soil temperature and ph on pratylenchus penetrans and p. crenatus in alfalfa and timothy. | numbers of pratylenchus penetrans in alfalfa and timothy, and to a lesser extent p. crenatus in timothy, increased substantially as temperature increased from about l0 c to 30 c. however, p. crenatus in alfalfa decreased in number as temperature increased. mobility of p. crenatus in vertical soil columns decreased as temperature increased from 9.5 c to 28.5 c. raising the soil ph from 5.0 to 6.9 in which alfalfa was grown increased the numbers of p. penetrans and greatly reduced the numbers of p ... | 1981 | 19300772 |
| nematicide treatments of turfgrass seed. | seed treatments of improved kentucky bluegrass and fescue cultivars with carbofuran, oxamyl, and phenamiphos dissolved in acetone reduced seedling emergence, but treatments were not extremely phytotoxic. phenamiphos was the most toxic, particularly at the 5,000 mug/ml concentration. fresh weight of grass clippings 35 d following planting generally was greater in treatments than in controls except for the 5,000 mug/ml phenamiphos treatments on certain cultivars. all nematicide seed treatments red ... | 1981 | 19300783 |
| interactions among selected endoparasitic nematodes and three pseudomonads on alfalfa. | meloidogyne hapla, pratylenchus penetrans, and helicotylenchus dihystera, reduced the growth of 'saranac ar alfalfa seedlings when applied at concentrations of 50 nematodes per plant. all except p. penetrans reduced seedling growth when applied at 25 per seedling. m. hapla reduced growth when applied at 12 per seedling. nematodes interacted with three pseudomonads to produce greater growth reductions than were obtained with single pathogens, suggesting synergistic relationships. ditylenchus dips ... | 1982 | 19295682 |
| suppression of alfalfa growth by concommitant populations of pratylenchus penetrans and two fusarium species. | growth of alfalfa (medicago sativa cv. vernal) seedlings was compared after inoculation with combinations of either pratylenchus penetrans and fusarium soloni or p. penetrans and f. oxysporum f. sp. medicaginis. a synergistic disease interaction occurred in alfalfa when f. oxysporum and p. penetrans were added simultaneously to the soil. alfalfa growth was suppressed at all inoculum levels of p. penetrans and f. oxysporum, but not with f. solani. seedlings inoculated with the nematode alone gave ... | 1982 | 19295722 |
| 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 |
| effect of age of alfalfa root on penetration by pratylenchus penetrans. | penetration by all migratory life stages of pratylenchus penetrans into roots of alfalfa (medicago sativa l. cv. du puits) was inversely proportional to tissue age. two-day-old tissue in the root hair zone was penetrated twice as much as 10- or 20-day-old sections of the tap root. age-related differences were also observed in branch roots; these differences were not affected by increasing the number of nematodes from 1 to 10 per inoculation site, nor by increasing the length of the incubation pe ... | 1982 | 19295681 |
| effect of foliar applications of carbofuran and a related compound on plant-parasitic nematodes under microplot and field conditions. | studies were conducted to investigate the basipetal translocation of nematicidal activity from foliar treatments of carbofuran and its analog, 2,3-dihydro-2,2-dimethyl-7-benzofuranyl ([dibutylamino]thio)methyl carbamate, on corn in microplot studies and on tobacco and potato in field trials. two and three foliar applications of either product at 2,400 mug/ml (9-20 kg ai/ha) significantly reduced populations of pratylenchus penetrans in roots and populations of tylenchorhynchus claytoni, xiphinem ... | 1982 | 19295698 |
| joint influence of pratylenchus penetrans (nematoda) and leptinotarsa decemlineata (insecta) on solanum tuberosum productivity and pest population dynamics. | the joint action of a plant parasitic nematode, pratylenchus penetrans (root-lesion nematode), and an insect defoliator, leptinotarsa decemlineata (colorado potato beetle), on growth, development, and yield of solanum tuberosum cv. superior was studied in the field. three population densities of p. penetrans were superimposed on each of three population levels of l. decemlineata. the major impact of p. penetrans on final yield was through a reduction in the number of tubers formed during tuber i ... | 1984 | 19294016 |
| anhydrobiosis in pratylenchus penetrans. | anhydrobiotic survival of pratylenchus penetrans was compared in several soil moisture regimes. bodies of anhydrobiotic nematodes were coiled. in slow-dried soils, vineland silt loam (vsl) and fox loamy sand (fls), 70 and 58% of the total p. penetrans populations were anhydrobiotic when soil moistures reached ca. 3% and water potential 15 kpa or greater. coiling began at a much lower water potential in fls than in vsl. in fast-dried soils, only 31 and 22% of the p. penetrans populations in the s ... | 1984 | 19294023 |
| response of peach seedlings to infection by the root lesion nematode pratylenchus penetrans under controlled conditions. | twenty-one open pollinated populations of peach rootstock seedlings were evaluated for their response to infection by the root lesion nematode, pratylenchus penetrans, over a period of 98 days. nematode-infected peach seedling populations were shorter in plant height and had less shoot weight but more dry root weight than nematode-free controls. rootstock differences were demonstrated for nematode increase over the 98-day period, and average total numbers of nematodes in soil and roots. rootstoc ... | 1984 | 19294029 |
| pathogenicity of pratylenchus penetrans to navy bean (phaseolus vulgaris l.). | the pathogenicity of pratylenchus penetrans (root-lesion nematode) to phaseolus vulgaris (navy bean) was evaluated in greenhouse experiments. shoot and root fresh weight of cv. sanilac plants were increased 4 and 21%, respectively, by an initial population density (pi) of 25 p. penetrans per 100 cm(3) soil. leaf area and shoot fresh and dry weights were decreased by a pi of 50 or more p. penetrans per 100 cm(3) soil. a significant positive linear relationship existed between initial soil populat ... | 1985 | 19294063 |
| influence of pratylenchus penetrans on plant growth and water relations in potato. | plants of potato (solanum tuberosum) cultivars katahdin and superior were inoculated with 0, 1,500, or 15,000 pratylenchus penetrans. transpiration, measured in the greenhouse with a porometer after 56 days of growth, was not significantly different among nematode inoculum levels or between cultivars. the rate of xylem exudation from decapitated root systems of katahdin plants inoculated with 1,500 or 15,000 p. penetrans and superior plants inoculated with 15,000 p. penetrans was lower than from ... | 1986 | 19294196 |
| plant parasitic nematodes associated with leatherleaf fern. | seven species of plant parasitic nematodes were found to be associated with leatherleaf fern (rumohra adiantiformis) in central florida. of these, pratylenchus penetrans, tylenchorhynchus claytoni, and criconemoides curvatum were commonly encountered. nematode communities generally included two or three species of plant parasitic nematodes, with greatest diversity in nematode species occurring in ferneries shaded by oak trees. species diversity was not correlated with fernery age. leatherleaf fe ... | 1986 | 19294134 |
| reaction of six solanum tuberosum cultivars to pratylenchus penetrans. | six potato cultivars - superior, yukon gold, monona, norchip, kennebec, and russet burbank - were grown in tioga loamy sand in tile microplots noninfested or infested with 9,800-11,500 p. penetrans/kg soil. at midseason, soil nematode population densities on superior potatoes were 39,800/kg compared with 17,500-25,800/kg on the other cultivars. at harvest, 118 or 139 days after planting depending on maturity date, the final soil p. penetrans population density was 24,400/kg with superior and 34, ... | 1986 | 19294140 |
| nematodes associated with potato in prince edward island and new brunswick. | analysis of soil and root samples collected from potato fields across prince edward island and the woodstock-grand falls region of new brunswick, canada showed that pratylenchus spp. were the dominant plant-parasitic nematodes. pratylenchus penetrans occurred more often on prince edward island, and p. crenatus predominated in new brunswick. it was estimated that about 10% of the sites from prince edward island had population levels of pratylenchus spp. that may have caused economic losses. | 1987 | 19290267 |
| anhydrobiosis in pratylenchus penetrans and tylenchorhynchus n. sp. in cultivated soils cropped to winter rye. | anhydrobiotes of pratylenchus penetrans were found in two cultivated soils sown to rye in southern ontario during the growing season. anhydrobiotes at the 0-2.5-cm depth were recovered from 9 and 6 of 11 samplings, respectively, of a vineland silt loam and a fox loamy sand during the dry summer of 1983. at the 2.5-15.0-cm depth, anhydrobiotes were recovered less frequently. in the summer of 1984, anhydrobiotes of p. penetrans were recovered once and anhydrobiotes of tylenchorhynchus n. sp. twice ... | 1987 | 19290125 |
| pratylenchus penetrans population dynamics on three potato cultivars. | reproduction of pratylenchus penetrans on the potato cultivars hudson, katahdin, and superior was determined in greenhouse and field microplot experiments. although all three cultivars were good hosts for p. penetrans, differences in reproductive rate were found. in one greenhouse experiment, katahdin plants inoculated with 1,500 or 15,000 p. penetrans per pot had larger population densities at harvest than did superior; however differences between these cultivars were not significant in three o ... | 1987 | 19290156 |
| effect of ditylenchus dipsaci and pratylenchus penetrans on verticillium wilt of alfalfa. | verticillium albo-atrum wilt symptoms appeared faster and were significantly more severe in the presence of ditylenchus dipsaci in vernal, a wilt-susceptible cultivar, than in marls kabul, a wilt-resistant cultivar. winter kill in the field was not affected by the nematode during the first winter, but 50% of plants were killed in the second winter. forage yield from nematode-infected plants was significantly reduced the second year. interaction with v. albo-atrum did not significantly reduce for ... | 1987 | 19290158 |
| effects of fumigants and systemic pesticides on pratylenchus penetrans and potato yield. | replicated trials were conducted near alliston, ontario, in 1983 and 1984 to evaluate the efficacy of five chemical treatments in controlling the root-lesion nematode pratylenchus penetrans on potato, solanum tuberosum cv. russet burbank. the fumigants vorlex, at 55 liters product/ha, and telone ii b, at 75 liters product/ha, were more effective in suppressing high initial population densities of 18,320 and 50,880 p. penetrans/kg soil in 1983 and 1984, respectively, than single applications of t ... | 1987 | 19290166 |
| control of pratylenchus penetrans and meloidogyne hapla and yield response of alfalfa due to oxamyl seed treatments. | alfalfa (medicago sativa l. cv. saranac) seed were soaked for 20 minutes in water, acetone, or methanol containing 10 or 50 mg/ml of oxamyl (vydate l) or coated with a 2% aqueous cellulose solution containing the same amounts of oxamyl. seed were analyzed for oxamyl by hplc immediately after treatment and after 9 and 26 months of storage. oxamyl content of alfalfa seed did not decline after 26 months of storage. the effects of seed treatment on growth of alfalfa and nematode control were examine ... | 1987 | 19290170 |
| influence of edaphic factors and previous crop on pratylenchus spp. population densities in potato. | root and soil samples from commercial potato fields were assayed for nematodes in 1983 and 1984. pratylenchus spp. population densities in suffolk county, new york, were consistently, though not always statistically, higher in potato fields that had been planted to rye or wheat rather than potatoes during the previous growing season. regardless of the previous crop, population densities in the two potato production areas in suffolk county differed significantly: population densities on the south ... | 1987 | 19290111 |
| relationship of yield and pratylenchus spp. population densities in superior and russet burbank potato. | number of pratylenchus spp. (primarily p. penetrans) were recorded at planting in experimental potato plots over a 9-year period at one location on prince edward island. tuber yields of 'superior' and 'russet burbank' potatoes in plots treated with aldicarb were compared with yields in adjacent untreated plots. there was a linear relationship between the number of root lesion nematodes at planting and tuber yield increases after treatment for superior, but not for russet burbank (p < 0.05). when ... | 1988 | 19290299 |
| growth of potato and control of pratylenchus penetrans with oxamyl-treated seed pieces in greenhouse studies. | oxamyl was applied to both uncut and cut potato tubers in aqueous solutions of 1,000 to 32,000 mug/ml. emergence in greenhouse pots was delayed for a day or more after soaking cut tuber pieces in 32,000 mug/ml. after 10 weeks plant growth was greater, relative to the control, when pratylenchus penetrans-infested soil was planted with cut tubers soaked for 20 minutes in 32,000 mug/ml. soaking for 40 minutes did not increase nematode control nor affect plant growth. oxamyl applied to tubers at 1,0 ... | 1988 | 19290230 |
| effects of fumigant and nonfumigant nematicides on pratylenchus penetrans and yield of potato. | in 1984-85 metham-sodium and the combination of 1,3-dichloropropene plus aldicarb decreased (p = 0.05) soil population densities of pratylenchus penetrans at planting, midseason, and at harvest relative to the untreated control. these treatments increased (p = 0.05) marketable potato tuber yield from 27% to 46% in 1984 and from 23% to 37% in 1985, as compared with the control. in 1984 oxamyl (10% granular and 24% liquid) applied immediately after planting increased (p = 0.05) only the total yiel ... | 1989 | 19287665 |
| control of pratylenchus penetrans on potato with metam-sodium applied in irrigation water. | in 1986, metam-sodium broadcast at 152, 76, 38, 19, and 9.5 kg a.i./ha suppressed the population density of 19,600 pratylenchus penetrans/kg soil at planting by 100, 90, 63, 23, and 14%, respectively, and in 1987, with 1,370 p. penetrans/kg soil, by 99, 88, 57, 11, and 1%. at harvest, soil population densities increased 2.2-fold in 1986 and 13.9-fold in 1987. rate of population increase was similar at all rates of nematicide except it was slower at 152 kg a.i./ha in 1987. in both years, shoot an ... | 1989 | 19287674 |
| efficacy of oxamyl coated on alfalfa seed with a polymer sticker in pratylenchus and meloidogyne infested soils. | a polymer sticker was used as a coating in which oxamyl was applied to seeds of alfalfa cultivar saranac for the control of pratylenchus penetrans and meloidogyne hapla. the sticker, diluted 1:1 (sticker:water) to 1:5, delayed seedling emergence during the first 4 days after planting. by day 13, however, emergence from all sticker treatments was comparable to the control. shoot growth of seedlings at day 21 was less than that of the control only from seeds coated with a 1:1 dilution; root growth ... | 1989 | 19287603 |
| effects of pratylenchus penetrans on the infection of strawberry roots by gnomonia comari. | the fungus gnomonia comari, causal agent of strawberry leaf blotch, was inoculated at the crown of young axenized strawberry plants growing in sterilized sand. only the roots were colonized, and the infection was symptomless. when the fungus colonized the roots in the presence of the root lesion nematode pratylenchus penetrans, the plants were extremely stunted and their root system was necrotic. fungal conidiospores were found attached to the cuticle of nematodes extracted from soil inoculated ... | 1989 | 19287646 |
| ultrastructural pathology of cells affected by pratylenchus penetrans in alfalfa roots. | cortical parenchyma cells penetrated and fed upon by pratylenchus penetrans for 48 hours contained only cytoplasmic debris. proximal cells had an increase in tannin deposits, degenerated mitochondria, increased numbers of ribosomes, and no internal membrane structure. often the endodermis was collapsed and contained massive tannin deposits on the inner cell wall and cell lumen. similar observations were made in the stele, except tannin deposits were not as prominent. multivesicnlate structures w ... | 1989 | 19287649 |
| nematode autofluorescence and its use as an indicator of viability. | representatives of 15 nematode genera were viewed with 450-490-nm epi-illumination and found to autofluoresce. the autofluorescence was limited to 1-5-mum-d globules in the intestinal cells of live nematodes. when adult pratylenchus penetrans or caenorhabditis elegans were killed with formaldehyde, freezing, or heat, autofluorescence dispersed throughout the body. mixed stages of p. penetrans were killed by freezing at several different temperatures. estimates of survival based on autofluorescen ... | 1989 | 19287626 |
| carbamate and organophosphorus nematicides: acetylcholinesterase inhibition and effects on dispersal. | the sensitivities of acetylcholinesterases (ache) from the fungus-feeder aphelenchus avenae and the plant-parasitic species helicotylenchus dihystera and pratylenchus penetrans and the housefly, musca domestica, were compared using a radiometric assay which utilized h(3) acetylcholine as a substrate. nematode ache were generally less sensitive to inhibition by organophosphorns and carbamate pesticides than were ache from the housefly. ache from the plant-parasitic species and a. avenae were gene ... | 1989 | 19287642 |
| effects of fenamiphos on pratylenchus penetrans and growth of apple. | a 3-year study was conducted to evaluate fenamiphos at 20.2 kg a.i./ha applied in both fall and spring or in spring only for the control of pratylenchus penetrans on apple, malus domestica cv. granny smith on m7a rootstock. the initial population densities of p. penetrans within the plot area were 89/250 cm(3) soil and 268/g root dry weight. fenamiphos increased (p < 0.05) trunk diameter in years 2 and 3 and shoot length in years 1 and 2. yield data obtained in year 3 showed that the spring only ... | 1990 | 19287796 |
| reproduction of pratylenchus penetrans on potato and crops grown in rotation with potato. | the relative suitability of potato and crops frequently grown in rotation with potato as hosts for pratylenchus penetrans was evaluated. suitability of rye, wheat, corn, oat, sorgho-sudangrass, and potato were compared in pot studies based on ratios of final population : initial population density and densities of nematodes in roots at harvest. population densities increased more on potato, oat, and corn than on rye, wheat, and sorgho-sudangrass. there were no differences among the four rye cult ... | 1990 | 19287696 |
| differences in egress of male and female pratylenchus penetrans from pea roots. | 1990 | 19287768 | |
| observations on the invasion and endoparasitic behavior of the root lesion nematode pratylenchus penetrans. | the endoparasitic behavior of pratylenchus penetrans was examined using video-enhanced contrast microscopy to observe living nematodes inside root tissue. feeding behavior could be separated into phases of probing, cell penetration by the stytet, salivation, and food ingestion for brief and extended periods. after cell penetration, a small "salivation zone" was formed around the stylet tip. no feeding tubes were observed. feeding and migration were interrupted by rest phases when a nematode beca ... | 1990 | 19287726 |
| plant-parasitic nematodes in maine agricultural soils. | in a survey of plant-parasitic nematodes associated with agricultural crops in nine maine counties, 744 soil samples from 26 potential host plants were analyzed between november 1987 and january 1989. the most commonly encountered nematode genus was pratylenchus, occurring in 85% of the samples from most crops, except blueberries and onions. pratylenchus penetrans and p. crenatus were found commonly as species mixtures, with p. penetrans composing 40-80% of the mixture. meloidogyne hapla was enc ... | 1990 | 19287791 |
| penetration of celery and alfalfa roots by pratylenchus penetrans as affected by temperature. | a greater percentage of females than juveniles or males of p. penetrans penetrated celery roots grown in infested soil at 5, 18, or 30 c; the difference was greatest at 5 c. the time of initial penetration of alfalfa seedlings inoculated with single nematodes on water agar varied with temperature. females penetrated the seedlings earlier and over a wider range of temperatures than did males or juveniles. the rate of penetration was highest for females. after initial penetration, the penetration ... | 1991 | 19283112 |
| morphological observations of pratylenchus penetrans from celery and strawberry in southern ontario. | pratylenchus penetrans was obtained from premier strawberry in norfolk county and the niagara peninsula and from celery in the latter area. host affected the dimensions of p. penetrans to a greater extent than geographical area in ontario. adults of p. penetrans from southern ontario tended to be smaller than those reported elsewhere. the presence of three lip annules was consistent in the seven populations studied, although in some specimens one of the annules did not entirely encompass the hea ... | 1991 | 19283114 |
| effect of oxamyl treatment of potato seed pieces on pratylenchus penetrans and yield. | in the first 2 years of a 3-year (1987-89) microplot study, aqueous solutions of oxamyl (32 mg/ml) were applied to cut potato (solanum tuberosum cv. russet burbank) tubers, grown in fine sandy loam infested with pratylenchus penetrans. the seed-piece treatment alone and the seed-piece treatment followed by three foliar sprays generally reduced (p = 0.05) population densities of p. penetrans in the soil at midseason and in the soil and roots at harvest, compared to the control. in 1989, all seed ... | 1991 | 19283188 |
| influence of irrigation and heterorhabditis bacteriophora on plant-parasitic nematodes in turf. | daily irrigated, 80% pan replacement, and nonirrigated field plots of kentucky bluegrass (poa pratensis l.) were inoculated with a mixture of steinernema carpocapsae (all strain) and heterorhabditis bacteriophora (hp-88 strain) in 1988. in 1989, daily irrigated and nonirrigated plots were inoculated with hp-88 alone. the turf and associated soil contained populations of tylenchorhynchus dubius, t. nudus, pratylenchus penetrans, paratylenchus projectus, and criconemella rustica. in irrigated plot ... | 1992 | 19283039 |
| effects of fumigant nematicides on yield and quality of paste tomatoes grown in southwestern ontario. | field trials were conducted at the delhi research station, ontario, canada, on a fox loamy sand soil during 1987 and 1988 to evaluate the effects of row application of the fumigants telone ii, telone c-17, vorlex plus, and vorlex plus cp on the yield and quality of paste tomato (lycopersicon esculentum mill. cv. ferry morse 6203). the four fumigants were equally effective in controlling the natural field populations of root lesion nematodes (pratylenchus penetrans cobb). a significant reduction ... | 1992 | 19283042 |
| modeling of yield loss in potato early dying caused by pratylenchus penetrans and verticillium dahliae. | yield-loss models were developed for potato early dying, caused by an interaction between verticillium dahliae and pratylenchus penetrans. yield data were collected over 5 years (1985-1989) from potato plants grown in microplots infested with v. dahliae and (or) p. penetrans. the model y = b + (1 - b)/(1 + [vd/36.7]), where y was the relative yield (with uninfested controls = 1.0) and vd was the preplant density of v. dahliae microsclerotia per cm(3) soil, was fitted to the data set. when p. pen ... | 1992 | 19283209 |
| a plant health care program for brambles in the pacific northwest. | pratylenchus and xiphinema species have been associated with decline and mortality of brambles (rubus species) in the pacific northwest of the united states. these nematodes cause direct feeding damage and (or) transmit viruses that result in poor fruit quality and plant decline. a nematode management program has been developed by the author to minimize chemical use and nematode-induced damage while optimizing fruit production. nematode management is an integral part of a total plant health care ... | 1992 | 19283023 |
| correlation of edaphic factors with plant-parasitic nematode population densities in a forage field. | two hundred soil samples from the a(p) horizon of a reed canarygrass field overlaying several different but related soils in northern minnesota were analyzed for plant-parasitic nematodes and 22 edaphic factors. pratylenchus penetrans was the predominant nematode taxon. others were aglenchus agricola, tylenchorhynchus spp., heterodera trifolii, paratylenchus spp., tylenchus maius, and criconemella sp. five nematode taxa, p. penetrans, a, agricola, tylenchorhynchus spp., h. trifolii, and paratyle ... | 1993 | 19279821 |
| management of pratylenchus penetrans on oriental lilies with drip and foliar-applied nematicides. | pratylenchus penetrans is a pest for producers of oriental lilies in northern california. concern over groundwater contamination from 1,2-dichloropropane following shank injections of 1,3-dichloropropene-l,2-dichloropropane mixture and granular applications of aldicarb prompted testing for alternative methods of controlling p. penetrans. in field trials, nematicides applied by drip irrigation (ethoprop, fenamiphos, oxamyl, sodium tetrathiocarbonate, water extracts of marigold and vetch, and 1,3- ... | 1993 | 19279836 |
| occurrence of the clover cyst nematode, heterodera trifolii, in prince edward island soils. | in a survey of potato and rotational crops on prince edward island, canada, the cyst stage of the clover cyst nematode, heterodera trifolii, was found in 43 of 63 sites sampled; however, only 12% of the cysts contained eggs. the root lesion nematode, pratylenchus penetrans, was the dominant plant parasitic nematode and was found in 56 sites. extraction of cysts from soil was similar using either the schuiling centrifuge or the fenwick can method, although the former was more convenient to use. t ... | 1993 | 19279856 |
| infection of pratylenchus penetrans by nematode-pathogenic fungi. | eleven fungal isolates were tested in agar dishes for pathogenicity to pratylenchus penetrans. of the fungi that produce adhesive conidia, hirsutella rhossiliensis was a virulent pathogen; verticillium balanoides, drechmeria coniospora, and nematoctonus sp. were weak or nonpathogens. the trapping fungi, arthrobotrys dactyloides, a. oligospora, monacrosporium dlipsosporum, and m. cionopagum, killed most of the p. penetrans adults and juveniles added to the fungus cultures. an isolate of nematocto ... | 1993 | 19279772 |
| comparative response of alfalfa to pratylenchus penetrans populations. | four populations of pratylenchus penetrans did not differ (p > 0.05) in their virulence or reproductive capability on lahontan alfalfa. there was a negative relationship (r = -0 .7 9 ) between plant survival and nematode inocula densities at 26 +/- 3 c in the greenhouse. all plants survived at an inoculum level (pi) of 1 nematode/cm(3) soil, whereas survival rates were 50 to 55% at 20 nematodes/cm(3) soil. alfalfa shoot and root weights were negatively correlated (r = - 0.87; p < 0.05) with nema ... | 1993 | 19279795 |
| resistance in potato to pratylenchus penetrans. | potato clones from five different breeding populations were evaluated for their relative resistance and susceptibility to pratylenchus penetrans. resistance and susceptibility were distinguished by an index of susceptibility (si) calculated from the numbers of p. penetrans (including eggs) per g of root of individual clones in relation to that of a susceptible control at 30 or 70 days after inoculation. evaluations were carried out using 7.5-cm clay pots in a growth chamber at 24 c with 15-hour ... | 1993 | 19279796 |
| interactions among pratylenchus penetrans, p. scribneri, and verticillium dahliae in the potato early dying disease complex. | microplots were infested with combinations of the fungus verticillium dahliae and pratylenchus penetrans and p. scribneri to test for individual and combined effects of these organisms on potato yield and nematode reproduction. verticillium dahliae alone caused yield losses in all 3 years of the experiment, and the interaction between p. penetrans and v. dahliae was significant (p </= 0.05) in 2 years. pratylenchus penetrans alone caused yield losses in 2 years and p. scribneri alone caused yiel ... | 1994 | 19279885 |
| effect of hirsutella rhossiliensis on infection of potato by pratylenchus penetrans. | we evaluated the ability of the nematode-pathogenic fungus hirsutella rhossiliensis (deuteromycotina: hyphomycetes) to reduce root penetration and population increase of pratylenchus penetrans on potato. experiments were conducted at 24 c in a growth chamber. when nematodes were placed on the soil surface 8 cm from a 14-day-old potato cutting, the fungus decreased the number entering roots by 25%. to determine the effect of the fungus on population increase after the nematodes entered roots, we ... | 1994 | 19279896 |
| inheritance of resistance to pratylenchus penetrans in alfalfa. | fifty-two alfalfa (medicago sativa l.) clones, randomly selected from the cultivar baker and the experimental line mngrn-4, were evaluated for resistance (based on nematode reproduction) to pratylenchus penetrans in growth chamber tests (25 c). twenty-five clones, representing the range of nematodes and eggs per plant, were selected and retested. four moderately resistant and two susceptible alfalfa clones were identified. inheritance of resistance to p. penetrans was studied in these six clones ... | 1994 | 19279915 |
| effect of single and interplantings on pathogenicity of pratyenchus penetrans and p. neglectus to alfalfa and crested wheatgrass. | alfalfa is a host of pratylenchus penetrans and p. neglectus, whereas crested wheatgrass is a host of p. neglectus but not of p. penetrans. in a 120-day greenhouse experiment at 24 ñ 3 c, p. neglectus inhibited the growth of 'lahontan' alfalfa and 'fairway' crested wheatgrass. there were no differences in persistence and plant growth of alfalfa and crested wheatgrass, or reproduction of p. neglectus, in single plantings of alfalfa (ao) or crested wheatgrass (cwo), or in interplanted alfalfa and ... | 1994 | 19279916 |