bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of lucerne transient streak virus, and evidence of its affinity to southern bean mosaic virus
Authors: FORSTER R. L. S. , JONES A. T. 
Published: February 2008

SUMMARYA virus obtained from naturally infected lucerne (Medicago sativa) in New Zealand reacted with antiserum to an Australian isolate of lucerne transient streak virus (LTSV). Some plants infected with New Zealand isolates showed yellow flecks along lateral veins of leaves; symptoms were transient in some lucerne plants but persistent in others. A New Zealand isolate (LTSV‐NZ) infected 14 of 39 plant species tested by mechanical inoculation, but was not transmitted by five aphid species. In sap of Nicotiana clevelandii, LTSV‐NZ was infective after storage for 4 wk at 20 oC, diluting to 10‐5, or heating for 10 min at 70 oC. Purified virus preparations contained a single electrophoretic component and a single sedimenting component (s20w= 112 S) which formed a single buoyant density component in CsCl (1.37 g cm‐3) but two density components in Cs2SO4 (1.26 and 1.32 g cm‐3). LTSV‐NZ particles were stable in 10 ITIM EDTA at pH 5, but not at pH 8, being degraded into two sedimenting components of 105 S and 92 S. Particles contained c. 18% RNA in the form of one single‐stranded RNA molecule of mol. wt 1–4 times 106, and a polypeptide of mol. wt c. 32 400. LTSV‐NZ was serologically unrelated to 24 other isometric plant viruses. However, its properties are similar to those of southern bean mosaic virus and allied viruses. The present cryptogram of LTSV is R/l: 1–4/(18):S/S:S/*.
Nematodes associated with carrots in Scotland
Authors: BOAG B. 
Published: February 2008

SUMMARYSix hundred and fifteen soil samples were collected from 59 farms growing carrots and examined for plant parasitic nematodes. Of the potentially economically important species found the most frequently occurring were Longidorus elongatus, Rotylenchus goodeyi and Tylenchorhynchus dubius. However, numbers were generally insufficient to cause damage. At a site heavily infested with R. robustus, treatments with the oximecarbamate, aldicarb or the soil fumigant, dichloropropene significantly increased the yields of carrots by an average of 17 and 47% respectively.
A technique to assess the efficacy of non‐volatile nematicides against the potato cyst nematode Globodera rostochiensis
Authors: HAGUE N. G. M. 
Published: February 2008

SUMMARYThe assessment of larval emergence from cysts, second stage larval behaviour in soil, invasion of roots, development within roots and the final population provides a technique which can be used for evaluating the efficacy of any non‐volatile organophosphate or carbamate nematicide.Oxamyl delayed emergence from cysts, disorientated second stage larvae in soil, delayed and reduced invasion of roots, reduced the number of eggs in the final population and markedly reduced the final population of cysts.
Control of stem nematode, Ditylenchus dipsaci, in onions, by granular nematicides applied to the soil
Authors: WHITEHEAD A. G. , TITE D. J. , FRASER JANET E. , FRENCH EILEEN M. 
Published: February 2008

SUMMARYAldicarb at 1.4–5.6 kg a.i. ha‐l or oxamyl at 1.3–5.2 kg a.i. ha‐1 applied over the seed furrows during sowing prevented much of the damage resulting from stem nematode attack in spring‐sown onions. Rotting of bulbs in store due to stem nematode infestation was sometimes lessened by these treatments. Neither sowing onion seeds on soil ridges, nor applying aldicarb in two equal doses, one over the seed furrows during sowing, the other over the plants mid‐season, controlled the nematode better or increased onion yields more than a single equivalent dose over the seed furrows. Applied as two doses in this way, aldicarb was sometimes more effective against the nematode in summer‐sown onions than was an equivalent amount applied over the seed furrows during sowing. Only 2.5 kg or less aldicarb ha‐1 can be applied to onions without leaving unacceptable residues (>0.15 μg g‐1) in the harvested bulbs.
The use of cultivar trials records in assessing the incidence of cereal disease in England and Wales. I. Septoria nodorum in wheat and Rhynchosporium secalis in barley
Authors: ROWE JANET 
Published: February 2008

SUMMARYThe incidence of Septoria nodorum and Rhynchosporium secalis in N.I.A.B. cultivar trials of wheat and barley respectively showed marked regional and seasonal variation. Peak annual incidence of the two diseases often coincided. Levels of S. nodorum infection in winter wheat generally exceeded those in spring wheat, while levels of R. secalis in winter and spring barley were usually similar. Annual peaks in mean disease levels were associated with above average rainfall and raindays and below average temperatures, especially during the period of epidemic development. Regional variation in disease incidence reflected the association with high rainfall. S. nodorum infection in wheat was more widespread, and incidence of leaf infection was higher, than R. secalis in barley. Annual and regional incidence of S. nodorum and R. secalis in trials was similar to that recorded in the Plant Pathology Laboratory surveys of commercial crops. Disease records from cultivar trials can provide useful additional information on the behaviour of S. nodorum and R. secalis nationally.
Yam mosaic, a new potyvirus infecting Dioscorea cayenensis in the Ivory Coast
Authors: THOUVENEL J.‐C. , FAUQUET C. 
Published: February 2008

SUMMARYThe major disease affecting Dioscorea cayenensis in the Ivory Coast is caused by a virus which was transmitted by mechanical inoculation to some Dioscorea spp. and Nicotiana benthamiana. In extracts of D. cayenensis leaves infectivity was lost after 10 min at 60 d̀C but not 55 d̀C and after dilution to 10‐3 but not 10‐2. A purification procedure is described. The virus particles are flexuous filaments c. 785 nm long. The virus was transmitted by four aphid species in the non‐persistent manner, and is serologically related to four African potyviruses. The name yam mosaic virus is proposed; the present cryptogram is: */*:*/6:E/E:S/Ve/Ap, potyvirus group.
The influence of morphological differences in bracken pinnules on the foliar uptake of aminotriazole
Authors: COOK G. T. , CARR KATHERINE E. , DUNCAN H. J. 
Published: February 2008

SUMMARYBracken growing on an open hillside had greater development of both the upper and lower cuticular membranes than that growing under moderate shade. However, in the latter, aminotriazole uptake was less. This could be due to decreased spreading of the applied solution on the upper surface of shade‐grown fronds and a decrease in stomatal and/or leaflet hair densities on the lower surface.
Postbloom fruit drop, a new disease of citrus associated with a form of Colletotrichum gloeosporioides
Authors: FAGAN H. J. 
Published: February 2008

SUMMARY Colletotrichum gloeosporioides was shown to be associated with postbloom fruit drop disease of citrus, a serious problem on sweet oranges in Belize.Early symptoms are brown or water‐soaked spots on the petals, followed by corolla necrosis. Subsequently most fruitlets absciss, leaving calyces and pedicels as characteristic green ‘buttons’.Susceptibility of flower buds to C. gloeosporioides infection was shown to increase up to the time of opening; blossom infection occurred within 18 h at 19–30°C.
The particle morphology and some other properties of chloris striate mosaic virus
Authors: FRANCKI R. I. B. , HATTA T. , GRYLLS N. E. , GRIVELL C. J. 
Published: February 2008

SUMMARYThe causal agent of Chloris striate mosaic disease appears to be a virus with polyhedral particles 18 nm in diameter usually occurring as paired structures about 18 times 30 nm in negatively stained preparations. These particles were detected in the nuclei of infected plants forming characteristic inclusions in all cells except those of the epidermis. Such particles were not detected in thin sections of viruliferous leaf hopper vectors (Nesoclutha pallida). Purified virus preparations were shown to be highly infective when assayed by feeding vector leaf hoppers through membranes and confining them on indicator plants.In particle morphology, chloris striate mosaic virus (CSMV) differs from other viruses of Gramineae in Australia but resembles maize streak virus isolated in Africa, which however is serologically unrelated.
The resistance of two clones of perennial ryegrass and their progeny to ryegrass mosaic virus from different parts of Britain
Authors: GIBSON R. W. , HEARD A. J. 
Published: February 2008

SUMMARYTwo clones (R1 and R2) of perennial ryegrass selected from cv.S.23 pastures for immunity to a few isolates of ryegrass mosaic virus (RMV) retained immunity when inoculated manually with isolates from 10 widely‐separated sites in Britain and when grown outside at eight other sites for 1 yr. At a ninth site (Saxmundham) an isolate (RMV‐Sax) capable of infecting both resistant clones (although only with difficulty) was detected in one plot. Resistance to a Rothamsted isolate of RMV and to RMV/Sax was also shown by R1 × R2 progeny. Clone R1 yielded more than S.23 in small field plots as did R1 × R2 and R2 × R1 progeny in a pot experiment.
The toxicity of some benzimidazole fungicides to the pea aphid, Acyrthosiphon pisum
Authors: PARTIS G. A. , BAILISS K. W. 
Published: February 2008

SUMMARYField bean plants were treated with benomyl in a glasshouse and nymphs of Acyrthosiphon pisum were then caged on the second pinnate leaf. Soil drenches of 75 μg benomyl/ml or above increased mortality of the aphid. The concentration of methyl benzimidazole‐2–yl carbamate (MBC = carbendazim) in leaf sap, determined by a Penicillium expansum bioassay, was proportional to the concentration of benomyl applied as a soil drench or foliar spray, but lower in sprayed plants than drenched plants. The compound persisted at high concentrations in the second leaf for 4 wk but was present in low amounts in young leaves. Nymphs were also fed through membranes on artificial diets incorporating benzimidazole compounds. In this artificial system a commercial formulation of Carbendazim (Bavistin) increased aphid mortality whereas the formulation medium was inactive. Thiabendazole (as the commercial formulation Tecto 60), 2–aminobenzimidazole and benzimidazole were also inactive. It is suggested that the carbamate moiety of carbendazim causes the aphicidal activity of the compound.
Control of white rot in dry bulb onions with artificial onion oil
Authors: MERRIMAN P. R. , ISAACS S. , MACGREGOR R. R. , TOWERS G. B. 
Published: February 2008

SUMMARYArtificial onion oil was evaluated as a soil treatment for control of white rot in onions caused by Sclerotium cepivorum. The treatment was tested at Werribee South in a red brown earth with a sclerotial population of c. 40–100/kg soil; and at Colac in a black clay loam with c. 180/kg soil. Treatments were applied before sowing and their effect on numbers of sclerotia, disease incidence and yield of dry bulb onions determined.At Werribee South onion oil reduced numbers of sclerotia at the 0–10 and 10–20 cm depths in soil, reduced disease incidence and increased yield in comparison with the controls. Onion oil at a concentration of 5% in water and injected (440 litredha) at 10 cm was most effective. The treatment reduced sclerotial numbers at 0–10 and 10–20 cm by 77 and 91% respectively, reduced disease from 57 to 13% and increased yield by 103%. Onion oil at 25% in water had no significant effect on populations of sclerotia or on incidence of disease.In an experiment at Colac, the application of onion oil at 5% in water reduced sclerotial numbers from 187 to 87/kg, but not incidence of white rot.
Detection of six nepoviruses in their nematode vectors by immunosorbent electron microscopy
Authors: ROBERTS I. M. , BROWN D. J. F. 
Published: February 2008

SUMMARYParticles of six nepoviruses were detected by immunosorbent electron microscopy (ISEM) in extracts of their respective vector nematodes. This technique was at least a thousand times more sensitive than conventional electron microscopy. It was also more rapid, reliable and sensitive than infectivity tests in which extracts of nematodes were inoculated to indicator plants. The viruses were detected in extracts of single nematodes, and in the roots and leaves of infector and bait plants.
A possible mechanism of action of asulam involving folk acid biosynthesis
Authors: STEPHEN N. H. , COOK G. T. , DUNCAN H. J. 
Published: February 2008

SUMMARYA range of plant species was sown in beakers containing vermiculite and treated with solutions of asulam. This resulted principally in stunting of the root system which could be reversed by the simultaneous addition of either p‐aminobenzoic acid or folic acid. Compounds related to p‐aminobenzoic acid had no such activity. It is proposed that a possible mechanism of action of asulam is the inhibition of folic acid synthesis resulting in impairment of biological methylations and hence inhibition of protein and nucleic acid synthesis.
Effects of 3,5–diiodo‐4–hydroxybenzonitrile (ioxynil) on barley root growth and uptake of phosphate from culture solutions
Authors: WAIN R. L. , WHITFORD P. N. 
Published: February 2008

SUMMARYLow concentrations (c. 10‐6 m) of 3,5–diiodo‐4–hydroxybenzonitrile (ioxynil) supplied to barley seedlings in culture solution promote a marked increase in root length and uptake of phosphate is also increased by this treatment. When [125I]ioxynil was supplied to barley seedlings through the roots for 7 days, the presence of 3,5–diiodo‐4–hydroxybenzoic acid (DIHB) was detected in the root tissue.
Protection of radish from cabbage root fly damage by seed treatments with organophosphorus and carbamate insecticides
Authors: THOMPSON A. R. , SUETT D. L. , PERCIVALL A. L. 
Published: February 2008

SUMMARYTen seed treatment formulations were assessed in the laboratory and glasshouse for their phytotoxicity to radish and effectiveness in preventing cabbage root fly damage. Bendiocarb, dimethoate, mecarphon and chlorfenvinphos were phytotoxic; carbophenothion, diazinon, iodofenphos and pirimiphos‐ethyl gave negligible protection. Chlorpyrifos and isofenphos performed adequately and so were compared at 14 and 20 g a.i./kg of seed in four field experiments with chlorfenvinphos soil treatments. With less than one‐third of the a.i. needed for soil treatments, the seed treatments gave similar or, in one experiment, better protection than 2·2 kg chlorfenvinphos/ha incorporated in the soil before sowing.Insecticide residues in mature radish from soil treated at 2·2 kg a.i./ha with a chlorfenvinphos e.c. were 0·04–0·06 μg/g, within the current Codex tolerance of 0·1 μg/g; the same dose of a granular formulation of chlorfenvinphos produced residues of 0·06‐0·21 μg/g. Chlorpyrifos residues in mature radish grown from seed treated at 20 g a.i./kg were 0·12‐0·65 μg/g, mostly less than the most relevant Codex tolerance, for carrots, of 0·5 μg/g. Seed treatment with the same dose of isofenphos, for which there are no Codex tolerances, produced residues of 0·17‐0·27μg/g.No insecticide treatments are currently approved in the U.K. to protect radish from damage by cabbage root fly larvae. Soil treatment with a chlorfenvinphos e.c. seems to be suitable for protecting single radish crops. If suitable formulations of chlorpyrifos or isofenphos were made available commercially, seed treatment with these insecticides would lessen the risk of residues accumulating in soil and contaminating successive radish crops grown in the same soil. Seed treatment would also provide an alternative to applying smaller doses to the soil for second or subsequent crops.
Differential host preference in Pseudocercosporella herpotrichoides with spring‐sown wheat and barley monoculture
Authors: CUNNINGHAM P. C. 
Published: February 2008

SUMMARYIncidence of eyespot was assessed in different‐length sequences of spring‐sown wheat and barley in field experiments. Disease levels in the fourth crop were greater with single cereal systems than when the alternative crop was grown in the fourth year. The existence of host specificity as a possible cause of this phenomenon was examined in comparative pathogenicity studies of isolate collections obtained from differentially‐cropped plots from the same field.In two experiments, isolates from the third, fourth or fifth consecutive barley crops produced more disease on barley than on wheat and isolates from wheat caused more disease on wheat than did isolates from barley. Isolates from 4‐yr wheat and barley sequences showed significant specificity of isolates for their original hosts but in another experiment such specificity was not detected in isolates from 3‐ and 7‐yr sequences of wheat and barley. However, there was a significant reduction in virulence of isolates in the seventh compared with the third crop, when comparisons were done on the alternative rather than on the original host species. This suggests that extreme selection pressure for pathogen virulence on a particular host species may lead to impairment of pathogenic range.
Studies on double strain occupancy of nodules and the competitive ability of Rhizobium trifolii on red and white clover grown in soil and agar
Authors: BROMFIELD E. S. P. , JONES D. GARETH 
Published: February 2008

SUMMARYAn investigation concerning double strain occupancy of nodules and the competitive ability for nodulation of Rhizobium trifolii strains 7A strr and 32 spcr was carried out using red and white clover varieties grown in agar and soil.Only two nodules of the 498 typed from plants grown in soil contained both inoculated strains and none of those analysed by the replica plating technique were formed by both 32 spcr and an indigenous strain. In contrast, plants grown on agar produced between 17% and 25% doubly infected nodules. Strain 32 spcr was more competitive for nodulation than 7A strr both in soil and agar. Indigenous rhizobia in soil were highly competitive for nodulation with the introduced strains; increasing the density of the inoculum resulted in an increase in the proportion of nodules occupied by the inoculated strains. The strains used as mixed inocula in soil were less successful in nodulation than the same strains used as pure inocula. The results also indicate that there was a host effect on the nodulation success of 7A strr.
Pepino mosaic virus, a new potexvirus from pepino (Solanum muricatum)
Authors: JONES R. A. C. , KOENIG RENATE , LESEMANN D. E. 
Published: February 2008

SUMMARYPepino mosaic virus (PepMV), a previously undescribed virus, was found in fields of pepino (Solanum muricatum) in the Canete valley in coastal Peru. PepMV was transmitted by inoculation of sap to 32 species from three families out of 47 species from nine families tested. It caused a yellow mosaic in young leaves of pepino and either a mild mosaic or symptomless infection in 12 wild potato species, five potato cultivars and potato clone USDA 41956 but S. stoloniferum and potato cultivars Merpata and Revolucion reacted with severe systemic necrotic symptoms. The virus was transmitted by plant contact but not by Myzus persicae. It was best propagated and assayed in Nicotiana glutinosa. Sap from infected N. glutinosa was infective after dilution to 10‐1 but not 10‐6, after 10 min at 65°C but not 70°C and after 3 months at 20°C.PepMV had filamentous particles with a normal length of 508 nm; the ends of some seemed damaged. Ultra‐thin sections of infected leaves of N. glutinosa revealed many inclusions containing arrays of virus‐like particles some of which were banded or whorled; small aggregates of virus‐like particles were also common. The virus was purified by extracting sap from infected leaves in a solution containing 0·065 M disodium tetraborate, 0·435 M boric acid, 0·2% ascorbic acid and 0·2% sodium sulphite at pH 7·8, adding silver nitrate solution to the extract, and precipitating the virus with polyethylene glycol followed by two cycles of differential centrifugation. Particles of PepMV normally yielded two proteins with molecular weights of 26 600 and 23 200, but virus obtained from infective sap aged overnight yielded only the smaller protein suggesting that it was a product of degradation of the larger one. The virus is serologically related to two potexviruses, narcissus mosaic and cactus X and its properties are typical of the potexvirus group.
The effect of increasing dosage of barley yellow dwarf virus on some resistant and susceptible barleys
Authors: BOULTON R. E. , CATHERALL P. L. 
Published: February 2008

SUMMARYFive spring barleys, grown either in pots out of doors or in the field, were inoculated with barley yellow dwarf virus (BYDV) using 5, 10, 20 or 50 infective aphids (Rhopalosiphum padi) per plant. Control plants of each variety received no aphids. Infection with all aphid numbers had highly significant adverse effects on all varieties except Cb 1029, an early maturing BYDV‐resistant barley of Ethiopian origin. 12583 Co, a locally bred, late maturing barley possessing the same resistance gene as Cb 1029 suffered more in a pot experiment, but less than three susceptible varieties all of which were severely damaged even when few infective aphids were used. Progressive effects with increasing aphid numbers, indicative of dosage response, occurred in some varieties. These effects included delay in heading and increased stunting, but not less yield. In Cb 1029, BYDV infection caused a reduction in the number of heads per plant, but this was partly compensated for by an increase in the number of grains per head. Conversely, BYDV infection in 12583 Co caused an increase in the number of heads, partly offset by a decrease in the number of Brains tier head.
Leaf mottling of Spartina species caused by a newly recognised virus, spartina mottle virus
Authors: JONES PHILIP 
Published: February 2008

SUMMARYThe cause of a previously undocumented leaf mottling of Spartina species was investigated. Negatively stained preparations of sap from mottled leaves revealed flexuous particles 725 × 12 nm. Pinwheels with associated laminar inclusion bodies were observed in thin sections of affected mesophyll cells. The virus was purified from infected Spartina anglica plants and had a sedimentation coefficient in 0·015 m borate of 150S. The virus was transmitted by inoculation of sap to healthy Spartina anglica, but not to a range of other graminaceous or dicotyledonous species tested. It was distantly serologically related to agropyron mosaic virus, but not to other viruses with similar morphology; the name spartina mottle virus is proposed.
Seed survival and periodicity of seedling emergence in some species of Atriplex, Chenopodium, Polygonum and Rumex
Authors: ROBERTS H. A. , NEILSON JUNE E. 
Published: February 2008

SUMMARYSeeds or fruits of 10 weed species were collected in each of 3 years and mixed with the top 7·5 cm of sterilised soil which was confined in cylinders sunk in the ground outdoors and cultivated three times yearly. The numbers of seedlings emerging were recorded for 5 yr and the numbers of viable seeds remaining then determined. Few, if any, seedlings of Atriplex, Chenopodium or Polygonum spp. emerged in the autumn of sowing; the main emergence was consistently in March–May (A. hastata, A. patula), April–May (P. lapathifolium, P. persicaria), April–June (C. polyspermum), May–June (C. rubrum) or June–August (C. hybridum). When sown before November, some seedlings of Rumex crispus, R. obtusifolius and R. sanguineus appeared immediately. Most emerged in April in subsequent years. Seedling emergence was usually greatest in the first year; thereafter, with all species, seedling numbers decreased approximately exponentially from year to year. The mean numbers of seeds found to be viable after 5 yr ranged from 2·5% (R. sanguineus) to 16·6% (C. rubrum) of those sown.