bluuebunny/crossref_metadata_2025_split huggingface dataset:
The germination of grass seeds after storage at different temperatures in aluminium foil and manilla paper packets
Authors: BEAN E. W. , SENGUL S. , TYLER B. F. 
Published: February 2008

SUMMARYThe germination of seeds of three species of forage grasses, Lolium perenne, Festuca pratensis and Dactylis glomerata, was studied after storage for 3–5 years under five different storage conditions: in aluminium foil packets at —25°C, 0°C and laboratory temperature (c. 18°C), and in manilla paper packets at 0°C and laboratory temperature. With Lolium perenne and Festuca pratensis high germination values at 3 and 7 days were obtained from seed stored at — 25 °C and 0°C in foil packets (5% moisture), but at laboratory temperatures, seed from foil packets gave lower germination values than those from manilla paper packets. At all three temperatures Dactylis glomerata germination after 7 and 14 days was higher in seed stored in foil than in manilla packages. With all three species stored in manilla packets, germination was higher after laboratory than cold storage.
Systematic differences in the population density of green spruce aphid, Elatobium abietinum in a provenance trial of Sitka spruce, Picea sitchensis
Authors: DAY KEITH 
Published: February 2008

SUMMARYAphid populations were evaluated on foliage samples within an experimental forest area. There were marked differences in aphid density between three areas within the experiment and between individual trees. Significant differences between provenances of Sitka spruce were of particular interest since aphid density appeared to be related to the latitudinal origin of the seed. The more southerly provenances were especially susceptible. The accumulated evidence suggests that no single physiological difference between trees will account for all observed variations in aphid density although the later growth cessation of susceptible provenances deserves further study.
The distribution and abundance of predatory arthropods overwintering on farmland
Authors: SOTHERTON N. W. 
Published: February 2008

SUMMARYSoil samples (0·04 m‐2) were taken from December to January in 1981‐82 and 1982‐83 from five crop and two non‐crop habitats on farmland in Hampshire to quantify the distribution and abundance of overwintering polyphagous predatory arthropods. Total numbers of overwintering polyphagous predators were greater in field boundaries, winter‐sown cereals and established grassland than in the other four habitats. Many individual species overwintered in significantly higher densities in field boundaries than in any other habitat; others predominated in woodland, grassland and winter‐sown cereals. The carabids Agonum dorsale and Demetrias atricapillus, probably the most important predators of cereal aphids, overwintered almost entirely in field boundaries.
Immunoenzymatic techniques for the detection of Phoma exigua in infected potato tissues
Authors: AGUELON M. , DUNEZ J. 
Published: February 2008

SUMMARYAntisera to Phoma exigua var. foveata and var. exigua were prepared by injecting rabbits and mice with protein solutions from mycelium. Specific antibodies were isolated and immunoenzymatic techniques (double antibody sandwich ELISA and indirect ELISA) were used to test for the fungus in inoculated tubers and sprouts and in stems grown from these tubers. The fungus was detected in these different tissues, with var. foveata being more aggressive, demonstrating the applicability and sensitivity of the techniques. The antibodies produced to the two varieties of the fungus were not specific to their own varieties. They also reacted with Phoma tracheiphila but did not react with several other common potato pathogens. Preliminary results obtained with antibodies from mouse ascite liquid suggest the possibility of producing specific monoclonal antibodies.
Galactogen, a virus‐like particle from slugs
Authors: KASSANIS B. , WOODS R. D. , MACFARLANE I. 
Published: February 2008

SUMMARYVirus‐like particles were isolated from three species of slugs. Further investigation showed that the preparations contained very little nucleic acid and not more than 2% protein. Colorimetric and chromatographic analyses showed that they were composed almost entirely of galactogen and glycogen.
Change of virulence of Septoria nodorurn during passage through barley and wheat
Authors: CUNFER BARRY M. 
Published: February 2008

SUMMARYThe barley biotype of Septoria nodorum was recovered from isolates of the wheat biotype after 2–6 passages through barley. Shifts in the population of the two biotypes during host passage were determined by isolating single spores after passage and observing changes in symptom expression on both hosts. The number of passages required before the barley biotype was recovered varied with the fungus isolate and barley cultivar. Attempts to recover the wheat biotype from isolates of the barley biotype during several passages through wheat were unsuccessful when 105 to 106 conidia m1‐1 were used as inoculum. However, the wheat biotype was recovered from two isolates of the barley biotype during a single passage when a very high concentration of conidia (>1012 ml‐1) were used as inoculum. From the results of this study and a previous report by the author, the biotype of S. nodorum on barley which occurs in the southeastern United States appears to be largely restricted to barley.
Characterisation of an Australian isolate of tomato yellow top virus
Authors: THOMAS J. E. 
Published: February 2008

SUMMARYAn Australian isolate of tomato yellow top virus (TYTV‐A) was transmitted in the persistent manner by the aphid Myzus persicae. Its host range was mainly restricted to the Solanaceae, though Capsella bursa‐pastoris and Gomphrena globosa were symptomlessly infected.TYTV‐A was purified from Physalis Joridana, using an enzyme‐assisted method in which the initial tissue homogenate was incubated with cellulase. Yields of purified virus were 100–900 μg/kg tissue and depended on the age of the infected plants. Maximum yields were obtained 4–5 wk after inoculation. The particles of TYTV‐A were c. 24 nm in diameter, had a buoyant density of 1.34 in caesium sulphate and a coat protein mol. wt of c. 25.7 × 103.TYTV‐A was shown to be closely related serologically to potato leafroll virus (PLRV), TYTV from New Zealand and more distantly related to several other luteoviruses. An antiserum to TYTV‐A was used in enzyme‐linked immunosorbent assay tests to detect TYTV in field‐infected tomato plants and also luteoviruses from potato plants with leafroll symptoms. It is clear that TYTV‐A is a luteovirus closely related to PLRV.
The effect of oxamyl and the growing of susceptible and resistant potato cultivars on the population dynamics of Globodera rostochiensis throughout the soil profile
Authors: STOREY G. W. 
Published: February 2008

SUMMARYComparisons are made between the population dynamics of potato cyst nematode and root growth of Pentland Crown and Maris Piper potato cultivars. Large changes in the number of eggs occurred to a depth of 48 cm, particularly in a peaty loam and in plots treated with oxamyl. Oxamyl delayed the hatch of eggs in the peaty loam but not in the sandy loam, giving the protected plants several weeks without invasion damage during which they became bigger with their roots better established deeper in the soil. Oxamyl killed or impaired the movement of second stage juveniles but appeared to have little systemic activity to hinder juvenile development within roots.
Mass algal culture in outdoor plastic‐covered minipond systems
Authors: WALMSLEY R. D. , SHILLINGLAW S. N. 
Published: February 2008

SUMMARYA comparative study was undertaken to evaluate the performance of algal cultures grown in plastic‐covered outdoor minipond systems. It was demonstrated that production in enclosed miniponds was higher than in open ones on account of the stimulatory effects of elevated temperatures which developed in the enclosed systems. Although the plastic covering reduced the amount of light which was available for photosynthesis, this had minimal effects on production due to the light saturation characteristics of the algal cells. The practice of enclosing mass algal cultures with transparent plastic appears to show promise in semi‐arid regions not only as a procedure to reduce evaporation, but also as one for increasing algal yields.
Effects of aphid alarm pheromone derivatives and related compounds on non‐ and semi‐persistent plant virus transmission by Myzus persicae
Authors: GIBSON R. W. , PICKETT J. A. , DAWSON G. W. , RICE A. D. , STRIBLEY M. F. 
Published: February 2008

SUMMARYA derivative, prepared from the aphid alarm pheromone (E)‐β‐farnesene and the saturated straight 14‐carbon chain dialkyl ester of acetylene dicarboxylic acid, was the most active compound tested for inhibiting acquisition by the aphid Myzus persicae of the non‐persistently transmitted potato virus Y (PVY). Derivatives lacking, or with shorter, or branched or partially‐unsaturated carbon side‐chains were less active. The one derivative tested also inhibited inoculation of PVY, and acquisition of beet mosaic virus (also non‐persistent) and the semi‐persistent beet yellows virus. However, it had no obvious effect on aphid probing behaviour; related compounds lacking the (E)‐β‐farnesene moiety also inhibited acquisition of PVY.
Biological treatments for the control of decay in tree wounds.: Field tests
Authors: MERCER P. C. , KIRK S. A. 
Published: February 2008

SUMMARYIn an attempt to control fungi causing decay a range of micro‐organisms, selected after laboratory tests, was inoculated into wounds made in the trunks of beech trees. The most successful micro‐organism was an isolate of Trichoderma viride, which, over a period of 4 years, maintained significantly lower colonisation by decay fungi at both sites ‐ c. 15% of the level found in uninoculated wounds. T. viride could be reisolated from the majority of wounds into which it had been inoculated up to 4 years later. No other antagonist persisted very effectively. Inoculation of T. viride in glycerol improved its establishment but malt extract and sucrose had no such effect. Both the addition of glycerol to wounds and the wrapping of them in black PVC sheet increased natural colonisation by T. viride. The use of PVC but not glycerol reduced numbers of decay fungi but not through the agency of T. viride present by natural infection, as this proved generally ineffective in the control of decay fungi. Another isolate of T. viride persisted considerably better when covered with a wound sealant.
A seed treatment for the control of Pythium damping‐off diseases and Peronospora parasitica on brassicas
Authors: WHITE J. G. , CRUTE I. R. , WYNN E. C. 
Published: February 2008

SUMMARYIn soil inoculated with Pythium ultimum or Pythium irregulare, seed treatment with either Apron 70 (=1 g metalaxyl and 1 g captan/kg seed) or thiram gave control of pre‐emergence damping‐off of Brussels sprout and cabbage seedlings. On cauliflower, Apron 70 was significantly more effective than thiram. No post‐emergence damping‐off occurred in either of these crops or in oil‐seed rape following seed treatment with Apron 70 whilst post‐emergence losses from untreated seed ranged from 10·2–19·4% and from thiram treated seed from 5·7‐7·4%. Apron 70 gave complete control of Peronospora parasitica on cauliflower inoculated 10 days after sowing; thiram was ineffective. Following seed treatment with Apron 70, metalaxyl was detected in the cotyledons, true leaves and roots of cabbage seedlings up to 4 wk from sowing.
Effects of soil treatments and cultivars on ‘early dying’ disease of potatoes caused by Globodera rostochiensis and Verticilliurn dahliae
Authors: HIDE G. A. , CORBETT D. C. M. , EVANS K. 
Published: February 2008

SUMMARYPlots in a field infested with Globodera rostochiensis and Verticillium dahliae were treated in 1971 with methyl bromide, dazomet, aldicarb, benomyl or aldicarb + benomyl and potatoes (cv. Pentland Dell) were grown in four consecutive years. In 1971, all treatments delayed the development of haulm symptoms, decreased soil populations of G. rostochiensis and increased yields. In the second year yields were increased by all treatments except dazomet whereas in the third and fourth years only benomyl or aldicarb + benomyl increased yields. Soil populations of V. dahliae were decreased by methyl bromide in 1971 but not by other treatments or in later years.In 1976, Pentland Dell and Pentland Crown were grown on an infested field in plots fumigated with methyl bromide. Fumigation slightly delayed shoot emergence but increased plant height, ground cover and the size and persistence of the leaves; development of haulm symptoms was delayed and yield increased. Fumigating with methyl bromide at five times the normal rate was more beneficial to Pentland Dell than to Pentland Crown.In a comparison of 10 cultivars in 1975, symptoms developed sooner and yields were smaller on a field infested with G. rostochiensis and V. dahliae than on a non‐infested field and on both sites Maris Peer plants died soonest and yielded least. Pentland Crown yielded most on the non‐infested field and Maris Piper on the infested field.
Nematodes associated with dipterous stem‐boring larvae (Chloropidae and Opomyzidae) in ryegrass
Authors: MOORE D. , HUNT D.J. 
Published: February 2008

SUMMARYAssociations between different species of nematodes and stem‐boring larvae were studied over two years. Howardula oscinellae was rarely found in stem‐boring larvae. Usually mermithids were also uncommon, but in one Italian ryegrass (Lolium multiforum) variety trial over 12.5% of stem‐boring larvae were attacked, with different levels of parasitism in larvae from the different ryegrass varieties. Panagrolaimus rigidus nematodes were also identified from stem‐boring larvae and Oscinella frit larvae were the most common host. Greater infestation levels of P. rigidus were found in larvae from grazed swards than from cut swards. P. rigidus may cause the death of some stem‐boring larvae.
The effect of aphid‐resistance in cowpea on infestation and development of Aphis craccivora and the transmission of cowpea aphid‐borne mosaic virus1
Authors: ATIRI G. I. , EKPO E. J. A. , THOTTAPPILLY G. 
Published: February 2008

SUMMARYThe virus‐vector‐host relationships of cowpea aphid‐borne mosaic virus (CAMV) and its vector, Aphis craccivora, were studied in cowpea lines differing in resistance to aphid infestation. CAMV was acquired and inoculated by its vector during brief probes, confirming that it is non‐persistently transmitted. On aphid‐resistant cowpea lines, the abundance and the relative sizes of aphids was less than in aphid‐tolerant and aphid‐susceptible lines. However, aphids were observed to make more numerous probes and probes of shorter duration on aphid‐resistant lines than on aphid‐susceptible lines. Resistance to aphid infestation in cowpea did not provide resistance to infection with CAMV.
Effects of water potential and temperature on the development of eyespot lesions in wheat
Authors: HIGGINS S. , FITT B. D. L. 
Published: February 2008

SUMMARYGrowth of Pseudocercosporella herpotrichoides on potato dextrose agar at water potentials from ‐0.5 to ‐6.9 MPa was optimal at 20°C. At 12 and 20°C, six isolates of P. herpotrichoides grew more rapidly at ‐0.5 to ‐2 MPa than at ‐6.9 MPa. Wheat plants inoculated with P. herpotrichoides and grown in columns of soil at either 15 or 20°C developed more severe eyespot lesions under a heavy watering regime than under medium or light watering regimes. P. herpotrichoides penetrated leaf sheaths of inoculated plants grown in compost more rapidly at 10°C night/15°C day temperatures than at 5/10°C; death of leaf sheaths was also more rapid and consequently there were fewer living infected leaf sheaths at 10/15°C than at 5/10°C. Irrigating for 5 wk before harvest increased the severity of eyespot lesions in a 1983 wheat crop.
Studies of the antagonistic activities of bacteria endemic to cereal seeds.
Authors: ADETUYI F. C. , CARTWRIGHT D. W. 
Published: February 2008

SUMMARYThe antagonistic activities in vitro of cereal seed‐coat isolates of Pseudomonas syringae and a member of the Erwinia herbicola group towards a wide range of plant pathogenic fungi were assessed quantitatively using a novel, agar‐based bioassay technique. When compared with the conventional streak bioassay technique, the new method, involving the use of concentric rings of bacterial inoculum, was found to have several advantages. Within 36 h of inoculation, isolates of both bacteria caused substantial, and at times complete, inhibition of the mycelial growth of almost all pathogens tested. Studies of the relationships between bacterial growth, the proximity of the bacterial ring to the fungal colony, and the levels of inhibition of mycelial growth, suggested that antagonism was primarily the result of the active production of antimycotic toxins by both bacteria, and indicated their potential as biological control agents for plant disease.
Viruses associated with chlorotic rosette and green rosette diseases of groundnut in Nigeria*
Authors: REDDY D. V. R. , MURANT A. F. , DUNCAN G. H. , ANSA O. A. , DEMSKI J. W. , KUHN C. W. 
Published: February 2008

SUMMARYGroundnut (Arachis hypogaea) plants from Nigeria with chlorotic rosette disease contained a manually transmissible virus, considered to be a strain of groundnut rosette virus (GRV(C)). GRV(C) infected nine out of 32 species in three out of nine families. It caused local lesions without systemic infection in Chenopodium amaranticolor, C. murale and C. quinoa, and systemic symptoms in Glycine max, Nicotiana benthamiana, N. clevelandii and Phaseolus vulgaris as well as in groundnut. Some ‘rosette‐resistant’ groundnut lines were also infected. GRV(C) was transmitted by Aphis craccivora, but only from groundnut plants that were also infected with an aphid‐transmissible second virus, which was not manually transmissible and was considered to be groundnut rosette assistor virus (GRAV). Plants infected with GRAV contained isometric particles c. 25 nm in diameter which were detectable by immunosorbent electron microscopy on grids coated with antisera to several luteoviruses, especially with antisera to bean leaf roll, potato leafroll and beet western yellows viruses. No virus‐like particles were observed in extracts from plants infected with GRV(C) alone.A single groundnut plant obtained from Nigeria with symptoms of green rosette contained luteovirus particles, presumed to be of GRAV, and yielded a manually transmissible virus that induced symptoms similar to those of GRV(C) in C. amaranticolor but gave only mild or symptomless infection of N. benthamiana and N. clevelandii. It was considered to be a strain of GRV and designated GRV(G).
The feasibility of producing inbred rather than F1 hybrid cultivars in Brussels sprouts: a preliminary genetical analysis and choice of material for inbreeding
Authors: SMITH B. M. , ROGERS W. J. , KEARSEY M. J. 
Published: February 2008

SUMMARYThe feasibility of producing commercially acceptable inbred lines of Brussels sprouts is investigated. Two experiments are described which examined the nature and extent of heterosis in this crop using the techniques of biometrical genetics. They indicate incomplete dominance for several production traits, lower F1 uniformity and the presence of inbreds that outyield some F1's. These results strongly suggest that recombinant inbred lines, possibly outyielding the better F1's could be produced. Five crosses were identified for inbreeding by SSD and 1000 lines are being produced from each. The principles upon which these crosses were identified are described.
Growth and sporulation of Oidium begoniae: development of a deterministic model
Authors: QUINN JAMES A. , JR. CHARLES C. POWELL 
Published: February 2008

SUMMARYGrowth and sporulation of Oidium begoniae (begonia powdery mildew) on detached leaves was observed daily under a stereomicroscope. A mathematical model of growth and sporulation was constructed based on the patterns observed. The essential components of the model are three genetically fixed components of colony growth and sporulation and six components which changed with environmental and physiological conditions. The genetically fixed components were: the ultimate number of germ tubes, the hyphal growth unit (HGU or mean length supporting one branch), and the diurnal periodicity of sporulation. These components were shown to have approximately the same values at 15 and 21 °C. Components which varied with temperature were: the latent periods of germination, branching and sporulation, the time taken to reach the ultimate germ tube number, and the number of conidiophores per HGU, The derived equations were tested against observed sporulation and resulted in highly significant correlations. Similar results were obtained with published observations for Erysiphe graminis f. sp. hordei. This colony‐level model can be used as units to construct models of disease progress and suggests that it is theoretically possible to model disease in the field from laboratory studies. The model can be used in computer simulations of colony growth as demonstrated by a computer program in the Appendix.
The colonisation of fallen apple leaves by Phytophthora syringae in relation to inoculum levels in orchard soil
Authors: HARRIS D. C. 
Published: February 2008

SUMMARYFreshly abscissed apple leaves were rapidly infected after inoculation with zoospores of Phytophthora syringae. Mesophyll was extensively colonised within 4 days, sporangia and sex organs were formed within 9 days, but oospore maturation took several weeks. Oospores developed abundantly in leaves of all nine apple cvs tested.The ability of P. syringae to colonise leaf tissue diminished rapidly as leaves senesced, was prevented if leaves were first killed by freezing or desiccation, but was unaffected by watersoaking leaves before inoculation.Of nine soil samples from five apple orchards analysed for P. syringae by dilution and baiting, seven contained from 7–16 infective units/g, one contained significantly more at 34 units/g and one was even more infectious but unquantifiable. These differences of inoculum content of soils, which were only partially corroborated by successive baitings of bulk soil through leaf fall, are discussed in relation to the timing of leaf fall, the activity of P. syringae and rainfall.
Sampling potatoes for the incidence of tuber diseases and levels of inoculum
Authors: ADAMS M. J. , HIDE G. A. , LAPWOOD D. H. 
Published: February 2008

SUMMARYIn three years, between three and six seed stocks of cv. Pentland Crown were planted in field experiments. Seed tubers, stem bases and progeny tubers from the growing crop and tubers at harvest and after storage were sampled intensively and estimates of inoculum and disease made for five principal tuber diseases: the blemishes skin spot (Polyscytalum pustulans), silver scurf (Helminthosporium solani) and black scurf (Rhizoctonia solani) and bacterial soft rot (Erwinia carotovora).The data were principally used to calculate sample variances after transformation of % values to logits. A variance of 0.010 was selected as giving acceptable accuracy for most purposes and to achieve such values substantial numbers of samples would have been needed. Five to ten 50‐tuber samples of seed tubers or 15–20 samples of a harvested or stored crop would have been required for assessing disease symptoms and similar numbers of samples for assessing gangrene potential by a standard damage test. The eye plug test for assessing inoculum of the three blemishing diseases used 15 or 20‐tuber samples and five such samples of seed or about ten from the growing crop would usually have been adequate. Variances were nearly always greater for black scurf assessments than for other blemishing diseases.The data also illustrated changes in inoculum and disease levels during the season and in store. Their significance for understanding the epidemiology of the diseases and for storage disease forecasting is discussed.