bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of silica in protecting Italian ryegrass (Lolium multiflorum) from attack by dipterous stem‐boring larvae (Oscinellafiit and other related species)
Authors: MOORE D. 
Published: February 2008

SUMMARYThe importance of the silica content of the plant as a protection against dipterous stem‐borers was studied. Levels of silica in the stubble were inversely related to the degree of infestation by stem‐borers in 13 varieties of established swards of Italian ryegrass and also in newly‐sown swards of four varieties. There were significant reductions in larval colonisation of Italian ryegrass (cv. RvP) grown on soil watered with sodium silicate solution. A small range of silica content in the stubble was related to large differences in the level of attack by stem‐borers.
Latex content and biomass increase in mycorrhizal guayule (Partheniurn argentatum) under field conditions*
Authors: BLOSS H. E. , PFEIFFER C. M. 
Published: February 2008

SUMMARYGuayule seedlings were inoculated with two Glomus species in pasteurised soil and grown in the glasshouse without added fertiliser for 8 wk prior to transplanting to the field. The survival rate of transplanted guayule seedlings was increased by inoculation with vesicular arbuscular mycorrhizal fungi compared with uninoculated controls. Inoculated guayule had greater concentrations of Ca, Fe, Mg and Mn at six months of age, and greater concentrations of Ca, Mg, and Zn at 12 months of age than did uninoculated plants. The latex content of both roots and shoots of guayule was greater in inoculated than in uninoculated guayule plants at 12 and 18 months of age. The resin content remained unchanged between treatments irrespective of sampling date.
The effect of fungicide application on seed yield in perennial ryegrass cv. S.24
Authors: HAMPTON J. G. , HEBBLETHWAITE P. D. 
Published: February 2008

SUMMARYEyespot stem lesions, mildew and leaf spots caused by Drechslera spp. and a Spermospora sp. were identified in perennial ryegrass seed production trials in 1981 and 1982, but their incidence was low, and only rarely was more than 10% of any particular leaf area lesioned at any time during the growing season. Fungicide application (triadimefon plus carbendazim plus captafol) at monthly intervals from tillering (February) until harvest (July) increased seed yield by 15% in 1981 and 43% in 1982, mainly through an increase in the number of seeds per spikelet. Seed yield increases were related to an increased leaf area duration, brought about by delays in senescence of photosynthetic tissue, rather than pathogenic effects. Reasons for this yield response to fungicide application in the virtual absence of pathogens are discussed.
The occurrence and importance of okra mosaic virus in Nigerian weeds
Authors: ATIRI G. I. 
Published: February 2008

SUMMARYThe Nigerian National Horticultural Research Institute experimental and commercial farm has a long history of okra mosaic virus (OMV) disease. In an attempt to determine possible sources of inoculum, weeds growing within or around the vicinity of the farm were investigated. Several weeds showed virus or virus‐like disease symptoms and mechanical inoculation of crude sap from three malvaceous weeds (Abutilon hirtum, Sida acuta, and Malvastrum coromandelianum) and one solanaceous weed (Physalis angulata) induced symptoms of OMV on okra test seedlings; serological tests confirmed the presence of OMV. Beetle vectors caught both from weeds and from okra were infective when confined on healthy okra seedlings for 48 h. Increase in the abundance of beetle vectors was accompanied by an increase in the incidence of OMV disease. The implications of these findings in the epidemiology and control of OMV are discussed.
Effects of temperature on the flowering and seed production of Stylosanthes guianensis cultivars
Authors: ISON R. L. , HUMPHREYS L. R. 
Published: February 2008

SUMMARYSeedlings of Stylosanthes guianensis var. guianensis were grown for 75 days in 16 h photoperiods and transferred to controlled environment cabinets for a further 112 cycles set at 12 h days and 18, 21, 24 or 27 OC constant temperatures. Floral initiation (FI) occurred in cv. Cook after 21 short‐day cycles of 12 h and was independent of temperature. Warm temperatures delayed FI in cv. Schofield and hastened it in cv. Endeavour. Rate of node appearance was positively and the duration of the phase FI to flower appearance negatively related to temperature. Spike production and floret number per spike were maximal for Cook and Endeavour at 24°C; seed setting was independent of temperature above 18°C in Cook. Growth, flowering, and seed production of Endeavour required warm temperatures, but Cook was more versatile in its adaptation to varying temperature regimens.
The potential of a sucrose ester coating material for improving the storage and shelf‐life qualities of Cox's Orange Pippin apples
Authors: SMITH S. M. , STOW J. R. 
Published: February 2008

SUMMARYA sucrose‐ester coating material was tested for its potential as a storage technique and as an extender of the shelf life of apple (cv. Cox's Orange Pippin).Apples treated with 1·25% sucrose ester formulation were stored in air at 3·5°C for up to 5 months. Sucrose ester treatment did not reduce detrimental changes in terms of fruit firmness, yellowing and weight loss but did increase core flush incidence.When applied after storage, the sucrose ester reduced yellowing and loss of firmness and markedly increased internal carbon dioxide levels during a 21 day simulated marketing period. Effects were enhanced with increasing sucrose ester concentrations between 1% and 4%. Sucrose ester did not markedly reduce weight loss in the fruit, did not cause accumulation of alcohol or induce any internal physiological disorders during the simulated marketing period.Treatment of fruit with an external atmosphere containing 8% carbon dioxide, a level similar to that found in fruit treated with 3% sucrose ester, did not have the same effects as 3% sucrose ester on firmness or ground colour changes, suggesting that the effects of the sucrose ester are not solely the result of the raised carbon dioxide level.
Effect of heat on zoospore motility and multiplication of Olpidium radicale and O. brassicae
Authors: TEAKLE D. S. , THOMAS B. J. 
Published: February 2008

SUMMARYWhereas zoospores of six cultures of O. brassicae were immobile after treating in glycine solution at 35–40°C for 10 min, those of a cucurbit culture of O. radicale were immobile only after heating at 45°C. Further, O. radicale multiplied in cucumber at 20°, 30° and 35°C, whereas O. brassicae multiplied at 20°, but not 30° or 35°C. Such differences in reaction to temperature might sometimes be useful in separating mixtures of the two species in common hosts such as cucumber.
Artificial infection of grasses with endophytes
Authors: LATCH G. C. M. , CHRISTENSEN M. J. 
Published: February 2008

SUMMARYThe endophytic fungi Acremonium loliae and a Gliocladium‐like sp. were isolated from Lolium perenne; A. coenophialum and a Phialophora‐like sp. from Festuca arundinacea; and Epichloe typhina from F. rubra. All five fungi infected endophyte‐free seedlings of the host grasses and F. arundinacea after artificial inoculation. All fungi except A. coenophialum were able to infect L. perenne. The inoculation technique involved placing endophyte mycelium into the coleoptile tissue of sterile seedlings growing on water agar in Petri dishes. Infection of mature plants with endophytes was not achieved. The presence of some endophytes in grasses can be beneficial to plant growth and persistence but deleterious to the health of animals which graze them. The desirability of infecting cultivars of grasses with endophytes is discussed.
Studies of the antagonistic activities of bacteria endemic to cereal seeds.
Authors: ADETUYI F. C. , CARTWRIGHT D. W. , AW D. 
Published: February 2008

SUMMARYThe seeds of two cultivars of rice and wheat were examined for the presence of bacteria antagonistic to the growth of fungal plant pathogens. A yellow‐pigmented bacterium was found to predominate on rice seed cv. Sasashigure, and in pure culture strongly inhibited mycelial growth of a wide range of pathogens. A similarly inhibitory, cream‐coloured bacterium was predominant on wheat seeds cv. Longbow.This paper describes the isolation and range of antagonism of these organisms, and details their identification as a member of the Erwinia herbicola group and Pseudomonas syringae respectively.
Host range, purification and some properties of rubus Chinese seed‐borne virus
Authors: BARBARA D. J. , ASHBY S. C. , MCNAMARA D. G. 
Published: February 2008

SUMMARYA previously undescribed virus, for which the name rubus Chinese seed‐borne virus (RCSV) is proposed, was isolated from a single, symptomless plant of an unidentified Rubus species grown from seed collected in the wild in the People's Republic of China, Experimentally RCSV infected 23 out of 39 spp. in six out of eight families. The virus was seed‐transmitted in Chenopodium quinoa (100%) and Nicotiana bigelowii (27%). RCSV was not transmitted by the nematodes Xiphinema diversicaudatum or X. index.The particles of RCSV were isometric, c. 30 nm in diameter with some penetrated by negative stains. In thin sections particles were found in double walled tubular structures with an outer membrane enclosing one or more tubules. In crude extracts some particles were found within single‐walled tubules. Two virus‐associated bands were seen in sucrose density gradients of purified preparations. The upper band was not infective and consisted of penetrated particles apparently devoid of nucleic acid. The lower, infective band was resolved into two components, of density 1.452 and 1.461 g/ml, in caesium chloride isopycnic gradients. There were two polypeptides (mol. wts c. 47 000 and 25 200 daltons) and two nucleic acid species (one of mol. wt c. 1.4 × 106 daltons; the second was poorly defined by the methods used but was of higher molecular weight).RCSV was distantly related serologically (6–7 SDI) to the type isolate of strawberry latent ringspot virus (SLRV) and also reacted with antisera to serologicaly distinct grape and olive isolates of SLRV. It did not react with antisera to 10 other isometric viruses.
Properties and partial purification of infective material from plants containing groundnut rosette virus*
Authors: REDDY D. V. R. , MURANT A. F. , RASCHKÉ J. H. , MAYO M. A. , ANSA O. A. 
Published: February 2008

SUMMARYGroundnut plants with chlorotic rosette disease contain a manually transmissible virus, groundnut rosette (GRV), which is also transmitted in the persistent (circulative) manner by aphids (Aphis craccivora), but only from plants that are co‐infected with a manually non‐transmissible luteovirus, groundnut rosette assistor virus (GRAV). Strains of GRV from plants with chlorotic or green forms of rosette are called GRV(C) and GRV(G) respectively. An isolate of GRV(C) from Nigeria remained infective in Nicotiana clevelandii leaf extracts for 1 day at room temperature and for 15 days at 4d̀C, but lost infectivity after 1 day at ‐20d̀C or after dilution to 10‐‐4. Its infectivity and longevity in vitro were not altered by addition of 1 mg/litre bentonite to the extraction buffer. Infectivity in leaf extracts was abolished by treatment with 50% (v/v) ether, 10% (v/v) chloroform or 8% (v/v) n‐butanol, but not by treatment for 30 min with RNase A at up to 100 ng/ml. In attempts to purify GRV(C), nearly all the infectivity from N. clevelandii extracts was found in the pellets from centrifugation at 65 000 g for 1. 5 h; infectivity also occurred in a cell membrane fraction that collected at the top of a 30% sucrose ‘cushion’ containing 4% polyethylene glycol and 0.2 M NaCI. However, no virus‐like particles were found in either type of preparation by electron microscopy.Nucleic acid preparations made directly from GRV(C)‐infected N. clevelandii leaves were very infective; this infectivity was totally inactivated by treatment for 30 min with RNase A at 10 ng/ml in buffers of both low and high ionic strength and was therefore attributed to ssRNA. When nucleic acid preparations were electrophoresed in gels no virus‐specific bands were visible but the position of the infectivity indicated that the infective ssRNA has an apparent mol. wt of c. 1.55 × 106. A similar mol. wt was indicated by the rate of sedimentation of the infective ssRNA in sucrose gradients. Preparations of dsRNA made from GRV(C)‐infected N. clevelandii leaves contained a species of mol. wt c. 3.0 × 106; in addition some dsRNA preparations contained an abundant component of mol. wt c. 0.6 × 106 together with several other components of intermediate mol. wt. Similar patterns of bands were observed in dsRNA preparations made from Nigerian‐grown groundnut material infected with GRV(C) alone, or with GRV(C) + GRAV, or with GRV(G) + GRAV.The properties of GRV closely resemble those of two other viruses that depend on luteoviruses for transmission by aphids, carrot mottle virus and lettuce speckles mottle virus.
Observations on the occurrence of Phalaris paradoxa in England and Wales
Authors: THURLEY B. , CHANCELLOR R. J. 
Published: February 2008

SUMMARYA study of the occurrence of Phalaris paradoxa in England and Wales was made during summer 1984. Visits were made to 73 farms reported to be infested with this species. The presence of P. paradoxa was confirmed on 68 of them. Three other Phalaris species were also recorded as weeds on five farms. Infested farms were located over a wide area of southern England, with a majority in Essex. Most infestations were apparently less than 10 years old. Many infested fields had P. paradoxa only in the headlands. Varying degrees of control had been achieved with herbicides, hand roguing, cutting down and planting fields to grass. Counts of the densest area in 24 fields gave a median density of 167 and a maximum density of 1289 heads m‐2. With a mean of 96 caryopses per head these densities represent a potential seed production of 16 000 and 120 000 caryopses m‐2 respectively. It is concluded that further spread of the weed could be limited by suitable publicity about its occurrence and the best methods of control.
Anther culture in Brussels sprouts (Brassica oleracea var. gemmifera).
Authors: OCKENDON D. J. 
Published: February 2008

SUMMARYEmbryo yields from anther culture were determined for seven F1 hybrid genotypes of Brussels sprouts, one of which was known to be highly responsive. At least 1400 anthers were cultured for each genotype and the genotypes were tested in two groups. Although the results were variable, the genotypes were provisionally grouped as follows: two were highly responsive (with up to 180 and 376 embryos per 100 anthers cultured), one was moderately responsive (with up to 53 embryos) and four were virtually non‐responsive. The possible genetic basis for the difference in responsiveness is discussed, together with the implications of the results for the utilisation of anther culture in Brussels sprouts breeding.
Evidence for resistance in wheat cultivars grown in sand culture to the take‐all pathogen, Gaeumannomyces graminis var. tritici
Authors: PENROSE L. 
Published: February 2008

SUMMARYA laboratory method to inoculate seedlings uniformly with Gaeumannomyces graminis var. tritici is described. Resistance is defined via the rate of hyphal entry into the vascular tissue of host seedlings, and is measured by direct observation and by early stelar lesion development in seminal roots. The two scores for resistance are compared and evaluated, for infection with an isolate of low virulence. Evidence was obtained for resistance in the roots of wheat seedlings to G. graminis.
Fungi growing on stored soybeans and their significance in lipid breakdown*
Authors: LISKER N. , BEN‐EFRAIM A. , HENIS Y. 
Published: February 2008

SUMMARYUS Grade 2 soybeans contain about 20% cracked and split seeds, 3% damaged seeds and 2% foreign material. Examination by scanning electron microscopy showed that intact seeds were externally almost free of microorganisms. In cracked seed coats and in damaged areas on broken soybeans, profusely developing fungal mycelia were frequently observed. Fungi penetrated the beans through these cracks and through the micropyle. Penetration through the hilum was observed only in cases where the seed coats showed pronounced signs of damage. No penetration through pore‐like structures in the seed coat could be observed. Light microscope observations of sections of naturally infested soybeans showed little penetration into the underlying cell layers. Sections of soybeans kept at 99% r.h. and 26d̀C for 4 days revealed profusely developing fungi colonising both seed coat tissue and cotyledons. In the cotyledonous tissue hyphae did not penetrate into the cells but developed only in the intercellular spaces.In inoculated, detached seed coats, fungi developed better on the inner than on the outer side. On cotyledons free of seed coats, fungal development was better than in the seed coat itself. In broken soybeans of commercial stock origin, free fatty acids (FFA), mould count and respiration rate increased 3.5‐, 3.5‐and 5.0‐fold, respectively as compared with intact ones. When broken and intact soybeans were mixed there was no increase in the rate of deterioration.It is concluded that fungi are involved in the increase of FFA in soybeans during storage and that this process is significantly faster in the broken bean fraction.
The effect of anti‐viral thermal treatments on germination of lettuce (Lactuca sativa) seeds and subsequent seedling development
Authors: DREW R. L. K. , BROCKLEHURST P. A. 
Published: February 2008

SUMMARYExperiments on the effects of virus‐inactivating high‐temperature (40d̀C) treatments (thermotherapy) of lettuce seeds partially imbibed in polyethylene glycol solution on subsequent germination and seedling development are described. Precise temperature control is shown to be important and subsequent recovery periods at lower temperature (20d̀C) may be beneficial. Fungal contamination which developed on seeds during thermotherapy was controlled, in some seedlots, by treatment in sterile conditions. The fungi were saprophytic on seeds killed by the thermotherapy. Old seed, even with high viability, was more susceptible to heat damage than fresh seed, and even fresh seed may be pushed close to its limits of tolerance by a 10‐day treatment. The techniques described may be suitable for producing small numbers of virus‐free plants for experimental or breeding purposes.
The resistance of genotypes of two species of Phaseolus beans to the leafhopper Empoasca kraemeri
Authors: GALWEYI N. W. , TEMPLE S. R. , SCHOONHOVEN A. VAN 
Published: February 2008

SUMMARYTo determine whether two species of Phaseolus beans differ in their suitability for reproduction of the leafhopper Empoasca kraemeri, resistant and susceptible genotypes of the two species were exposed to egg laying leafhoppers and the resultant numbers of nymphs on each were compared. Resistant genotypes of P. acutifolius bore fewer nymphs than any genotype of P. vulgaris. Even susceptible P. acutifolius genotypes bore no more nymphs/leaf than resistant P. vulgaris genotypes though they did bear more nymphs/cm2 of leaf area. These results indicate that P. acutifolius may be a useful donor of oviposition non‐preference, increased egg mortality, or possibly nymphal non‐preference, and confirm that counts of nymphs provide a useful screening technique in the selection of parental genotypes for an improvement programme.
Negative cross‐resistance between benomyl and MDPC in British isolates of Botrytis cinerea, Pseudocercosporella herpotrichoides and Verticillium fungicola var. fungicola
Authors: NATHANIELS N. Q. R. , WILSON KATHRYN , FLETCHER J. T. 
Published: February 2008

SUMMARYFifteen isolates of Pseudocercosporella herpotrichoides, four isolates of Botrytis cinerea and four isolates of Verticillium fungicola var. fungicola were examined on potato dextrose agar amended with benomyl or methyl N‐(3, 5‐dichlorophenyl)‐carbamate (MDPC). Negatively correlated cross‐resistance was clearly demonstrated with the isolates of P. herpotrichoides and B. cinerea. There were indications that the same phenomenon might also operate with the isolates of V. fungicola var. fungicola.
Hypersensitivity in apple to feeding by Dysaphis plantaginea: effects on aphid biology
Authors: LYTH M. 
Published: February 2008

SUMMARYEffects on rosy apple aphid (Dysaphis plantaginea) of hypersensitivity to aphid feeding in apple were assessed in a series of insectary experiments in 1980–82. Hypersensitive plants rapidly produced tissue necroses at aphid feeding sites. Inoculation with apterae demonstrated that, in comparison with aphids on susceptible plants, aphids on hypersensitive plants showed symptoms characteristic of host antibiosis, including increased mortality, failure to reproduce and slower development. Embryo number indicated that fecundity of surviving adults was lower on hypersensitive plants and mean relative growth rate of aphids was reduced. Hypersensitivity did not prevent colonisation by gynoparae returning from the summer host, nor subsequent egg‐laying. It conferred, however, a strong resistance against colonisation after egg‐hatch the following spring. The potential of hypersensitivity as a field‐resistance is discussed.
The effect of root‐knot nematode on vascular resistance to Fusarium oxysporum f. sp. vasinfectum in the stems of cotton plants
Authors: HILLOCKS R. J. 
Published: February 2008

SUMMARYThe effect of root‐knot nematode (Meloidogyne incognita) on external wilt symptoms and on the cotton plant's vascular response to stem‐inoculation with Fusarium oxysporum f. sp. vasinfectum was investigated. Wilt symptoms were more severe in all plants inoculated with both organisms than with the fungus alone but relative wilt resistance of the cultivars was maintained. Greater symptom severity was associated with greater fungal proliferation in the stele and this was related to the ability of the nematode to reduce the efficiency of vascular occlusion. The nematode had no effect on the accumulation of infection‐induced terpenoid aldehyde compounds.
Yield responses of two ryegrass and two white clover varieties grown in contrasting mixtures with applications of phosphate at different depths and on different soils
Authors: GOODMAN P. J. , COLLISON M. 
Published: February 2008

SUMMARYTo validate earlier findings using 32P in upland soil and at different depths in lowland soil, ryegrass varieties S.23 or Titania were grown in mixtures with white clover varieties S.184 or Olwen. Unlabelled phosphate (0 or 43 kg P/ha) was applied to the surface or at 30 cm depth in lowland soil, and dry matter yields of grass and clover were measured. In June, on lowland soil, the greatest yield of clover was obtained by surface application. The most productive mixture was S.23/Olwen, although in August Titania outyielded S.23. By October S.23 again outyielded Titania. These results validated the isotopically discovered interactions between phosphate depth and grass/clover mixtures.On upland peat and mineral soil, 0 or 43 kg P/ha was surface applied to the same varietal mixtures. In May, phosphate application to mineral soil slightly decreased clover presence, while clover was increased by mixture with Titania rather than S.23. In July, no significant phosphate effects were found, but in October phosphate increased clover yield and, at least on mineral soil, S.23/Olwen responded most.