bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ullucus virus C, a newly recognised comovirus infecting Ullucus tuberosus (Basellaceae)
Authors: BRUNT A. A. , BARTON R. J. , PHILLIPS SUE , JONES R. A. C. 
Published: February 2008

SUMMARYUllucus virus C (UVC) is a comovirus prevalent in Ullucus tuberosus grown at high altitudes in the Bolivian and Peruvian Andes. It was transmitted mechanically to U. tuberosus (Basellaceae) and to five of 26 species from three of eight other families, infecting U. tuberosus symptomlessly but inducing conspicuous systemic infection in Chenopodium amaranticolor and C. quinoa. Sap from infected C. quinoa was usually infective after 10 min at 70 but not 75 °C, after dilution to 10‐7 but not 10‐8, and after 8 but not 16 wk at 20 °C. UVC was not transmitted by either of two aphid species (Aphis gossypii and Myzus persicae) or through seed of C. quinoa, but it was transmitted by leaf contact between infected and healthy plants.UVC has isometric particles which, in neutral phosphotungstate, are c. 28 nm in diameter. The particles sediment as three components (T, M and B) with sedimentation coefficients (s˚20, w) of 51 S (T), 95 S (M) and 116 S (B). M component particles have a buoyant density (g cm‐3) in caesium chloride of 1.404, and B component particles separated into minor and major sub‐components with densities of 1.409 and 1.463, respectively. T, M and B particles were serologically indistinguishable, and each contained similar relative amounts of two polypeptides of mol. wts 20 700 and 45 100. T particles contained only protein, but M particles also contained c. 30% ss‐RNA of mol. wt 1–45 ×106 and B particles c. 38% ss‐RNA of mol. wt 2·2 × 106.The virus is serologically distantly related to cowpea mosaic virus but, as it showed no relationship to any of 11 other similar viruses, it is probably a distinct member of the comovirus group.
Effects of infection with a spiroplasma virus on the symptoms produced by Spiroplasma citri
Authors: ALIVIZATOS A. S. , TOWNSEND R. , MARKHAM P. G. 
Published: February 2008

SUMMARYMultiplication of a virus resembling spiroplasma‐virus citri type 3 was observed in Spiroplasma citri cells within an infected Madagascar periwinkle plant showing unusually mild symptoms. Sap filtrates from this plant contained virus particles which gave rise to plaques on lawns of the lethal SP‐A strain of S. citri. Transmission of spiroplasmas containing virus to plants already infected with strain SP‐A resulted in suppression of symptoms and a reduction in the number of viable spiroplasmas.
The ATP method for rapid assessment of the efficacy of a single application of a fumigant against Globodera spp. in field soils
Authors: STOREY R. M. J. 
Published: February 2008

SUMMARYPopulation estimates were carried out for Globodera pallida by both visual egg counts and measurement of the adenosine triphosphate (ATP) content of cysts from 26 fields in Northern England. The two methods agreed for seven non‐fumigated fields but covariance analysis suggested that the visual assessment underestimated mortality for all 19 fields shortly after a single treatment with a fumigant nematicide. Both methods indicated that three fields were safe for cropping for potatoes but the ATP method suggested that cropping was possible on a further eight fields considered unsuitable by visual assessments.The results indicated that a high peat content contributed to the low efficacy of the fumigants in three fields. Comparison with previous results for the ATP method using cysts from 40 Dutch fields suggested that fumigation in early autumn was required for a satisfactory single treatment. The results show that the ATP method can assess the efficacy of a single application of a fumigant for economic control in time to allow retreatment when necessary or a change in the decision to plant potatoes the following season.
Laboratory assessments of resistance to the aphids Sitobion avenae and Metopolophium dirhodum in three Triticum species and two modern wheat cultivars
Authors: SOTHERTON N. W. , EMDEN H. F. VAN 
Published: February 2008

SUMMARYThree ancient varieties of wheat and two spring‐sown modern varieties were screened in the laboratory to assess their resistance to the cereal aphids Sitobion avenae and Metopolophium dirhodum. Resistance was measured in terms of non‐preference and antibiosis on plants at three growth stages. The ancient variety Einkorn was the most resistant in terms of both non‐preference and antibiosis to both species of aphids at all growth stages examined. The ancient variety Emmer and the modern Sicco exhibited some resistant properties, whereas the ancient Spelt and modern Timmo were relatively susceptible to aphid attack.
The possible role of two species of Orthoptera in the dissemination of a plant pathogenic fungus
Authors: HASAN S. 
Published: February 2008

SUMMARYThe ability of the locusts, Locusta migratoria and Schistocerca gregaria, to disseminate Colletotrichum graminicola, the fungal pathogen of maize anthracnose, were studied. The insects were fed with the diseased plants and spores were recovered in viable condition from the faeces. The spores recovered were able to grow on artificial media and were still infectious to the host plant.
The effect of host plant on the control of Pratylenchus penetrans by aldicarb
Authors: ALPHEY T. J. W. 
Published: February 2008

SUMMARYReplicated pot tests were made to study the effect of a host plant, red raspberry (Rubus idaeus), on the control of Pratylenchus penetrans by aldicarb.Preliminary work indicated that nematodes from planted and fallowed soils could be distinguished by significantly different levels of lipid reserves in their bodies; and that the populations differed in their susceptibility to aldicarb.In pot tests aldicarb (6 mg. a. i. or 12 mg a. i. per 15‐cm pot) was added to P. penetrans infested soil which was either left fallow or planted with a single raspberry host plant before, at the time of, or after treatment. The results indicated that nematodes in the presence of a plant were more susceptible to aldicarb treatment than those in fallow soil. The results showed that the closer treatment‐time was to planting‐time the greater the nematicidal effect.It is suggested that P. penetrans may exist in different physiological states, active and quiescent, influenced by the presence of a host plant and that these two states differ in their susceptibility to the effects of aldicarb.
The effect of pesticides on establishment of grass swards in England and Wales
Authors: CLEMENTS R. O. , FRENCH N. , GUILE C. T. , GOLIGHTLY W. H. , LEWIS SERFIAH , SAVAGE AND M. J. 
Published: February 2008

SUMMARYPesticide applications made at the time of sowing significantly improved seedling stand and/or herbage dry matter yield at 20 of 45 sites studied during 1977‐79 in England and Wales. More autumn‐sown swards responded to pesticide treatment than spring‐sown ones and re‐seeded grass was attacked more often than grass sown after arable crops.Pest damage was seldom obvious although some noticeable attacks by frit fly occurred. Slugs and leatherjackets appeared to be unimportant. The effect of nematodes was unresolved.
Resistance to Didymella applanata in red raspberry and some related species
Authors: JENNINGS D. L. 
Published: February 2008

SUMMARYWhen raspberry canes were inoculated in summer with a mycelial inoculum of Didymella applanata resistant genotypes developed relatively small lesions which produced few fruiting bodies in the following spring. Scores of the frequency of these fruiting bodies provided the best discrimination between genotypes. Very strong resistance was found in R. pileatus, R. occidentalis and R. coreanus and in hybrids of these species with red raspberry. Hybrids with R. crataegifolius were less resistant. Resistance was also found in Malling 1473/35, a derivative of red raspberry cv. Chief, and in red raspberry segregates with gene H which determines cane pubescence. Both the expression of resistance and the ranking of resistance sources for their resistance was similar for D. applanata to that reported for Botrytis cinerea.
Specificity and mode of action of BTS 44584 and chlormequat chloride on wheat and soybeans
Authors: SMITH AILEEN R. , THOMAS T. H. , GARROD J. F. 
Published: February 2008

SUMMARYThe selective action of the growth retardants chlormequat chloride and BTS 44584 on the growth of wheat and soybean was investigated. Chlormequat chloride retarded the growth of wheat whether applied as a seed soak, foliar spray or soil drench, at concentrations from 10‐2 M to 10‐4 M, although effectiveness depended on the age of the plant at application. BTS 44584 retarded the growth of wheat only when applied to the seeds. In soybeans, chlormequat chloride did not retard elongation growth when applied as a seed soak but showed some effects when applied as a foliar spray and more especially as a soil drench. Irrespective of the type of application, treatment with BTS 44584 retarded growth of soybeans. Thus, the selective action of the two compounds was not solely related to different species but also to timing and mode of application.
Specificity and mode of action of BTS 44584 and chlormequat chloride on wheat and soybeans
Authors: SMITH AILEEN R. , THOMAS T. H. , GARROD J. F. 
Published: February 2008

SUMMARYIncreased gibberellin activity was detected in wheat and soybean plants following seed soaks with either BTS 44584 or chlormequat chloride. Foliar sprays with either compound did not affect the gibberellin levels in wheat plants but soybeans sprayed with BTS 44584 did not contain as much extractable gibberellin in the shoots as did control plants. It is concluded that there was little correlation between gibberellin content and the effect of the chemicals on growth of wheat and soybeans.
The effect of water potential on soil‐borne diseases of wheat seedlings
Authors: CASSELL DIANE , HERING T. F. 
Published: February 2008

SUMMARYUnder glasshouse conditions, Fusarium culmorum caused more injury to wheat seedlings in soil at 33% saturation (approximately – 1 bar) than at 66% (–0·1 bar). The same effect occurred with inoculated seeds raised on soil moisture tension tables at –0·1 and –0·5 bar, at 20° and at 15°C. In controls, spontaneous infection by soil‐borne F. culmorum was unaffected by soil water potential. Inoculated F. nivale, at 127deg; and at 15°C, showed a similar, but smaller, effect to that with inoculated F. culmorum. Water potential in this range did not affect disease incidence with inoculated Gaeumannomyces graminis, but disease was more severe in the drier soil. On tension tables, seedlings did not consistently develop faster under wetter conditions, and factors other than host growth rate probably played a part in limiting fungal attack.
Spacing and sucker management in the commercial plantain production in the rainforest belt of Nigeria
Authors: OBIEFUNA J. C. , MAJUMDER P. K. , UCHEAGWU A. C. 
Published: February 2008

SUMMARYMaintaining one, two or three suckers per rootstock in plantain (Musa spp.) populations of 2000, 1600 and 1333 per hectare were evaluated for sustained yield in the orchard for three harvest cycles. The yield per plantain for the plant crop was not significantly affected by either population density or the number of suckers maintained. However, the total yield significantly increased with the increased plantain population per hectare.The yield per plantain decreased in the first and subsequent ratoon crop harvests as the original plantain population per hectare doubled or tripled when two or three suckers were maintained respectively per rootstock. Although the total yield per hectare was significantly higher when two or three suckers were maintained per rootstock, the individual bunch weight and the fingers significantly decreased to an unacceptable size to the consumers. Establishment of orchards at 1600 plantains per hectare with two suckers maintained per rootstock in subsequent cycles produced consistently good quality marketable fingers and sustained high yield.
The effects of ripening and drying of carrot seed (Daucus carota) crops on germination
Authors: GRAY D. , STECKEL JOYCE R. A. 
Published: February 2008

SUMMARYCarrot seeds taken from the parent plant were capable of germinating before the stage when maximum seed dry weight was reached but even after this stage, when the seed moisture content had fallen below 20%, improvement in seed germination characteristics continued. In the latter stages of seed growth losses by shedding were 12–20 kg/ha/day. For low density crops (10 plants/m2) the yield of viable seed was at a maximum in crops whose seed was harvested with a moisture content of between 20 and 40% but no consistent relationship could be established for high density crops (80 plants/m2).There were no effects of umbel order or plant density on mean germination time or spread of germination. At any early harvest, percentage germination was highest for primary‐umbel‐seeds and seeds from low density crops but the differences between the seed origins diminished with later harvests.Drying the seeds on the umbels improved the percentage germination, reduced the mean germination time and the spread of germination particularly at the early harvests compared with seeds removed from the umbels and germinated immediately without drying.
The development of a sampling method for the tick Ixodes ricinus and its use in a redwater fever area
Authors: GRAY J. S. , LOHAN G. 
Published: February 2008

SUMMARYTick sampling methods based on blanket dragging and flagging were assessed with a view to carrying out a tick survey in an area of endemic babesiosis. The strip‐flag method was finally selected for its efficiency, consistency, and practicality.This method was used to sample larval tick populations on ten farms with endemic babesiosis and it was found that these farms harboured very low densities of ticks compared with a control site. Possible explanations for this finding are discussed.
Observations on the biology and ecology of Apion vorax (Coleoptera: Apionidae), a vector of broad bean stain and broad bean true mosaic viruses
Authors: COCKBAIN A. J. , BOWEN ROBERTA , BARTLETT PAUL W. 
Published: February 2008

SUMMARYIn spring 1974 and 1975 many adult Apion vorax were found at Rothamsted in woods bordering fields that had been cropped with field beans (Vicia faba) the previous season. The weevils were most common on bramble (Rubus spp.), dog's mercury (Mercurialis perennis) and nettle (Urtica dioica). A decrease in the woodland population in May coincided with the appearance of the weevil on field bean crops in neighbouring areas.In laboratory feeding tests, adult weevils fed more on field bean leaves than on leaves of plants on which they were common in woodlands, and they fed more on field beans in May than at other times of the year. No difference was observed in the feeding of male and female weevils.Many A. vorax were caught on sticky traps in woodlands at Rothamsted in 1975, particularly in April and May, but very few were caught on sticky traps in bean crops. The numbers of A. vorax recorded on the upper foliage of bean crops at Rothamsted in June each year from 1970 to 1980 ranged from 0 to 10 per 10‐m row.Eggs, larvae and pupae of A. vorax were found in field bean flowers collected from field crops. The larvae were feeding on the tips of the pistils and stamens. Adult weevils that emerged in mid‐June from the flowers of autumn‐sown beans mated and produced a second generation when caged on glasshouse‐grown plants. Some Apion larvae, possibly A. vorax, were found inside flowers of common vetch (Vicia sativa).The name ‘bean flower weevil’ is considered a suitable common name for A. vorax.
Studies of the incidence, severity and distribution of false rust (Synchytrium psophocarpi), leaf spot (Pseudocercospora psophocarpi) and powdery mildew (Oidium sp.) on winged bean (Psophocarpus tetragonolobus) in Papua New Guinea
Authors: PRICE T. V. , DRINKALL M. J. , MUNRO PATRICIA E. 
Published: February 2008

SUMMARYThe incidence, severity and distribution of false rust, (Synchytrium psophocarpi), leaf spot (Pseudocercospora psophocarpi) and powdery mildew (Oidium sp.) on winged beans (Psophocarpus tetragonolobus) were evaluated on pure lines and mixed stands grown in Papua New Guinea between 1976 and 1978. Almost all of the 148 pure lines were susceptible to false rust and leaf spot and the incidence of these diseases increased with plant age. Standard area diagrams were superior to disease keys in evaluating disease severity. Levels of false rust on 10 promising agronomic lines differed according to the locality where the lines were grown. Two Thai lines showed resistance to false rust but P. scandens was immune to false rust and leaf spot.Surveys of 51 sites containing mixed stands of winged beans in the Eastern Highlands, Western Highlands, East New Britain, East Sepik, Madang and Morobe Provinces of Papua New Guinea indicated that leaf spot and false rust were present in both the wet and dry seasons and the apparent absence of disease was probably due to time and size of samples. The diseases appeared to be present in all the traditional winged bean growing areas of Papua New Guinea. It was difficult to obtain evidence of differences in palatability of tissues infected with false rust.The value of surveys and disease assessment in relation to evaluation of crop losses of winged bean caused by these pathogens and selection for resistance is discussed.
Effects of barley mildew on green leaf area and grain yield in field and greenhouse experiments
Authors: CARVER T. L. W. , GRIFFITHS AND ELLIS 
Published: February 2008

SUMMARYIn 1980 the relationships between mildew severity, green leaf area (GLA) and grain yield of spring barley were examined using greenhouse‐grown plants and plants grown in micro‐plots in the field. Mildew, by causing premature senescence, reduced GLA and grain yield was strongly correlated with GLA integrated from growth stages 2–10.5 on the Feekes scale.Early mildew attack reduced all yield components (including grain size) even when fungicidal control had eliminated mildew by anthesis. Analyses of culms at anthesis and harvest supported the view that the smaller grain size associated with early mildew attack resulted from a deficiency in carbohydrate stored in culms before anthesis and available for retranslocation to the developing grain. Amounts of total soluble carbohydrate at anthesis and the amounts lost beween anthesis and harvest were both strongly correlated with GLA up to anthesis.
Wetting and temperature requirements for infection of mature apples by Venturia inaequalis in South Africa*
Authors: SCHWABE W. F. S. 
Published: February 2008

SUMMARYConidia of Venturia inaequalis were used to inoculate mature (picking ripe stage) Granny Smith fruit in greenhouse inoculation chambers and in the orchard. Wetting periods necessary for fruit infection were longer than those previously reported for leaves, while continuous wetting was followed by heavier infection than intermittent wetting. Temperatures during storage affected symptom development and the degree of infection was greatly influenced by the inoculum potential (number of conidia). At high inoculum potentials and with infection indices [fruit wetting period (h) × mean temperature (°C)] of 440–600, 601–1000 and >1000 subsequent disease development was ‘light’, ‘moderate’ and ‘heavy’, respectively if fruit was unprotected by fungicides. It was concluded that after conditions favouring infection, fruit should not be stored for long periods, but should be marketed for consumption immediately after harvest.
Studies of the cereal cyst‐nematode, Heterodera avenae under continuous cereals, 1974–1978. I. Plant growth and nematode multiplication
Authors: KERRY B. R. , CRUMP D. H. , MULLEN L. A. 
Published: February 2008

SUMMARYPopulation changes of Heterodera avenae and crop growth in a sandy loam soil were studied from 1974 until 1978; the nematode decreased plant growth but failed in two of the years to multiply on susceptible hosts. Spring oats were the most heavily invaded cereal and produced the smallest shoots. Second‐stage juveniles invaded cereal roots in decreasing numbers: spring oats > autumn oats > spring barley > spring wheat > autumn barley > autumn wheat. Numbers of females developing on the different cultivars were in a similar order. Most females developed on roots in 1976 despite poor crop growth in the severe drought.Numbers of H. avenae in soil treated with oxamyl (Vydate) at 8.8 kg/ha a. i. were less in all years except 1975. In the dry winter and spring of 1975/76 nematode multiplication was prevented in soil treated with oxamyl before drilling in the autumn.In all years large numbers of females were produced on the roots of all cultivars but in 1975 and 1978 nematode populations declined because few females survived to form cysts containing eggs and their fecundity was reduced. Numbers of cysts after harvest were not affected by formalin (38% formaldehyde) applied as a drench at 3000 litres/ha in 1977 but fecundity doubled in treated soil, and nematode multiplication increased from 3.8 × in untreated plots to 18.6 ×. When the plots were irrigated in 1978 numbers of cysts and fecundity increased in formalin treated soil resulting in an increase in multiplication from 0.3 × to 14.6 ×. Fungal parasites attacking H. avenae females and eggs are considered responsible for the poor multiplication of the nematode.
Helicotylenchus vulgaris and its association with damage to sugar beet
Authors: SPAULL ALISON M. 
Published: February 2008

SUMMARYSevere and irregular stunting of sugar beet has been associated with Helicotylenchus vulgaris but little is known of the pathogenicity of this nematode. A survey was made at 10 sites in East Anglia on calcareous soils (Wantage series) on which the original damage was reported. Numbers were usually maintained under a variety of crops, despite fluctuations during the period. In field trials, aldicarb treatment did not improve the yield of either sugar beet or winter wheat on land infested with H. vulgaris. In pot tests growth of sugar beet was stimulated by low nematode inocula; this effect diminished as numbers inoculated increased. Sugar beet grown at 10 °C and 15 °C with H. vulgaris grew markedly better in sterilised soil than in untreated field soil, especially at the higher temperature early in the experiment.It is concluded that though H. vulgaris may damage sugar beet it requires an atypical combination of external conditions to cause significant yield loss.
Effects of the nematicide oxamyl on life cycle stages of Globodera rostochiensis
Authors: EVANS SUSAN G. , WRIGHT DENIS J. 
Published: February 2008

SUMMARYHatched second stage juveniles of Globodera rostochiensis were found to be more sensitive than either unhatched juveniles or adult males to low concentrations of oxamyl (EC50 value for activity 0.5 μg oxamyl ml‐1). Development of juveniles in roots was significantly inhibited by 2.0 μg oxamyl ml‐1 probably due to impairment of normal feeding activity. The behavioural events necessary for orientation of juveniles towards roots for invasion and orientation of males towards females for fertilisation were found to be impaired by 0.5 and 1.0 μg oxamyl ml‐1 respectively. A comparison with previous work on Meloidogyne incognita showed G. rostochiensis juveniles to be more sensitive to oxamyl.