bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effectiveness of soil sampling for virus‐vector nematodes in MAFF certification schemes for fruit and hops
Authors: COTTEN J. 
Published: April 2007

SUMMARYIn fruit and hop certification schemes of the Ministry of Agriculture, Fisheries and Food, sites used for the propagation of high‐grade virus‐tested stocks are soil sampled to detect vector nematodes before planting. Of 326 sites in England and Wales sampled for Foundation and Elite strawberry certification between 1963 and 1976, vector nematodes were detected in 22 per cent of sites, and most of these sites were rejected. Consideration of the theoretical aspects of sampling for vector nematodes, and of virus acquisition and transmission shows that, although soil sampling will reduce the risk of re‐infection by nematode‐borne viruses, it cannot prevent re‐infection. However, nematode‐transmitted virus infections are seldom detected during growing‐season inspections of strawberry runners entered for certification, which suggests that in practice the risks are small, probably because few vector populations are transmitting virus.
Susceptibility of plants to fungal pathogens when grown by the nutrient–film technique (NFT)
Authors: EVANS S. G. 
Published: April 2007

SUMMARYPlants grown by the nutrient‐film technique (NFT) in a glasshouse became infected when fungal pathogens were introduced into the nutrient solution. Isolates of Pythium ultimum infected cucumber. Phytophthora cryptogea, Didymella lycopersici, Verticillium dahliae and Fusarium oxyspomm f. sp. lycopersici infected tomato, but Phytophthora nicotianae var. parasitica did not. Carnations were systemically infected by Fusarium oxyspomm f. sp. dianthi, but Phytophthora cryptogea was recovered only from the roots and caused no aerial symptoms.
Mushroom virus diagnosis: the relationship between mycelial growth rate and infection with mushroom virus four
Authors: HILL S. A. , WRIGHT DAPHNE M. 
Published: April 2007

SUMMARYThere was an inverse relationship between mycelial growth rate in culture and the numbers of particles of mushroom virus four found by electron microscopy in sporophores submitted for disease diagnosis during 1974–76. Mycelial isolates from sporophores in which few virus particles were detected often showed no decrease in growth rate. Electron microscopy alone is considered to be a satisfactory method of detecting infection by mushroom viruses.
Long‐term survival of sclerotia of Rhizoctonia tuliparum
Authors: COLEY‐SMITH J. R. , HUMPHREYS‐JONES D. R. , GLADDERS P. 
Published: April 2007

SUMMARYIn 1974 a severe outbreak of grey bulb rot (Rhizoctonia tuliparum Whetzel & Arthur) occurred on tulips in Lincolnshire in a field not planted with a highly susceptible crop for six years. A long‐term experiment on the survival of R. tuliparum showed that about 10 per cent of sclerotia can remain viable for at least 10 years. Where severe outbreaks of disease have occurred, longer intervals between susceptible crops are suggested.
Effect of four crops on the reprodnction and development of Xiphinema diversicaudatum and on the pore space, moisture content and temperature of the soil
Authors: COTTEN J. , ROBERTS HELEN 
Published: April 2007

SUMMARYIn a two‐year experiment from 1977 to 1979 in microplots growing strawberry, perennial ryegrass, spring barley or sugar beet, Xiphinema diversicaudatum(Micol.) Thorne reproduced and developed best under strawberry and least well under sugar beet. Total numbers of X. diversicaudatum were similar under spring barley and perennial ryegrass but nematode development beyond first‐stage juveniles was less under barley, probably because of the early season senescence of this crop. Differences in the host status of strawberry, barley and sugar beet could not be attributed to changes, caused by cropping, in the pore space or moisture content of the soil. It was not possible to assess the effect of pore space or soil moisture under ryegrass. During the summer and autumn of 1977 and 1978, under strawberry, barley and sugar beet, soil pores with necks large enough to admit X. diversicaudatum and even those that would admit only the first‐stage juveniles were frequently drained. The small differences in the soil temperatures recorded under the four crops had little effect on nematode reproduction and development.
A simple kit for detection of plant viruses by the latex serological test
Authors: TALLEY JANINE , WARREN FRANCES H. J. B. , TORRANCE L. , JONES R. A. C. 
Published: April 2007

SUMMARYSerological tests were made using a simple kit consisting of dropper bottles filled with latex sera or buffer, a plastic mixing plate, plastic pipettes, wooden cocktail sticks, a black glass reaction plate and polythene bags, packed in a plastic sandwich box. Potato viruses X, S and Y were readily detected in infected potato leaves in tests done both in the laboratory and in the field. Results were obtained in 4–10 min.
Factors aflfecting the development of silver scurf (Helminthosporium solani) on potato tubers
Authors: LENNARD J. H. 
Published: April 2007

SUMMARYWhen potato tubers with small amounts of silver scurf at lifting (less than 10 per cent of surface cover) were stored over periods of about five months in a dry condition, very little silver scurf developed irrespective of storage temperature. At high humidity, there was little disease after storage at 5°C and very little at temperatures below 4°C: moderate to severe infection (20 per cent or more of surface area covered) occurred at storage temperatures of about 6°C or above. Weight losses of tubers with severe silver scurf (50 per cent surface area affected) stored in a dry atmosphere for 27 weeks were greater than those of tubers with moderate (25 per cent area cover) and slight infection (5 per cent area cover), 8·5, 5·9 and 4·5 per cent respectively. However, tubers stored iti a dry atmosphere showed greater weight losses than tubers stored in a humid atmosphere, despite having less silver scurf infection. Low storage temperatures aggravated symptoms of skin spot.Slightly affected seed tubers gave rise to more silver scurf in the subsequent crop than tubers with over 75 per cent surface affected, and crops from light sandy soils showed more infection at lifting than crops from heavier soils. These differences persisted during storage, but were largely masked if storage conditions favoured disease development, indicating that in normal stocks there is always an adequate inoculum, at lifting to produce severe symptoms. Very small amounts of inoculum giving little silver scurf after storage, resulted from using seed from stem‐cutting material or by treating seed with benomyl.
The effect of seed and stem‐base treatments with thiophanate‐methyl on the control of white rot disease (Sclerotium cepivorum) of autumn‐sown salad onions
Authors: ENTWISTLE A. R. , MUNASINGHE H. L. 
Published: April 2007

SUMMARYIn 1976/77, effective control of white rot (Sclerotium cepivorum Berk.) in autumn‐sown salad onions on field plots was obtained by seed treatment with thiophanate‐methyl at 250 g/kg followed by either three stem‐base applications of the same fungicide at 0.3 g/m row/application (equivalent to 34 kg/ha) or by four stem‐base applications at 0.15 g/m row/application (equivalent to 26 kg/ha). Seed treatment alone with thiophanate‐methyl at 125 or 250 g/kg controlled the disease in the autumn but was ineffective by harvest in June the following year.
Chemical control of onion fly, Delia antiqua (Meig.)
Authors: EMMETT B. J. , SAVAGE M. J. 
Published: April 2007

SUMMARYIn eight field plot trials in Cambridgeshire and Bedfordshire in 1977–79, insecticidal seed treatments and granules were tested against onion fly larvae. Carbophenothion, chlorfenvinphos, dieldrin, fonofos, iodo‐fenphos, permethrin and pirimiphos‐ethyl were tested as seed treatments in soil. Chlorpyrifos, dieldrin and pirimiphos‐ethyl were tested as seed treatments in peat blocks. Chlorfenvinphos and pirimiphosethyl were also tested as granules incorporated in soil and in peat blocks.Pirimiphos‐ethyl at 5 or 10 g a.i.†/kg seed and chlorfenvinphos, carbophenothion or fonofos each at 10 g a.i./kg seed gave good control of onion fly: all seed had been treated in the laboratory. Chlorpyrifos and pirimiphos‐ethyl seed treatments at 10 g a.i./kg seed were effective but severely phytotoxic to plants grown in peat blocks. Iodofenphos at 5 or 10 g a.i./kg seed was unsatisfactory when the seed was treated in the laboratory, but commercial treatment of seed gave adequate protection from attack. Permethrin at 2.5 g a.i./kg seed gave poor control and dieldrin at 30 g a.i./kg seed provided good control only where flies were not resistant. Granules of pirimiphos‐ethyl at 1.1 kg a.i./ha or chlorfenvinphos at 2.3 kg a.i./ha generally gave satisfactory control when incorporated in the top 2 cm soil at sowing, but the chlorfenvinphos treatment reduced seedling emergence. Chlorfenvinphos granules incorporated in peat blocks at 22.0 mg a.i./peat block (0.45 g a.i./kg peat) and pirimiphos‐ethyl granules at 2.5 mg a.i./peat block (0.05 g a.i./kg peat) gave only moderate control of onion fly attack, but pirimiphos‐ethyl granules at 5.0 or 10.0 mg a.i./peat block (0.1 or 0.2 g a.i./kg peat) were effective without apparent phytotoxicity. None of the seed treatments or granules entirely prevented egg laying by onion fly females. Following seed treatment, residues of chlorpyrifos, fonofos, iodofenphos and pirimiphos‐ethyl in harvested onions were <0.3 mg/kg.
Recent developments in serological methods suited for use in routine testing for plant viruses
Authors: TORRANCE L. , JONES R. A. C. 
Published: April 2007

SUMMARYSince the mid 1950s, there have been many developments in serological techniques for testing for plant viruses. Certain of these can provide great savings in time, labour and cost in routine testing situations and are well suited for use by advisory services, certification schemes and healthy stock programmes, statutory and quarantine authorities, and plant breeders. The recent developments are described under the headings flocculation in liquid media, gel diffusion, labelled antibodies and electron microscope serology, Flocculation tests depend on observation of aggregates formed in a liquid medium. The microprecipitin and chloropiast agglutination tests are simple forms which are still widely employed routinely. However, sensitivity is greatly improved by using flocculation tests in which antibodies are adsorbed to the surface of larger inert carrier particles, such as polystyrene latex spheres, tanned red blood cells or bentonite. Latex particles are the most widely used of these because they are easy to sensitise with antibodies, little antiserum is required and the sensitised latex can be stored for years without loss of activity. The latex test is also very simple to do, is well suited for routine checks on either small or large numbers of samples which can be grouped and can be used with many virus–crop combinations.Gel diffusion tests depend on observation of precipitin lines formed in an agar gel medium. They are of two main types, single (= simple) diffusion and double diffusion. Both can be used effectively with viruses which have isometric or ‘near isometric’ particles but not with those which have elongated particles because these do not diffuse readily through agar. Recent developments which involve breaking elongated particles into sub‐units or fragments which can diffuse through agar now permit gel diffusion to be applied with almost all viruses. Various treatments are useful in breaking particles, the most effective of which employ detergents or other disruptive chemicals such as pyridine, pyrrolidine and ethanolamine, However, although gel diffusion tests which incorporate one or other of these treatments have been employed routinely for testing for viruses in several different crops, such tests are relatively insensitive, require much antiserum and conditions must be carefully controlled to avoid formation of nonspecific precipitin lines.Antibodies can be labelled to make virus—antibody aggregates readily observable, or to obtain increased sensitivity in testing, or both. The only form of labelled antibody test widely employed in routine screening for plant viruses is enzyme‐linked immunosorbent assay (ELISA), in which antibody is labelled with an enzyme and positive results are observed as an enzyme‐mediated colour reaction. Since its introduction to plant virology in 1976, ELISA has been very widely applied in situations where large numbers of either individual or grouped
Rapid spread by mites of ryegrass mosaic virus from old sward to seedling ryegrass and its prevention by aldicarb
Authors: GIBSON R. W. 
Published: April 2007

SUMMARYIn experiments in 1979 and 1980 in eastern England, the spread of eriophyid mites and ryegrass mosaic virus (RMV) from transplanted old sward through plots of newly sown Italian ryegrass greatly exceeded spread by windborne mites from outside the plots. During the summer and autumn of each year, mites and RMV spread at least one metre through the ryegrass (6/7 rows) from the old sward. Applying aldicarb (10 kg/ha equivalent) to the seedbed before sowing the Italian ryegrass prevented colonisation by mites and greatly decreased spread of RMV from old sward. It is concluded that old diseased swards should be completely killed before reseeding and that RMV is likely to spread quickly to plants slot‐seeded into old pastures. The use of acaricides might prevent this spread but would be costly.
Control of the mushroom phorid Megaselia halterata (Wood) with dichlorvos applied by an automatic atomiser
Authors: WHITE P. F. 
Published: April 2007

SUMMARYAs a protection against invading Megaselia halterata adults, a newly spawned mushroom crop was treated for four weeks with intermittent sprays of small volumes of dichlorvos from an automatic atomiser. Efficient control of adults was obtained in small‐ and large‐scale tests by spraying 0.3 mg/m3 of air every 24 min. Automatic spraying of dichlorvos achieved better and cheaper control than that obtained by the incorporation of diazinon in the compost (30 mg/kg).
An effective lure for use in pheromone traps for monitoring pea moth, Cydia nigricana (F.)
Authors: WALL C. , GREENWAY A. R. 
Published: April 2007

SUMMARYLures containing different doses of (E)‐10‐dodecen‐l‐yl acetate (E 10–12: Ac), a sex atfractant for the pea moth, Cydia nigricana (F.), were evaluated for use in monitoring traps at sites in eastern England in 1977 and 1979.A natural‐rubber serum stopper impregnated with 3 mg E10–12: Ac was shown to be an effective and long‐lasting lure; it was equally effective at different population densities and remained constantly attractive for at least the whole flight season of the male moth. Such lures, which are being used by growers in the United Kingdom to monitor moth populations in dried pea crops, do not need to be renewed during the season nor allowances made for reduced attractiveness.
Aetiology of barley net blotch caused by Pyrenophom teres and some effects on yield
Authors: JORDAN V.W.L. 
Published: April 2007

SUMMARYLaboratory and glasshouse tests showed that seed from barley crops in south‐west England with much net blotch was often infected with Pyrenophora teres Drecksler. After sowing, mycelium in the caryopsis grew to infect the developing coleoptile and hence was carried above ground. On the growing foliage the fungus multiplied by conidial infection and also formed perithecia in late summer. The perithecia persisted in debris and released many ascospores in autumn which may infect volunteer plants and newly emerging barley seedlings. Pycnidia also developed on debris but the pycnidiospores were non‐infective.Mycelial infection from seed often produced streaks on the coleoptile that quickly penetrated to the underlying leaves. This symptom was therefore often distinguishable from those resulting from air‐ or splash‐ dispersed conidia or from ascospores. In optimum weather (20°C, 100 per cent r.h.) net blotch lesions developed and sporulated within five days from inoculation and if suitably positioned could kill a leaf within 15 days.Severe leaf infection during tillering of winter barley (cv. Sonja) grown in pots outdoors significantly decreased yield both by decreasing the number of grains per ear and the thousand grain weight. In a fungicide trial on winter barley (cv. Hoppel) field plots sprayed with propiconazole yielded 23 per cent more than untreated plots, mostly because individual grains were larger.
Differential sensitivity of Pyrenophom teres to organomercury formulations
Authors: LOCKE T. , THORPE I. G. , CARTER MARGARET A. , GAY CAROLINE E. 
Published: April 2007

SUMMARYIn agar plate tests, all 45 isolates ol Pyrenophora teres Drechsler tested were less sensitive to methoxyethyl mercury acetate (MEMA) as ‘Panogen M’ than to phenyl mercury acetate (PMA) as‘Agrosan D’, In further tests with eight isolates selected at random, mean ED50 values (p.p.m. Hg) for inhibition of mycelial growth at 17°C were 0.620 for MEMA, 0.098 for PMA, 0.070 for ethyl mercury phosphate and 0.060 for phenyl mercury chloride.In field trials on spring barley in 1980 at seven different sites throughout England and one in Scotland, mean seedling infection of 5.8 percent was reduced to 1.2 per cent by PMA and to 1.9 per cent by MEMA.
Root‐lesion nematodes (Pratylenchus spp.) in raspberry‐cane beds entered for certification in England
Authors: GOTTEN J. , ROBERTS HELEN 
Published: April 2007

SUMMARYBetween 1978 and 1980 a total of 33 raspberry‐cane beds at eight nurseries in England were sampled to detect root‐lesion nematodes in the roots of the canes and in the soil. Pratylenchus crenatus Loof was found in 20 cane beds (five nurseries) and was the most abundant species in the roots. P. thomei Sher & Allen was found in nine cane beds and P. neglectus (Rensch) Chitwood & Oteifa in eight (four and three nurseries respectively). P. fallax Seinhorst was found in four cane beds at one nursery only and P. penetrans (Cobb) CMtwood & Oteifa in one cane bed only. At each nursery, different cultivars tended to be uniformly infested with the same species or mixture of species. There was no association between the occurrence of the different species of root‐lesion nematodes and the mineral matter content or the particle size distribution of the soil.
Relationship between eyespot severity and yield loss in winter wheat
Authors: CLARKSON J. D. S. 
Published: April 2007

SUMMARYBetween 500 and 1000 winter wheat plants were taken at random immediately before harvest from crops with naturally or artificially created attacks of eyespot (Pseudocercosporella herpotrichoides (Fron) Deighton) at eight sites in eastern England from 1975 to 1979. The individual shoots of each plant were placed in one of four categories: healthy, or slightly, moderately or severely infected with eyespot. Healthy shoots were sub‐divided into those from plants with all shoots healthy and those from plants with at least one infected shoot. Ears were threshed individually and average dry weight of grain per ear, grain number per ear and 1000‐grain dry weight were computed for each infection category and both healthy shoot categories.Slight eyespot had no effect on yield. Moderate eyespot reduced yield per ear, grain number per ear and 1000‐grain weight by 10, 8 and 5 per cent respectively; severe eyespot caused corresponding losses of 36, 29 and 15 per cent.Healthy shoots showed no apparent compensation for yield loss in eyespot‐infected shoots on the same plant.The equation y= O.lX1+ 0.36x2, where y= percentage yield loss, x1= percentage of moderately infected shoots and x2= percentage of severely infected shoots, was applied to the results of ADAS winter wheat disease surveys from 1975 to 1980. National yield losses due to eyespot in these years were estimated tobe 0.9, 0.3, 1.1, 1.2, 0.7 and 0.3 per cent respectively.
Fumigation of soil with methyl bromide to kill diapausing Colorado beetles
Authors: POWELL D. F. 
Published: April 2007

SUMMARYDiapausing adult Colorado beetles (Leptinotarsa decenilineata (Say)) were buried at various depths up to 30 cm in the soil of an experimental plot in Hertfordshire in July 1977. The plot was then covered with polythene sheeting and fumigated with methyl bromide at a rate of 1 kg/10 m2. Gas concentrations were measured at the soil surface and at a depth of 23 cm during the four days following application of the gas; leakage of gas along the edges of the plot was also measured. The gas concentrations achieved within the plot during the first eight hours (minimum 37 mg/1.) were more than sufficient to kill Colorado beetle and none of the test insects survived. Plots in Suffolk were fumigated in March 1979 witiiout test insects to determine the gas concentrations and distribution in a soil differing in temperature, moisture content and degree of compaction. Penetration and distribution of the gas were less good in these plots, the soil of which was colder, wetter and more lumpy than that in the Hertfordshire plot, and the concentration of gas was insufficient in some places to guarantee killing Colorado beetles.
The use of metalaxyl to control Phytophthora syringae rot of apple fruits
Authors: EDNEY K. L. , CHAMBERS D. A. 
Published: April 2007

SUMMARYIn an orchard in Kent, metalaxyl applied to the soil at 0.5 or 1.5 kg/ha on 20 July and to fruit as a 0.03 per cent spray on 3 September 1979 controlled rotting of Cox's Orange Pippin apples by Phytophthora syringae. There was also a residual effect of similar treatments applied in the previous year. Dipping fruits in 0.03 per cent metalaxyl controlled infections which had been developing on zoospore‐inoculated apples for five days at 10°C but not when the incubation period was longer. In post‐harvest dip treatments, the ability of metalaxyl at 0.01 per cent to control the spread of rotting by contact with apples inoculated with P. syringae was not affected if it was mixed with 0.05 per cent benomyl.
A genetic study of the relationship between height, time of ear emergence and resistance to Septoria nodorum in wheat
Authors: SCOTT P. R. , BENEDIKZ P. W. , COX CHERYL J. 
Published: April 2007

Winter wheat cultivars of varying height were intercrossed and the progeny were studied in field trials to determine whether the greater resistance to S. nodorum of the taller cultivars was fortuitous or the result of genetic association.Variation in height, in resistance and in time of ear emergence was continuous, providing no evidence of the existence of individual genes of major effect. In F2 and backcross generations, the inheritance of all three characters was principally additive. Among random F3 and F4 families there was a clear tendency for tall straw and resistance to segregate together, proving that the association between these characters was not fortuitous and providing evidence of linkage or pleiotropy in their genetic control. There was a similar though less consistent tendency for late ear emergence and resistance to segregate together. There was substantial residual variation in resistance, not associated with variation in height or time of ear emergence, but its heritability was difficult to prove by comparisons between F3 and F4 generations, perhaps partly because of genotype x environment interaction.It is proposed that resistance is under polygenic control and pleiotropy rather than linkage is suggested as the explanation of its genetic association with height and with time of ear emergence. The existence of genes affecting resistance independently of height and time of ear emergence is also inferred. It is suggested that they permit the breeding of resistant cultivars of any height, though with increasing difficulty as height is reduced.