bluuebunny/crossref_metadata_2025_split huggingface dataset:
The host range and vector species of viruses from Cola chlamydantha K. Schum., Adansonia digitata L. and Theobroma cacao L
Authors: LEGG J. T. , BONNEY J. K. 
Published: February 2008

SUMMARYSeventeen species in the Tiliaceae, Sterculiaceae and Bombacaceae were tested for susceptibility to three virus isolates from naturally infected Cola chlamydantha trees and three from Adansonia digitata trees in Ghana. Seven species of Pseudococcidae were tested as vectors of the six isolates. These studies indicate that the Cola isolates should be classified with cocoa swollen shoot virus and those from Adansonia with cocoa mottle leaf virus.
The transmission of strawberry latent ringspot virus by Xiphinema diversicaudatutn (Nematoda)
Authors: HARRISON B. D. 
Published: February 2008

SUMMARYStrawberry latent ringspot virus (SLRV) was found in diseased rose bushes growing in a glasshouse where the soil contained Xiphinema diversicaudatum (Micol). Adult female, adult male and juvenile X. diversicaudatum all transmitted the virus to cucumber seedlings, and nematodes kept without plants for 32 days after acquiring SLRV later transmitted it. When transferred to fresh plants every 2–4 days for 3 weeks, single nematodes transmitted up to three times; one nematode did not transmit until 19 days after the transfers began. One adult X. diversicaudatum, out of 141 tested, transmitted both SLRV and arabis mosaic virus. In all respects X. diversicaudatum behaved as a vector of SLRV as it does as a vector of arabis mosaic virus.
Increased susceptibility of black‐currant bushes to the gall‐mite vector (Phytoptusribis Nal.) following infection with reversion virus
Authors: THRESH J. M. 
Published: February 2008

SUMMARYHealthy black‐currant bushes (var. Wellington XXX) and others infected systemically with a virulent strain of reversion virus were exposed equally to infestation by the gall‐mite vector (Phytoptus ribis Nal.). Shoots with malformed leaves caused by mites feeding at the stem apices were virtually restricted to the virus‐infected bushes. Buds infested with mites became rounded galls, which were far fewer and more localized on shoots of healthy bushes than on infected ones.Similar results were obtained in further experiments with Wellington XXX and seven other varieties. Bushes infected systemically with an avirulent strain of reversion virus developed more galls than healthy bushes, but fewer galls than bushes infected with a virulent strain.The young buds of virus‐infected bushes were 170 times more susceptible to dispersing mites than those of healthy bushes. The axillary buds of healthy bushes resisted infestation and the apical meristems were virtually inaccessible to mites, whereas the axillary and apical buds of virus‐infected bushes were invaded readily.An experiment with bushes var. Cotswold Cross that were either healthy or partially or completely infected with reversion virus was retained for two years. Each year there was a relationship between symptom expression and mite infestation; only shoots with chronic virus symptoms developed mite‐affected leaves and numerous galls.Virus infection increased the vulnerability and accessibility of the apical and axillary buds by decreasing the density of hairs on the stems and leaves. Infected bushes also presented a greater catchment area to dispersing mites and more shoots and buds were available for colonization than on healthy bushes.The interactions between virus, host and vector are discussed, together with their implications in nature, in experimental design and in disease control.
Experiments on the time of application of insecticide to decrease the spread of yellowing viruses of sugar beet, 1954‐66
Authors: HULL R. , HEATHCOTE G. D. 
Published: February 2008

SUMMARYSprays of demeton‐methyl insecticide decreased the spread of yellowing viruses by aphids in sugar‐beet crops in England. Between 1957 and 1960, when yellows was prevalent, the incidence, assessed as ‘infected‐plant‐weeks’, was decreased by 36–41 % by one spray, depending on when it was applied, and by 55 % by two sprays, giving average yield increases of 1½ and 2 ton/acre of roots respectively. Between 1962 and 1966, when yellows spread less, a spray at the time when growers were advised to spray by the British Sugar Corporation decreased yellows incidence by 37 %, whereas sprays 2 weeks earlier or later decreased it by 24 % and 25 % respectively. Between 1958 and 1966 an annual average of 160000 of the country's 440000 acres of sugar beet has been sprayed, often to control Aphis fabae as well as to check the spread of yellows. A spray gives a profitable yield increase when yellows incidence in unsprayed plots is 20 % at the end of August.
The effects on soil fauna of insecticides tested against wireworms (Agriotes spp.) in wheat
Authors: GRIFFITHS D. C. , RAW F. , LOFTY J. R. 
Published: February 2008

SUMMARYThe organophosphorus insecticides Bayer 38156 (O‐ethyl S‐p‐tolyl ethyl phosphonodithioate), trichloronate, Stauffer N 2790 (O‐ethyl S‐phenyl ethyl phosphonodithioate), thionazin and fenitrothion were compared with aldrin, dieldrin and γ‐BHC for their effects on soil fauna, particularly wire‐worms, and on crop yields in 1964 and 1965. At 1·5 lb active ingredient/acre, none of the organophosphates had as great an effect on wireworms as an aldrin spray at 2·25 lb a.i./acre or a dieldrin seed dressing at 2·25 lb a.i./acre. Some treatments significantly increased and some significantly decreased numbers of mites and Collembola. Except for Allolobophora chlorotica in plots treated with Bayer 38156, earthworm numbers were greater in plots sprayed with Bayer 38156 or aldrin, or sown with dieldrin‐dressed seeds, than in untreated plots. In May 1964, one month after sowing, untreated plots had significantly fewer plants than plots sprayed with aldrin, trichloronate or Bayer 38156, or sown with γ‐BHC or dieldrin‐dressed seeds, but yields from untreated plots at harvest were high for such a large wireworm population and did not differ significantly from yields of treated plots in either year.The persistence of thionazin and Bayer 38156 in treated plots was measured by a bioassay using Collembola. Bayer 38156 was detected in plots 1 month after spraying but not after 6 months. Thionazin left detectable residues 1 month after spraying in the two acid plots but not in the two alkaline plots. More frequent samples taken from thionazin‐treated plots in 1965 showed a similar pattern of persistence, and laboratory tests, using soil mixed with various amounts of powdered calcium carbonate, confirmed that thionazin persisted longer in more acid soils.
Pesticides and the soil fauna: effects of aldrin and DDT in an arable field
Authors: EDWARDS C. A. , DENNIS E. B. , EMPSON D. W. 
Published: February 2008

SUMMARYAldrin dust (3 cwt. of 1¼% per acre) or DDT dust (2 cwt. of 5 % per acre) was applied to small plots replicated four times and four plots were untreated. All plots were kept fallow for one year. Soil samples were taken at 2 to 3‐monthly intervals and the fauna extracted by a notation method. The insecticides did not affect Lumbricidae, Enchytraeidae or Nematoda. Nearly 100 species of arthropods were found, and the greatest effects were those of DDT on mesostigmatid mites and of aldrin on entomobryid or isotomid Collembola and on Pauropoda. Most species of Collembola increased in DDT‐treated plots, apparently because mesostigmatid mites were reduced. In terms of biomass Coleoptera and Diptera were most affected. Both insecticides killed more pests than predators or beneficial animals. The effects of the insecticides were greatest during late summer or autumn.
The incidence of virus diseases in the honey bee
Authors: BAILEY L. 
Published: February 2008

SUMMARYChronic bee‐paralysis virus and sacbrood virus occur commonly in apparently normal honey‐bee colonies in Britain. Most sick adult bees not affected by Nosema apis, Malpighamoeba mellificae or Acarapis woodi have chronic paralysis and most dead larvae not affected by micro‐organisms have sacbrood. Both virus diseases are probably limited by hereditary factors, but unknown environmental factors also seem to influence disease. Paralysed bees from Australia, Canada, Eire, Germany and Mexico were found to be infected with chronic paralysis virus.
Some effects of supplying benzyladenine to leaves and plants inoculated with viruses
Authors: ALDWINCKLE H. S. , SELMAN I. W. 
Published: February 2008

SUMMARYWith tomato spotted wilt virus in petunia leaf strips, N‐6 benzyladenine (BA) was as effective as kinetin in decreasing numbers of local lesions, a result which could not be attributed to an effect on the virus per se. Benzimidazole, adenine and ammonium nitrate were without effect. Benzyladenine was more effective than kinetin when supplied through the petioles of excised whole leaves.Local lesions and infectivity of TSWV in detached leaves of Nicotiana rustica were decreased by supplying BA before and after inoculation. Lesions and infectivity were also decreased in attached leaves when BA was applied 9 days before inoculation. BA supplied to attached leaves after inoculation increased infectivity.Supplying BA to the lower leaves of tomato plants before inoculating with TSWV decreased infectivity of unsprayed, systemically infected tip leaves taken as inoculum; BA supplied after inoculation increased infectivity.Local lesions caused by lucerne mosaic virus in excised leaves of Phaseolus vulgaris were decreased in number by supplying BA.The effects of pre‐ and post‐inoculation sprays of BA are considered in relation to cell metabolism. Since pretreating leaves with kinins did not prevent infection, it is suggested that those which move freely through plants without adverse effects on normal growth may prove of value in increasing the tolerance of plants to virus infection.
Field experiments on sugar‐beet downy mildew (Peronospora farinosa)
Authors: BYFORD W. J. 
Published: February 2008

SUMMARYThe numbers of sugar‐beet plants infected with downy mildew in experimental crops increased slowly over a period of 8–15 weeks from late May. Few new infections appeared after the middle of August, although less than half the plants were then infected. Most infected plants recovered, and recovery was most rapid and complete in young plants, irrespective of the weather. Plants infected when young produced small roots, but their sugar content and juice purity at harvest was similar to those of uninfected plants. Plants first infected in late July and early August had the smallest sugar content and most juice impurities.
Host/parasite interaction in blackspot disease of roses caused by Diplocarpon rosae Wolf
Authors: SAUNDERS P. J. W. 
Published: February 2008

SUMMARYThe utilization of amino acids by Diplocarpon rosae Wolf was investigated and compared with amino acid compositions of leaves of resistant and of tolerant roses. No amino acid appeared to determine resistance of roses to blackspot on a nutritional basis, but phenylalanine marginally increased resistance when taken up by wounded leaves of resistant or tolerant varieties. There is an accumulation of phenolic compounds in response to infection by D. rosae. Most phenolic compounds are toxic to D. rosae in vitro, particularly ellagic acid and p‐coumaric acid, but their presence and quantity in healthy rose leaves could not be related to disease resistance. Inhibition of germination on rose leaves of conidia of the fungus was determined in a manner that suggested production of a phytoalexin. It is suggested that resistance of roses to D. rosae may be related to accumulation of polyphenols and possibly to the production of a phytoalexin.
Studies on the persistence and effects on soil fauna of some soil‐applied systemic insecticides
Authors: Way M. J. , SCOPES N. E. A. 
Published: February 2008

SUMMARYGranular formulations of menazon, phorate and thionazin were applied to a sandy loam soil (pH = 6·1)in April and May as in‐row treatments at commercial rates. They were also broadcast and mixed into the top 4 in of soil at concentrations (10 and 250 ppm of dry soil) which simulated the local in‐row concentrations in areas large enough for sampling.Bioassays showed that 50 % of phorate, thionazin and menazon equivalents had disappeared in about 68, 57 and 23 days respectively from soil treated with 10 ppm of the insecticides. Small residues of the 250 ppm treatments still remained 2 years later. The initial rate of loss of activity of thionazin applied at 250 ppm was much slower than from a 10 ppm application whereas the activities of 250 and 10 ppm of menazon disappeared at similar rates.Phorate at 250 ppm killed almost all earthworms, Collembola, Acarina, free‐living saprophytic and parasitic nematodes and Protozoa; 10 ppm phorate and 250 ppm of menazon also killed almost all Collembola and Acarina but the menazon was relatively harmless to earthworms. Collembola and mite populations began to increase when residues of phorate and menazon equivalents had decreased to about 2 and 20 ppm respectively, and after 15 months they were similar to those in untreated plots.The broadcast treatments initially decreased the rate of breakdown of leaf discs put in the soil but, after about 4 weeks, breakdown increased, sometimes above that in untreated plots. This was associated with a large increase in numbers of Enchytraeidae which were apparently unaffected by the insecticides.Four months after application, 1 lb/acre of phorate and 2 lb of menazon applied in seed drills 2 ft apart were not affecting Collembola in soil between the rows but were still decreasing the numbers within them. In ‐row phorate distributed along a 1·5 in diameter band of soil, 3 in deep, killed Collembola 3 in on either side but not 6 in away. It did not spread upwards in toxic quantities, but after rainfall, sufficient to kill Collembola leached at least 3 in downwards.We conclude that commercial in‐row applications of chemicals like phorate are most unlikely to harm soil fertility, especially as the leaf‐litter‐destroying function of Collembola and other animals killed by phorate may be taken over by Enchytraeidae.
Studies on the nature of resistance in tomato plants to Verticillium albo‐atrum
Authors: SINHA A. K. , WOOD R. K. S. 
Published: February 2008

SUMMARYExtracts of healthy resistant and of healthy susceptible plants of tomato had the same effect on growth of Verticillium albo‐atrum in vitro. Tracheal saps from resistant and from susceptible plants showed no difference in their effect on spore germination and mycelial growth of V. albo‐atrum.Cuttings from resistant plants, inoculated with V. albo‐atrum and fed with low concentrations of casamino acids, or glucose, at first wilted more than controls but soon recovered. Continuous treatment with dilute ethanol solutions for 2 weeks induced marked wilting in inoculated cuttings of resistant plants: treatment for shorter periods caused less severe symptoms, from which cuttings recovered slowly. Metabolic inhibitors did not break resistance of cuttings, but the pathogen survived longer in cuttings treated with sodium diethyldithiocarbamate, salicylaldoxime or 8‐hydroxyquinoline than in controls.When one end of segments of stems of resistant plants was inoculated with the pathogen, and 48 h later the uninoculated end was placed near a colony of V. albo‐atrum on agar, growth of the fungus colony towards the stem segment was sometimes inhibited. There was no such inhibition when segments from susceptible plants were used. Both tracheal sap and diffusates from segments of inoculated resistant plants supported less growth of germ tubes of V. albo‐atrum than sap and diffusates from uninoculated plants. These differences were not obtained with the susceptible variety and production of fungitoxic substances in resistant plants after infection is inferred.
The control of re‐invasion by rats of part of a sewer network
Authors: GREAVES J. H. , HAMMOND L. E. , BATHARD A. H. 
Published: February 2008

SUMMARYRe‐infestation by rats (Rattus norvegicus Berk.) of a section of a sewer network was studied by recording bait consumption in the manhole chambers for periods up to 18 weeks after each of three attempts to rid the section of rats. The mean rate of increase of the rat population was of the order of 20 % per week both when the section was surrounded by a permanently poison‐baited zone as a barrier against re‐invasion from the connected, still heavily‐infested sewers, and when this barrier was absent. When, however, infestation in the connected sewers was reduced by poisoning, and the poison‐bait barrier was maintained, the mean weekly rate of increase in the section declined to 4·4% and could be attributed substantially to breeding.It is concluded that the type of poison‐bait barrier used in the present trials is insufficient to prevent invasion of one part of a sewer network from another if the population density in the latter is high.
The effect of pollen grains on infections caused by Botrytis cinerea Fr
Authors: CHOU MYRA CHU , PREECE T. F. 
Published: February 2008

SUMMARYThe addition of pollen to spores of Botrytis cinerea Fr. in droplets of distilled water stimulates spore germination, growth of germ tubes and lesion development. Aqueous diffusate from pollen is as effective as pollen grains, and frozen pollen is more stimulatory than freshly collected pollen. The presence of pollen grains reduces considerably the number of spores needed to allow infection to occur. The lost germination ability and infectivity of old spores is restored by pollen.The stimulatory effect of the presence of pollen has been demonstrated both in vitro and on the surfaces of strawberry petals, strawberry fruits and broad bean leaves. Complete removal of the source of pollen, the anthers from strawberry fruits, markedly affected the speed and severity of infections of strawberry fruits. On broad bean leaves the addition of pollen grains to spores induced the development of spreading aggressive lesions.Preliminary work indicates that the effective principle in pollen is water‐soluble, dialysable and heat‐stable. Although glucose and fructose are important components of diffusate, neither glucose solution nor fructose solution nor a mixture of the two showed as marked effects as did pollen. Orange juice produces similar effects.
The relationship between chemical constitution and antifungal activity in arylhydrazono ‐isoxazolone compounds
Authors: SUMMERS L. A. , BYRDE R. J. W. , HISLOP E. C. 
Published: February 2008

SUMMARYFrom a study of compounds related to the mildew fungicide, 4‐o‐chloro‐phenylhydrazono‐3‐methyl‐5‐isoxazolone, it is apparent that high antifungal activity is associated with the arylhydrazonoisoxazolone structure. Differences in the relative effectiveness of o‐chlorophenylhydrazono‐, m‐chlorophenyl‐hydrazono‐ and phenylhydrazono‐ derivatives against Botrytis fabae on beans and Podosphaera leucotricha on apples may be due to different modes of action. Several possible mechanisms of action are discussed.
The elimination of four viruses from carnation and sweet william by meristem‐tip culture
Authors: STONE OLWEN M. 
Published: February 2008

SUMMARYCarnation mottle virus (CarMV), carnation ringspot virus (CRSV), carnation vein mottle virus (CarVMV) and carnation latent virus (CarLV) were all eliminated from both carnation (Dianthus caryophyllus) and sweet william (D. barbatus) plants by meristem‐tip culture. Carnation mottle virus was more readily eliminated from D. barbatus than from carnation. Carnation vein mottle and carnation latent viruses were more readily eliminated from carnation than from sweet william: they are rarely found in carnation but CarVMV is found frequently in sweet william. Carnation ringspot was eliminated equally readily from both hosts.
Groundnut rosette and its assistor virus
Authors: HULL R. , ADAMS A. N. 
Published: February 2008

SUMMARYChlorotic rosette from Malawi (isolate CR1), passed through Stylosanthes gracilis and S. juncea, was not subsequently transmissible from groundnuts (Arachis hypogaea) by Aphis craccivora or A. gossypii, but with S. mucronata transmissibility was occasionally regained after a period of time. Aphid transmissibility was similarly lost after passage of two isolates (a chlorotic rosette from Rhodesia, CR2, and a green rosette from Nigeria, GR) through soybean (Soja max) and after manual inoculation to groundnuts. Groundnut plants that remained symptomless after exposure to rosette infection by aphids often contained a virus that restored aphid transmissibility when introduced into groundnuts containing the vectorless virus from that isolate. Groundnut rosette disease therefore consists of a symptom‐inducing virus that we call groundnut rosette virus (GRV) and a symptomless assistor virus (GRAV) that must be present for aphid transmission. The interactions between the GRV and GRAV of chlorotic and green rosette, and their transmission by different vector races, are described.
The association of Xiphinema diversicaudatum (Micoletsky) with strawberry latent ringspot and arabis mosaic viruses in a raspberry plantation
Authors: TAYLOR C. E. , THOMAS P. R. 
Published: February 2008

SUMMARYAn outbreak of strawberry latent ringspot virus (SLRV) in a plantation of Mailing Jewel raspberry coincided with the greatest abundance of the nematode vector, Xiphinema diversicaudatum. Arabis mosaic virus (AMV) was not detected in the crop but was, together with SLRV, in many weed species present. AMV was transmitted through the seed of Poa annua, Capsella bursa‐pastoris and Senecio vulgaris and SLRV through the seed of Mentha arvensis. X. diversicaudatum were more numerous within the rows than between them and vertical sampling showed that most occurred between 4 and 12 in depth in both locations. Monthly sampling showed that egg laying occurred from April to July; populations increased to a peak in late autumn but declined during the winter, resulting in about a twofold annual increase in numbers. Females, males and juveniles transmitted AMV and SLRV to cucumber seedlings, and in the absence of plants the nematode retained AMV for 112 days and SLRV for 84 days.
Wheat bulb fly, Leptohylemyia coarctata Fall., and its effect on the growth and yield of wheat
Authors: BARDNER R. 
Published: February 2008

SUMMARYIn two experiments done in successive years to compare the growth and yield of Cappelle wheat either protected from or exposed to attacks by larvae of wheat bulb fly, the plots were previously fallowed, but egg laying was prevented on half of each plot by using Polythene soil covers. In the first season wheat was sown at the end of October, November and December and in the second season in late October and in early January, when there were two sowings, one with and one without a spring application of herbicide. The infestation rate was 1·1‐1·7 million eggs per acre, typical of a moderate attack. Larvae had little effect on the yield of October‐sown wheat as the plants had two shoots each when first attacked and few were killed. On plots sown late, yield was decreased by up to 22%, as plants had only a single shoot when attacked and many were killed.The main effect of wheat bulb fly was to reduce the number of ear‐bearing shoots by killing plants and restricting the production of new shoots. Surviving plants partially compensated by producing more ear‐bearing shoots with heavier ears and slightly heavier seeds than normal.Killed plants were not distributed uniformly but were often in patches several feet across. Wheat on the attacked plots ripened more slowly and unevenly than on the unattacked plots.Weather affects the growth of the plants and activity of the larvae and thus partly determines percentage shoot survival.