bluuebunny/crossref_metadata_2025_split huggingface dataset:
The flow of water into fruit trees. II. Water intake through a cut limb
Authors: BAXTER P. , WEST D. 
Published: February 2008

SUMMARYWater was supplied to trees directly through cut limbs in order to bypass the relatively high root resistances to water flow. Addition of the reducing agents 8‐hydroxyquinoline citrate, sodium iso‐ascorbate or ascorbic acid singly or in combination significantly increased the time for which water could be supplied through a cut limb before xylem blockage reduced water inflow. Supply of water to apple trees through a cut limb increased fruit size compared with non‐irrigated control trees.Application of water by this method also allowed detection of the presence of vascular blockages in trees affected by a root weevil (Leptopius squalidus).
Preferential feeding and damage to cultivars of Nigerian cassava by the variegated grasshopper (Zonocerus variegatus)
Authors: TERRY By E. R. , SCHAEFERS G. A. , GARBER M. J. 
Published: February 2008

SUMMARYLarge populations of Zonocerus variegatus invaded a cassava crop established during the dry season. The resultant damage was severe, certain cultivars being totally destroyed. The grasshoppers exhibited a statistically significant preference for certain cultivars the defoliation of which shifted attacks to less preferred ones. On a particular variety (Isunikankiyan), populations increased and persisted even after defoliation, probably due to
The development on potatoes of a glasshouse strain of Myzus persicae resistant to organophosphorous insecticides
Authors: DUNN J. A. , KEMPTON D. P. H. 
Published: February 2008

SUMMARYWhen potato tubers infested with a strain of Myzus persicae resistant to organophosphorus insecticides were planted, the tops became heavily colonized despite a furrow‐application of disulfoton granules. The observation showed a more feasible way for resistant aphids of glasshouse origin to establish themselves in the field than by direct migration by alates.
Biochemical characterization of some additional mycelial cultures of basidiomycetes
Authors: TAYLOR J. B. 
Published: February 2008

SUMMARYTwenty‐six biochemical tests were used to study cultures of basidiomycetes isolated from roots of fruit‐trees and other plants. The results enabled isolates to be placed into one of sixteen groups. Three of these groups were identified as Collybia drucei, Corticium utriculicum and Heteroporus biennis by matching their biochemical reactions with those of isolates from fruiting bodies of these fungi. This suggests that the other groups might also correspond to species. The three named fungi are indigenous, the first two not having been recorded elsewhere. Thus, root infections by these fungi may have originated from the indigenous fungal flora. Isolates of C. utriculicum and Stereum purpureum which were indistinguishable in culture were also separated using biochemical tests.
Variation in reaction to barley yellow dwarf virus in ryegrass and its inheritance
Authors: WILKINS P. W. , CATHERALL P. L. 
Published: February 2008

SUMMARYGenotypes of Italian and perennial ryegrass differed greatly in their reaction to infection with barley yellow dwarf virus (BYDV). One genotype of perennial ryegrass appeared unaffected, whilst the yield and height of other genotypes were reduced. Progeny of the Italian ryegrass genotypes showed a similar degree of variation. Tolerance, assessed by the effect of the virus on yield, was inherited in a wholly additive manner. Symptoms were rare and their severity was under both additive and non‐additive genetic control and strongly correlated with increasing severity of reaction.The utilization of the variation in BYDV reaction in breeding programmes may prove difficult because plants with the highest performance tended to suffer most from BYDV infection, and half‐sib progeny ranked in a different order of tolerance in the glasshouse from that of their respective parent genotypes in the field. It is suggested that the observed variation in BYDV response results from a readjustment in the balance of genotypically controlled and environmentally conditioned variation in plant growth.
The fungal flora of loganberries in relation to storage and spoilage
Authors: DAVIS R. P. , DENNIS C. 
Published: February 2008

SUMMARY Botrytis cinerea, Cladosporium spp., Penicillium spp., Aureobasidium pullulans, Mucor mucedo, Phoma state of Didymella applanata, Cryptococcus laurentii var. laurentii, C. albidus var. albidus, Candida sake and Sporobolo‐myces roseus were consistently present on freshly harvested loganberries. Botrytis cinerea was the main spoilage organism with Mucor mucedo of minor importance. The importance of benomyl‐resistant strains of B. cinerea is discussed.
RNA and protein components of maize streak and cassava latent viruses
Authors: BOCK K. R. , GUTHRIE E. J. , MEREDITH GINA , BARKER H. 
Published: February 2008

SUMMARYPolyacrylamide gel electrophoresis indicated that maize streak (MSV) and cassava latent (CLV) viruses each contain one species of protein and two of RNA. The estimated protein mol. wt is 28000 for MSV and 34000 for CLV. The mol. wts obtained for the two RNA species using formamide‐containing gels were the same for the two viruses: 17×108 and 1–3 × 106. It is suggested that the viruses have a two‐part genome and that the tendency of their nucleoprotein particles to form pairs favours the delivery of complete genomes to sites of infection.
Assessment of the potential for and development of organophosphorus resistance in field populations of Myzus persicae
Authors: BAKER J. P. 
Published: February 2008

SUMMARYA survey of esterases in field populations of the peach‐potato aphid, Myzus persicae was made during the spring of 1975. Assay was by electrophoresis of single aphid homogenates, and the known association between the activity of an esterase and resistance to organophosphorus insecticide (OP) was used to infer resistance in field populations. The resistant variant replaced the susceptible in populations which had been treated with OP and another variant with threefold (approximately) more esterase activity appeared to be replacing the resistant variant in populations which have been treated twice with OP. The significance of this for control of M. persicae is discussed. Differences in resistance between aphids in different parts of the same field, and the widespread association of these esterase variants in favoured combinations with two electrophoretic variants at another locus have also been investigated.
Temperature sensitive phases during the germination of lettuce (Lactuca sativa) seeds
Authors: GRAY D. 
Published: February 2008

SUMMARYLettuce seeds cvs Hilde, Feltham King and Avoncrisp were subjected, at different phases during imbibition at 22°C, to a high temperature (33°C) inhibitory for germination, for periods ranging from 4 to 144 h, before returning them to 22°C.The results showed, that the first 4h of imbibition and also the phase between the commencement of mitosis and the onset of radicle emergence were more sensitive to the effects of high temperature than other phases in the germination process. Short exposures (8–24 h) to 33°C commencing at the latter phase delayed germination by up to 4 days, and at the earlier by up to 8 days. Percentage germination was unaffectd except after prolonged exposures (> 48 h) from the beginning of imbibition, which reduced it.Seedling emergence from moist sieved soil was both delayed and reduced when imbibing seeds were exposed for a short period from the beginning of imbibition to 33°C compared with seeds imbibing continuously at 19°C. Germination was delayed and not reduced when seed was exposed to 33°C at the phase between commencement of mitosis and the onset of radicle emergence.
The genetics of race specific resistance in lettuce (Lactuca sativa) to downy mildew (Bremia lactucae)
Authors: JOHNSON A. G. , CRUTE I. R. , GORDON P. L. 
Published: February 2008

SUMMARYData are presented on the segregation of resistance to five British races and two Dutch races of Bremia lactucae in the F2 progenies of crosses involving seven resistant and several susceptible lettuce cultivars. These data and also those previously published by other workers are considered in relation to the systematic model proposed by Crute & Johnson (1976) to explain the genetics of race specific resistance to B. lactucae in lettuce. It is shown that, with minor modifications, the model accommodates almost all of the previously published data and correctly predicts the new data, except for one set which cannot at present be interpreted.It is concluded that genetic evidence exists for the presence, among various cultivars of lettuce, of at least four and possibly five different dominant resistance genes of major effect designated Dm2, Dm3, Dm4, Dm6 and Dm8; and of a pair of dominant genes with complementary effect designated Dm7/1 and Dm7/2. The resistance conferred by these genes is specified in relation to five British races, five Dutch, three Israeli and one United States race of the fungus. Resistance genotypes are proposed for cultivars Avoncrisp, Avondefiance, Calmar, Great Lakes 659, Kares, Meikoningen, Mildura, Proeftuins Blackpool, Solito, Valverde, Ventura and the USDA line PI 164937.
Effects of soil applications of benomyl and captan on the growth of onions and the occurrence of endophytic mycorrhizas and rhizosphere microbes
Authors: BERTOLDI M. de , GIOVANNETTI M. , GRISELLI M. , RAMBELLI A. 
Published: February 2008

SUMMARYWhen grown for 6 months in the absence of pathogens, repeated soil applications of benomyl or captan significantly and similarly decreased growth of onion seedlings by 22–25% (diameter) and 31–34% (dry weight). The losses were associated with differing effects on soil microbes. Whereas captan had no effect on the occurrence of vesicular‐arbuscular mycorrhizas it appreciably decreased populations of rhizosphere fungi. In contrast benomyl inhibited mycorrhiza formation but had a relatively small effect on rhizosphere fungi.
A banana fruit spotting disorder in the Yemen Arab Republic
Authors: WALLER J. M. , HINDORF H. 
Published: February 2008

SUMMARYA fruit spot of young bananas has recently become prevalent in the Yemen Arab Republic. The spots appear initially on fruit soon after they emerge from the bract, first as small water‐soaked lesions which subsequently become necrotic; the pericarp then splits and the whole fruit rots before maturity. The symptoms are unlike those of previously recorded banana diseases and pathogenic organisms were not consistently associated with the lesions. Possible etiology is discussed.
Flight regulation in the green spruce aphid (Elatobium abietinum)
Authors: CARTER C. I. , COLE JANICE 
Published: February 2008

SUMMARYIn Britain the flight of alate parthenogenetic viviparae of Elatobium abietinum was found to occur only in early summer. Data for this study were extracted from suction trap catches and weather records obtained from meteorological stations adjacent to the traps.The duration of the flight period increased with latitude. At 51° N 95 % of the trap catch was taken in 24 days and at 55° N in 32 days. A flight threshold temperature of 12–13°C was deduced from trap catches taken within the forest crop. Displacements in median flight days at various sites in Britain could be related to values of accumulated day‐degrees but not to differences in photoperiod. The median flight day can be predicted empirically by accumulating day‐degree values over 8°C from 1 January up to a total of 115 day‐degrees.The implications of seasonal flight activity on crop reinvasion is discussed.
Effects of earthworms, nematodes, cultivations and host plants on Verticillium wilt of peach and cherry
Authors: NDUBIZU THOMAS O. C. 
Published: February 2008

SUMMARY Verticillium dahliae but not V. albo‐atrum Berth was isolated from eight out of twenty‐one stone fruit orchards surveyed for Verticillium wilt disease in western New York. Wilt incidence was related to the cultivation of tomato or legumes as previous or inter‐crop with stone fruit trees. A limited cross species inoculation using isolates of V. albo‐atrum and V. dahliae from woody and herbaceous plants showed that peach and cherry were susceptible to both species. The effect of V. dahliae on growth of cherry seedlings in the presence of Tylenchorynchus claytoni, Pratylenchus penetrans and Meloidogyne hapla was compared. P. penetrans and M. hapla produced more severe growth reduction than T. claytoni. The adverse effect of Verticillium on the growth of cherry seedlings was greater acting together with any one of the three nematodes than acting alone. V. dahliae was shown to be capable of passage through earthworms without loss of infectivity.
Occurrence, purification and properties of narcissus tip necrosis virus
Authors: MOWAT W. P. , ASJES C. J. , BRUNT A. A. 
Published: February 2008

SUMMARYNarcissus tip necrosis virus (NTNV), a previously undescribed virus, was detected in the Netherlands and the United Kingdom in plants of twenty‐one cultivars of trumpet, large‐cupped, small‐cupped, double, tazetta and poeticus narcissus. In some cultivars distinct leaf symptoms were sometimes associated with infection but in others infected plants remained symptomless and detection was dependent on serological tests. The virus was readily transmitted by manual inoculation to narcissus, but it failed to infect any of forty‐six other plant species from fourteen families. Up to 50 mg of virus/kg of tissue were obtained by differential centrifugation of narcissus leaf extracts previously clarified with either diethyl ether, n‐butanol or a mixture of n‐butanol and chloroform. The virus particles are isometric, c. 30 nm in diameter, have a sedimentation coefficient (s°20 w) Of 123 S a buoyant density of 1·356 g/cm3, migrate as a single component in polyacrylamide gel electrophoresis, and contain a single RNA species of mol. wt 1·6×106 and two major polypeptides of mol. wt 42000 and 39000. Although NTNV resembles tombusviruses it showed no serological relationship to the type member or six putative members of this group or to thirty‐four other viruses with isometric particles. Its present cryptogram is R/*:1.6/(18):S/S:S/*.
Partial purification and some properties of wineberry latent, a virus obtained from Rubus phoenicolasius
Authors: JONES A. T. 
Published: February 2008

SUMMARYWineberry latent virus (WLV) was obtained from a single symptomless plant of American wineberry (Rubus phoenicolasius) originally imported from the United States of America. On graft inoculation, WLV infected but induced no distinctive symptoms in several Rubus species including those used as indicators for known Rubus viruses. It was not seed‐borne in wineberry.WLV was mechanically transmitted to several herbaceous species but induced local lesions in only a few; it was weakly systemic in some Chenopodium species. Infective C. quinoa sap lost infectivity after diluting to 10‐4, heating for 10 min at 70°C, and storage either for 8 days at 18°C or for 32 days at 4°C. Sap from infected plants contained flexuous filamentous particles c. 510°12 nm. WLV was partially purified by extracting infected C. quinoa leaves in 0·05 M tris‐HCl buffer (pH 7) containing 0·2% thio‐glycerol and 10% (v/v) chloroform and concentrating virus by precipitation with 7% (w/v) polyethylene glycol (PEG, mol. wt 6000) and 0·1 NaCl. The virus was then pelleted through a 30% (w/v) sucrose pad containing 7% PEG+0·1 M NaCl and finally sedimented through a sucrose density‐gradient. These preparations had A260/280 ratios of 1·26, contained end to end aggregates of WLV particles and formed a partly polydispersed peak in the analytical ultracentrifuge. WLV did not react with antisera to four potex‐viruses, or to apple chlorotic leaf spot or apple stem grooving viruses.
Nematode transmissibility of pseudo‐recombinant isolates of tomato black ring virus
Authors: HARRISON B. D. , MURANT A. F. 
Published: February 2008

SUMMARYPseudo‐recombinant isolates of tomato black ring virus (TBRV), containing RNA‐i of the potato bouquet serotype and RNA‐2 of the beet ring‐spot serotype, were transmitted by the nematode Longidorus elongatus, which also transmits the beet ringspot serotype but not the potato bouquet serotype. Transmissibility by L. elongatus was correlated with antigenic specificity of the virus particles, providing further evidence that nematode transmissibility depends on the structure of the virus coat protein. The distribution of genetic determinants for biological properties between the RNA‐1 and RNA‐2 of TBRV resembles that for raspberry ringspot virus.
Selecting for resistance to downy mildew of sugar beet
Authors: BROWN S. J. 
Published: February 2008

SUMMARYSugar beet seedlings were evaluated for resistance to downy mildew by exposing them to natural infection in a glasshouse maintained at a high relative humidity (c. 95–98%). Exposure to natural infection for at least 3 days was required for adequate infection levels which occurred in the majority of tests; failure in others was related to decreases in relative humidity during clear weather. Seedling disease symptoms were different from those of mature plants. In most instances there was adequate differentiation among seedlings in populations with low, but worthwhile, levels of variation for resistance. The application of the method in selection programmes for resistance is discussed.
Effects of soil density on yield and fertilizer requirement of sugar beet
Authors: JAGGARD K. W. 
Published: February 2008

SUMMARYThree experiments (1971–3) on medium‐textured soils of low organic‐matter content examined the effects of soil density on seedling emergence and yield of sugar beet, and the interactions between soil density and the requirement for nitrogen (N) and phosphate (P2O5) fertilizers. Three soil densities were produced by rolling and harrowing, dutch harrowing twice, and power harrowing once; each was tested with 75, 150 and 225 kg ha‐1 N and 0, 100 and 200 kg ha‐1 P2O5.Most seedlings emerged on the medium‐density treatment produced by dutch harrowing twice. The crop in the least dense soil treatment, produced by power harrowing once, consistently yielded slightly more sugar than the medium‐density treatment, which yielded significantly more than the most dense treatment. In dense soil, created by rolling and harrowing, there was a response to more fertilizer N than the less dense ones; the crop did not respond to phosphate fertilizer. Mechanical impedance, not toxic concentrations of ethylene in the soil atmosphere, appeared to be the cause of reduced yield on the dense soils; these reductions were considerable at dry soil bulk densities in excess of 1·5 g ml‐1.
Yield components and cultivar, sowing date and density in field beans (Viciafaba)
Authors: THOMPSON R. , TAYLOR H. 
Published: February 2008

SUMMARYDelay in sowing the cultivars Ostlers (Viciafaba var. equina) and Herz Freya (V.faba var. minor) beyond late February depressed yield. Densities of at least sixty plants per m2 were required to ensure that yield was not limited by sowing rate.Differences in yield in response to changes in density were reflected particularly in changes in numbers of pod‐bearing nodes per plant, but also to a lesser extent in numbers of pods per pod‐bearing node. The inherently larger seed weight of cv. Ostlers compared with cv. Herz Freya did not confer any yield advantage, differences in number of beans per pod and number of pods per pod‐bearing node tending to equalize the yield of the two cultivars. The most stable component of yield throughout was number of beans per pod, and the least stable was number of pod‐bearing nodes per plant.
Effects of Botrytis fabae infection and mechanical defoliation on seed yield of field beans (Vicia faba)
Authors: GRIFFITHS ELLIS , AMIN SUPAAD M. 
Published: February 2008

SUMMARYEffects on seed yield of mechanical defoliation and inoculation with Botrytis fabae were compared using pot‐grown plants of Vicia faba (cv. Maris Beagle). Treatments, which were made at the end of flowering, were applied singly and in all combinations to leaves (a) below, (b) at, and (c) above the flowering nodes (i.e. 23 factorial).Yield was unaffected by treatments applied to leaves below the flowering nodes. Removal of leaves at flowering nodes did not reduce the number of pods but yield was reduced because there were fewer and smaller seeds. Inoculation of this zone also reduced yield; pods were lost at some nodes but it could also be shown that, irrespective of pod loss, yield at individual nodes was reduced in proportion to the severity of infection on leaves at the same nodes. Removal of leaves above flowering nodes reduced yield almost to the same extent as removal of leaves at flowering nodes but inoculation resulted in only a small amount of infection and yield was not reduced significantly.These results, taken in conjunction with recent studies on the physiology of the host plant, show that beans are exceptionally vulnerable to attack by B. fabae at the stage of flowering and early pod development. At later stages of development infection is unlikely to have a substantial effect on yield.
The use of garlic (Allium sativum) extracts to control foot rot of Phaseolus vulgaris caused by Fusarium solani f.sp. phaseoli
Authors: RUSSELL P. E. , MUSSA A. E. A. 
Published: February 2008

SUMMARYGarlic extract, prepared as a juice from crushed garlic cloves inhibited the in‐vitro growth of Fusarium solani f.sp. phaseoli. Adequate in‐vivo control of foot rot of Phaseolus vulgaris cv. Seafarer was achieved by seed treatment with either the extract from crushed cloves or with an aqueous preparation of commercial lyophilized garlic powder.
Rubus host range, symptomatology and ultrastructural effects of a British isolate of black raspberry necrosis virus
Authors: JONES A. T. , ROBERTS I. M. 
Published: February 2008

SUMMARYScions from red raspberry (Rubus idaeus) plants naturally infected with an aphid‐ and sap‐transmissible virus, code‐named 52V, always induced apical necrosis in R. occidentals signifying the presence of black raspberry necrosis virus (BRNV), whereas plants free from 52V did not. These and other findings provide strong circumstantial evidence that 52V is an isolate of BRNV, the heat‐labile member of the pair of viruses that together cause raspberry veinbanding mosaic disease.On grafting with R. idaeus scions containing a 52V culture of BRNV free from other detectable viruses, all of twenty‐two red raspberry cultivars and four other Rubus species were infected symptomlessly but apical necrosis developed in R. henryi and R. molaccanus.Electron microscopy of thin sections of 52V‐infected Chenopodium quinoa, R. henryii and R. occidentalis showed areas of dead cells in the vascular tissue and leaf blade. Some of the cells adjacent to these areas had cell wall outgrowths and many of the plasmodesmata contained virus‐like particles c. 25 nm in diameter arranged in a single file.
Trapping, parasitism, and poisoning of nematodes by fungi
Authors: Godfrey B. E. 
Published: February 2008

ABSTRACTNaturally occurring toxins and nematode‐destroying fungi are the two major factors controlling soil nematode populations. Nematode‐destroying fungi fall into two groups ‐ hyphal forms, producing traps which capture nematodes, and endoparasitic forms, both common in natural soils. Nematode‐destroying fungi have been used in attempts to control levels of pathogenic nematodes in agricultural soils with limited success.
The dispersion of mononchid nematodes in the soil
Authors: Small R. 
Published: February 2008

ABSTRACTPrevious research on the Mononchidae has centred on the taxonomy and geographical distribution of the group. Observations of cultures of Prionchulus punctatus, maintained in the laboratory, have demonstrated the presence of feeding aggregations. A study of the dispersion of the nematodes within the soil has confirmed that this behavioural pattern also occurs under natural conditions. The results of this study were presented.