bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surveys of beet cyst nematode in England 1977–80
Authors: SOUTHEY J.F. , ALPHEY T.J.W. , COOKE D. A. , WHITEWAY JENNIE A. , MATIIIAS P. L. 
Published: April 2007

Surveys of sugar beet crops for beet cyst nematode (Heterodera schachtii Schmidt) in seven selected areas of England have provided data on distribution of the pest and on some factors affecting its occurrence. These data were mapped by CAMGRID computer program.Infestations occurred mostly on the East Anglian fenland (14% of fields infested) and in this area were more frequent nearer the sugar beet processing factory. In the remaining areas the few infested fields (5% or less) were generally scattered but a small concentration of infestation occurred in the West Midlands in an area of intensive horticulture with frequent brassica crops. The survey data did not support the view that beet cyst nematode infestations occur more frequently near access points to the crop. In the surveyed areas frequency of host crops appears to be more important than soil type in determining the likelihood of infestation.
The effect of Phragmidium mucronatum on rose understocks and maiden bush roses
Authors: SHATTOCK R. C. , BHATTI M. H. RAHBAR 
Published: April 2007

Persistent infection of field‐grown Rosa laxa hort, by the rust fungus Phragmidium mucronatum was observed throughout summer and autumn in 1979 and 1980. Rust significantly reduced shoot number, length and fresh weight (to 85 and 54% of the control after one and two seasons respectively) along with flower number and fruit yield. Root weight was also reduced to 55% of the control over two seasons.The growth of four bush rose cultivars budded on to rusted Laxa stocks was reduced, affecting bush quality. Overall, rust‐free stocks produced twice as many saleable maidens as rusted stocks but bud take was not affected by P. mucronatum.
The effects of various crops on the survival and carry‐over of the wheat take‐all fungus Gaeumannomyces graminis var. tritici
Authors: KOLLMORGEN J. F. , GRIFFITHS J. B. , WALSGOTT D. N. 
Published: April 2007

The effects of various crops on the saprophytic survival and carry‐over of Gaeumannomyces graminis var. tritici were studied in the glasshouse and field.In the glasshouse, survival of G. g. tritici was greater in unplanted pots than in pots planted with either cereals or non‐cereals. In the field, fallow and various non‐cereal crops reduced carryover of take‐all but the disease was severe after wheat, barley and triticale. Grain yields were higher after fallow and non‐cereals than after cereal crops.
The use of methyl bromide and carbendazim for the control of lettuce big‐vein disease
Authors: WHITE J.G. 
Published: April 2007

Lettuce seedlings raised in peat blocks placed on contaminated soil subsequently developed lettuce big‐vein disease symptoms when grown in pots of sterilized compost. Incorporation of 0.01 g carbendazim per 4.3 cm3 peat block reduced the number of plants with disease symptoms but did not prevent root infection by Olpidium brassicae, the vector of the big‐vein agent. Similar results were obtained when seedlings propagated in the absence of big‐vein disease were grown in pots of contaminated soil but carbendazim was less effective when the treated blocks were planted in contaminated field plots. Methyl bromide applied at 500, 750 or 1000 kg/ha temporarily controlled the disease but re‐contamination occurred and was complete after three consecutive crops.Bromide residues in lettuce heads reached 9240 μg/g dry tissue in the first crop but fell to a maximum 772 μg/g by the third crop. Bromide residues in soil fell to natural levels over this period.
The nature and distribution of Verticillium albo‐atrum strains highly pathogenic to the hop
Authors: SEWELL G. W. F. , WILSON J. F. 
Published: April 2007

During routine, annual, field wilt‐resistance trials of hop progeny, ‘breakdowns’ of resistance occurred in control varieties. Pot‐plant pathogenicity tests of isolates from these trials, and other isolates obtained during farm surveys, confirmed the existence of apparently new strains potentially highly pathogenic to resistant cultivars. Results of the tests provided little evidence that enhanced pathogenicity was associated with specificity. The assumption of essentially host nonspecific pathogenicity was consistent with other observations on the inheritance of resistance.Highly pathogenic strains were identified among isolates from nine farms in Kent. The locations and ownership of these farms, and their wilt histories, provided strong circumstantial evidence that these strains had spread from a single focus, as did progressive wilt originally. Legislation, introduced to restrict further spread, may have been too late.
A taxonomic study of the host ranges of tymoviruses
Authors: GUY P. L. , DALE J. L. , ADENA M. A. , GIBBS A. J. 
Published: April 2007

Published data on the susceptibility of plant species to 18 tymoviruses were collated. These data showed that tymoviruses infected more species from the family of their natural field host than species from other families. The data also indicated that tymoviruses infected a greater proportion of species from the same primary division of the dicotyledons (crassinucellate or tenuinucelate) as their natural host than other species, but the correlation was not statistically significant.The susceptibility of 18 crassinucellate and 18 tenuinucellate test plant species to 10 tymoviruses was determined. The viruses infected about three times more plant species from the primary taxonomic division that contained the family of their field host than species from the other division; this difference was statistically significant.The separation of tymoviruses into two groups based on the taxonomic division containing their natural hosts and most of their experimental hosts correlates broadly with a classification of the tymoviruses based on the serological relationships of their particle coat proteins.
The sensitivity and specificity of a rapid nucleic acid hybridization method for the detection of potato virus X in crude sap samples
Authors: BAULCOMBE D. , FLAVELL R. B. , BOULTON R. E. , JELLIS G. J. 
Published: April 2007

A DNA copy (cDNA) of the common European strain (strain‐group 3) potato virus X RNA (PVX3‐RNA) was prepared by reverse transcription of PVX‐RNA and amplified by cloning into E. coli plasmid pBR322. This DNA hybridizes with PVX‐RNA and not at all to RNA of potato virus Y. A low amount of cross‐hybridization was observed with strain‐group 2 of PVX (PVX2). However, by hybridization of PVX2‐RNA to restriction endonuclease fragments of PVX3‐cDNA, it was demonstrated that cross‐homology was not present in all regions of the PVX genome.The cloned PVX3‐cDNA was hybridized to viral RNA in crude sap samples which had been spotted on to nitrocellulose membrane. The signal, which was assayed by autoradiography, allowed the detection of 50 pg of viral RNA. This value was not adversely affected by encapsidation of the RNA, nor by components of crude sap. The sap spot hybridization was as effective as enzyme‐linked immunosorbent assay both in detection of small quantities of purified PVX3, and in screening of plants from a breeding programme for immunity to PVX3 infection.
Phytoalexin accumulation during infection of bean and soybean by ascospores and mycelium of Sclerotinia sclerotiorum
Authors: SUTTON D. C. , DEVERALL B. J. 
Published: April 2007

Infection by ascospores of Sclerotinia selerotiorum caused hypersensitivity in epidermal cells in leaves and etiolated hypocotyls of bean and soybean. In bean, phaseollin and phaseollidin accumulated in leaves but kievitone alone in hypocotyls. In soybean, no phytoalexins were detected in leaves but glyceollin accumulated in hypocotyls.Mycelial infection caused water‐soaked spreading lesions in leaves and etiolated hypocotyls of both hosts. In bean, no phytoalexins were detected in leaves but kievitone alone accumulated in hypocotyls. In soybean, glyceollin accumulated in leaves but was not sought in hypocotyls.Transfer of bean hypocotyls infected with mycelium from 18 to 28°C caused lesion limitation and marked accumulation of phaseollin and kievitone.Phaseollin, kievitone and glyceollin inhibited ascospore germination and growth of hyphae from preformed germ‐tubes and established mycelia, phaseollin being most active and glyceollin least active. Hyphal growth from mycelia was least affected by the phytoalexins.
Retention of iprodione on salad onion leaves in relation to the control of Botrytis spp.
Authors: PRESLY A. H. 
Published: April 2007

Using bioassay and fluorescent tracer techniques it was demonstrated that more fungicide was retained on mature leaves of summer salad onion crops if 1 kg/ha iprodione wettable powder (w.p.) formulation plus wetting agent was sprayed at 280 1/ha than at 560 1/ha or 1120 1/ha.The lowest spray volume (280 1/ha) with four sprays of iprodione w.p. (0.5 kg in October, November, December and January) gave effective control of Botrytis cinerea and significantly increased plant stand and yield. More fungicide was required to obtain equivalent results using a mixed programme of two thiram (4 kg/ha total) and two iprodione w.p. (2 kg a.i./ha total) sprays at the same application volume and intervals. Where the mixed programme was applied at 1 1 20 1/ha, 1 2 kg a.i. (total fungicide) was necessary to achieve equivalent disease control.At 280 1/ha, retention and persistence of iprodione on onion foliage was greater with the oil‐based than with the wettable powder formulation. In summer especially this resulted in improved Botrytis control and greater numbers of marketable onions. In winter onions, oil and w.p. formulations were equally effective and gave equivalent improvements in plant stand and yield.
Isolation of a tobamovirus from rose
Authors: HICKS R. G. T. , FROST R. R. 
Published: April 2007

The Rosaceae contain several natural hosts of tobacco mosaic virus (TMV), including apple (Kirkpatrick & Lindner, 1964), pear (Gilmer et al., 1966), cherry (Cilnier, 1967), plum (Albrech‐tova et al., 1974) and strawberry (Yankulova & Schmidt, 1974). In 1974 we isolated a virus, serologicalty related to TMV from rose (Hicks. 1979): the first record, we believe, of a tobamo virus in this host.Petals (150 g) from an unidentified climbing cultivar (probably Danse de Feu) with symptoms (Fig. 1) similar to rose flower break (Farrar & Frost, 1972) were homogenized in cold 0.01 M borate buffer pH 7.8 containing 0.01 M sodium ethylene diamine tetra‐acetate and 0.01 M sodium sulphite, filtered through muslin, and given one cycle of low‐ and high‐speed centrifuga‐tion. The pellet was resuspended in 2 ml of 0.01 M borate buffer pH 7.8. centrifuged at low speed, and assayed on a range of test plants, which were grown in Levington compost (Fisons Ltd) at mean temperatures of either 22° or 26°C, given supplementary lighting in winter, shaded
Further studies on resistance‐breaking strains of potato virus X
Authors: JONES R. A. C. 
Published: April 2007

A stock culture of isolate CP of potato virus X (PVX) maintained by serial subculture in plants of Nicotiana glutinosa was found to contain PVX strain group four in addition to the original strain group two. The group four strain was separated from the mixture by sap‐inoculation to potato cultivars Maris Piper and Pentland Dell, both of which carry PVX hypersensitivity genes Nx and Nb, by graft‐inoculation to Maris Piper and by sap‐inoculation to cultivar Pentland Ivory which carries Nb but not Nx. Strain group four seemed to be a minor component of the strain mixture in N. glutinosa as few potato plants became infected with it when insusceptible plants were sap‐inoculated or when sap inoculum was diluted 500 times. The group four strain passed readily through tubers of infected potato plants and was stable on serial sub‐culture in N. glutinosa. When stock cultures of PVX group two isolates B and EX kept in N. glutinosa were tested on cultivar Pentland Dell, they also proved to be mixtures of group two and group four, indicating that spontaneous appearance of group four in cultures of group two strains may occur readily.When group four strains derived from isolate CP and from PVX common strain isolate DX were graft‐inoculated to many plants of cultivar Cara, which carries PVX immunity gene Rx, there was no evidence of selection of a strain like HB which overcomes this gene. In mixed infection with isolate DX, HB was still present after passage through two generations of progeny tubers of cultivar Pentland Crown which lacks any resistance genes, indicating that HB is a fully competitive strain.
Cultivar dependence of polyacrylic acid effects on Pseudomonas syringae in Nicotiana tabacum
Authors: AHL PATRICIA , GIANINAZZI S. , SAMSON REGINE , BENJAMA A. 
Published: April 2007

Polyacrylic acid (PAA) protected Xanthi‐nc tobaccos against necrosis provoked by Pseudomonas syringae (hypersensitive reaction). When highly concentrated bacterial suspensions (1 × 108 b/ml) were injected into PAA‐treated leaves, tissue collapse was delayed; with more dilute bacterial suspensions (3 × 107 or 1 × 107 b/ml), a significant reduction or a total suppression of necrosis was observed. This phenomenon occurred when the PAA treatment was applied 4 days prior to injection of the bacteria, but not when it was applied 3 h prior to injection. No such protection occurred in Samsum NN tobaccos. PAA had no toxic effect on P. syringae when added to the injected suspensions, or in vitro in culture media. The bacterial population remained constant in protected tissue, but declined sharply in necrosing tissues. These results suggest that host metabolism is involved in PAA‐induced suppression of necrosis.Induced suppression of necrosis due to bacteria shows some analogies with induced resistance to viruses. The possibility of common steps in their biochemical mechanism is discussed.
Metalaxyl resistance in Phytophthora infestans on greenhouse tomatoes in Greece
Authors: PAPPAS A. C. 
Published: April 2007

In winter/spring 1984 resistance to metalaxyl developed in Phytophthora infestans within tomato greenhouses in Preveza, Greece. The appearance of resistant isolates followed continuous applications of metalaxyl and prevalence of weather conditions favourable for late blight. The majority of resistant isolates grew on tomato leaf discs floated on solutions containing 100 μg/ml metalaxyl whereas sensitive isolates were inhibited at concentrations of 0.1 μg/ml.In trials within polyethylene tunnels metalaxyl had no effect on the development of the late blight induced by resistant strains but both a mixture of this fungicide with mancozeb and mancozeb alone, gave satisfactory control of the disease when applied in a 7‐day schedule.
Thiabendazole as an iatrogenic agent in carrot black rot
Authors: REIFSCHNEIDER F. J. B. , VECCHIA P. T. DELLA 
Published: April 2007

Negligible amounts of carrot (Daucus carota L.) seed were produced in Brazil prior to the release of cv. Brasilia in 1982. This cultivar is tolerant of high temperature and resistant to leaf blight caused by Alternaria dauci (Kühn) Groves & Skolko (Vieira et al., 1983). Since 1982 technology for production of Brasilia seed has developed rapidly and over 40 t of seed have been produced, representing more than 8000 ha planted. Fungicides are widely used on carrot root crops and growers have naturally extended their use to carrot seed crops. Mancozeb, thiabendazole, captafol and chlorothalonil, applied at weekly intervals, are the most common fungicides used although their efficacy in this new situation has not been evaluated.A survey of pathogens associated with carrot seed production (Reifschneider & Della Vecchia. 1983) has shown that the most common fungal pathogen is Alternaria radicina Meier, Dreschler & Eddy, a species which is a common seed‐borne pathogen in the USA (Rader, 1952) and has been present in Brazil since 1970 or earlier (Luz, 1970).Since information concerning the control of A. radicina in carrot seed crops is lacking we established a preliminary fungicide experiment in July 1982 within a 5‐ha commercial field planted with artificially vernalized roots of which 90% were infected, to varying degrees, with A. radicina. Plots were 25 m2 and each treatment (Table 1) was replicated five times, in a completely randomized design. Seeds were harvested manually at maturity and dried by forced air at c. 30°C. Infection by A. radicina was detected using the method of Soteros (1979) in which heat‐treated seeds (100°C for 1 h) are plated on malt agar. A total of 200 seeds per plot (20 seeds per plate) were used. Identification of A. radicina was based on conidium and conidiophore morphology (Ellis & Holliday, 1972).
Factors influencing the production of basidiocarps and the deposition and germination of basidiospores of Crinipellis perniciosa, the causal fungus of witches' broom on cocoa (Theobroma cacao)
Authors: ROCHA H. M. , WHEELER B. E. J. 
Published: April 2007

The production of basidiocarps by Crinipellis perniciosa on detached, dead witches'brooms from cocoa was assessed in relation to temperature, light, cocoa clone, age of broom and type of tissue, in cabinets with a daily cycle of 8 h wet and 16 h dry. More basidiocarps formed and matured at 20–25°C than at 25–30°C. In the latter regime the pilei were smaller and white, instead of the usual crimson colour, and the stipes were longer. No basidiocarps formed at 30–35°C. At 20–25°C. more basidiocarps formed and matured with light at 100 μE m‐2 s‐1 during the wet period than at 10 μE m‐2 s ‐1. Only one basidiocarp and five primordia developed on 20 brooms kept in the dark. Brooms from 10 cocoa clones at Pichilingue. Ecuador, differed in basidiocarp productivity. most basidiocarps forming on brooms from Seavina and least on ICS clones. The numbers of basidiocarps produced on brooms aged 1.2.3 or 4 months when detached from cocoa trees were similar but time to initiation of the first primordium differed considerably. More basidiocarps formed at nodes than internodes.The discharge of basidiospores was optimal at 20–25°C and 80% RH: germination was optimal in water agar films. Neither process was dependent on light.
Morphology, benomyl resistance and pathogenicity to wheat and rye of isolates of Pseudocercosporella herpotrichoides
Authors: HOLLINS T. W. , SCOTT P. R. , PAINE J. R. 
Published: April 2007

Seventy‐one isolates of Pseudocercosporella herpotrichoides, a non‐random sample obtained from cereal crops in Britain between 1981 and 1983, were classified as either sensitive or resistant to 2 mg/l benomyl. In agar culture, isolates were of two distinct morphological types, described as ‘fast‐even’ and ‘slow‐feathery’. Pathogenicity to wheat and rye seedlings was determined for 21 fast‐even and 32 slow‐feathery isolates. Fast‐even isolates were much more pathogenic to wheat than to rye; nearly all slow‐feathery isolates were about equally pathogenic to wheat and rye. Thus, in morphology and pathogenicity, irrespective of sensitivity to benomyl, fast‐even isolates conformed to the published descriptions of W‐types, while slow‐feathery isolates conformed to the descriptions of R‐types.Sensitivity to 2 mg/l benomyl was determined for 97 isolates, including W‐types and R‐types, collected between 1956 and 1983, mainly from England but including some from nine other countries. Only 16 isolates were resistant; three were fast‐even and 13 were slow‐feathery. All were collected in England since 1981, suggesting that resistance has been rare until recently. Resistance was not a feature of R‐type isolates collected before 1981. The increase in the proportion of resistant isolates since 1981 appears to have coincided with an increase in the proportion of R‐type isolates.
Studies on Botrytis spp. occurring on onions (Allium cepa) and leeks (Allium porrum)
Authors: PRESLY A. H. 
Published: April 2007

Botrytis byssoidea(mycelial neck rot) was more prevalent thanB. allii(sclerotial neck rot) on the leaves of field onions and the bulbs of stored onions grown in some of the areas where onions or onions and leeks had previously been grown sequentially.B. byssoideaandB. porriwere also isolated from leeks. Spores ofB. allii, B. byssoidea(from onions and leeks),B. porri, andB. squamosacaused infection of seedlings of salad (green) and bulb onions.Inoculation withB. squamosaspores caused severe infection of seedling leaves, but inoculation with mycelial discs caused little damage to onion bulb tissue. By comparison, mycelial discs of the remaining species were highly pathogenic to bulbs.The practical implications of disease transfer of certain of these species between onions and leeks are discussed.
Yellow leaf curl and other virus diseases of tomato in Cyprus
Authors: IOANNOU N. 
Published: April 2007

Outdoor and greenhouse tomato plantings in the main production centres of Cyprus were surveyed for virus diseases during 1978–1982. A disease characterized by prominent leaf yellowing and curling was the most prevalent and damaging. The causal agent was identified as tomato yellow leaf curl virus (TYLCV) because it infected Datura stramonium but not the tobacco cultivars Havana 423 or Virginia, was graft‐transmissible but not mechanically or seed‐transmissible, and was transmitted persistently by the tobacco whitefly, Bemisia tabaci. Minimum acquisition and inoculation feeding periods were 20–30 and 10–20 min. respectively; the latent period was 21–24 h. The vector was infective for about 12 days, but there was no transovarial transmission to progeny.Four other, mechanically transmissible, viruses were also isolated from tomato and identified on the basis of symptomatology, indicator host reactions and serology; tobacco mosaic virus (TMV), potato virus Y (PVY). potato virus X (PVX), and cucumber mosaic virus (CMV). These viruses, especially TMV, were commonly associated with mosaic symptoms and occasionally with other leaf or fruit disorders; coinfection with TYLCV occurred frequently.
Life‐history of Phragmidium rubi‐idaei on red raspberry in the United Kingdom
Authors: ANTHONY VIVIENNE M. , SHATTOCK R. C. , WILLIAMSON B. 
Published: April 2007

Phragmidium rubi‐idaei produced five spore stages on red raspberry and overwintered as teliospores adhering to canes. In the field spermagonia appeared in a single flush in early summer on leaves of the primocanes (first‐year canes) and on leaves of the lateral shoots of fruiting canes, and were followed by aecia, uredinia and telia. Aecia and uredinia occasionally appeared on petioles and sepals and uredinia on drupelets of mature fruit. Lesions caused by aecia and uredinia on the bases of primocanes did not become cankerous in the following fruiting year. Necroses associated with large aecia produced a shot‐hole effect and leaflets heavily affected by either aecia, uredinia or telia abscissed prematurely.The sequence of spore stages on pot‐grown plants inoculated with mature overwintered teliospores took 60 days to the reappearance of telia. The rate of development of uredinia and associated necroses was faster on younger than on older leaves but the cumulative spore yield was not significantly different.Optimum temperature for germination of urediniospores in vitro (18.4–20.9°C) was higher than for mature teliospores (14.6–18.4°C). Light inhibited germination of both types of spores. Teliospore germination was inhibited by wavelengths of 590–750 nm, but this was partially reversible under other light conditions. A reversible inhibition of basidiospore formation was also observed under shorter wavelengths.