bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of skin spot and silver scurf on stored cv. King Edward potatoes by chemical and non‐chemical methods
Authors: HIDE G A , HALL SHARON M , READ P J 
Published: February 2008

SummaryIn 3 years, seed tubers of cv. King Edward were planted in field experiments and diseases assessed on the daughter tubers after storage for 24–26 wk. In 1991 and 1992, the seed tubers were treated with a mixture of thiabendazole and imazalil at two rates. Tubers were harvested on several dates from late August to early October and dried under different conditions before storage.In 1990, silver scurf after storage was decreased equally by dry curing for 2 wk and windrowing for 2 h whereas skin spot was decreased most by dry curing, and these effects were greater the earlier tubers were harvested. In 1991, dry curing for 2 wk decreased skin spot and silver scurf more than dry curing for 1 wk, and skin spot was slightly decreased by windrowing for 2 h; windrowing improved the control of both diseases when tubers were subsequently dry cured. In 1991 and 1992 fungicide treatment of seed tubers greatly decreased skin spot after storage and was also effective against silver scurf, but increased black dot when tubers were harvested in September or October.Skin spot was controlled equally well by the two rates of fungicide but silver scurf was less well controlled when the dose was decreased by 75%. It is suggested that amounts of fungicide applied to seed tubers could be decreased provided that the efficiency of application is improved and that crops are harvested early and dried before storage.
A comparison of methods for inoculating bean plants with Elsinoë phaseoli and some factors affecting infection
Authors: PHILLIPS A J L 
Published: February 2008

SummaryBean (Phaseolus vulgaris) leaves were inoculated with a conidial suspension of Elsinoe phaseoli by spraying, by applying a 10 μl drop, by a cotton wool technique or by using a camel hair brush. Spray application resulted in a uniform distribution of lesions over the leaf surface and gave consistent levels of infection between repetitions. Drop application allowed good control of the amount of inoculum applied. Although brush or cotton wool techniques gave high levels of infection it was not possible to control the amount of inoculum. Only immature tissues were susceptible to infection.Five cultivars were inoculated with two isolates and disease was scored on the basis of numbers of lesions and lesion type (scab severity). The small white cvs PAN 181 and Teebus were the most resistant; lesions were small and generally fewer than on the large‐seeded red speckled sugar bean cvs Umlazi and Umvoti. The value of the different inoculation techniques in studies on bean scab is discussed.
Inoculation and acquisition of maize bushy stunt mycoplasma by its leafhopper vector Dalbulus maidis
Authors: LEGRAND ANA I , POWER ALISON G 
Published: February 2008

SummaryMaize bushy stunt mycoplasma (MBSM), a mycoplasma‐like organism, is transmitted in a persistent manner by the corn leafhopper, Dalbulus maidis, to maize (Zea mays). The influence of the duration of acquisition access and inoculation access periods on the transmission of MBSM by D. maidis was investigated. The proportion of plants infected by D. maidis increased significantly from 0 to 0.51 as the inoculation access time to a plant increased from 10 min to 72 h (X2= 101.5, P < 0.001). Likewise, the proportion of insects acquiring MBSM from infected plants increased from 0 to 0.19 as the acquisition access time to the source plant increased from 10 min to 72 h (X2= 53.2, P < 0.001). The data were fitted to a loglinear regression model. No significant association was found between the sex of the insects and vector ability.
Properties of a host range and coat protein variant of broad bean true mosaic comovirus from Vicia faba
Authors: JONES A T , MITCHELL M J 
Published: February 2008

SummaryUnlike other described isolates of broad bean true mosaic comovirus (BBTMV), a variant, code name SB, infected some non‐leguminous plant species and, in N. benthamiana, induced systemic mottling and puckering of the leaves. However, like other described BBTMV isolates, purified SB particle preparations contained isometric particles c. 28 nm in diameter that sedimented as two nucleoprotein components with S20, w values of 90S and 109S; some preparations occasionally contained a component of c. 50S. Virus particles contained two ssRNA species which, when denatured in glyoxal, had estimated MT values of 2.1 × 106 and 1.3 × 106 and co‐electrophoresed with cowpea mosaic virus RNA‐1 and RNA‐2 respectively. Isolate SB was serologically indistinguishable from British and German isolates of BBTMV. However, SB virus particles contained a major polypeptide (L) of Mr between c. 31 000 and up to three minor ones (S) or Mr between c. 20 000 and 24 000. This contrasts with protein preparations from other BBTMV isolates that typically contain only two polypeptides of Mr c. 37 000 (L) and 21 000 (S). Following isopycnic centrifugation in CsCl, SB particles purified from pea separated into two major components with densities of 1.39 and 1.44 g cm‐3 and a minor component of estimated density 1.43 g cm‐3. In Cs2SO4, virus preparations separated into three major components with densities of 1.30, 1.32 and 1.36 g cm‐3 and a minor one of density 1.27 g cm‐3. In CsCl isopycnic gradients, SB particles purified from TV. benthamiana separated into two components with densities of 1.38 and 1.43 g cm‐3. During immuno‐electrophoresis in agarose gels, freshly prepared virus and preparations stored for up to 4 days at 4°C contained a single component that migrated rapidly to the anode, whereas similar preparations of an English isolate of BBTMV migrated as a single component that moved only slowly toward the anode but which, within 48 h, contained an additional component with a migration rate similar to that of isolate SB. Isolate SB is therefore a host range variant of BBTMV which, in comparison with previously described isolates of BBTMV, has an increased negative charge of its particles prior to any appreciable degradation of its S protein, and S protein that is degraded less rapidly. These features probably account for the anomalies observed in isopycnic centrifugation.
The development of plant‐parasitic nematode infestations on micro‐propagated banana plants following field control measures in Côte d'Ivoire
Authors: MATEILLE THIERRY , QUÉNÉHERVÉ PATRICK , HUGON RÉMI 
Published: February 2008

SummaryOf the weeds that were found in banana production areas, only Asystasia gangetica was parasitised by Radopholus similis; Helicotylenchus multicinctus and Hoplolaimus pararobustus were able to parasitise all weed species. Field trials were carried out in Cote d'Ivoire to assess the potential for using nematode‐free micro‐propagated banana plants following cultural and chemical methods for nematode control. Banana (Musa acuminata) cv. Poyo was examined for nematodes after weed fallow, flooding and chemical treatment. Before replanting bananas, nematode assays showed that: i) all nematode species declined but were not eliminated after a 1,3‐dichloropropene soil treatment; ii) H. multicinctus, H. pararobustus and Cephalenchus emarginatus were still present after either a 2‐year weed fallow (dominated by Chromolaena odorata or Asystasia gangetica) or a 10‐week flooding; iii) R. similis did not persist after fallowing or flooding. All nematode species were found in plots treated with 1,3‐dichloropropene and that had been planted with bullheads, suckers or nematode‐free micropropagated plants. After both fallow and flooding, R. similis was reintroduced on infested planting materials (bullheads and suckers) even when they were pre‐treated with a nematicide. When fallow and flooded plots were planted with nematode‐free materials (vitro‐plants), R. similis did not appear in the roots for two vegetative cycles. The other species, still present in the soil, invaded the roots and increased slowly in numbers. These results were confirmed in commercial banana plantations.
The use of hydrogen peroxide to control postharvest decay on ‘Galia’ melons
Authors: AHARONI YAIR , COPEL AZICA , FALLIK ELAZAR 
Published: February 2008

SummarySanosil‐25, a disinfectant containing 48% hydrogen peroxide and silver salts as stabilising agents, inhibited the mycelial growth of the two main decays causing fungi of melons, Alternaria alternata and Fusarium solani in vitro at concentrations between 5000 and 10 000 μl litre‐1. However, in in vivo experiments, Sanosil‐25 markedly decreased decay at a concentration of 5000 μl litre‐1 when incorporated into a wax treatment and produced no phytotoxic effect. This treatment may provide an alternative to imazalil which, although more effective, gives problems with residue levels. A concentration of 10 000 μl litre‐1 proved phytotoxic.
A decimal code describing the developmental stages of head cabbage (Brassica oleracea var. capitata)
Authors: EVERAARTS A P 
Published: February 2008

SummaryThe developmental stages of head cabbage (Brassica oleracea var. capitata) as a vegetable have been characterised by a decimal code. Five primary stages are recognised: germination, emergence and establishment, leaf formation, head formation and maturity. Each primary stage is divided into secondary stages, which apply both to single plants and to crops. Maturity is defined as the head having obtained a marketable weight and density. The standing ability is defined as the number of days from 90% of the crop being marketable to 25% of the crop having become unmarketable.
Falling aphids enhance impact of biological control by parasitoids on partially aphid‐resistant plant varieties
Authors: GOWLING G R , van EMDEN H F 
Published: February 2008

SummaryCage experiments, in which the population increase of Metopolophium dirhodum was measured either in the absence or presence of the parasitoid Aphidius rhopalosiphi, showed reductions of peak populations in the presence of the parasitoid of 30% on the susceptible wheat cultivar Armada, but of 57% on the partially resistant Rapier. On both cultivars, aphid population curves in the presence and absence of the parasitoid diverged before the first mummies were formed. The number of aphids leaving plants was measured, and was found to increase in the presence of the parasitoid, particularly with Rapier (almost double). Most aphids (about 75%) which left plants fell, and a smaller proportion regained plants when parasitoids were present than when they were absent. A field experiment with Brevicoryne brassicae and natural predation on Brussels sprouts also showed an increase in aphids leaving a less susceptible compared with a more susceptible cultivar.
The relationship between colonisation and crown rot symptoms in strawberry plants infected with Phytophthora cactorum
Authors: PETTITT T R , PEGG G F 
Published: February 2008

SummaryStrawberry tissues infected with Phytophthora cactorum were comminuted and plated in a selective antibiotic agar medium to determine levels of tissue colonisation as indicated by the number of colony forming units (CFU) recovered per gramme of infected tissue. The number of CFU recovered per gramme of tissue increased logarithmically with the amount of necrosis in infected crown, leaf and petiole tissues. Under the conditions of enhanced susceptibility to infection and colonisation caused by cold storage treatments, this relationship between colonisation and necrosis was not significantly altered in the susceptible cv. Tamella. A recovery index was used to determine the effect of infected tissues on the recovery of CFU. This indicated that increasing levels of host colonisation stimulated CFU recovery and may partly explain the large increase in CFU g‐1 with larger amounts of necrosis.The amount of tissue colonisation was greater in inoculated plants of the susceptible cv. Tamella than in less susceptible cv. Cambridge Favourite, although the necrotic tissues of the latter contained more CFU g‐1, indicating a greater level of tolerance to colonisation. In cv. Tamella small amounts of colonisation were capable of causing wilt symptoms, although no wilted plants contained less than 200 CFU g‐1. Conversely, plants containing more than 1000 CFU g‐1 always wilted. In the early stages of infection, low levels of colonisation could be detected in strawberry crowns in the absence of symptoms. Dormant strawberry plants of cv. Tamella were readily infected by P. cactorum zoospore inoculations but, unlike actively growing plants, the majority of infections remained latent. These latent infections exhibited little or no symptoms and CFU recoveries from infected tissues were always below 100 CFU g‐1.
Modelling the relationship between purple blotch and yield loss in garlic and effect of leaf damage on bulb yield
Authors: BISHT I S , AGRAWAL R C 
Published: February 2008

SummaryAn AUDPC model was developed to describe the relationship between Alternaria porri infection and yield loss in garlic. Percentage yield loss was regressed against AUDPC and gave an acceptable fit to a linear model with an intercept of ‐0.35, a slope of 0.09 and R2= 0.85 during 1990–91 and an intercept of 1.91, a slope of 0.08 and R2= 0.87 during 1991–92. The effect of various levels of leaf damage on garlic bulb yield was also studied to simulate damage caused by A. porri. Significant yield reduction by 25% defoliation at 5 wk, 50% defoliation at 4 wk and 75% defoliation at 3 wk before bulb maturity were recorded. No significant yield reduction from 2 wk before bulb maturity could, however, be noticed even at the highest levels of leaf damage. Linear regression models were fitted for predicting yield at various levels of defoliation at different weeks before bulb maturity.These models can be used to describe the consequences of disease epidemics, projecting possible losses during the season and justifying the need for chemical disease control.
Differentiation of Erwinia carotovora subsp. atroseptica and carotovora by RAPD‐PCR
Authors: MÄKI‐VALKAMA T , KARJALAINEN R 
Published: February 2008

SummarySix different 10‐mer oligonucleotide primers were used to differentiate Erwinia carotovora subsp. atroseptica (Eca) and carotovora (Ecc) using RAPD‐PCR. All primers gave different banding patterns for Eca and Ecc indicating their value for identification. UPGMA clustering analysis clearly showed two separate clusters, one for Eca and the other for the Ecc group. Similarity within Eca strains was very high, over 85% among most isolates but within the Ecc group extensive genetic diversity was found and many of the Ecc strains were no more than 50% similar. Similarity between the 10 Eca and 10 Ecc strains was generally only 10–25% based on the results from six primers.Three RAPD fragments from Eca group, which were amplified by three different RAPD primers, were isolated and used as probes for Southern hybridisation to test, if homologous fragments were amplified from Ecc strains. All these probes hybridised only with Eca isolates indicating that these fragments could be useful in order to develop a PCR‐based detection system for Eca strains.
Detection and differentiation of whitefly‐transmitted geminiviruses in plants and vector insects by the polymerase chain reaction with degenerate primers
Authors: DENG D , MCGRATH P F , ROBINSON D J , HARRISON B D 
Published: February 2008

SummaryDegenerate oligonucleotide primers, designed for amplification of an approx. 500 bp fragment of DNA‐A of five well characterised whitefly‐transmitted geminiviruses, were used in the polymerase chain reaction (PCR) to detect known or putative geminiviruses infecting seven plant species and originally obtained from Africa, India, America or Europe. Although nucleotide sequences are published for only four of the viruses, all 13 were detected. Six of the viruses were also detected in single viruliferous whiteflies (Bemisia tabaci). Virus was detected both in fresh B. tabaci and in specimens that were frozen and dried before being dispatched from their country of origin. Individual viruses could be distinguished by the patterns of DNA fragments obtained by the action of restriction endonucleases on the PCR products. This approach also allowed six virus isolates from leaf curl‐affected tomato to be assigned to four country‐specific forms.
Antigenic analysis of potato virus A particles and coat protein
Authors: ANDREEVA LEENA , JÄRVEKÜLG LILIAN , RABENSTEIN F , TORRANCE LESLEY , HARRISON B D , SAARMA M 
Published: February 2008

SummaryFive monoclonal antibodies (MAbs) were prepared to particles of potato virus A (PVA), isolate B11. In immunoblots, MAbs A1D8 and A5B6 reacted only with full length molecules of PVA coat protein (CP). Pepscan tests with overlapping octapeptides representing the whole sequence of PVA CP showed that the epitope detected by MAb A5B6 is contained in its N‐terminal octapeptide. MAbs A9A4, A3H4 and A6B8 reacted with CP molecules that lacked about 5 kD of sequence at their end(s) and detected epitopes at residues 52 to 62, 64 to 73 and 75 to 82 respectively, all of which lie in the protease‐resistant core of the CP. The epitope which reacts with MAb A3H4 is in a region predicted to be hydrophobic and is not detected in intact virus particles, indicating it is a cryptotope. In contrast, MAbs A6B8 and A9A4 reacted with freshly purified PVA particles but more strongly with partially degraded ones. Pepscan tests with polyclonal antibodies to PVA isolate B11 identified five additional immunogenic sequences in PVA CP and showed that regions at the N‐termini of the intact and core molecules are immunodominant.PVA isolate B11 was not transmitted by aphids, and its CP N‐terminal octapeptide contains the sequence DAS, which is associated with aphid‐non‐transmissibility in other potyviruses. MAb A5B6, which detects this region, reacted strongly in ELISA with three out of four other aphid‐non‐transmissible PVA isolates but only weakly with three aphid‐transmissible ones, suggesting that differences in N‐terminal sequence may underlie most of the differences in aphid transmissibility.
Weed seed banks in arable fields under contrasting pesticide regimes
Authors: MARSHALL E J P , ARNOLD G M 
Published: February 2008

SummaryViable weed seed banks on a clay soil were estimated for five years from 11 arable fields receiving one of three levels of pesticide application. Low seed densities, averaging 2000 m‐2, were recorded, but dicotyledonous weed seed numbers usually increased following oilseed rape crops, reaching 26 000 m‐2 in one field. Field‐to‐field variability was large. Samples could be grouped using multivariate techniques into those dominated by grass weed seeds and those containing mainly dicotyledonous weed seeds. Within TWINSPAN classifications, most fields maintained similar seed banks during the study period, indicating relative stability of communities. Differences present at the outset of the experiment, including variation between fields in the same treatment area, were maintained for the five years. Patterns were not associated with straw disposal or spring herbicide application. Oilseed rape crops did not cause qualitative change in seed bank communities, but allowed certain species, notably Stellaria media and Sonchus asper, to increase seed numbers. Smaller and less diverse seed banks in the area receiving most herbicide were not statistically significant. Seed banks gave poor predictions of following weed populations.
The ploidy composition of offspring from Solanum tuberosum (4×) ×S. phureja (2×) crosses with special reference to triploid frequencies
Authors: DE M J 
Published: February 2008

SummaryData on the production of offspring of 4×× 2× crosses in potato are presented. The ploidy composition of seedlings varied from year to year and parent to parent. Products of dihaploid induction crosses were chiefly 2× or 3× whereas crosses between S. tuberosum cultivars and unreduced gamete‐producing S. phureja clones were mainly 3× or 4×.Substantial percentages of 3× seedlings were produced by some crosses in some years. It was concluded that the so‐called ‘triploid block’ in potatoes is a variable phenomenon and that factors which increase seed production may suppress the proportion of triploids produced.
A description and code of development of evening primrose (Oenothera spp.)
Authors: SIMPSON M J A 
Published: February 2008

SummaryA description and code of development is proposed which divides the life cycle of evening primrose (Oenothera spp.) into seven stages, namely germination and emergence, leaf production, stem extension, flower bud development, flowering, spike development in terms of seeds and spike development in terms of pods. The description and code are based on a system devised for oilseed rape but are modified to suit evening primrose growers and those who require simple and accurate identification of critical crop stages such as harvest stage. The relationship between the proposed code and the general BBCH scale is indicated.
Arable acronyms analysed – a review of integrated arable farming systems research in Western Europe
Authors: HOLLAND J M , FRAMPTON G K , ÇILGI T , WRATTEN S D 
Published: February 2008

SummaryArable production has come under increasing economic and environmental pressures, especially in the last decade. These have derived from over‐production, decreased farm incomes and a concern with the possible environmental effects of intensive pesticide use associated with such intensive cultivation. A number of long‐term research programmes on integrated farming systems and their sustainability have recently been completed or are currently under way. In the UK, these include the ‘Boxworth’ project, ‘SCARAB’, TALISMAN’, RISC, ‘LINK Integrated Farming Systems’, ‘LIFE’ and the demonstration‐only programme ‘LEAF’. These projects are reviewed in terms of their objectives, designs and results to date, and are compared with some parallel programmes in Germany, the Netherlands, Switzerland and France.
Interactions between the diamondback moth, Plutella xylostella L. and glasshouse and outdoor‐grown cabbage cultivars
Authors: VERKERK R H J , WRIGHT D J 
Published: February 2008

SummaryInteractions between Brassica cultivars (cvs) and adult and larval stages of Plutella xylostella L. were examined. In six‐way choice oviposition experiments, glasshouse‐grown Chinese cabbage cv. Tip Top was preferred to five outdoor‐grown temperate cabbage cultivars but was similar to four out of five tropical cultivars. Bionomic studies with neonate larvae on temperate cabbage cultivars showed that mean larval duration was longer and percentage survival less on older compared with younger plants but that plant age or cultivar had little effect on pupal weight. The fecundity of P. xylostella reared on outdoor‐grown cabbage cultivars varied ten‐fold between the poorest and the best cultivar but plant age had little effect on P. xylostella reared on Chinese cabbage. In a glasshouse experiment, survival of P. xylostella on Chinese cabbage was significantly greater compared with field‐grown glossy‐leaved, normal bloom green cabbage and red cabbage. In bioassays with neonate larvae, when the leaves were placed vertically instead of horizontally a significant level of intrinsic resistance was revealed for glasshouse and field‐grown glossy‐leaved cabbage but not for Chinese cabbage. Observed differences in host status to P. xylostella are discussed in relation to the potential for partial plant resistance in control programmes.