bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of different chemicals for osmotic treatment of vegetable seed
Authors: BROCKLEHURST P. A. , DEARMAN JANE 
Published: February 2008

SUMMARYSamples of carrot, celery, leek and onion seed were treated before sowing by imbibition in osmotic solutions of polyethylene glycol 6000 (PEG), glycerol and potassium dihydrogen orthophosphate (KH2PO4). The solutions were sufficiently concentrated to prevent germination during treatment, and within each species, the amount of water taken up by the seeds during treatment did not vary greatly between solutions. All treatments increased the rates of seed germination and seedling emergence compared to untreated controls, but glycerol‐treated seeds germinated and emerged significantly more slowly than did PEG‐ and KH2PO4‐treated seeds. The effects of PEG and glycerol treatments on percentage germination and seedling emergence were small, but KH2PO4 treatment tended to reduce percentage germination and emergence, most markedly in leek and one cultivar of celery. It is concluded that PEG treatment gives the most consistently beneficial effects for the range of species tested.
Development of a combined cold storage and methyl bromide fumigation treatment to control the American serpentine leaf miner Liriomyza trifolii (Diptera:Agromyzidae) in imported chrysanthemum cuttings
Authors: MORTIMER E. A. , POWELL D. F. 
Published: February 2008

SUMMARYIndividual chrysanthemum cuttings and leaves infested with eggs and larvae of the alien leaf miner Liriomyza trifolii, and batches of pupae, were treated in the laboratory to find an effective quarantine treatment to control the pest in imported cuttings. The laboratory tests were based on a statutory quarantine treatment of 2 days' cold storage at 1–2°C followed by methyl bromide fumigation at 15°C with a concentration time product (CTP) of 54 g h/m3, which is used to control Spodoptera littoralis on imported chrysanthemum cuttings. Treatments of 2 days' storage at 1–2°C followed by methyl bromide fumigation at 15°C with a range of CTPs were used to obtain accurate dose‐response lines and estimate the LD99 and LD99 9 for each stage of L. trifolii. The largest estimates of the LD99 for eggs, larvae and pupae up to 3 days old were 40·04, 34·49 and 42·64g h/m3 respectively. These results indicate that the Spodoptera treatment should give high levels of kill of most stages of L. trifolii. However, the LD99 values for pupae more than 3 days old were greater than those for eggs, larvae and young pupae. Therefore if this treatment were adopted as a quarantine measure against L. trifolii, good prophylactic treatments and rigorous pre‐packing inspections in exporting countries would need to be maintained, to minimise any risk of importing pupae. It would also be necessary to ensure that the temperature of the imported cuttings was raised uniformly to 15°C after cold storage and prior to fumigation. The practicality of the technique as a commercial treatment will depend on whether it is possible to achieve this without causing unacceptable phytotoxicity.
Saprophytic survival of Gaeumannomyces graminis and Phialophora spp. at various temperature‐moisture regimes
Authors: WONG P. T. W. 
Published: February 2008

SUMMARYThe saprophytic survival of the pathogen, Gaeumannomyces graminis var. tritici and two isolates each of three avirulent fungi, G. graminis var. graminis, Phialophora graminicola and a lobed‐hyphopodiate Phialophora sp. was studied in two soil types under controlled temperature and moisture conditions in the laboratory. In general, the fungi survived longest in the cool, dry soil (15°C, < ‐10 MPa) followed by the warm dry soil (30°C, < ‐10 MPa). All the fungi were virtually eliminated from the warm, moist soil (30°C, ‐0.3 MPa) after 3 months. Survival was intermediate under cool, moist conditions (15°C, ‐0.3 MPa). Under cool, moist conditions, G. graminis var. graminis survived better than the other three fungi in the first 3 months in both soil types and continued to do so for a further 3 months in one soil. Both isolates of the lobed‐hyphopodiate Phialophora sp. survived poorly in the two soil types being almost eliminated after 3 months. There were considerable differences between the survival of the two isolates each of G. graminis var. graminis and P. graminicola, especially under cool, moist conditions. Of the six avirulent isolates studied, one isolate of G. graminis var. graminis (DAR24167) survived best under the three temperature‐moisture regimes which showed differences. It also survived better than the take‐all fungus under moist, cool conditions and at a comparable rate under dry conditions. Therefore, this variation in survival should be considered when selecting antagonists for the biological control of take‐all.
The influence of growth stage and foliage or soil application on the activity of AC 222,293 against Alopecurus myosuroides and Arena fatua
Authors: PILLMOOR J. B. , CASELEY J. C. 
Published: February 2008

SUMMARYAC 222,293 was active against both Alopecurus myosuroides and Avena fatua following foliage or root entry. The most effective site of application was the foliage for A. fatua and the soil for A. myosuroides. In glasshouse and controlled environment studies, growth inhibition was transient with extensive subsequent regrowth occurring following applications at below recommended field doses. Performance declined when application was delayed until A. fatua had more than five and A. myosuroides more than six leaves. This lower activity could be only partly explained by lower spray retention and uptake of the herbicide, since there were no differences in either translocation from the treated laminae or metabolism to the biologically active free acid. Other factors that may have contributed to the reduced performance are discussed.
Characteristics of resistance to the grain aphid Sitobion avenue in winter wheat
Authors: LOWE H. J. B. 
Published: February 2008

SUMMARYFive stocks of winter wheat were resistant to S. avenae in glasshouse screening tests, where resistance was more evident in older than younger plants but different types of resistance were not separated.Antibiosis was measured from the growth and reproduction of caged individual aphids and antixenosis from the settling of adult aphids on detached leaf portions. Cvs Bounty, Rapier and Virtue were resistant due to antibiosis, whilst cv. Kador and line A4501‐4E showed antixenosis. These and other differences indicated that these five wheat stocks probably include at least four distinct sources of resistance to S. avenae. The existence of different types of resistance could account for variability in the results of screening tests.
Taxonomy, evolution and domestication of Vicia in relation to aphid resistance
Authors: HOLT J. , BIRCH N. 
Published: February 2008

SUMMARYThirty Vicia species and 28 V. faba cultivars were evaluated for Aphis fabae resistance by measuring rates of aphid population increase (rm) on the host plants. A subset of these species (22) and cultivars (five) were evaluated for resistance to Acyrthosiphon pisum and Megoura viciae. For the same subset of 22 Vicia species and all three aphid species, positive correlations were observed between the concentration and numbers of leaf and stem non‐protein amino acids and the level of aphid resistance. Correlations were also observed between trichome density, on some organs of the host, and both nymphal survival and development time. Aphid resistance, together with these possible physical and chemical resistance mechanisms, showed a pattern which was described in relation to the taxonomy of the genus Vicia and the degree of domestication of the host. The least advanced Vicia species were most resistant whilst the more specialised species and those most closely related to V. faba and V. faba itself were most susceptible. Within each taxonomic group (subgenus or section), the most domesticated species were least resistant. The merits of utilising the resistance found in some V. faba cultivars and in other wild Vicia species were considered.
Differences in the relative resistance of two carrot cultivars to carrot fly attack over five seasons
Authors: ELLIS P. R. , FREEMAN G. H. , HARDMAN J. A. 
Published: February 2008

SUMMARYA comparison was made over five seasons of carrot fly (Psila rosae) damage on two carrot cultivars, Sytan and Danvers, which represented the extremes of resistance discovered in screening trials at Wellesbourne. Plants were harvested regularly during the seasons and at each harvest the number and weight of roots was recorded and carrot fly damage was assessed using various techniques; in 1979‐80 the numbers of carrot fly larvae and pupae in and around root samples were counted. The experiments confirmed repeatedly the relative resistance of cv. Sytan compared with Danvers. The estimated reduction in carrot fly larvae on Sytan relative to Danvers in early November in four seasons ranged from 40% to 67%. When tested against first generation carrot fly attack the reduction in larvae on Sytan was 54%. There were 45% fewer mines per root on Sytan resulting in less damage at each harvest in all seasons. Larvae took longer to develop on Sytan than Danvers and 18% more plants of Sytan survived carrot fly attack. Differences in seedstock, season, sowing time, generation of carrot fly, plant size and density did not account for observed differences in damage between the two cultivars. The studies indicated satisfactory practical techniques for assessing carrot fly damage in cultivar screening trials.
A glasshouse screening method to assess resistance in onions to damage by onion fly (Delia antiqua) larvae
Authors: SONI S. K. , FREEMAN G. H. , ELLIS P. R. 
Published: February 2008

SUMMARYFactors influencing the resistance of onion (Allium cepa) cultivars to onion fly (Delia antiqua) damage were investigated. These included different environments, methods of plant raising and egg inoculation, and plant size. A glasshouse compartment maintained at 14 to 37 °C was as satisfactory for assessing the resistance as a controlled environment.The basic test unit comprised 10 onion seedlings raised in a 400 × 50 × 50 mm deep plastic trough and inoculated with 50 onion fly eggs from a laboratory culture. Resistance was assessed by counting wilted plants every two or three days for 21 days after egg inoculation. The reciprocal of number of days for each plant to wilt (wilting rate) was an appropriate variate for statistical analysis, adjusted for the length of the longest leaf at the time of inoculation. The method enables cultivars or breeding lines of onion species to be reliably screened for resistance to larvae of this pest in a glasshouse so that only the most promising need be tested in the field.
Desiccation studies in relation to the storage of Araucaria seed
Authors: TOMPSETT P. B. 
Published: February 2008

SUMMARYRelationships between seed moisture content (fresh weight basis) and germination were examined for nine Araucaria species by desiccation under mild environmental conditions. The lowest safe moisture content, below which germination percentage begins to decline, was estimated in each case. Seeds can be grouped into three moisture content categories: the first group (including A. araucana, A. angustifolia, A. hunsteinii and A. bidwillii) cannot be safely dried to below 25–40%; the second group (including A. columnaris, A. rulei, A. nemorosa and A. scopulorum) cannot be dried to below about 12% without damage; the third category contains A. cunninghamii, which can be dried to 2% without damage.Seeds in the first group should be stored at 0–5 °C with moisture contents above the lowest‐safe value. Provided freezing damage does not exceed 10%, seeds in the second group should be kept at ‐ 18°C or lower with about 7% moisture content for long‐term storage and at 0–5 °C with about 12% moisture content in the short term. Seed of A. cunninghamii is best retained at near 5% moisture content and in ‐18°C or lower.The lowest‐safe moisture content was found to be associated with seed size and weight, higher moisture content values coinciding with greater size and weight of seed. Food reserve materials also differed among the groups; seeds of the first group were mainly starchy, whilst those in the other categories possessed a high lipid content.
Effects of activated charcoal on attack by larvae of the wheat bulb fly, Delia coarctata
Authors: SCOTT G. C. , GREENWAY A. R. 
Published: February 2008

SUMMARYActivated charcoal interferes with normal host‐seeking by larvae of the wheat bulb fly, Delia coarctata, by adsorbing arrestant compounds exuded from the plants. Thus, in laboratory tests, activated charcoal in soil surrounding one of two rows of wheat seedlings decreased larval attack on the treated row. Charcoal in soil above the level of the seeds decreased attack but had no effect when below the seeds. However, there was no decrease in attack when both rows were in charcoal. Attempts to develop a practical application of this effect in the field are described.
Intercontinental variation of Sclerospora graminicola
Authors: BALL S. L. , PIKE D. J. 
Published: February 2008

SUMMARYCollections of S. graminicola were made from local pearl millet crops in West Africa and India. Asexual inoculum was derived from the collections in Polythene tunnels and used to infect pearl millet cultivars from both continents. Analysis of deviance of the incidence of disease was performed on the logit scale using GLIM. The host × pathogen interactions were interpreted by use of the Finlay‐Wilkinson regression technique widely used in the study of genotype × environment interactions. While the West African collections were consistently more pathogenic than the Indian ones, West African hosts were potentially more susceptible to Indian than to West African pathogen isolates; conversely some Indian hosts were more vulnerable to West African than to Indian isolates. There was a fairly stable relationship between incidence of disease and relative pathogenicity of West African isolates but the Indian isolates were more variable in their susceptibility to changing background levels of disease. These results could influence resistance breeding strategies in pearl millet improvement programmes. The methods of analysis could be valuable for application to other complex and ill‐defined pathosystems.
The epidemiology of anthracnose disease of mango: inoculum sources, spore production and dispersal
Authors: FITZELL R. D. , PEAK C. M. 
Published: February 2008

SUMMARYAnthracnose disease spreads within mango trees by water‐borne conidia of Colletotrichum gloeosporioides var. minor. Conidia were produced in lesions on leaves, defoliated branch terminals, mummified inflorescences and flower bracts. Conidia were trapped from these sources in the orchard during periods when anthracnose disease was developing both in flush growth and in flowers. The majority of conidia were trapped from lesions in young leaves.Conidia were produced in the laboratory from acervuli in leaf lesions over a wide temperature range (10–30°C) both in wet and humid (95–97% r.h.) conditions. Conidia would be present for dispersal within the tree throughout the entire season.Large numbers of conidia were trapped during prolonged periods of rain, and when these occurred during active growth or flowering, severe outbreaks of disease were recorded. No conidia were trapped following dews.Ascospores of Glomerella cingulata var. minor were not trapped while the disease was active in the orchard. These spores do not appear to contribute to the infection cycle of mango anthracnose.
Production and field evaluation of codling moth granulosis virus for control of Cydia pomonella in the United Kingdom
Authors: GLEN D. M. , PAYNE C. C. 
Published: February 2008

SUMMARYCodling moth granulosis virus (Cp GV) was produced in larvae of Cydia pomonella reared on artificial diet. The average yield of virus (9 × 109capsules/larva) was increased by raising the larvae on diet containing methoprene, a juvenile hormone analogue.In field trials in 1978 and 1979, one or two high‐volume applications of Cp GV at 7 × 1010 capsules/litre achieved reductions in numbers of mature larvae and damaged fruit that were little different from those obtained by two applications of azinphos‐methyl. A field trial in 1980 showed that at concentrations of Cp GV ≥ 6 × 108 capsules/litre, damaged diminished slowly with increasing virus concentration. Following virus application in 1980, Cp GV infectivity was reduced by half in 3 days, but some activity persisted at least 4–8 wk after spraying. The results indicate that codling moth GV is an effective control agent particularly in reducing numbers of larvae and the more severe forms of fruit damage.
Codling moth granulosis virus: effects of its use on some other orchard arthropods
Authors: GLEN D. M. , WILTSHIRE C. W. , MILSOM N. F. , BRAIN P. 
Published: February 2008

SUMMARYIn four field trials from 1978 to 1980, sprays of codling moth granulosis virus (CpGV) plus 1·0% skimmed milk powder did not significantly affect damage to fruit by leaf rollers (tortrix moths). In laboratory tests, survival of larvae of the leaf roller Archips podana fed on leaves sprayed with CpGV plus milk was unaffected and they grew faster than on unsprayed leaves, because of the milk deposits. This might increase damage by A. podana if CpGV plus milk were applied during the feeding period of this species. In one field trial an unusual infestation of fruit by larvae of pith moth Blastodacna atra was not affected by CpGV. Azinphos‐methyl significantly reduced damage by B. atru and, in one field trial where sprays were correctly timed, that by leaf rollers. CpGV had no consistently significant effects on numbers of fruit tree red spider mite Panonychus ulmi or its predators, whereas azinphos‐methyl induced outbreaks of P. ulmi by killing its predators.
Variation among British isolates of potato leafroll virus
Authors: TAMADA T. , HARRISON B. D. , ROBERTS I. M. 
Published: February 2008

SUMMARYTwenty isolates of potato leafroll virus (PLRV) were readily transmitted by Myzus persicae from a wide range of potato cultivars to Physalis floridana. The isolates also infected Montia perfoliata but not turnip or broad bean, and all were readily detected by direct enzyme‐linked immunosorbent assay. Four isolates, selected to represent the range of differences in severity of symptoms in P. floridana, also induced symptoms of differing severity in M. perfoliata, but their virulence in one species did not necessarily parallel that in the other. In general, virus concentration increased with increasing symptom severity. None of these four isolates was transmitted readily by Macrosiphum euphorbiae and their particles were antigenically indistinguishable in gel‐diffusion precipitin tests.Further tests on one PLRV‐infected potato plant from which virus was at first not transmitted by M. persicae showed that it contained a poorly‐transmissible isolate (isolate 15). The inefficient transmission of this isolate could not be attributed to inadequate uptake or retention by M. persicae of virus from P. floridana, and aphids failed to transmit isolate 15 when it was acquired from purified preparations in membrane‐feeding tests. Although the poor aphid transmissibility of isolate 15 is therefore an intrinsic property of its particles, these were antigenically indistinguishable from the particles of readily aphid‐transmissible isolates.Immunoelectron microscopy tests showed that PLRV and beet mild yellowing virus are antigenically closely related.
Large scale production, storage and transport of the insect‐parasitic nematodes Neoaplectana spp. and Heterorhabditis spp.
Authors: BEDDING R. A. 
Published: February 2008

SUMMARYA method for producing up to 2000 million infectives of Neoaplectana bibionis per container is described and is applicable to other species of Neoaplectana and Heterorhabditis spp. The nematodes were cultured within autoclavable plastic bags, on crumbed polyether polyurethane sponge coated with chicken offal homogenate that had been sterilised and inoculated with the primary form of the appropriate symbiotic bacterium (Xenorhabdus spp.). Procedures for extracting and cleaning the nematodes on a large scale are described. Nematodes were stored and transported on clean sponge in aerated polyethylene tubes. The techniques are suitable for industrial use with little further development.
The effect of fungal parasitism and predation on the population dynamics of nematodes in the activated sludge process
Authors: GRAY N. F. 
Published: February 2008

SUMMARYNematophagous fungi, both predators and endoparasites, were found to be common components of activated sludge. Although rotifers and ciliate protozoa (both potential prey) were also abundant, no fungi were parasitic on these organisms. Endoparasitic fungi, which were far more abundant than predators, were able to infect nematodes and complete their life cycles successfully. Neither of the predatory fungi observed were able to produce conidia: an unidentified net‐forming species lived saprophytically and failed to capture any prey, although it played a minor role in the formation of microbial flocs, and a single conidium of Dactylella mammillata was observed to capture a nematode by spontaneous trap formation. Several endoparasites were recorded although single species dominated each sludge examined; these were Meria coniospora and Catenaria anguillulae. Both endoparasites were related to the population dynamics of the nematodes with 100% of the nematode population becoming infected at certain times. Clear predator (parasitetprey (host) associations were discernible and these are discussed.
Sampling conditions for reliable routine detection by enzyme‐linked immunosorbent assay of three ilarviruses in fruit trees
Authors: TORRANCE L. , DOLBY C. A. 
Published: February 2008

SUMMARYEnzyme‐linked immunosorbent assay (ELISA) was used to test plum trees for prune dwarf (PDV), Prunus necrotic ringspot (NRSV) and apple mosaic (ApMV) viruses, cherry trees for PDV and NRSV, and apple trees for ApMV. Optimum conditions were determined for sampling in large‐scale surveys for these viruses. All three viruses were detected throughout the growing season in individual samples of young leaves, or twigs with newly formed buds. However, when single infected leaves were combined with different numbers of healthy leaves, tests were most successful for all three viruses early in the growing season. PDV was detected in 1/40 (infected/total leaves) cherry leaves in April and May and 1/40 plum leaves until July, whereas NRSV was detected in 1/20 cherry leaves until July and 1/20 plum leaves until May. ApMV was detected in 1/20 apple or plum leaves until June but was detected less readily in mature leaves after June than either NRSV or PDV. There was no evidence of uneven distribution of virus infection in the trees. The viruses were detected in leaf samples kept for 8 wk at 3°C but freezing was less reliable for storage especially with ApMV. ApMV was detected in tests on plants held for several weeks at 25°C, and PDV and NRSV in plants held at 30°C.