bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forecasting the airborne spread of Mycosphaerella fijiensis, a cause of black Sigatoka disease on banana: estimations of numbers of perithecia and ascospores
Authors: BURT P. J. A. , ROSENBERG L. J. , RUTTER J. , RAMIREZ F. , GONZALES O H 
Published: February 2008

SUMMARYBanana leaves showing different levels of black Sigatoka disease were collected from an unsprayed plantation in Costa Rica during two separate periods representing the wet to dry season transition (October 1993 – February 1994) and the dry to wet season transition (April – September 1995). Laboratory studies were used to investigate the relationship between the release of Mycosphaerella fijiensis ascospores and the amount of inoculum on banana plants showing different levels of infection, as assessed by leaf necrotic area. The number of perithecia present in the necrotic area was used as an indication of potential ascospore loads and was investigated as a series of regression equations. A series of rewetting and incubation regimes was used to investigate spore release under field conditions (21°C and 100% relative humidity in the early morning and 28°C, 60% relative humidity on days when it rained in mid‐afternoon). Results suggest that rainfall, combined with a high temperature, may lead to peaks of ascospore release but without necessarily increasing overall numbers released over periods of up to 4 days and that a high level of spore release was less sensitive to changes in temperature once it had been initiated. The exact role of temperature in spore release is still unclear, however, as leaf samples kept at atypically low temperatures also released non‐germinating ascospores. An average of 4.5 ascospores was released per perithecium. This does not resolve ambiguities in the literature regarding the number of ascospores present in each perithecium. A linear model relating the average ascospore numbers and necrotic area, using quick estimates of the amounts of necrotic area on the leaves of a random sample of plants across a plantation, is proposed, to give an indication of the relative amount of airborne inoculum potentially available between different plantations.
Long‐term effects of asparagus virus 2 infection on growth and productivity in asparagus
Authors: JASPERS M. V. , FALLOON P. G. , PEARSON M. N. 
Published: February 2008

SUMMARYAn asparagus field trial was established with clonal plants to determine the long‐term effects of asparagus virus 2 (AV2) infection on spear production. Yield data, analysed by ANOVA, showed that AV2 infection caused significant (P < 0.05) decreases in spear yield which became more pronounced as the trial progressed. Mean marketable spear yields were reduced by 14%, 28%, 20%, 48% and 57% and reject spear yields were increased by 93%, 105%, 207%, 352% and 167%, during harvest years 1–5 respectively. Marketable spear yields from AV2–free plants increased annually to yr 5, but for AV2–infected plants, yields increased to yr 3 and decreased annually thereafter. Spears from AV2–infected plants were thinner than those from AV2–free plants, resulting in more reject thin spears by 109%, 88%, 220%, 499% and 216% during harvest yr 1–5, respectively. Further, data collected in yr 4 and 5 showed that AV2 infection had caused a 31 % reduction in mean spear diameter and reductions of 27% and 22% respectively, in diameter and height of fern stalks. Clearly, plants with smaller fern stalks were less able to accumulate carbohydrate reserves and therefore produced fewer, smaller spears and fern stalks the following spring. This may result in annual cycles of diminishing productivity in which the size and number of spears and fern stalks decrease with each successive year. The type and timespan of symptoms caused by AV2 infection in this trial are similar to those reported for asparagus decline syndrome and therefore it is likely that AV2 infection is a factor contributing to asparagus decline.
Effects of turnip mosaic virus and turnip yellow mosaic virus on the survival, growth and reproduction of wild cabbage (Brassica oleracea)
Authors: MASKELL L. C. , RAYBOULD A. F. , COOPER J. I. , EDWARDS M‐L , GRAY A. J. 
Published: February 2008

SUMMARYWild plants of Brassica oleracea (wild cabbage) are commonly infected with turnip mosaic poty virus (TuMV), turnip yellow mosaic tymovirus (TYMV) and several other viruses. A field experiment in which plants were inoculated either with TuMV or TYMV showed that virus infection significantly reduced survival, growth and reproduction. Relative to water inoculated‐controls, plants infected with TYMV had greater mortality, were shorter, had a smaller leaf area and number, showed a greater amount of damage from herbivory and chlorosis, were less likely to flower and produced fewer pods and lower total seed output. Plants infected with TuMV did not appear to be adversely affected at first; however, mortality after 18 months was higher than control plants. Although TuMV infection had no effect on the number of plants flowering, the infected plants did produce fewer pods and a lower total seed output. We conclude that both viruses can significantly affect vegetative and reproductive performance of wild cabbage and hence that introgression of virus resistance (particularly when conferred by a major gene or a transgene) from a crop might increase plant fitness in natural populations of this species. Ecological risk assessments of virus resistance transgenes must do more than survey adult plants in natural populations for the presence of the target virus. Failure to detect the virus could be due to high mortality on infection with the virus.
Mode of action of fosthiazate used for the control of the potato cyst nematode Globodera pallida
Authors: WOODS S. R. , HAYDOCK P. P. J. , EDMUNDS C. 
Published: February 2008

SUMMARYFosthiazate (Nemathorin 10G Ishihara Sangyo Kaisha Ltd, Japan) is a new nematicide approved for use on potatoes Solanum tuberosum L. in die UK for die control of die potato cyst nematodes Globodera rostochiensis (Woll). Skarbilovich and G. pallida (Stone). Fosdiiazate delayed and suppressed hatch of die potato cyst nematode Globodera pallida in bom in vitro laboratory tests and a glasshouse pot experiment. In vitro hatch was temporarily inhibited by fosdiiazate concentrations above 0.09 μg ml‐1 and increasing me fosdiiazate concentration further prolonged the duration of hatch inhibition. Analysis of fosthiazate soil concentrations, using high‐pressure liquid chromatography, during me glasshouse experiment showed mat hatch was suppressed in the soil at concentrations above 0.5 mg kg‐1. Other factors such as the paralysis of hatched nematodes in the soil solution are also involved.
Temperature and heterogeneity of emergence time in oilseed rape
Authors: SQUIRE G. R. 
Published: February 2008

SUMMARYEmergence of oilseed rape cultivars with known differences in germination profile was examined by controlled sowings in the field at mean temperatures between 2 and 10°C. Early percentiles, up to the 50th in two cultivars (Rocket and Martina) and up to the 20th in a third (Comet), responded to temperature similarly at all sowings, in that 1/time to emergence of a percentile (emergence rate) increased exponentially with temperature above an intercept of‐1°C. For these percentiles, emergence occurred at a similar thermally weighted time over the whole range of temperature, indicating the peak of the first flush of seedlings is predictable. Percentiles higher than those cited above displayed increasing non‐germination (probably secondary dormancy) as temperature declined towards winter. The maximum non‐germination ranged between 50% and 80% among the cultivars. In sowings during and just after winter, the emergence rate of these higher percentiles was lower than at a comparable temperature before winter. A portion of non‐germinating seeds of the two most heterogeneous cultivars overwintered and emerged synchronously in April from a range of pre‐ and post‐winter sowings, probably stimulated by increasing diurnal temperature amplitude from 7 to 15K. At low temperature, therefore, cultivars exhibited great heterogeneity in the emergence profile, those with more heterogeneity being more likely to give rise to temporally separate weed or feral populations. The findings are discussed in the context of weediness and transgene movement in the oilseed rape metapopulation.
Molluscicidal and slug‐repellent properties of anaerobically digested organic matter
Authors: SPEISER B. 
Published: February 2008

SUMMARYSlug problems in arable crops and vegetables have increased drastically during the past few decades. Observations on slug damage to oilseed rape suggested that fresh, anaerobically digested organic material from a biogas production plant is molluscicidal. To find out whether digested matter can be used for the control of agricultural pest slugs, a series of exeriments were carried out. The laboratory experiments demonstrated strong mollusc repellent and molluscicidal effects of digested organic matter against the three most important pest slugs of Switzerland,Arion lusitanicus, A. distinctusandDeroceras reticulatum.The effects were restricted to fresh digested matter and were rapidly lost when the material was stored, and also after application in the field. In the field experiment, fresh digested matter greatly reduced slug damage to lettuce in comparison with the untreated plots. At present, the chemical nature of the molluscicidal compound(s) in digested matter is unknown, but environmental pollutants such as heavy metals can be ruled out. Current research aims at a new formulation which is easier to apply and has a longer‐lasting molluscicidal or slug‐repellent effect, and at optimising the dosage and number of applications.
Capture efficiency of insect natural enemies from tall and short vegetation using vacuum sampling
Authors: HOSSAIN Z. , GURR G. M. , WRATTEN S. D. 
Published: February 2008

SUMMARYExperiments were conducted in lucerne to determine the efficiency of vacuum sampling of insects and whether this was affected by the height of vegetation sampled. Three insects of significance as predators of pests in Australian lucerne were studied: transverse ladybird beetle (Coccinella transversalisFabricius), pollen beetle (Dicranolaius bellulus(Guérin‐Méneville)), and spined predatory shield bug (Oechalia schellembergii(Guérin‐Méneville)). In a preliminary experiment comparing a commercially harvested area of lucerne with an unharvested area within the same crop, the proportions of released insects recaptured from unharvested lucerne were significantly lower than recoveries from the shorter, harvested lucerne. Resampling the tall lucerne after it was cut by hand gave cumulative recapture proportions which did not differ from those observed for the harvested lucerne. A second experiment with a randomised replicated design re‐tested the hypotheses of the preliminary experiment for two insect species. Very similar results were obtained. This verification showed that recapture efficiencies from tall lucerne ranged between 0.60 and 0.74 but that resampling after hand cutting gave cumulative recapture proportions in excess of 0.86 which did not differ from recapture proportions from short lucerne.
Discrimination of cachexia disease agents among citrus variants of hop stunt viroid
Authors: REANWARAKORN K. , SEMANCIK J. S. 
Published: February 2008

SUMMARYDescription of a cachexia disease specific oligonucleotide is presented which may be employed as a probe in molecular hybridisation as well as a primer in reverse transcriptase‐polymerase chain reaction (RT‐PCR) procedures to segregate cachexia‐inducing citrus viroids (CVd) from the non‐cachexia variant, CVd‐IIa, known to introduce commercially desirable effects on tree growth and performance. The cachexia‐specific probe also demonstrates the ability to discriminate between the severe cachexia variants, CVd‐IIb and CVd‐IIc, and moderate to mild variants, Ca903 and Ca909.
Comparison of subjective and objective methods to assess flax straw cultivars and fibre quality after dew‐retting
Authors: SHARMA H. S. S. , FAUGHEY G. J. 
Published: February 2008

SUMMARYSubjective and objective methods were compared for the assessment of the quality of unretted and retted straw, and the fibres obtained after dew‐retting of four flax cultivars, Ariane, Evelin, Laura and Viola. Maturity of straw, degree of retting, ease of decortication after retting, divisibility, handle, cleanliness and colour were assessed as subjective factors and of these, degree of retting and handle appear to be useful for assessing quality. The samples were also analysed for physical and chemical differences using a range of objective methods. Straw quality could not be graded using height and maturity, although stem diameter and technical length could indicate quality. Changes in N, lipid and ash content, as a result of retting, were observed. The increase in the proportions of fibre fractions present in retted compared with unretted straw, due to microbial degradation of pectin, could be identified by thermal analysis. Analyses of the fibre samples to determine fineness, strength, cellulose, hemicellulose, lignin and minerals were carried out and significant differences in some of the parameters were identified. Cultivar Laura produced the best fibre. Fibre fineness, ash, lipid, caustic weight loss and fibre fractions as determined by thermal analysis were found to be important objective parameters for quality assessment. The assessment of fibre samples performed subjectively by an expert grader and by selected objective methods gave similar quality rankings.
A laboratory assessment of the relative susceptibility of Molinia caerulea (L.) Moench and Calluna vulgaris (L.) Hull to a range of herbicides
Authors: MILLIGAN A. L. , PUTWAIN P. D. , MARRS R. H. 
Published: February 2008

SUMMARYThere is a concern that Molinia caerulea (L.) Moench may be increasing in upland moorland communities at the expense of Calluna vulgaris (L.) Hull and other ericaceous species. In order to develop a strategy for the control of Molinia, laboratory studies were carried out to determine the dose‐response relationships of seven graminicides and glyphosate on both Molinia caerulea and Calluna vulgaris. Plants were grown under laboratory conditions and sprayed with increasing doses of herbicide using a precision sprayer. Results were highly variable, indicating the great morphological plasticity of these two species, making determination of the ED50 difficult. Glyphosate, quizalofop‐ethyl and sethoxydim successfully reduced various measures of Molinia growth to 50% of control levels (ED50 estimates ranged from 0.41–0.67 kg a.i. ha‐1, 0.18–1.20 kg a.i. ha‐1and 0.37–0.49 kg a.i. ha‐1respectively). In contrast, only glyphosate reduced Calluna growth significantly (ED50s ranged from 0.025–0.45 kg a.i. ha‐1), whilst selective herbicides left it undamaged. A comparison of the results for Molinia and Calluna suggests that there is no application rate of glyphosate which will reduce Molinia effectively whilst leaving Calluna undamaged. Recommendations for field testing of selective herbicides are discussed.
The effects of priming treatments using seaweed suspensions on the water sensitivity of barley (Hordeum vulgareL.) caryopses
Authors: MÖLLER M. , SMITH M. L. 
Published: February 2008

SUMMARYTwo seaweed suspensions, one prepared fromAscophyllum nodosum(Linnaeus) Le Jolis (ANS), another fromLaminaria hyperborea(Gunn.) Foslie (LHS), were evaluated for their effects on the water sensitivity of barley (Hordeum vulgareL.) seeds. Priming in either seaweed suspension did not reduce viability. Priming in ANS was beneficial to seeds germinated in elevated water levels. The suspension ofA. nodosumreduced the water sensitivity of barley seeds better than either water or polyethylene glycol (PEG) priming treatments. ANS also reduced the microbial population on the seeds by 86%. The hygroscopic properties and the antibiotic effect of the suspension ofA. nodosumresulted in greater oxygen availability to the embryo, enabling more seeds to germinate under oxygen deficient conditions.
Floral biology of ‘Bulida’ apricot trees subjected to postharvest drought stress
Authors: RUIZ‐SANCHEZ M. C. , EGEA J. , GALEGO R. , TORRECILLAS A. 
Published: February 2008

SUMMARYDrip irrigated ‘Búlida’ apricot trees (Prunus armeniaca L., on Real Fino apricot rootstock) were submitted to drought stress by withholding irrigation for two different postharvest periods for two consecutive years. The first treatment (T–1) started immediately after harvest, and lasted 11/2 months, while the second treatment (T–2) started when the first treatment finished and lasted 2 months. These stress treatments were compared with a control treatment (T–0), which was irrigated throughout the year so that it received an amount of water equivalent to 100% of the crop evapotranspiration (ETc) demand. Flowers from the three treatments showed similar quality (fresh weight, petal surface area and pistil length) and frequent macrostyle (stigma located above the anthers). A lower percentage of pollen germination was observed in grains from the following year's bloom in plants from the T–1 treatment. The T–1 drought stress also induced a significant decrease in fruit yield, due to an increase in fruitlet drop, which led to significantly lower fruit set. The T–2 treatment did not affect these processes and was not critical as regards apricot yield. The fruits harvested met the required standards of quality in all treatments.
Rice Ragged Stunt Oryzavirus: role of the viral spike protein in transmission by the insect vector
Authors: GUOYING ZHOU , XIONGBIN LU , HUIJUAN LU , JUANLI LEI , SHENGXIANG CHEN , ZUXUN GONG 
Published: February 2008

SUMMARYA 39 kDa protein, known as the viral spike protein or one of the protein components forming the viral spike, encoded by genomic segment 9 (S9) of Rice Ragged Stunt Oryzavirus (RRSV) was obtained by enzymatic cleavage of a fusion protein expressed by S9 cDNA in bacteria with proteinase factor Xa. The feeding of an insect vector — the rice brown planthopper (Nilaparvata lugens) on purified expressed 39 kDa protein before the inoculation of the insects on diseased rice plants could completely inhibit the vector transmission ability of the insect. The presence of a 32 kDa insect cell membrane protein which could bind to 39 kDa viral spike protein indicated that the inhibition might be resulted from the competition in the interactions of 39 kDa protein and intact virus with the virus receptors on the insect cells. These results suggest that the spike proteins of the plant reoviruses are essential for the virus infection in the interactions of virus, insect vectors and host plants. These results are also useful in the practical applications.
Detection of wheat‐alien recombinant chromosomes using co‐dominant DNA markers**
Authors: KHAN IMTIAZ AHMED 
Published: February 2008

SUMMARYA study of homoeologous recombination along almost the complete genetic length of two homoeologous chromosomes in the Triticeae was conducted. Sears' phlb mutant was used to induce homoeologous pairing between chromosomes 7A of common wheat and 7Ai–l of Agropyron intermedium. 390 ph1b ph1b homozygous F3 progeny were screened using six co‐dominant DNA markers (RFLP loci). 63 of the progeny (16%) were putative recombinants, showing dissociation of RFLP markers within the arm(s). Progeny tests of self‐fertile putative recombinants confirmed the dissociation phenotypes observed in the F3 progeny. No recombination could be confirmed in 117 F3 progeny plants having the Ph1– allele (control population). Frequencies and distribution of chiasmata along the chromosome arm 7AS were analysed using additional RFLP markers. The patterns of recombination between the two homoeologous chromosomes were found similar to those reported for homologous recombination between the same markers on short arms of group 7 chromosomes of Triticeae.
Cell cycle inhibition of potato root tips treated with Imazethapyr
Authors: SPACKMAN V. M. T. , COBB A. H. 
Published: February 2008

SUMMARYImazethapyr inhibits the progression of the cell cycle in potato (Solanum tuberosum L.) root tips. A variety of existing methods were developed and adapted for the determination of mitotic index in potatoes. Significantly lower numbers of mitotically dividing cells were recorded after just 30 min of incubation with imazethapyr (0.35 μM) and the effect was characterised as an inhibition of mitotic entry. Imazethapyr inhibits a key enzyme in the biosynthesis of the branched‐chain amino acids, valine, leucine and isoleucine. The inhibition of mitotic entry can be considered to be a secondary manifestation of a primary metabolic change induced by imazethapyr.
A review of the status of the New Zealand flatworm in the UK
Authors: CANNON R. J. C. , BAKER R. H. A. , TAYLOR M. C. , MOORE J. P. 
Published: February 2008

SUMMARYThe indigenous terrestrial planarian fauna (three species) of the UK is outnumbered by introduced exotics, of which there are at least nine species. The New Zealand flatworm,Arthurdendyus triangularis, is one of the most widespread and apparent of these non‐indigenous earthworm predators, particularly in Northern Ireland and central Scotland. Despite its having been in the UK for at least 35 yr, our knowledge of the biology and ecology of this species remains somewhat limited.In Scotland,A. triangularisoccurs predominantly in botanical and domestic gardens, and is not generally considered to be a problem on agricultural land. The situation in Northern Ireland is different; although predominantly found in domestic gardens, it appears to have colonised grass leys many localities although the impact on earthworm populations remains ambiguous. In England, records are increasing, predominantly from northern regions.Studies have indicated that earthworm species vary in terms of their vulnerability to predation byA. triangularis;surface‐active and anecic species are considered to be most at risk. However,A. triangulatusand earthworm populations are known to coexist, apparently in a state of dynamic equilibrium, in a number of localities.Naturally‐occurring planarian populations are often severely constrained by food supply, but individuals survive lengthy periods of starvation. Such behaviour may preclude the natural recolonisation of habitats by prey species. Very much higher rates of population growth can be achieved where food is not limited, and where favourable conditions result from horticultural practices. The mobility of the prey species may determine the dispersal strategy of the flatworm predator, and a propensity not to move away from centres of prey density might account for the relatively low rate of colonisation of agricultural land byA. triangulatus.Additionally, reliance on protected refuges, may explain the present, somewhat limited distribution in the UK, particularly in southern England.It is difficult to estimate the potential distribution ofA. triangulatus, because of the lack of fundamental knowledge of its ecoclimatic requirements. A better understanding is needed of the precise habitat requirements (and constraints) ofA. triangulatus, particularly where this species appears to have adapted to rural conditions.