bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of different slug species in damage to oilseed rape bordering on sown wildflower strips
Authors: FRANK T. 
Published: February 2008

Summary.Damage caused by different slug species on above and below ground parts of young oilseed rape bordering on sown wildfower strips was studied. Slug densities and damage were recorded in the field and damage rates for each slug species were measured in the laboratory. Severe slug damage was observed in rape areas 1 m from the wildflower strips. Damage rates of slug species feeding above ground were distinctly higher than those feeding below ground. The estimated damage caused by above‐ground feeding in all four study fields ranged between 72% and 89 % and was always distinctly higher than damage caused by below‐ground feeding (11% to 28 %). The estimated damage caused by Arion lusitanicus above ground was between 54% and 69 %, followed by Deroceras reticulatum (3% to 26 %). Thus A. lusitanicus was responsible for the majority of damage in the rape crops studied.
Typing Primus necrotic ringspot virus isolates by serology and restriction endonuclease analysis of PCR products
Authors: SPIEGEL S. , TAM Y. , MASLENIN L. , KOLBER M. , NEMETH M. , ROSNER A. 
Published: February 2008

SUMMARYPrimus necrotic ringspot virus (PNRSV) isolates were characterised by bioassays, serotyping and restriction fragment length polymorphism (RFLP) analysis of PCR products. Based on symptoms in host trees and bioassays it was concluded that only one of the 16 tested isolates is severe. The serotyping results demonstrated that by using four different MAbs in TAS‐ELISA the tested isolates could be divided into four subgroups, however, the severe isolate could not be singled out. RFLP analysis of PCR products supported the serotyping data but did not differentiate between isolates of the two main serological subgroups. A restriction map, derived from sequence analysis of the PCR products obtained from selected isolates, allowed exact location of the restriction sites within the PCR products of each isolate. A mild isolate with a unique genome structure was identified by both serological and RFLP assays. As far as we are aware, this is the first report on sub‐grouping of PNRSV isolates by bioassays, serotyping with MAbs and RFLP analysis.
The effect of rabbit (Oryctolagus cuniculus) grazing damage on the growth, botanical composition and yield of a ryegrass re‐seed
Authors: BELL A. C. , BYRNE P. M. , WATSON S. 
Published: February 2008

SUMMARYA perennial ryegrass sward was established in the autumn of 1989 in an enclosed 0.3 ha site and was exposed to captive wild rabbit (Oryctolagus cuniculus) grazing. Rabbit numbers were varied from 16 rabbits ha‐1 in winter to 55 rabbits ha‐1 corresponding to natural fluctuations in the field. The original sward was grown for three seasons (1989/1990 to 1990/1991) and a range of grazing regimes imposed. In 1989/1990 four grazing regimes were arranged in a replicated split block design in the experimental area. These were ungrazed, winter grazed, spring grazed and totally grazed. In the second year of the experiment all plots were exposed to grazing with the exception of the originally protected plots. This was to examine the effects of longer‐term grazing damage on a ryegrass sward. In the final year half of all treatments were protected to study recovery of a sward which had been damaged previously. The remainder of the plots were exposed to grazing.Three cuts were harvested in each year and the productivity assessed in terms of yield and botanical composition. There was a significant reduction in ryegrass proportion in grazed swards following the first winter of grazing, while clover, other grasses and weeds were enhanced. The promotion of clover content in grazed swards was a feature throughout the 3 yr of the study. In the second year, protection of grazed swards led to a restoration of yields, although the botanical composition remained altered. The exposure of previously ungrazed plots in the final year of the experiment showed that these swards were particularly attractive to rabbits and they suffered the greatest yield losses relative to the protected plots at the first cut in 1991. In this year dry weather conditions were experienced following the first cut and demonstrated that yield losses are exacerbated when rabbit grazing is compounded with adverse growing conditions. The results overall indicate that protection of ryegrass swards at the establishment phase is important, but that a degree of recovery is possible by providing protection at a later stage, although the ryegrass component is still impaired in swards which suffer early damage.
Production of Bean yellow mosaic virus resistant subterranean clover (Trifolium subterraneum) plants by transformation with the virus coat protein gene
Authors: CHU P. W. G. , ANDERSON B. J. , KHAN M. R. I. , SHUKLA D. , HIGGINS T. J. V. 
Published: February 2008

SUMMARYTransgenic lines of subterranean clover were constructed that contained three different Bean yellow mosaic virus (BYMV) coat protein (CP) gene constructs; full‐length CP, the core region of the CP, and full‐length CP plus the 3′ untranslated region of the viral genome. Transgenic plants containing the full‐length and core CP gene constructs showed high and moderate levels of BYMV resistance. Resistance was measured as a lack or amelioration of viral disease symptoms, which was correlated with a reduction in virus levels and yield loss. A range of different resistance phenotypes was observed. They included reduced infection rates, delay and reduction in local lesion development, and delay and reduction in severity of systemic symptom development. Resistance levels were not correlated with transgene mRNA levels and no transgene‐encoded protein was detected in any of the transgenic lines. This is the first example of genetically engineered virus resistance in a clover.
Interactive effect of salt (NaCl) and nitrogen form on growth, water relations and photosynthetic capacity of sunflower (Helianthus annum L.)
Authors: ASHRAF M. 
Published: February 2008

SUMMARYThe effects of the ammonium (NH4+) and nitrate (NO3‐) forms of nitrogen and NaCl on the growth, water relations and photosynthesis performance of sunflower (Helianthus annuus L.) were examined under glasshouse conditions. Eight‐day‐old plants of cv. Hisun 33 were subjected for 21 days to Hoagland's nutrient solution containing 8 mol m‐3N as NH4+or NO3‐, and salinised with 0, 60, or 120 mol m‐3NaCl. Fresh weights of shoots and roots, and leaf area of NO3‐supplied non‐salinised plants were significantly greater than those of NH4+‐supplied non‐salinised plants. But addition of NaCl to the rooting medium of these plants had more inhibitory effect on the growth of NO3‐‐supplied plants than on NH4+‐supplied plants. Both leaf water and osmotic potentials of plants grown with NH4+were lower than those of plants given NO3‐under both non‐saline and saline conditions. Chlorophylls a and b concentrations were higher in plants grown with NH4+than N03‐‐supplied plants at the lower two levels of salinisation. The rate of photosynthesis in plants was considerably higher in non‐salinised plants grown with NO3‐than with NH4+, but with increase in salinisation the photosynthesis rate decreased in NO3‐‐supplied plants, but not in those given NH4+. The rate of transpiration was increased significantly by salinisation in NO3‐‐supplied plants, but not consistently so in NH4+‐supplied plants. The stomatal conductances were much higher in plants given NO3‐than with NH4+when grown under non‐saline conditions, but not when salinised. As a consequence, water‐use efficiency in NO3‐‐supplied control plants was better than in NH4+‐supplied under non‐saline conditions, but worse under saline conditions. The different forms of nitrogen and the addition of NaCl to the growing medium did not affect the relative intercellular concentrations of CO2 (Ci/Ca). Overall, the NH4+form of nitrogen inhibited the growth of sunflowers under non‐saline conditions, but NO3‐and NaCl interacted to inhibit growth more than did NH4+under saline conditions.
Epidemiology of Leptosphaeria maculans in relation to forecasting stem canker severity on winter oilseed rape in the UK
Authors: WEST J. S. , BIDDULPH J. E. , FITT B. D. L. , GLADDERS P. 
Published: February 2008

SUMMARYIn the UK, ascospores of Leptosphaeria maculans first infect leaves of oilseed rape in the autumn to cause phoma leaf spots, from which the fungus can grow to cause stem cankers in the spring. Yield losses due to early senescence and lodging result if the stem cankers become severe before harvest. The risk of severe stem canker epidemics needs to be forecast in the autumn when the pathogen is still in the leaves, since early infections cause the greatest yield losses and fungicides have limited curative activity. Currently, the most effective way to forecast severe stem canker is to monitor the onset of phoma leaf spotting in winter oilseed rape crops, although this does not allow much time in which to apply a fungicide. Early warnings of risks of severe stem canker epidemics could be provided at the beginning of the season through regional forecasts based on disease survey and weather data, with options for input of crop‐specific information and for updating forecasts during the winter. The accuracy of such forecasts could be improved by including factors relating to the maturation of ascospores in pseudothecia, the release of ascospores and the occurrence of infection conditions, as they affect the onset, intensity and duration of the phoma leaf spotting phase. Accurate forecasting of severe stem canker epidemics can improve disease control and optimise fungicide use.
Effects of cyromazine and abamectin on the leafminer, Liriomyza huidobrensis and its parasitoid, Diglyphus isaea in celery
Authors: WEINTRAUB PHYLLIS G. 
Published: February 2008

SUMMARYField trials were conducted for 2 yr on celery (Apium graveolens L.) to determine the effects of two translaminar insecticides (abamectin and cyromazine) on the agromyzid leafminer, Liriomyza huidobrensis (Blanchard), and the eulophid parasitoid, Diglyphus isaea Walker. Abamectin and cyromazine were applied once early in the growing season by spray or drip application. Yellow sticky traps and leaf samples were used to monitor population levels; a gas chromatograph‐mass spectrometer was used to monitor cyromazine residues within the celery plants during 1 yr. Spray applications of abamectin and cyromazine significantly reduced larval leafminers and D. isaea. Contrary to grower practices, application of cyromazine by drip irrigation systems had minor effects on larval leafminer and D. isaea as compared to spray application. Cyromazine residues in the plants treated by spray application declined sharply after 1 wk, and no residues were detected 2 wk after application; less than 0.05 ppm cyromazine residues were detected in plants treated by drip application. Implications of these results on management practices are discussed.
Host‐plant susceptibility to the carrot fly, Psila rosae. 1. Acceptability of various host species to ovipositing females
Authors: DEGEN THOMAS , STÄDLER ERICH , ELLIS P R 
Published: February 2008

SummaryA preference hierarchy of the oligophagous carrot fly for 30 umbelliferous host‐plant species or varieties and six non‐hosts was assessed. Foliage of the test plants was presented to a laboratory population of the fly in oviposition choice experiments together with leaves of a standard plant, the susceptible carrot cultivar “Danvers”. Only two species (Anthriscus cerefolium, Carum carvi) were more acceptable than the standard plant, while about half the species received significantly fewer eggs. Some umbellifers (Anethum graveolens, Pimpinella major) had a low acceptability similar to that of non‐hosts (non‐umbelliferous plants). The results obtained with dual and multiple choice assays were in agreement. A multiple choice assay with potted plants yielded a similar ranking of the species as assays using detached leaves, indicating that foliage is representative for whole plants. Variability in the exploratory runs performed by the females on the leaves prior to egg‐laying is described and quantified for hosts and non‐hosts. Differences in post‐alighting pre‐ovipositional behaviour of the female flies on the leaves accounted for a major part of the variation recorded in egg‐laying.
Somatic chromosome number doubling of selected potato genotypes using callus culture or the colchicine treatment of shoot nodes in vitro
Authors: MAINE M J DE , SIMPSON GAIL 
Published: February 2008

SummaryExperiments were carried out to double the somatic cell chromosome numbers of a monoploid and dihaploid of Solanum tuberosum and a genotype of S. circaeifolium subsp. quimense. Colchicine was used in vitro on shoot nodes from which the axillary meristems had been removed. Plants with doubled chromosome numbers were obtained from shoots grown from the tertiary, sub‐axillary meristems of all three genotypes. The callus culture of stem and leaf explants was found to produce more shoots with doubled chromosome numbers than the colchicine treatment in the case of the dihaploid and quimense genotypes but no shoots were obtained from callus culture of the monoploid.Fifty‐two % of the shoots from the dihaploid and 63% from the quimense clone were ploidy doubled in the case of the best callus culture system. Using a sub‐lethal dose of colchicine, the dihaploid yielded 37% ploidy‐doubled shoots whereas all the shoots produced from the monoploid were doubled and the quimense clone produced 27% doubled plants.Callus culture was highly dependent upon the type of growth medium and other, unknown, factors. The colchicine treatment, although yielding fewer products, was more reliable for achieving ploidy doubling in selected clones if the number of plants produced is not important.
The development of an action threshold for cabbage aphid (Brevicoryne brassicae) in oilseed rape in the UK
Authors: ELLIS S A , OAKLEY J N , PARKER W E , RAW K. 
Published: February 2008

SummaryReplicated small plot field experiments were done at two sites growing winter oilseed rape (ADAS Boxworth, Cambridgeshire and ADAS High Mowthorpe, North Yorkshire) and two sites growing spring oilseed rape (ADAS Bridgets, Hampshire and ADAS Rosemaund, Herefordshire) to investigate the effect of cabbage aphid (Brevicoryne brassicae) on crop yield and quality. All four sites were included in the first 2 yr of the experiment in 1994 and 1995 but only those with winter oilseed rape were continued into the final year in 1996. Plots were artificially inoculated with cabbage aphids at either five aphid 4 m‐2 or 5 aphids 16 m‐2 or left uninoculated to become naturally infested. In 1995 and 1996 the naturally infested treatment was omitted. Sprays of the aphicide pirimicarb at GS 3.3, 3.7, 4.5, 4.9 and 5.5 were used to manipulate aphid populations. Once a plot had been treated at a target growth stage it was sprayed on all subsequent occasions to prevent recolonisation. Aphid numbers were assessed prior to each spray date and their effect on the crop measured in terms of yield of seed and oil and glucosinolate content. Artificial inoculation of aphids was often successful in establishing different populations of the pest at a range of growth stages. Results showed that cabbage aphid sometimes reduced both crop yield and quality. Yield responses to insecticide treatment tended to be larger in spring oilseed rape than in winter oilseed rape mainly because it became more heavily infested at an early growth stage. Tentative thresholds are proposed for control of the pest in both winter and spring oilseed rape. It is stressed that cabbage aphid is a sporadic pest and rarely likely to reach these threshold levels in field crops.
Comparison of responses of ascospores and mycelium by ELISA with anti‐mycelium and anti‐ascospore antisera for the development of a method to detect Sclerotinia sclerotiorum on petals of oilseed rape
Authors: JAMAUX‐DESPRÉAUX ISAB E LLE , SPIRE DIDIER 
Published: February 2008

SummaryThe goal of this project was the development of a serological test for the detection of Sclerotinia sclerotiorum on oilseed rape petals. Since the fungus exists in two forms on petals, as ascospores and mycelium, the responses of anti‐mycelium and anti‐ascospore antisera against these two kinds of antigens were compared. Two anti‐mycelium sera, Smy and Smy', were produced against mycelial soluble extracts at different concentrations (0.3 mg and 0.1 mg of protein ml‐1). Smy gave the greatest response level with eight S. sclerotiorum mycelial extracts tested. It had a very superior level of recognition to that of anti‐ascospore serum, Ssp, when mycelium was tested as antigen. In contrast, Ssp and Smy were equally reactive when exposed to ascospores but the sensitivity of the assay was low. For each antiserum, the solution from which ascospores had been removed reacted similarly to the original suspension containing ascospores. A collection of fungi likely to be found on oilseed rape petals was examined. Cross‐reactions were produced with both antisera, especially with Botrytis cinerea for which greater cross‐reactivities were produced with Smy. The cross‐absorption of antiserum Smy with a mycelial extract of B. cinerea considerably reduced this cross‐reaction. The choice of antiserum for the development of a reliable detection system is discussed.
Basal fertiliser application method, tuber initiation nitrogen, foliar NPK and the tolerance of potatoes to infection by the potato cyst nematodes Globodera rostochiensis and G. pallida
Authors: GROVE I G , HAYDOCK P P J , EVANS K. , LEWIS D J 
Published: February 2008

SummaryThe effects of broadcast granular, placed liquid and foliar fertilisers on the tolerance of potatoes to infection by potato cyst nematodes were investigated. The tolerance of the potato cv. Pentland Dell was not significantly improved by fertiliser application type but placed liquid fertiliser, with or without foliar applications, increased the concentrations of N, P and K measured in whole plant dry matter of PCN infected plants. The tolerance of the potato cv. Sante was not statistically improved by altering the balance of fertiliser nitrogen applications between planting and tuber initiation or by applying foliar nitrogen. Nitrogen applications of 120 kg N ha‐1 at planting and a further 120 kg N ha‐1 at tuber initiation supplemented with foliar N, however, achieved a larger tuber yield than the same nitrogen programme without foliar N and gave a significantly greater yield than the application of 240 kg N ha‐1 at planting plus foliar N. The emergence of both cultivars was delayed in the absence of oxamyl. N, P and K concentrations within whole plant dry matter were significantly higher in plants from oxamyl treated plots and both N and K concentrations were significantly increased by increasing the quantity of N at planting, at 56 DAP. Splitting the fertiliser N between planting and tuber initiation appears to be important in maintaining the availability of this nutrient to PCN infected plants throughout the season.
Effects of sulphur dioxide preservation of flax straw on fibre components and microbial colonisation during dew‐retting
Authors: SHARMA H S S , McCALL R D , FAUGHEY G. , LYONS G. 
Published: February 2008

SummaryThe changes in flax straw structure when treated with sulphur dioxide (SO2) and consequent effect on dew‐retting of the treated straw were investigated. The active oxoanions released by sulfurous acid degraded phenolics bound to the polysaccharides and lipids leading to an increase in water‐soluble carbohydrates and polyphenols. As a result, proportions of hemicellulose, nitrogen, sulphur, ash and caustic weight loss were higher in treated straw while lipid was reduced. The coarseness of treated fibre was possibly caused by in situ dryback of the hydrolysed polysaccharides. The deposition of salts containing high concentrations of sulphur, calcium and potassium in the vicinity of the fibre bundles and epidermal layer was observed and investigated. In a dew‐retting trial comprising SO2‐treated and untreated samples, the SO2 treatment delayed microbial colonisation and, consequently, retting by nearly 2 wk compared to the controls. The changes in pH, fungal population and polysaccharide degrading enzymes were monitored. The differences in fibre yield, fineness and strength are presented.
The response of alpha‐amylase activity during wheat grain development to nitrogen fertiliser
Authors: KETTLEWELL P S 
Published: February 2008

SummaryThe aim of this study was to test whether the effect of nitrogen fertiliser on Hagberg falling number of winter wheat (Triticum aestivum) grain in the absence of sprouting is mediated by pre‐maturity alpha‐amylase activity and is related to grain drying rate. A field experiment with two cultivars (Avalon and Mercia) in 1990 and 1991 compared four application rates of nitrogen. Samples of grain were taken at intervals during development for moisture determination and alpha‐amylase assay. Grains from plots given nitrogen dried faster in both years, but alpha‐amylase activity and Hagberg falling number responded differently to nitrogen in the two years. In the warmer and drier year of 1990, alpha‐amylase activity declined throughout development leading to very high Hagberg falling number at harvest, with little effect of nitrogen. In the cooler and wetter year of 1991, alpha‐amylase activity declined until about 30% moisture. After this stage, alpha‐amylase activity increased in the absence of sprouting in grain from plots receiving little or no nitrogen. This resulted in a linear increase in Hagberg falling number in response to nitrogen fertiliser. Electrophoresis of alpha‐amylase isozymes indicated that the increase in Hagberg falling number in response to nitrogen was not mediated by a decrease in retained pericarp alpha‐amylase activity, but by a reduction in pre‐maturity alpha‐amylase activity. These results support the hypothesis that slow grain drying enhances pre‐maturity alpha‐amylase formation, and also support the hypothesis that an additional environmental factor varying between seasons is involved in pre‐maturity alpha‐amylase formation.
Effects of sheath tube length on leaf development in perennial ryegrass (Lolium perenne L.)
Authors: CASEY I A , BRERETON A J , LAIDLAW A S , McGILLOWAY D A 
Published: February 2008

SummaryPosition in and contribution of leaf laminae to the canopy of forage grasses are important both in determining herbage growth rates and intake rate by grazing animals. These canopy characteristics are controlled by the way dry matter is apportioned between sheath and lamina in growing leaves. The objective of this work was to determine how the development of individual leaves is affected by altering the effective length of the psuedostem tube, on the assumption that the light environment within the tube varied. The development of a leaf from initiation at the apex to maturity was followed by successive destructive dissections of tillers. Vertical incisions were made in the pseudostem of each tiller to three different depths. The three treatments imposed were — no incision (control), moderate and severe incision of the sheath length. Destructive harvests of tillers followed 3, 6, 12 and 24 days after imposition of treatments. Incision resulted in the length of the monitored leaf being reduced significantly at all harvests, and differentiation of the sheath beginning earlier. The length reduction reflected a reduction in both cell size and cell number and the effects were evident at the earliest harvest. The data support the theory that leaf size and timing of onset of sheath development are influenced by the environment of the developing leaf. The present results indicate that sheath tube length affects leaf development and suggests that the effects are substantially explained by a direct light effect on the location and depth of the elongation zone.