bluuebunny/crossref_metadata_2025_split huggingface dataset:
Competition between effective and ineffective bradyrhizobia nodulating peanuts (Arachis hypogaea)1
Authors: BYALEBEKA J. B. , WYNNE J. C. , SCHNEEWEIS T. J. , ELKAN G. H. 
Published: February 2008

SUMMARYThe competitive ability of effective and ineffective isolates of Bradyrhizobium to form nodules on four peanut (Arachis hypogaea) genotypes from which they were originally isolated was investigated in a greenhouse study. Pregerminated seeds of each genotype were inoculated with five ratios of ineffective effective bradyrhizobia: 104:0, 104:102 104:104 102:104 and 0:104. Plants were harvested 35 days after planting and nitrogenase activity, total nodule number per plant, plant shoot dry weight and the proportion of nodules formed by each Bradyrhizobium isolate were determined. Nodulation suppression occurred on plants inoculated with the mixed cultures, especially on those inoculated with the 104:102 ineffective effective inoculum ratio. More than 85% of the nodules on plants inoculated with the 104:104 and 102:104 ineffective effective Bradyrhizobium mixtures were formed by the effective isolates. The number of effective nodules per plant, nitrogenase activity and plant shoot dry matter production all increased with the proportion of the effective bradyrhizobia in the inocula.
Ice‐nucleation on kiwifruit
Authors: YOUNG J. M. 
Published: February 2008

SUMMARYIce‐nucleating capability of the kiwifruit vine, Actinidia deliciosa, was examined. Pseudomonas viridiflava, present as an epiphyte on the vine, was an effective icenucleating agent. The presence of other sources of ice nuclei on the surface of the vines, leaves and fruit, which could not be inhibited by anti‐bacterial agents, was also demonstrated.
Effect of osmotic priming, rinsing and storage on the germination and emergence of carrot seed
Authors: DEARMAN JANE , DREW R. L. K. , BROCKLEHURST P. A. 
Published: February 2008

SUMMARYCarrot seed, osmotically primed in polyethylene glycol solution (273 g/kg water) for 10 days at 15°C, was given 0–5 rinsing cycles, where each cycle comprised agitating the seed in 10 times its own bulk volume of distilled water for 20 to 30 s.Priming decreased the germination and emergence times whether the seeds were rinsed or not, and these effects were maintained even after storage for 450 days. The number of rinsing cycles had no effects, except that seed given five rinsing cycles deteriorated after 270 days storage.
Distribution of Rhopalosiphum padi (Hornoptera: Aphididae) on spring barley plants
Authors: WIKTELIUS S. 
Published: February 2008

SUMMARYThe distribution of Rhopalosiphum padi on spring barley plants in the field and the laboratory is described. Aphids fed mainly on the lower parts of the plants in both the field and the laboratory. A relatively large proportion of the field population was found beneath the soil surface early in the season. In the laboratory, aphids preferred the stem base and auricles of young and old plants respectively. The highest soluble nitrogen concentration was found in the stem base of young plants. The aphids avoided temperatures above 25°C in a temperature gradient (20°C‐40°C). The soil surface temperature in a barley stand can reach lethal levels for aphids during clear days early in the season. It is concluded that the preference of R. padi for the lower part of young spring barley plants is mainly a consequence of the stem base being the most nutritious part of the plant and that a harsh microclimate possibly forces the aphids beneath the soil surface. This tendency to feed near or below soil level must be taken into account when assessing field densities of R. padi.
The role of grasslands in the yearly life‐cycle of Rhopalosiphum padi (Homoptera: Aphididae) in Sweden.
Authors: WIKTELIUS S. 
Published: February 2008

SUMMARYThe population density of the bird cherry‐oat aphid (Rhopalosiphum padi) was monitored in spring sown barley and in grasslands (leys and pastures) and a suction trap was used to monitor the flight periodicity of the aphids. Emigrants from the primary host (bird cherry) colonised both grass and cereals in spring and a migration from cereals to grasses took place in mid‐summer. There was a negative correlation between the sizes of summer and autumn migration. There was a positive relationship between late summer growth in leys and the size of autumn migrations. It is concluded that the size of the autumn migration is mainly dependent on aphid population growth in grasslands during late summer and autumn.
Association of Phoma aquilina and Ascochyta pteridis with curl‐tip disease of bracken
Authors: IRVINE J. I. M. , BURGE M. N. , McELWEE MARION 
Published: February 2008

SUMMARYMany spores of Phoma aquilina and Ascochyta pteridis were rinsed from dry infected litter obtained from a site where curl tip was prevalent. More spores were released from litter which had been incubated under moist conditions for 24 h before rinsing. P. aquilina, known to cause curl‐tip symptoms in bracken when inoculated via wounds (McElwee, 1983), did not damage healthy plants when spores were applied to intact tissues. A. pteridis appeared to infect undamaged plants under humid conditions causing the initial ‘fleck’ symptoms associated with the disease. Flecks formed on plants by A. pteridis may permit subsequent infection by P. aquilina.For bracken control, treating plants with fungal inoculum in disease‐free areas may result in disease if inoculum supplements can be found which permit initial infection by A. pteridis or damage plants sufficiently to allow colonisation by P. aquilina directly.
Effects of net blotch on growth and yield of spring barley
Authors: DEADMAN M. L. , COOKE B. M. 
Published: February 2008

SUMMARYThe effect of net blotch on the growth and yield of cv. Beatrice spring barley was examined in a greenhouse experiment. Separate inoculations at growth stages 21 and 34 reduced green leaf area, root weight, leaf sheath and stem weight and tiller number. The early inoculated plants, which responded and recovered more rapidly than later treated ones, suffered a loss in grain yield and this was related to the amount of disease, the loss in green leaf area and the reduction in unit leaf rate.
Fungicidal control of Rhizoctonia solani in relation to soil texture, organic matter and clay minerals
Authors: KATARIA H. R. , SUNDER S. 
Published: February 2008

SUMMARYIn pot tests, MEMC, quintozene, captafol, carboxin, thiabendazole, carbendazim, benomyl and thiophanate‐methyl used as seed treatments gave much better control of cowpea seedling rot in light‐textured sandy and loamy sand soils than in heavy‐textured loam and silt loam soils inoculated with Rhizoctonia solani. Disease control by chloroneb was not altered by soil texture. Amendment of sandy soil with montmorillonite reduced disease control with all fungicides, except chloroneb and carboxin; similar amendments with kaolinite decreased efficacy of MEMC and captafol. Green manuring with cluster bean reduced disease control by MEMC, captafol, benomyl and thiophanate‐methyl; sunnhemp reduced efficacy of MEMC. Most fungicides gave poor disease control when farm yard manure or biogas sludge was added to soil, the sludge having the more marked effect. All the fungicides tested, except carboxin, were inactivated to different extents by humic acid extracted from farm yard manure.
Glasshouse evaluation of fungicides for the control of sunflower downy mildew (Plasmopara halstedii)
Authors: OROS G. , VIRÁNYI F. 
Published: February 2008

SUMMARYA precise, reproducible and easy‐to‐handle glasshouse test is described for the evaluation of the systemic activity of chemicals for the control of Plasmopara halstedii, the downy mildew pathogen of sunflower. Four‐day‐old sunflower germlings were inoculated by immersing them in a zoosporangium suspension. Seedlings were then immersed in appropriate concentrations of the chemicals to be tested. Plants were grown in a glasshouse and assessed on three occasions to determine successively antisporulant, curative (systemic fungistatic), and eradicant effects.Sporulation in general was inhibited by lower concentrations than those required to exert an eradicant effect. There was a highly significant correlation between the ED50 values for visually recognised disease symptoms (stunting, dampingsff and leaf chlorosis) and for both curative and eradicant effects.Among 13 compounds tested, metalaxyl, RE 26745, furalaxyl, LAB 149202F and cymoxanil showed sufficient eradicant activity, to justify field evaluation for eradication of seed infections.
The effects of time of sowing and harvest on carrot biochemistry and the resistance of carrots to carrot fly
Authors: COLE ROSEMARY A. , PHELPS KATHLEEN , ELLIS P. R. , HARDMAN J. A. 
Published: February 2008

SUMMARYTwo carrot cultivars which represented contrasting levels of resistance to carrot fly, Psila rosae, were grown in a replicated field experiment at Wellesbourne in 1984–85. Seed was sown on five occasions between April and August 1984 and the crop harvested after a minimum growth in the field of 16 wk on seven occasions between August 1984 and February 1985. A highly significant correlation (r = ‐0.78; P > 0.001) between the levels of carrot fly damage and the concentration of chlorogenic acid in the roots enabled a model to be formulated to predict the relative predisposition to carrot fly larval damage; high levels of chlorogenic acid early in the season predisposed roots to severe attack when they were older.
Inhibition of degreening in the peel of bananas ripened at tropical temperatures
Authors: SEYMOUR G. B. , THOMPSON A. K. , JOHN P. 
Published: February 2008

SUMMARYBananas (Musa AAA Group, Cavendish Subgroup) were ripened over a range of temperatures from 15 to 35°C. The rate of ripening in both pulp and peel was accelerated with an increase in storage temperature up to about 24°C. Above this temperature the pulp softened and sweetened without the development of a fully yellow peel due to a decrease in the rate of chlorophyll breakdown. Peel carotenoid content was higher at 35°C than at 20°C.
The effects of cutting and asulam on numbers of frond buds and biomass of fronds and rhizomes of bracken Pteridium aquilinum
Authors: LOWDAY J. E. 
Published: February 2008

SUMMARYThe effects of cutting and the herbicide asulam for the control of a dense uniform stand of bracken Preridium aquilinum were investigated experimentally over a 6 —yr period in Norfolk, England. Bracken is a particularly difficult species to control by either mechanical or herbicidal means because of its extensive and complex rhizome network, containing large reserves of dry matter and a large number of frond buds. Cutting bracken in the summer removed dry matter from the system and reduced frond vigour but did not reduce the number of frond buds to a critical level. Whereas the first few cuts substantially reduced the standing crop of fronds, relatively stable standing crops of fronds were observed in future years despite continued cutting. Asulam caused a 99% reduction in the standing crop of fronds in the year after spraying, but in the absence of further treatment, fronds recovered to pre‐spray levels after 6 yr. Asulam caused severe localised damage to frond buds and rhizome apices, but otherwise the rhizome network remained intact. New sections of frond bearing rhizome (short shoots) developed on storage rhizome (long shoots) deep in the soil of both the asulam plots and those cut.
An evaluation of the potential of low temperature pre‐sowing treatments of tomato seeds as a means of improving germination performance
Authors: COOLBEAR P. , NEWELL A. J. , BRYANT J. A. 
Published: February 2008

SUMMARYLow temperature pre‐sowing treatment of tomato seeds substantially enhanced germination rates and was much more effective at improving uniformity of germination than equivalent osmotic treatments. Although radicle emergence was inhibited by the low temperature, imbibition studies showed that seeds were maintained at lag‐phase moisture contents during treatment and some aspects of germinative metabolism began. No evidence was found for improved seedling growth rates per se as a result of pretreatment: in fact, initial axis growth may be temporarily reduced, probably as a consequence of depletion of reserves during the treatment period.
The role of parasitic nematodes and hymenopterous parasitoids in causing premature death of Oscinella spp. larvae
Authors: MOORE D. , HUNT D. J. 
Published: February 2008

SUMMARYThere was a range of severity of parasitism of stem‐borer larvae by Hymenoptera and Nematoda and much premature death of the larvae. A nematode, Panagrolaimus rigidus, normally considered to be saprophytic, was implicated in some mortality of stem‐borer larvae.
The efficacy of sex‐attractant monitoring for the pea moth, Cydia nigricana, in England, 1980–1985
Authors: WALL C. , GARTHWAITE D. G. , SMYTH J. A. BLOOD. , SHERWOOD A. 
Published: February 2008

SUMMARYThe efficacy of monitoring the pea moth (Cydia nigricana) in dry‐harvested pea fields with pheromone traps was evaluated on commercial farms in Eastern England used by ADAS as back‐up monitoring sites. In particular the use of a ‘threshold’ catch to determine both the need for and timing of insecticide sprays was evaluated. Fields in which ‘threshold’ catches were achieved had more damage in unsprayed plots than fields in which there were no ‘threshold’ catches. When two sprays were applied to crops at ‘threshold’ sites, the timing of the first predicted by the monitoring system, excellent control was achieved with 85% of crops having less than 1% peas damaged, and none more than 2–3%. Incorrectly timed sprays, or even one correctly timed spray, produced erratic control.Simple assessments of economic loss show that it is unnecessary to spray crops in which a ‘threshold’ is not achieved. Spraying ‘threshold’ crops, however, is very worthwhile and applying two sprays, the first timed with pheromone traps, will be particularly advantageous to both growers of peas for human consumption when ‘clean’ crops are at a premium, and to seed producers.The data can be used to predict the probabilities of damage levels, assuming different control strategies.
Variation in annual and regional damage to sugar beet by pygmy beetle (Atomaria linearis)
Authors: COCHRANE J. , THORNHILL W. A. 
Published: February 2008

SUMMARYThe reported amount of damage done by pygmy beetle to the sugar‐beet crop varies greatly with year and with region. Annual variation in damage is most strongly correlated with soil temperatures of the previous August, implying improved breeding success in warm summers. The value of predicting damage using this relationship is discussed. Damage is most severe in areas of intensive beet growing, particularly on low‐lying areas around The Wash.There was no relationship between damage and the numbers caught in a 12.2 m suction trap in the spring. It is suggested that much of the damage is done by beetles which are present in the beet fields at or shortly after sowing, having arrived there before the great majority fly in May‐July.
Infection of sunflower leaves by ascospores of Sclerotinia sclerotiomm
Authors: SEDUN F. S. , BROWN J. F. 
Published: February 2008

SUMMARYAscospores of Sclerotinia sclerotiorum infected fully expanded sunflower leaves in the absence of added nutrients, wounds or senescent tissue. The site of infection was confined to a specific region around the junction of the leaf blade and the petiole and was associated with sites of sucrose secretion by the host. In these areas ascospores germinated and formed extensive colonies on the leaf surface. Simple appressoria were visible at 24 h, and complex appressoria at 48 h, after inoculation. Ascospores that germinated in areas where sucrose was not secreted produced germtubes that were shorter (less than 50 μm at 48 h after inoculation) than those produced at sites where sucrose was secreted (greater than 5 mm in length). Infections also developed on severely wounded main leaf veins. Leaf wetness was required for infection, with maximal infection occurring after a 72 h dew period.
The effect of temperature on the response of canes of red raspberry cv. Mailing Jewel to infection by Didymella applanata
Authors: WILLIAMSON B. , PEPIN H. S. 
Published: February 2008

SUMMARYA single population of container‐grown red raspberry plants cv. Mailing Jewel was divided and grown in two environments prior to wound inoculating young canes with Didymella applanata in late July. The plants were then sub‐divided and held in one of three contrasting post‐inoculation environments. Various assessments were made to examine the effect on spur blight of the different environmental treatments.Inoculation of internodes showed that D. applanta produced longer lesions and more pseudothecia on canes grown in spring in an unheated glasshouse than on canes grown outside, but post‐inoculation conditions had little effect on these aspects of disease. Petiole inoculations showed that dwarfing of axillary buds in the first season and lateral shoot failure in the year after infection were most serious on canes grown outside in spring but held at relatively high temperatures in August and September after inoculation. The results indicate that spur blight may have the potential to cause higher yield losses in areas with warmer spring and autumn conditions than those usually experienced in north‐east Scotland.
Effect of nitrogen nutrition on the concentration of viruses, phospholipids and galactolipids of barley leaves infected with barley stripe mosaic virus (BSMV)
Authors: ÁDÁM A. , GÁBORJÁNYI R. , TOBIAS I. , KIRÁLY Z. 
Published: February 2008

SUMMARYThe effect of infection of barley with barley stripe mosaic virus on the chlorophyll, phospholipid and galactolipid content was examined in plants grown in sand culture with a range of nitrogen concentrations. The systemic yellowing and mosaic symptoms of infection were associated with a reduction in the chlorophyll and galactolipid content and an increase in the phospholipid content of leaves. The effects of the virus were not reversed by high nitrogen.The effects of virus infection are interpreted as a stress‐induced phenomenon and the effects compared with those brought about by other stresses.
The interactions of potato cyst nematodes and Verticillium dahliae on early and maincrop potato cultivars
Authors: EVANS K. 
Published: February 2008

SUMMARYThe effects of potato cyst nematodes (Globodera rostochiensis and G. pallida) on the growth of early and later maturing potato cultivars, with or without the H, resistance gene, were compared in pot experiments and the effects of introducing Verticillium dahliae into the system were studied. The influence of the nematodes on root function and structural integrity was inferred from their effects on calcium and water uptake. Early maturing cultivars were less tolerant of nematode attack than later maturing ones, and those with the H1 resistance gene were more tolerant of G. rostochiensis than G. pallida. When V. dahliae was introduced, Verticillium wilt symptoms appeared much earlier on the early than the maincrop cultivars. Also, Maris Anchor (first early) died before Maris Peer (second early) and death of both when infected by nematodes and fungus was much earlier than uninfected control plants or plants infected with G. rostochiensis only. Maris Peer infected by both organisms snowed symptoms much more severe than when infected by either organism alone, whereas Maris Anchor was almost as severely affected by V. dahliae alone as both organisms together. Pentland Javelin (first early) developed Verticillium wilt symptoms several weeks later than other cultivars and the addition of nematodes failed to increase the severity of the symptoms. These differences in cultivar susceptibility to the combination of nematodes and fungus may be due to the nematodes causing different degrees of trauma in the roots of the three cultivars: measuring calcium uptake per unit water uptake showed that nematodes dramatically increase calcium uptake but that the proportional change is least in Pentland Javelin. If this is a reflection of less damage by nematodes to the endodermis of this cultivar, it may explain the greater resistance of its roots to penetration by V. dahliae.
The consequences, for malting quality, of Hordeum laevigatum as a source of mildew resistance in barley breeding
Authors: SWANSTON J. S. 
Published: February 2008

SUMMARYBarley cultivars which include Hordeum laevigatum in their pedigree, have harder endosperms, higher β‐glucan and lower α‐amylase levels than do other cultivars of poor malting quality. Good malting cultivars are characterised by high hot water extracts, soft endosperms, low β‐glucan and high α‐amylase levels. Introgressions of exotic genes for mildew resistance, into breeding populations, may be accompanied by factors adversely affecting malting quality.
The efficiency of visual selection in early generations of a potato breeding programme
Authors: BROWN J. , CALIGARI P. D. S. , MACKAY G. R. , SWAN G. E. L. 
Published: February 2008

SUMMARYThe efficiency of visual selection in the early generations of a potato breeding programme is examined. Tubers from 571 potato genotypes were scored by four breeders after being grown, from true seed, in a glasshouse and in the field for three consecutive years. The four breeders were in good agreement as to which clones would be selected in any environment. The association between breeders was greatest when the clones were grown in plots in the field. All correlations of breeders' preferences between different environments were significantly greater than zero, but only accounted for a small percentage of the total variation. Selection in both the glasshouse and first clonal year produced a desirable response. However, such selection carried a high cost in terms of losing clones with commercial potential. Comparison of a random sample of clones with ones from the same crosses which had been selected, indicated that selection in the glasshouse and first clonal year was at best random with some suggestion, however, of a negative effect.
The repeatability of progeny means in the early generations of a potato breeding programme
Authors: BROWN J. , CALIGARI P. D. S. , MACKAY G. R. 
Published: February 2008

SUMMARYThe progenies from eight crosses between potato clones were examined. The clones were grown as seedlings in a glasshouse and subsequently from tubers in the field at two sites in two consecutive years. At harvest, all the clones were visually assessed by four breeders using a 1–9 scale of increasing desirability. Although there was a formally significant interaction between progenies and environments, the rank of the mean of a cross remained relatively consistent over different growing conditions. It is suggested, therefore, that progeny evaluation by breeders' visual preference can be used to identify the crosses with the highest potential of producing commercial cultivars.