bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between fungicide, plant growth regulator, nitrogen fertiliser applications, foliar disease and yield of winter barley
Authors: JORDAN V. W. L. , STINCHCOMBE G. R. 
Published: February 2008

SUMMARYLeaf size and foliar disease in winter barley increased with increasing total amounts of nitrogen applied to the crop: flag leaf areas increased at an average of 10% per 35 kg N ha‐1 Nitrogen top dressing applied in mid‐March (G.S. 31) resulted in larger leaves, more foliar disease, more straw, delayed ear emergence, fewer grains ear‐1 and less grain yield than nitrogen applied in mid‐April (G.S. 31). Application of chlormequat at G.S. 30 gave a variable response, but overall it increased fertile stems m‐2 and crop yield and decreased crop height but had no significant effect on straw yield. Fungicide treatments suppressed foliar disease and improved yield. Yield responses were greater when plant growth regulator and mid‐March nitrogen had been applied at sites where more disease prevailed than with April‐applied nitrogen. In one of the field experiments, on cv. Sonja, delaying the main nitrogen application until April, without fungicide treatment, gave a similar yield to that provided by nitrogen in March with two or three fungicide sprays.
Longevity, fecundity, change in degree of gravidity and lipid content with adult age, and lipid utilisation during tethered flight of alates of the corn leaf aphid, Rhopalosiphum maidis
Authors: LIQUIDO NICANOR J. , IRWIN MICHAEL E. 
Published: February 2008

SUMMARYThe longevity, daily fecundity, degree of gravidity and lipid content of alates of varied ages, and lipid utilisation during sustained tethered flight of the corn leaf aphid, Rhopalosiphum maidis, were studied. Alates had a mean longevity of 9.7 days and a mean fecundity of 14.9 nymphs. A significant increase in the lipid content of alates before emerging as adults was observed. Newly emerged and half‐day‐old alates had more lipid reserve and embryos than 1‐, 2‐, 4‐, 8‐, and 16‐day‐old specimens. The lipid content of alates decreased significantly with age. The alates' degree of gravidity and lipid content had a low but significant correlation.Half‐ to 1‐day‐old alates flew readily and could fly for much longer durations than 2‐ and 4‐day‐old. Eight‐day‐old alates were not capable of flight. R. maidis utilised lipid during prolonged tethered flight. Our data suggest that there is a threshold point when alates cease utilising stored lipid as the energy source and start utilising non‐lipid sources as flight fuel energy.
Modelling adult survival in the laboratory of diapause and non‐diapause Colorado beetle Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) from Normandy, France
Authors: BARTLETT PAUL W. , MURRAY ALISTAIR W. A. 
Published: February 2008

SUMMARYAdult Leptinotarsa decemlineata from a culture originally from Normandy, France were kept in a controlled environment and fed daily on potato foliage. Dead beetles were scored and removed. Setting up the experiment was spread over 212 days and 1135 beetles were used. After 21 days each group was divided into two, some remained active and others were induced to diapause for 221 days before becoming active once again. Life span varied from 1 to 504 days and could be extended to 770 days by diapause. A model was derived which describes the mortality over time by assuming that a proportion of the population had an exponential distribution of lifetime and the remainder had a Weibull distribution which allowed for a hazard rate increasing with time. In the model 17% were short‐lived, having a mean lifetime of 8 days, and the remainder were long‐lived having a mean lifetime of 139.5 days. An exponential survivor function describes the post‐diapause cohort, which had a mean lifetime of 129 days after diapause.
Prevention of rice tungro virus disease and control of the vector with granular insecticides
Authors: SATAPATHY M. K. , ANJANEYULU A. 
Published: February 2008

SUMMARYThirteen granular insecticides were screened under glasshouse conditions for their ability to kill the vector, Nephotettix virescens, and to prevent tungro virus infection. Carbofuran, bendiocarb, isoprocarb, BPMC, disulfoton, mephosfolan and phorate caused 100% vector mortality, but only the first four reduced virus infection to an acceptable level; the remainder killing the vector too slowly to prevent virus transmission. Seven of these compounds were evaluated in the field on two test cultivars, Traichung Native 1 and Pankaj. Carbofuran, isoprocarb and BPMC gave acceptable control of the disease on both cultivars and diazinon on cv. Pankaj only.
Characterisation of populations of Sclerospora graminicola
Authors: BALL S. L. , PIKE D. J. , BURRIDGE C. Y. 
Published: February 2008

SUMMARYNine cultivars of pearl millet were inoculated with 12 collections of Sclerospora graminicola from various locations in Africa and India in a series of experiments which constituted an almost balanced incomplete block design spanning an entire growing season. The character of each pathogen population was defined in terms of incidence of disease on the hosts. Generally the pathogen collections from the sub‐Sahel regions of West Africa were more pathogenic than those from Senegal, Zambia or India. All but one host cultivar possessed relative resistance which decreased as the overall pathogenicity of the collections increased. There was one notable exception which exhibited stable resistance to all the pathogen collections tested and may have potential for future resistance breeding programmes.
Multiplication of corn stunt spiroplasma in Dalbulus maidis and transmission in vitro, following injection
Authors: ALIVIZATOS A. S. , MARKHAM P. G. 
Published: February 2008

SUMMARYCorn stunt spiroplasma (CSS) multiplied in all injected Dulbulus maidis, reaching titres of over 1 × 106 colony forming units (cfu)/insect and 1 × 104 cfu/salivary gland of each insect. Spiroplasmas could be isolated from the haemolymph and from the salivary glands 1 h after injection and at any time subsequently. Insect extract at a concentration greater than the equivalent of 0.1 insects/ml was inhibitory to the growth of CSS in cultures.Helices could be seen in the haemolymph at any time after injection. However, distorted or partially deformed cells and small aggregates were not present until 2–3 wk after injection. The salivary gland cells of injected insects contained membrane‐bound ‘pockets’ or ‘colonies’ packed with pleomorphic organisms, which included some filamentous forms. Intracellular colonies were always on the periphery of cells and were easily detectable by fluorescent microscopy. Both pleomorphic and filamentous forms were also seen intercellularly in the salivary glands.Following injection, transmission of CSS to maize and to sterile feeding solution were compared using 1 day feeding periods. A proportion of injected leafhoppers began to transmit to maize by the third day following injection (5%) and reached a maximum of 72% by day 14. By day 9, 82% of the population had transmitted at least once to plants and by day 12, 100% had transmitted. Similar insects transmitted through membranes to sterile feeding solution on day 4 (3%) reaching a maximum of 62% by day 14.
Interaction of vesicular‐arbuscular mycorrhizal fungi and root knot nematode on cultivars of tomato and white clover susceptible to Meloidogyne hapla
Authors: COOPER KAREN M. , GRANDISONS G. S. 
Published: February 2008

SUMMARYThe interactive effects of vesicular‐arbuscular mycorrhizal (VAM) fungi and root‐knot nematode (Meloidogyne hapla) were studied on nematode‐susceptible cultivars of tomato (cv. Scoresby) and white clover (cv. Huia) at four levels of applied phosphate. The relative merits of simultaneous inoculation with mycorrhizal fungi and nematodes and of inoculation with mycorrhizal fungi prior to nematode inoculation were evaluated. Mycorrhizal plants were more resistant than non‐mycorrhizal plants to root‐knot nematode at all phosphate levels and growth benefits were generally greater in plants preinfected with mycorrhizal fungi. Nematode numbers increased with increasing levels of applied phosphate. In mycorrhizal root systems, nematode numbers increased in the lower phosphate soils; at higher phosphate levels nematode numbers were either unaffected or reduced. The numbers of juveniles and adults per gram of root were always lower in mycorrhizal treatments. Mycorrhizal root length remained unaffected by nematode inoculation.Mycorrhizal inoculation thus increased the plants' resistance to infection by M. hapla. This was probably due to some alteration in the physiology of the root system but was not entirely a result of better host nutrition and improved phosphorus uptake by mycorrhizal plants.
Resistance to the aphid Metopolophium festucae cerealium: effects of the host plant on flight and reproduction
Authors: DENT D. R. 
Published: February 2008

SUMMARYThe levels of resistance present in two cereal and four grass hosts of M. f. cerealium were assessed in terms of the percentage of alatae flying from the host and reproductive rates of alatae. Festuca rubra and F. arundinacea exhibited highest levels of resistance, inducing a greater proportion of the alatae to fly (94% and 84% respectively) after producing only a few nymphs. Although between 38% and 64% of alatae flew from L. multiflorum, oats, L. perenne and wheat these alatae deposited more nymphs on the hosts before flight than occurred on Festuca. The weight of alatae did not influence the flight response.The differences in the flight/reproductive response of M. festucae to various host plants are discussed in relation to possible host selection strategies of this species and to antixenotic/antibiotic host resistance experiments in general.
The use of multivariate morphometric methods in the separation of alate morphs of the rose‐grain aphid, Metopolophium dirhodum
Authors: HAND S. C. 
Published: February 2008

SUMMARYA preliminary morphometric analysis of alate Metopolophium dirhodum was carried out. The alate morphs studied were: gynoparae and alate emigrants (collected from Rosa), summer exules (collected from maize in the field and from wheat in the laboratory) and winter exules (collected from grasses). Comparing the different morphs using canonical discriminant function analysis gave good separations (always in excess of 80% and often 100%). If this result is found to hold for specimens from a wider temporal and geographical range, it may be used to determine the sources of flying alatae, particularly spring colonists.
The movement and dispersal of Liriomyza trifolii (Diptera: Agromyzidae) in a chrysanthemum greenhouse
Authors: JONES VINCENT P. , PARRELLA MICHAEL P. 
Published: February 2008

SUMMARYInvestigation of the dispersal of Liriomyza trifolii in a 1–2 ha chrysanthemum greenhouse indicated that the average distance flown by female flies was greater than that flown by male flies. However, flies of both sexes were found at the furthest distance from the release point (102 m) which indicates that flies in the greenhouse could be considered to be a single inter‐breeding population. When the data were fitted to a generalised distance‐dispersal model, examination of the parameters revealed density decreased with distance more rapidly for males than females. Also, the model showed that males tended to be slightly more attracted to each other than were females. The applicability of these results to the development of pest management systems for L. trifolii is discussed.
Virulence of Bremia lactucae in Sweden and race‐specific resistance of lettuce cultivars to Swedish isolates of the fungus
Authors: GUSTAFSSON INGRID 
Published: February 2008

SUMMARYVirulence surveys of Swedish Bremia lactucae populations confirmed that the virulence factors vl to v12 were present in high or very high frequencies. Virulence associated with recently defined new resistance genes was also present. Laboratory tests of lettuce cultivars and Lactuca accessions using different Bremia isolates and field tests with natural inoculum showed that previously undetected virulence factors were present.Due to a lack of highly effective genes for specific resistance and the frequent sexual recombination of virulence genes it is suggested that any future breeding programmes concentrate on non‐specific resistance.
The phylloplane microflora of ripening wheat and effect of late fungicide applications
Authors: MAGAN N. , LACEY J. 
Published: February 2008

SUMMARYFlag leaves and ears of spring wheat cv. Timmo (in 1980) and winter wheat cv. Maris Huntsman in 1981 and 1982 were colonised by a variety of micro‐organisms whose numbers increased rapidly between anthesis and harvest. The predominant mycoflora were yeasts, yeast‐like fungi and filamentous fungi which included Cladosporium spp., Verticillium lecanii, Alternaria alternata, Fusarium spp. and Epicoccum nigrum. Although similar species were isolated, their relative abundance on flag leaves and ears differed. The fungicide captafol was most effective as a protectant and significantly decreased populations of fungi on flag leaves and ears for 6 and 4 wk respectively, compared to untreated controls. Benomyl and Delsene M (carbendazim + maneb) were the most effective of the systemic sprays and formulations. In general, fungicides affected populations of yeasts, yeast‐like fungi and Cladosporium spp. most while Alternaria was tolerant of all treatments. Yields of winter wheat were increased in two seasons by an average 0–2 t ha‐1 (2–4%) following a single late fungicide treatment at G.S. 50 or 60 and 0–41 t ha‐1 (5‐1%) when this was combined with an early spray against foliar diseases (G.S. 38–40). Individual treatments increased yield by up to 12% with little difference between applications at G.S. 50 or 60. The yield benefit came mainly from increased 1000‐grain weights. Germination of the treated grain was increased only slightly.
Factors affecting bacterial black spot of mangoes caused by Xanthomonas campestris pv. mangiferaeindicae
Authors: MANICOM B. Q. 
Published: February 2008

SUMMARYBacterial black spot of mango caused by Xanthomonas campestris by. mangiferaeindicae was found to be essentially a wound pathogen of leaves under glasshouse conditions, with maximum infection occurring at a temperature regime of 22/26 oC (night/day). There were significant differences in leaf susceptibility among cultivars, cv. Sensation being less, and cv. Haden more susceptible than cvs Zill and Kent, which agrees with field observations of fruit infection.The organism is a phylloplane resident year round in the field and inoculum levels in the tree canopy affect ultimate fruit infection. The major weather factor affecting fruit infection was rainfall which showed a significant correlation (r = 0–77) with levels of infection after allowing for an approximate 2 wk latent period.Other significant correlations were with a wind/rain index (r = 0–73) and a storm index (r = 0–66). The correlation of disease with the duration of free water was non‐significant (r = 0–22).
Detection and characterisation of bean yellow mosaic virus in corms of Gladiolus grandiflorus
Authors: STEIN ADINA , SALOMON R. , COHEN J. , LOEBENSTEIN G. 
Published: February 2008

SUMMARYBean yellow mosaic virus (BYMV) could not be detected in corms of infected gladioli unless they were cut 6–60 days before testing. Detection after cutting was time‐ and temperature‐dependent, was restricted to the cut area, and varied among cultivars. Virus could be recovered from uncut corms after storage for over 2 yr at 6 oC. BYMV in corms could be detected by enzyme‐linked immunosorbent assay and by immunosorbent electron microscopy with antisera against a gladiolus isolate purified from gladiolus leaves or corms. It could not be detected in corms with antiserum against a lupin isolate which readily detected BYMV in gladiolus leaves. Protein subunits of corm‐BYMV banded in SDS‐PAGE as a single 31 000 dalton polypeptide, while leaf‐BYMV produced a major 34 000 and several smaller polypeptides. Both major polypeptides retained the different serological properties of their source virions but their peptide maps indicated a common origin. It is suggested that the smaller polypeptide from corm‐BYMV is a stable cleavage product of the intact leaf‐BYMV coat subunits. Corm‐BYMV, although lacking some of the antigenic properties of leaf‐BYMV, was still infective.
Hatching from cysts and egg sacs of Heterodera cruciferae and effects of temperature on hatching and development on oilseed rape
Authors: KOSHY P. K. , EVANS K. 
Published: February 2008

SUMMARYJuveniles hatched readily from field cysts and very readily from eggs in egg sacs of Heterodera cruciferae, when exposed to oilseed rape root diffusate. They hatched very poorly, however, from white or brown females from which the above egg sacs had been removed. Some hatching occurred at 8 oC but much more occurred at12, 16, 20 and 24 oC, with most at 16 oC.Development of juveniles in roots of oilseed rape occurred throughout the range 8–24 oC, and proceeded faster the higher the temperature. The basal development temperature was taken as 5 oC and the number of day degrees above this temperature required to reach each stage of development was calculated. From invasion of roots to the hatching of F1 juveniles required an average of 680 day degrees, but only 210 day degrees were required for the first appearance of egg sacs on adult females. On this basis, two consecutive generations of H, cruciferae would be possible on autumn‐sown oilseed rape in southern England, but the second would mature fully only after the crop was harvested. In Scotland, two consecutive generations could also occur but the second would be much less mature by harvest: only about 850 day degrees are available compared to almost 1100 in southern England. In practice, however, overlapping generations probably occur due to flushes of hatching of juveniles (i) at sowing, (ii) when soils warm up after winter and (iii) when the first generation completes its development.The proportion of eggs found in egg sacs was never more than 37% and some field cysts contained about 220 eggs; their egg sacs may, therefore, have contained as many as 150 eggs. Any study of population dynamics or damage assessment will require a quantification of the contribution of eggs in egg sacs to population density. Oilseed rape is direct drilled and may, therefore, be more sensitive to a given population density of the nematode than host crops which are transplanted.
The effect of cold treatment during seed imbibition on lettuce radicle length and the uniformity of seedling emergence
Authors: FELLOWS JANE R. , WURR D. C. E. 
Published: February 2008

SUMMARYTwo experiments were conducted to determine how a period of exposure to 0 oC, between two periods of imbibition at 20 oC, affected radicle development and the uniformity of seedling emergence.In both experiments cold treatments, given 12 h after seed imbibition began, produced shorter radicles than those given at 0, 4, 8, 16 and 20 h. Increasing the duration of exposure to 0 oC gave longer radicles and reduced the spread of seedling emergence. It is concluded that lettuce seeds are particularly sensitive to a temperature change about 12 h after seed imbibition starts.
The combined use of mineral oils and pyrethroids to control plant viruses transmitted non‐ and semi‐persistently by Myzus persicae
Authors: GIBSON R. W. , RICE A. D. 
Published: February 2008

SUMMARYA mixture of the pyrethroid WL85871 (an enriched form of cypermethrin) and the mineral oil SC811 intoxicated adult apterae of an insecticide‐susceptible clone of the peach‐potato aphid Myzus persicae at a similar rate to a treatment containing only WL85871, but the mixture killed more. Mixtures of WL85871 andSC811 also gave better control of both acquisition and inoculation by M. persicae of the non‐persistent potato virus Y (PVY) than either component alone. A mixture of the pyrethroids deltamethrin, cypermethrin and PP321 with SC811, or a mixture of WL85871 with the mineral oil Bayol 52 also decreased acquisition of PVY, and a mixture of WL85871 with SC811 decreased acquisition of another non‐persistently transmitted virus, beet mosaic virus. Control with mixtures was generally better than that provided by each component applied separately. When testing acquisition or inoculation of the semi‐persistent beet yellows virus, fewest plants were infected in treatments incorporating both WL85871 and SC811.
The effect of previous host plant on the fecundity of Myzus persicae and its ability to transmit beet yellows virus
Authors: GLADDERS D. W. , PETERS D. 
Published: February 2008

SUMMARY Myzus persicae transferred to rape produced offspring with higher survival, larger weight and faster development than aphids transferred to beet, irrespective of whether they had been reared on rape or beet. Aphids transferred from rape to beet produced fewer offspring than those reared continuously on rape. On beet, rape‐reared adults produced progeny with lower survival, slower development, smaller adult size and lower fecundity than the progeny of beet‐reared individuals, but there were no differences in these characteristics associated with host plant after one generation. Aphids from rape were less than half as efficient in transmitting beet yellows virus as aphids reared continuously on beet but after one subsequent generation on beet this difference had disappeared completely. These results are discussed in relation to field conditions.
Microorganisms associated with the retting of flax treated with the herbicide glyphosate
Authors: MERCER P. C. , FRASER T. W. 
Published: February 2008

SUMMARYGreater numbers of fungi were isolated from stems of flax following treatment with the herbicide glyphosate than from untreated stems although there was also a general increase in numbers with time. The fungal genera isolated were the same from both treated and untreated plants, the most common being Cladosporium, Aureobasidium, Epicoccum and Botrytis with Cladosporium being predominant. Populations of bacteria were generally not enhanced after glyphosate treatment. Partial dew‐retting of crops resulted in the reduction in numbers of Cladosporium compared with conventionally‐treated flax.The increase in numbers of fungi was associated with an increase in retting. Overretting also occurred, particularly in discrete pale areas on the stem. These were associated with colonisation by Botrytis cinerea and the tensile strength of fibres from these areas was 15 times weaker than from surrounding darker areas of the stem.Light microscopy showed death of cells after glyphosate application, followed by invasion and degradation of the epidermis and cortex by fungi and other microorganisms. Fibre bundles were partially dissociated but the individual fibres remained largely intact as did the xylem and medulla.
Sudden death of cocoa in Papua New Guinea associated with Phytophthora palmivora cankers invaded by bark beetles
Authors: PRIOR C. 
Published: February 2008

SUMMARYAn extensive survey in 1976‐82 indicated that sudden death of cocoa was widespread in Papua New Guinea with losses up to 1% per month in trees over 10‐yr‐old, especially in neglected plantations. Over 95% trees affected had large Phytophthora palmivora canker lesions and over 90% of the cankers were invaded by bark beetles. In an intensive single year survey of one plot 18‐8% of 69 healthy trees died. Ambrosiella spp., P. palmivora and Fusarium solani were isolated from wood surrounding beetle tunnels but only the last two caused extensive lesions when inoculated into the xylem of healthy trees. The evidence obtained indicated that the sudden death syndrome is initiated by P. palmivora cankers on trunks and main branches but bark beetles are a major contributory factor and fungi associated with their tunnels may contribute to the problem. There is a risk of further outbreaks of the disease as cocoa cultivars susceptible to P. palmivora continue to be planted.