bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing Fi hybrids of Brassica oleracea for sibs by seed isoenzyme analysis
Authors: WILLS A. B. , FYFE SHEENA K. , WISEMAN EVELINE M. 
Published: February 2008

SUMMARYExtracts of seeds of Brassica oleracea L. cultivars were separated by electrophoresis on polyacrylamide gels and stained for 14 enzymes to investigate the possibility of utilising isoenzyme variation to determine sib frequencies in hybrid cultivars. Acid phosphatase (EC 3.1.3.2), cr‐amylase (3.2.1.1), carboxylesterase (3.1.1.1), β‐galactosidase (3.2.1.23), β‐glucosidase (3.2.1.21), leucine aminopeptidase (3.4.11.1) and peroxidase (1.11.1.7) reactions gave discrete bands. Three broad zones of acid phosphatase activity occurred and control of banding patterns in the intermediate zone by a series of co‐dominant alleles was confirmed. The locus is designated acp‐1. Sib frequencies could be estimated in eight of 21 F1, cultivars examined, since their parent lines were homozygous for different acp‐1 alleles. This method of estimation has several advantages and offers a practical alternative to current methods. Routine determination of sib frequencies by using any of the other enzymes investigated is impractical.
Patterns of unobstructed splash dispersal
Authors: STEDMAN O. J. 
Published: February 2008

SUMMARYUnobstructed splash dispersal patterns were measured in the absence of rain over mown grass using a fluorescent tracer, and a colorimetric method was used indoors in still air. When drops fell into a thin horizontal water film 0–1 mm deep, the volume of the incident drops dissipated as splash droplets was similar to the volume splashed from the film, irrespective of the distance of fall of the drops. Drop size, angle of inclination and distance of fall had significant effects on the volume of drops splashed from an inclined surface. The effects of rigidity, inclination and nature of surface were found to be significant when drops impacted onto surfaces with or without a wax covering and either rigidly or loosely supported. When splash‐ and dry‐air‐dispersed Lycopodium spores were simultaneously released, many more splashed spores were caught close to the source, but the dispersal gradient of splashed spores was steeper than that of dry‐air‐dispersed spores. Splash‐dispersed spores were caught on slides, cylinders and rotorods but trap efficiency could not be evaluated.
The occurrence of Phytophthora syringae in fallen apple leaves
Authors: HARRIS D. C. 
Published: February 2008

SUMMARYFallen apple leaves from orchards at East Malling Research Station contained oospores of Phytophthora syringae, often in large numbers. Oospores identical in appearance were also observed in pear leaves but their incidence was less than in apple. The colonisation of fallen leaves by P. syringae is considered the principal means of inoculum accumulation in orchard soil and therefore of great importance in the epidemiology of the fruit rot caused by this fungus.
Control of Botrytis cinerea on glasshouse tomato by high volume sprays
Authors: MORGAN W. M. 
Published: February 2008

SUMMARYThe new fungicides iprodione, vinclozolin and prochloraz, and also a mixture containing carbendazim and maneb, were compared with the established protectant fungicides dichlofluanid and chlorothalonil for effectiveness against grey mould (Botrytis cinerea) in an unheated tomato crop. Iprodione and vinclozolin gave the best control of lesions on leaves and stems but dichlofluanid was the most effective in controlling ghost‐spotting of fruit. The carbendazim/maneb mixture was effective against a carbendazim‐sensitive isolate but not against an insensitive isolate of B. cinerea. When applied 1 or 2 days after inoculation, all five protectant fungicides controlled the insensitive isolate better than the sensitive isolate.
Improved growth of white clover in hill grasslands by mycorrhizal inoculation
Authors: HAYMAN D. S. , MOSSE B. 
Published: February 2008

SUMMARYField trials in a hill grassland area of mid‐Wales showed that growth of white clover could be improved by inoculation with selected vesicular‐arbuscular (VA) mycorrhizal fungi. After one growing season mycorrhizal inoculation had approximately doubled shoot dry weight, runner number and nodulation at two sites previously improved by adding lime and fertiliser and by replacing the native vegetation mainly with rye‐grass and white clover. At a previously unimproved site, limed at the time of planting, mycorrhizal inoculation increased shoot dry weight by up to two and a half times, almost doubled runner formation, and increased nodulation up to five‐fold where 90 kg P/ha as basic slag had been applied. Responses to mycorrhiza at this site were smaller with 22‐5 kg P/ha as basic slag and were absent where no P was added. After two growing seasons inoculation responses were even more pronounced at this previously unimproved site; where clovers were being overgrown by adjacent native grasses only those given both 90 kg P/ha and mycorrhizal inoculation survived well.
Bud necrosis of groundnut (Arachis hypogaea) in India caused by tomato spotted wilt virus*
Authors: GHANEKAR A. M. , REDDY D. V. R. , IIZUKA N. , AMIN P. W. , GIBBONS R. W. 
Published: February 2008

SUMMARYChlorotic ringspots or chlorotic leaf specking, terminal bud necrosis, axillary shoot proliferation and severe stunting of groundnut (Arachis hypogaea) were shown to be caused by tomato spotted wilt virus (TSWV).All 28 species of plants tested were susceptible to the virus. Cowpea (Vigna unguiculata cv. C‐152) was found to be a good assay host. TSWV remained infective in buffered sap of groundnut at a dilution of 10‐2.5, after storage for 4 h at room temperature (30 oC) and for 10 min at 40 but not 45 oC.The haemagglutination test was adapted to detect TSWV in crude extracts of groundnut. Sap from infected groundnut and tomato contained spherical membrane‐bound virus particles 70 to 90 nm diameter. The virus was transmitted by thrips (Scirtothrips dorsalis).The prevalence of TSWV in India and the high incidence in groundnut indicates that the virus is economically important.
Evidence for the involvement of calcium in the hatching of Globodera rostochiensis
Authors: ATKINSON H. J. , BALLANTYNE A. J. 
Published: February 2008

SUMMARYLow concentrations of ruthenium red and lanthanum chloride inhibited hatching of juveniles from eggs in cysts of Globodera rostochiensis in potato root diffusate. Pro‐bit analysis for 31 cysts at seven concentrations of ruthenium red showed that 50% inhibition with 95% fiducial limits occured at 47 ± 23 μm; a similar value of 59 ± 14 μm was obtained using eggs removed from cysts. Results for 10 to 20 cysts at six concentrations of lanthanum chloride suggested a somewhat higher value for 50% inhibition of 110 ± 83 μM. In contrast hatching of eggs in cysts of Heterodera schachtii in water was unaffected by 5 ITIM lanthanum chloride and 625 μM ruthenium red, concentrations which cause over 90% inhibition of hatch in G. rostochiensis.Two calcium ionophores synergised hatching of a 1971 population of G. rostochiensis in dilute diffusate. Optimal concentrations of 2 μM for A23187 and 10 μM for BrX537A increased the hatch from 17 ± 3–6 juveniles/cyst to 114 ± 44 juveniles/cyst and 138 ± 40 juveniles/cyst respectively. Ionophores in the absence of diffusate hatched very few eggs of this population but caused a greater hatch in a second (1975) population which gave a high hatch in water of 43 ± 10 juveniles/cyst. This was increased by A23187 to 181 ± 41 juveniles/cyst. The results with both the inhibitors and the ionophores suggest that hatching in G. rostochiensis might be a calcium‐mediated process.
An explanation of the decimal code for the growth stages of cereals, with illustrations
Authors: TOTTMAN D. R. , MAKEPEACE R. J. , BROAD HILARY 
Published: February 2008

SUMMARYThe decimal code for the growth stages of cereals devised by Zadoks, Chang & Konzak (1974) is reproduced here with expanded definitions of some of the descriptive phrases and stylised drawings of selected stages of wheat, barley and oat plants.
Control of aphids in glasshouses with the fungus, Verticillium lecanii
Authors: HALL R. A. , BURGES H. D. 
Published: February 2008

SUMMARYIn small glasshouses, aqueous sprays of spores of the entomopathogenic fungus, Verticillium lecanii, eliminated small populations of the aphid Brachycaudus helichrysi in the vegetative tips of chrysanthemum plants but not when they were in an exposed position on mature flower buds. Control of the chrysanthemum aphid, Macrosiphoniella sanborni, was however variable and usually commercially unsatisfactory. In contrast, in both small and large glasshouses, sparse populations of the major aphid pest Myzus persicae were successfully and consistently controlled, sometimes spectacularly. The inherent susceptibilities of these aphid species, measured by laboratory bioassay, did not account for the differences in control observed in the glasshouse. It is thought that a combination of species‐characteristic feeding site preferences on the exposed parts of plants, where microclimate humidity was probably low, and relative immobility of M. sanborni and B. helichrysi explain why these aphids were less well‐controlled than My. persicae. However, it should be possible to control satisfactorily all aphid species in large commercial glasshouses where humidity might be higher than in the small experimental glasshouses. A single spray was sufficient to introduce infection that controlled aphids for the duration of the crop.
The elimination of cocksfoot streak virus, cocksfoot mild mosaic virus and cocksfoot mottle virus from Dactylis glomerata by shoot tip and tiller bud culture
Authors: DALE PHILIP J. 
Published: February 2008

SUMMARYShoot tips from 0.2 to 4.8 mm long and tiller buds 0.2 to 5.1 mm long were cultured from cocksfoot (Dactylis glomerata) plants known to be infected with combinations of cocksfoot streak, cocksfoot mild mosaic and cocksfoot mottle viruses. Regenerated plants were tested for the presence of viruses by electron microscopy, serology and the expression of symptoms. All viruses were eliminated by culturing shoot tips and tiller buds less than 1.2 mm long but the maximum explant size capable of regenerating healthy plants depended upon the infecting virus. Viruses were not detected in shoot tip and tiller bud samples of similar size to the explants that gave healthy plants. The method is of value in eliminating viruses from desirable stocks of D. glomerata that must be vegetatively propagated.
Detection of potato leafroll and potato mop‐top viruses by immunosorbent electron microscopy
Authors: ROBERTS I. M. , HARRISON B. D. 
Published: February 2008

SUMMARYAttachment of virus particles to antiserum‐coated electron microscope grids (immunosorbent electron microscopy) provided a test that was at least a thousand times more sensitive than conventional electron microscopy for detecting potato leafroll (PLRV) and potato mop‐top (PMTV) viruses. The identity of the attached virus particles was confirmed by exposing them to additional virus antibody, which coated the particles.PLRV particles (up to 50/μm2 of grid area) were detected in extracts of infected potato leaves and tubers, infected Physalis floridana leaves, and single virus‐carrying aphids. On average, Myzus persicae yielded 10–30 times more PLRV particles than did Macrosiphum euphorbiae.PMTV particles (up to 10/μm2 of grid area) were detected in extracts of inoculated tobacco leaves, and of infected Arran Pilot potato tubers with symptoms of primary infection. Particles from tobacco leaves were of two predominant lengths, about 125 nm or about 290 nm, and fewer particles of other lengths were found than in previous work, in which partially purified or purified preparations of virus particles were examined, using grids not coated with antiserum.
Measurement of the adenosine triphosphate content of cysts of Globodera rostochiensis as a method for assessing the efficacy of fumigant nematicides
Authors: STOREY R. M. J. , ATKINSON H. J. 
Published: February 2008

SUMMARYThe measurement of the adenosine triphosphate (ATP) content of samples of 50 cysts of Globodera rostochiensis collected from 40 fields in the Netherlands has been tested as a method for determining the mortality of the nematodes achieved by fumigation of these field soils. The technique used is based on bioluminescent photometry and it has been fully described previously. The ATP assessment has been compared with results obtained by the advisory service in the Netherlands using hatching tests based on samples of 100 cysts from the same field soils. The ratio of the values before and after soil treatment showed that the methods usually provided similar estimates of mortality. The relationship between ATP and hatched juveniles was also similar from pre‐treatment and post‐treatment samples. The amount of ATP, calculated from these results, which is equivalent to the maximum post‐treatment hatch allowed for a successful treatment in the Netherlands was used in conjunction with the mortality estimates to assess the success of the fumigation. On this basis the two methods disagreed in the overall assessment of fumigation in only five of the 40 fields. This frequency of disagreement is not significantly greater than expected from the variability of either method. The ATP technique clearly offers a reliable and relatively inexpensive method for estimating the efficacy of fumigant nematicides and is much more rapid than the alternative hatching tests or egg counts. Therefore, it could replace these in situations where the grower wanted a rapid assessment on the success, or otherwise, of his fumigation.
Effects of short‐term waterlogging on the growth and yield of peas (Pisum sativum)
Authors: CANNELL R. Q. , GALES K. , SNAYDON R. W. , SUHAIL B. A. 
Published: February 2008

SUMMARYThe effects of waterlogging the soil for up to 5 days on the growth of peas at different stages of development were investigated in glasshouse and outdoor experiments. During waterlogging the oxygen content of the soil declined to less than 2% within 2–3 days. Subsequently, leaf senescence was hastened, stem growth rate was slowed and yield was decreased. The effects on yield were mainly attributable to the development of fewer nodes and fewer pods. Waterlogging for 24 h or more just before flowering restricted growth and yield. The effects of waterlogging at earlier and later stages were less marked. Waterlogging at any period after flower buds were visible prevented further increase in root dry weight.
Date of onset of regrowth dieback and its relation to summer drought in eucalypt forest of southern Tasmania
Authors: WEST P. W. 
Published: February 2008

SUMMARY‘Regrowth dieback’, a disease of Eucalyptus obliqua and E. regnans is causing serious degradation of high yield, even‐aged, regrowth forest in south‐eastern Tasmania. Dieback symptoms in crowns of diseased trees were first observed in the region in 1964 and since then the disease has continued to develop. Visual symptoms of the disease can be discerned only in crowns of dominant and co‐dominant trees since sub‐dominant and suppressed trees show similar symptoms due to normal stand competition. This work shows that for increment periods which finished in 1958 or earlier, basal area increments of dominant and co‐dominant trees from a number of growth plots in the region were slightly lower in trees which were affected by the disease in 1971 than in those which were not. There were much larger reductions in increments of affected trees measured in increment periods which finished in 1960 or later. It was concluded that an agent very damaging to forest health appeared in the region in 1959 or early 1960. This coincides with the start of a period of several years of unusually dry summers in the region. These findings conform with an earlier suggestion that the disease may have been initiated by drought with secondary damage by the root‐rotting fungus Armillaria sp. and/or the defoliating beetle Chrysophtharta bimaculata. The fungus is ubiquitous in the region and has frequently been associated with decayed roots of affected trees. The beetle is believed to have caused episodic tree defoliation in the region. It is suggested that the secondary agents normally cause death or ill‐health of a few trees in otherwise healthy forest. Physiological weakening of trees by drought may have allowed the effects of these agents to increase substantially after 1959.
Hirsutella thompsoniU a fungal pathogen of mites. II. Host‐pathogen interactions
Authors: GERSON U. , KENNETH R. , MUTTATH T. I. 
Published: February 2008

SUMMARYThe moniliaceous fungus, Hirsutella thompsoniU grown on potato‐dextrose agar (PDA) or on sterile wheat bran, was highly pathogenic to the carmine spider mite, Tetranychus cinnabarinus, and, grown on PDA, to the oriental spider mite, Eutetranychus orientalis. The fungus penetrated the mites' integument mainly through the legs and formed hyphal bodies in chains in the haemolymph. Hyphae, on which the spores were produced, began to emerge through the genital and anal apertures and then all over the body. Various mycophagous mites, a predaceous species and the tick Argas persicus were immune. H. thompsonii grew well on cadavers of diverse insects and mites.The fungus killed most mites and quickest, usually by the 2nd day, at 25o, 27o and 30 oC; least at 13o and 35 oC. It sporulated best on mites at 24o, 27o and 30 oC (full sporulation at 27 oC took place within 12 h after death); it was good, but slower, at 13o and 35 oC. The fungus germinated, penetrated mites and sporulated there very poorly below 100% r.h. When the daily number of hours at 100% r.h. was reduced from 24 to 18 or 6 h, fungus‐associated mortality dropped greatly.In the field, use of the fungus for mite control would be suitable particularly in tropical and humid subtropical areas, and its success in Israel would not be assured. In glasshouses, H. thompsonii could induce epizootics in Israel and elsewhere only if humidities were raised to saturation and the daytime temperature kept below 37 oC.
Fungitoxic and phytotoxic effect of some surface‐active agents applied for the control of apple powdery mildew
Authors: BURCHILL R. T. , FRICK E. L. , COOK M. E. , SWAIT A. A. J. 
Published: February 2008

SUMMARYMixtures of methyl esters of fatty acids (‘Off‐Shoot O’) and mixtures of fatty alcohols (‘Off‐Shoot T’), applied during the late autumn (November), eradicated apple powdery mildew (caused by Podosphaera leucotricha) from infected buds. Applications in the spring at bud‐burst were less effective.The autumn sprays caused little damage to the cultivars Bramley's Seedling, Cox's Orange Pippin and Golden Delicious but on Worcester Pearmain 50% of the buds were killed by a 5% Off‐Shoot O spray. The bud‐burst sprays were damaging and reduced yield on the Cox and Bramley trees.A 5% a.i. mixture of nonanol/lissapol applied to a range of commercial cultivars was effective in eradicating powdery mildew but was more phytotoxic than the Off‐Shoot compounds. Spraying Cox trees later in the winter failed to reduce the damage.Eradication of the overwintering stage of the disease resulted in low spore concentrations during the following spring and early summer, enabling some economies to be made in the summer mildew fungicide programme.
The detection of apple chlorotic leafspot virus by a modified procedure of enzyme‐linked immunosorbent assay (ELISA)
Authors: FLEGG CAROLINE L. , CLARK M. F. 
Published: February 2008

SUMMARYThe technique of enzyme‐linked immunosorbent assay (ELISA) was modified to enable detection of apple chlorotic leafspot virus (CLSV) both in herbaceous hosts and in several naturally infected fruiting and ornamental woody host species. Some of the characteristics of the modified method as used with different virus‐host combinations are described.
The effect of infection with potato leaf roll virus (PLRV) on yield and some of its components in a variety of potato (Solanum tuberosum)
Authors: KILLICK R. J. 
Published: February 2008

SUMMARYIn a trial of over 2000 potato plants 11 ‐8% of them were found to be infected with potato leaf roll virus. Infection caused reduction in the number of stems and reduced the number, weight and mean weight of both chats and ware tubers produced per hill. It also reduced the number and weight of ware tubers produced per stem. The health status of neighbouring plants was found to influence the weight and mean weight of ware tubers of healthy, but not of infected plants. This yield compensation is described in an appendix.
Effect of ryegrass mosaic virus on the quality of perennial ryegrass
Authors: HOLMES S. J. I. 
Published: February 2008

SUMMARYIn 1976 fields of perennial ryegrass located on two farms in the west of Scotland were found to be far more severely and extensively infected by ryegrass mosaic virus (RMV) than had been seen in earlier surveys of ryegrass fields in 1972 and 1973.The chemical analysis of samples of ryegrass from 10 of the fields examined in 1976 showed that RMV significantly reduced the organic matter content, organic matter digestibility, water soluble carbohydrate content and D value of the grass. Furthermore, the losses suffered by grass with the severe necrotic symptom of RMV were significantly greater than those incurred by the grass with the mild mottle only.A correlation analysis between water soluble carbohydrate level and D value showed that whilst the loss in water soluble carbohydrates in mottled grass accounted for much of the loss in digestibility this was not the case in the necrotic grass where loss of green tissue appeared to be a more important contributory factor.
The influence of tillage and method of straw disposal on the survival and growth of black‐grass, Alopecurus myosuroides, and its control by chlortoluron and isoproturon
Authors: MOSS S. R. 
Published: February 2008

SUMMARYA winter wheat crop was established in a field infested with black‐grass. Three cultivation systems were used ‐ ploughing, tine cultivation and direct drilling. Straw of the previous wheat crop was either spread and burnt or removed by baling. Chlortoluron at 1–60 and 3–20 kg/ha pre‐emergence and isoproturon at 1 14 and 2–27 kg/ha pre‐ and post‐emergence were applied to sub‐plots of all cultivated treatments.Ploughing substantially reduced black‐grass infestation compared with the other two cultivations. Straw burning was effective in destroying many seeds and resulted in less black‐grass in the crop.The pre‐emergence herbicide applications were more effective after ploughing than after direct drilling, irrespective of straw disposal method. When the straw was burnt, black‐grass control on the tine cultivated plots was at least as good as after ploughing but where the straw was baled, poorer control was obtained. Chlortoluron gave better control than isoproturon but the relative effects of cultivations and straw disposal method were similar with both herbicides. The post‐emergence herbicide treatments gave excellent control after all cultivations.Many black‐grass seeds in the surface soil were shown to remain dormant, but viable, from autumn until the following April.
A comparison of the excretion rates of Aphis fabae on artificial diet and on bean plants
Authors: HO S. H. 
Published: February 2008

SUMMARYThe performance of Aphis fabae on an artificial diet was assessed by comparing the aphid's excretion rate on the diet with that on bean plants to investigate the possibility of using this diet in toxicological studies. No significant difference was found in the rates of honeydew excretion, but the diet‐fed aphids were noticeably smaller than those fed on beans.