bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biochemical tests for identification of mycelial cultures of basidiomycetes
Authors: TAYLOR J. B. 
Published: February 2008

SUMMARYTwenty‐four biochemical tests have been developed to identify basidiomycetes from mycelial cultures. Eleven are designated ‘instant tests’ because results are obtained within 24 h; ten of these test for specific enzymes, the other is based on a reaction between vanillin and unknown fungal metabolites. The remaining thirteen tests require incubation periods ranging from 1 to 4 days and are thus designated ‘incubated tests’.Sixteen of these tests were applied first to identified isolates of Peniophora sacrata, Sclerotium rolfsii, Stereum purpureum and Trametes versicolor. They distinguished these species satisfactorily, so these sixteen tests, and eight others devised subsequently, were applied to unidentified basidiomycetes isolated from diseased roots of fruit crops. The results of these tests enabled the isolates to be placed in seven groups. All isolates in a particular group were morphologically similar which further suggested that each group might correspond to a species and that isolates could be defined on the basis of biochemical tests.
Insecticide granule distribution and the control of Lycoriella auripila (Diptera: Lycoriidae) in mushroom casing material
Authors: BINNS E. S. 
Published: February 2008

SUMMARYIn laboratory tests the distribution of insecticide in peat–chalk mushroom casing greatly affected the number of adult sciarids which emerged from larvae placed in 50 g samples. Only thionazin markedly reduced emergences when granules were clumped in the centre of the sample of casing. The slope of dosage mortality data for clumped granule treatments was less steep than for mixtures and gave estimated LD95 values of 16300 and 26.8 ppm respectively. Thus, the number of adults which emerged when granules amounting to 6.4 mg of chlorfenvinphos were clumped was 65% of those emerging when only 0.4 mg a.i. was mixed into 50 g casing. However, adults did not emerge when 3.2 mg of the same insecticide was mixed throughout the sample. Increased doses did not, therefore, compensate for inadequate mixing.With 0.2–0.4 mg a.i. chlorfenvinphos mixed through the casing, about three times as many sciarids emerged with the intact granules than when pulverized granules were used. This showed the lack of mobility of this chemical in peat‐chalk mixtures and the need for it to be homogeneously incorporated in commercial casing. Pirimiphos‐ethyl, diazinon and thionazin also gave improved kills when mixed into the casing rather than clumped.A χ2 test of the mortality data suggested a non‐linear dosage‐mortality relationship for treatments amounting to half the dish. However, LD95 estimates of 37.5 and 62.2 ppm were obtained for mixed and quadrant treatments. Thus, when 3.2 mg chlorfenvinphos was mixed into only half of the volume of casing, the number of adults emerging was only 6% of that from untreated casing. However, larval movement was negligible in untreated casing and this appeared to limit the effectiveness of chlorfenvinphos and pirimiphos‐ethyl when they were not evenly distributed throughout the casing. With thionazin and diazinon, mobility of the insecticide appeared to compensate for uneven distribution.
Some biophysical principles underlying the controlled atmosphere storage of plant material
Authors: BURTON W. G. 
Published: February 2008

SUMMARYControlled atmosphere (CA) storage is of use for commodities which potentially can undergo rapid and unacceptable biochemical change. In air, the oxygen status of most plant material, including fleshy storage organs and fruits, suffices, even in the centre, for cytochrome oxidase to be fully saturated. Conflict of evidence exists as to possible O2 and CO2 gradients in fruit which, though physiologically unimportant in air, could be important under CA conditions. CA storage gives possible control of internal O2 from o to about 80–95%; internal CO2 from about 3–4 to 100%; and both simultaneously to intermediate values. Calculated molarities of dissolved O2, CO2 and ethylene are given for various atmospheres.The differences in the O2 concentrations recommended for different varieties of apple are not readily explicable. Varietal differences in susceptibility to CO2 injury could possibly result from anatomical, rather than biochemical, differences. This could be determined partly by resolving the conflict of evidence mentioned above. Variability of plant material prevents precise control of intercellular atmosphere; recommended atmospheres can be designed only to avoid completely anaerobic conditions and a harmful level of CO2 in the centre of the least permeable individual fruit or vegetable. Effects of low O2 and high CO2 are briefly described.
The development and quality of forage grass seeds produced under different isolation conditions
Authors: BEAN E. W. 
Published: February 2008

SUMMARYThe effects of five different environments, outside under natural conditions, glasshouse, Polythene enclosures (two designs), and muslin shades, upon seed development and seed quality in four varieties of forage grasses were investigated in two years. In 1972 pollen release occurred first in the Polythene enclosure and the highest pollen counts were obtained from this treatment and under glasshouse conditions. Plants in which seed development occurred in the glasshouse had the highest floret fertility, 1000 seed weight and seed weight per inflorescence, while those grown under Polythene gave low values for all these characters. Plants in which seed development occurred under muslin shades, where light intensity was reduced by half, gave seed yields equal to those grown in full day‐light. In 1973 the germination rate was highest in seeds produced under Polythene and lowest in those produced under outside conditions. The dry weights of seedlings from the outside treatment were lower than those from the glasshouse and Polythene enclosures in four of the five experiments. It is suggested that isolation methods for the production of small seed lots should be standardized, and that glass isolation chambers are the most efficient method of producing small seed lots for plant breeding and agronomic investigations.
Some observations on a Tylenchid nematode Howardula sp. parasitizing the mushroom phorid Megasalia halterata (Phoridae, Diptera)
Authors: RIDING IRENE L. , HAGUE N. G. M. 
Published: February 2008

SUMMARY Howardula sp. parasitizes the Mushroom phorid fly Megasalia halterata destroying the fat body and follicular membrane of the fly, decreasing copulation and egg output. With increasing hyperinfestation the fly is rendered sterile. Howardula sp. is host density dependent and reaches a maximum incidence in September and October. Under laboratory conditions fly populations were eliminated in three to five generations. The implications for possible biological control of M. halterata are discussed.
Studies on the feeding behaviour of the eriophyid mite Abacarus hystrix, a vector of grass viruses
Authors: GIBSON R. W. 
Published: February 2008

SUMMARYOn Italian ryegrass (Lolium multiflorum cv. S 22), the eriophyid mite Abacarus hystrix usually fed on the bulliform epidermal cells at the base of the grooves on the adaxial leaf surface. Scanning electron micrographs illustrate (1) the external morphology of the mouthparts of the mites, (2) how, prior to feeding, they remove cuticular leaf wax with their rostra and (3) feeding punctures in epidermal cells made by the styliform chelicerae. Of eleven graminaceous species tested, A. hystrix only settled on Festuca pratensis, L. perenne and L. multiflorum. On L. multiflorum, the mites preferred the youngest leaves and on mature leaves, preferred the youngest part.
Effects of dual infections of Puccinia hordei and Erysiphe graminis on barley, cv. Zephyr
Authors: SIMKIN M. B. , WHEELER B. E. J. 
Published: February 2008

SUMMARYIn replicated field trials in 1971 and 1972, plots of Zephyr barley were obtained with (1) powdery mildew, (2) brown rust, (3) both diseases or (4) neither disease, by using appropriate systemic fungicides.Mildew was fairly severe (up to 40% infection of individual leaves) and significantly reduced yield and grain size in both years. Rust was not severe (< 5 % on any leaf) in either year and it reduced yield and grain size only in 1972. In these conditions the mean percentage losses (relative to treatment 4) in plots with both diseases were approximately equivalent to the sum of those from powdery mildew and brown rust alone. There was no significant mildew × rust interaction in respect of yield or senescence of leaves, but comparisons of the infection rate of Erysiphe graminis on leaves with and without rust in similar situations within the 1972 trial suggested that rust affected the development of mildew on the same leaf. Experiments in the glasshouse using the first leaf of seedlings, not chemically treated, confirmed that there could be marked interactions between the pathogens on a single leaf. Pre‐inoculation with one pathogen generally reduced the development of the other.
Seasonal changes in infection of barley seedlings by Erysiphe graminis f.sp. hordei
Authors: JENKYN J. F. 
Published: February 2008

SUMMARYInfection of artificially inoculated barley seedlings, exposed out of doors, was variable but there was a seasonal trend. As temperature affects both incubation time and the proportion of successful infections, these two factors will have additive effects on disease development. Infections developed only slowly in winter but, in both 1972 and 1973, conditions became much more favourable to infection in late April or early May.
Field experiments in the control of Verticillium dahliae and Heterodera rostochiensis on potatoes
Authors: HIDE G. A. , CORBETT D. C. M. 
Published: February 2008

SUMMARYPotatoes were grown in soil infested with Verticillium dahliae and Heterodera rostochiensis and treated with methyl bromide, aldicarb or benomyl. Successive crops were grown in subsequent years on the same plots but without further treatment. Largest yields in the year of treatment were from plots fumigated with methyl bromide but in the second crop benomyl‐treated plots yielded most. Neither methyl bromide nor aldicarb affected yields from trie third crop.After lifting the first crop, soil from plots treated with methyl bromide or benomyl contained less V. dahliae than that from plots receiving aldicarb or nothing. Soil was also less infective after the second crop following methyl bromide fumigation, but not the third. Plots treated with methyl bromide or aldicarb contained many fewer H. rostochiensis than untreated plots after the first crop, slightly less after the second and equal numbers after the third crop. H. rostochiensis were also fewer in benomyl‐treated plots than in untreated after the first crop, but, surprisingly, were fewest after the second crop. The increased yield after applying benomyl to soil seems to depend more on its effect on H. rostochiensis than on V. dahliae.Fumigating with methyl bromide decreased common scab and black scurf on progeny tubers but increased infections by Oospora pustulans.
Experiments with MBC derivatives for the control of Dutch elm disease
Authors: GIBBS J. N. , CLIFFORD D. R. 
Published: February 2008

SUMMARYPreparations of methyl benzimidazol‐2‐ylcarbamate (MBC) hydrochloride stabilized with HC1, MBC nitrate stabilized with lactic acid and MBC bisul‐phate stabilized with KHS04 were made from technical MBC. As it was the least phytotoxic to elm shoots, the hydrochloride was selected for field experiments on the control of Dutch elm disease using 6 m elms. In protectant experiments using 1.51 of 0.25 or 0.5 % MBC per tree, only five of eighteen injected trees became infected while all the control trees were severely diseased. In curative experiments, injection with 0.25 % MBC 2 and 4 wk after inoculation with Ceratocystis ulmi kept symptoms to < 1 and 5% respectively, compared with 76% in untreated inoculated trees. MBC at 0.5 % Save similar results.
Control of pea cyst‐nematode, Heterodera goettingiana, by small amounts of aldicarb, Du Pont 1410, Ciba‐Geigy 10576 or Dowco 275 applied to the soil at planting time
Authors: WHITEHEAD A. G. , TITE D. J. , FRASER JANET E. , FRENCH EILEEN M. 
Published: February 2008

SUMMARYAldicarb, or Du Pont 1410 (S‐methyl‐I‐(dimethylcarbamoyl)‐N‐[(methyl‐carbamoyl)oxy]thioformimidate), at 2.8–22.4 kg a.i./ha incorporated in the seed‐bed before sowing greatly increased the yield of peas in a clay loam and two sandy clay soils infested with pea cyst‐nematode, Heterodera goettingiana, and lessened or prevented increase in the number of nematodes. CibaGeigy 10576 (an organophosphorus compound) at 5.6–22.4 kg a.i./ha was similarly effective in a sandy clay soil. Dowco 275 (O, O‐diethylO‐(6‐fluoro‐2 pyridyl) phosphorothioate) at 5.6 or 11.2 kg a.i./ha also controlled the nematode well in the clay loam and in a sandy clay soil but although it greatly increased the yield of peas in the clay loam, it did not increase yield in the sandy clay.
The utilization of recently assimilated carbon in graminaceous plants
Authors: RYLE G. J. A. , POWELL C. E. 
Published: February 2008

SUMMARYIsotopic carbon and infra‐red gas analysis techniques were used to measure the following growth attributes in maize, sorghum, winter wheat and perennial ryegrass: the rate of entry of carbon into each main shoot leaf; the rate of translocation of leaf assimilate to meristems; the fraction of leaf and total shoot assimilate respired in one diurnal period; and the distribution of residual assimilate to new leaf, stem, axillary shoots and root.The two tropical plants possessed higher leaf assimilation rates and larger leaves than the temperate species, but their efficiency of translocation was only marginally superior in the experimental conditions. In all species, c. 25% of the assimilate generated in the 8·4h photoperiod was respired in in the same diurnal period. Maize and sorghum partitioned a greater proportion of their total shoot assimilate to new leaf tissue at the main shoot apex and to root than wheat and ryegrass. On the other hand, wheat and ryegrass exported up to 30% of their assimilate to axillary shoots; in sorghum, little assimilate was translocated to axillary shoots, while in maize this activity was completely absent.Plant habit, as exemplified by the contrast between the annual, single‐axis maize plant and the perennial, multi‐tillering ryegrass plant, appears to be a reflexion of the pattern of assimilate distribution to areas of potential growth. With the exception of superior leaf assimilation rates in maize and sorghum, the four species showed no marked differences in respect of the production, transport and respiratory utilization of assimilates.
Factors affecting field‐scale production of seed of F1 hybrid Brussels sprouts
Authors: FAULKNER G. J. 
Published: February 2008

SUMMARYThe two main factors involved in field‐scale production of seed of F1 hybrid Brussels sprouts are pollen availability and honeybee behaviour. Pollen availability depends upon the extent of winter survival of the parent inbreds, their flowering times, plant size and on the number of flowers per plant. Plant losses varied between inbreds and between sites and seasons. Differences in the commencement of flowering time in pairs of inbreds varied from 7 to 21 days, and plant size affected flower number. In hybrid seed‐production there was a direct relationship between the number of mature flowers on each inbred and the percentage of non‐hybrid seed produced from that inbred.Bees were highly selective in their visits to inbreds, and a mean selfing‐to crossing‐movement ratio of 30:1 was observed. This behaviour, together with pollen availability, greatly influenced the production of ‘sibs’.Radioactive experiments showed that the amount of cross‐pollen carried by a bee decreased by about 30% at each flower visited but radioactive pollen grains were detected on the tenth flower visited. Of a number of factors investigated as possibly influencing bee behaviour, differences in flower colour and plant height were associated with discrimination between inbred lines.
The inheritance of resistance to Rhynchosporium secalis in some European spring barley cultivars
Authors: HABGOOD R. M. 
Published: February 2008

SUMMARYThe inheritance of partial resistance to Rhynchosporium secalis, which appears to be race non‐specific, was studied in a diverse range of European spring barley cultivars. Data from the F2 generation of a 6 × 6 diallel cross and the F3 generation of three crosses selected from this diallel set suggested that resistance was complex in inheritance, the results being incompatible with any hypothesis involving less than four genes. The F2 studies indicated that both dominant and recessive genes were active in conferring resistance, and that there were significant additive gene effects. Transgressive segregation occurred in all cross combinations in the F3 material. Consequently the alleles conferring resistance were not completely concentrated in the most resistant cultivar studied (cv. Proctor).Heritability estimates obtained from F2 and F3 material suggested that field selection was of limited reliability, even when spreader drills were incorporated amongst the segregates. Single‐plant selection (in F2) was considered to be of little value, and the results of Fa head‐row tests would require confirmation by replicated tests in subsequent generations.
Host and environmental effects on post‐penetration development of Puccinia graminis avenae and P. coronata avenae
Authors: KOCHMAN J. K. , BROWN J. F. 
Published: February 2008

SUMMARYAfter inoculation of Avena sterilis and the oat cultivars Algerian and Garry with Puccinia graminis avenae the time required for the eruption of pustules of the rust was markedly less at 30–35 than at 20–25 oC. In addition, the area of pustules and number of uredospores produced were significantly greater at 30–35 than at 20 oC. Peaks of uredospore production occurred between 12 and 22 days after inoculation.In comparable experiments, the time required for pustules of P. coronata avenae to erupt, and the size of pustules, were relatively insensitive to change of temperature, although weight of uredospores produced was greater at 20 than at 30 oC. Peaks of uredospore production occurred between 14 and 18 days after inoculation.Both rusts showed straight‐line relationships between pustule area and number of uredospores produced. The percentage of infection foci that developed into pustules was similar with both rusts and on all the oat cultivars examined. Both rusts produced susceptible reaction types on all the hosts tested.Pustules of P. graminis avenae were smaller and fewer and generation time longer on cv. Garry than on cv. Algerian or Avena sterilis and the numbers of pustules per unit of inoculum of both rusts were greatest on Algerian, least on Garry. It is suggested that these quantitative differences in phases of the infection process contribute towards the ‘slow‐rusting’ reaction of cv. Garry.
The control of apple canker (Nectria galligena) in a young orchard with established infections
Authors: SWINBURNE T. R. , CARTWRIGHT J. , FLACK N. J. , BROWN AVERIL E. 
Published: February 2008

SUMMARYIn a factorial experiment on canker control the efficiency of phenylmercurie nitrate (PMN) applied at leaf fall, before bud burst or both was compared with the application of dodine, dithianon, triforine, thiabendazole, benomyl or carbendazim in May and June. Of the total number of cankers which developed in unsprayed trees 76–78% resulted from infections in April to August of each year of the experiment. Infection was reduced significantly by all of the fungicides applied in summer. Of these carbendazim was outstanding, controlling both summer and autumn infections. Sporulation throughout the summer was suppressed by carbendazim and to a lesser extent benomyl, but whereas the suppressant effect of carbendazim persisted until long after leaf fall that of benomyl was evident only until August. Dodine, dithianon, triforine and thiabendazole had no significant effect on spore production. Dithianon and dodine showed highest toxicity to the germination of Nectria galligena spores of all fungicides used in summer. All of the fungicides controlled apple scab (Venturia inaequalis) although thiabendazole was the least effective.Autumn applications of PMN reduced canker incidence but their value alone was not as great as carbendazim, dithianon, benomyl or dodine applied in summer. PMN applied in spring reduced the number of cankers in trees receiving no other fungicides but tended to increase the incidence of infections, particularly in autumn, when used in conjunction with fungicides applied in May and June. PMN applied before bud burst reduced sporulation of N. galligena for a few weeks, after which production resumed and in late summer and autumn actually exceeded the controls. None of the fungicides had any direct effect on leaf fall.Infection of the crotch and basal leaf scars was more common in summer than in autumn whereas infection of leaf scars above the basal region was more common in autumn than in summer. The rootstocks of many of the trees became infected via callus tissue associated with adventitious root development and this was controlled by the carbendazim treatment.
Testing potatoes bred from Solarium vernei for resistance to the white potato cyst‐nematode, Heterodera pallida
Authors: HOWARD H. W. , FULLER J. M. 
Published: February 2008

SUMMARYThree clones of potatoes bred from Solanum vernei were tested for their resistance to the white potato cyst‐nematode, Heterodera pallida, both by root‐ball counts and by estimates of total cysts produced. Two susceptible clones were used as controls. Root‐ball counts suggested a higher degree of resistance than that based on total cysts produced. There were differences in pathogenicity between the two populations. The degree of resistance found was such that in practice the resistant clones would be best used in conjunction with nematicide treatment in a system of integrated control.
Fluctuations and regulation of wheat‐bulb fly populations at Rothamsted
Authors: RYAN M. F. 
Published: February 2008

SUMMARYFour populations of the wheat‐bulb fly studied at Rothamsted incurred substantial and regulatory losses of larvae caused by food shortage. The following hypothesis is proposed to explain population changes of the fly. Fluctuations caused by weather are stabilized by density‐dependent larval mortality caused by food shortage. The effect of weather is, however, pervasive as it also affects food shortage by influencing the number of shoots available to larvae.
A rickettsia‐like organism associated with diseased white clover
Authors: MARKHAM P. G. , TOWNSEND R. , PLASKITT KITTY A. 
Published: February 2008

SUMMARYDiseased white clovers (Trifolium repens), with symptoms similar to clover club leaf, were found in England. Electron microscopy of thin sections revealed rickettsia‐like organisms, 1–2 μm long by 0–2‐0‐3 μm diameter, in the phloem cells of these diseased plants. They were not present in healthy clover plants. At 23–30 °C the organisms multiplied rapidly and symptoms became more severe. After treatment with penicillin the organisms degenerated and plants showed remission of symptoms.
Ethylene control of growth in maize seedlings in relation to auxin metabolism
Authors: Malloch K. Rachel , Osborne Daphne J. 
Published: February 2008

ABSTRACTAlthough elongation growth is reduced by ethylene, swelling responses do not occur. Ethylene reduces neither transport nor metabolism of applied IAA in either mesocotyl or coleoptile. We propose that maintenance of high auxin levels within these tissues sustains polar transport and contributes to the relative insensitivity of maize to applied ethylene.