bluuebunny/crossref_metadata_2025_split huggingface dataset:
The life‐history of the Indian meal‐moth, Plodia interpunctella (Hübner) (Lep. Phycitidae) in a warehouse in Britain and on different foods
Authors: WILLIAMS GWYNETH C. 
Published: February 2008

SUMMARYIn a population of Plodia interpunctella living on 4 tons of bagged American maize stored in a Nissen hut, fewer adults than expected emerged in the spring, as many pupae were killed by high temperatures close to the roof. In spite of this, a population of approximately eighteen adults gave rise 3 months later to 643 larvae. There were indications that the life cycle might be completed in 9 weeks, as a second generation of adults started to emerge within this period.Larvae preferred bags stacked flat to those stacked upright. They tended to occur in the upper parts of stacks, to spin their cocoons in the necks of bags and to remain in their existing sites without showing any indication of migrating.Of four food materials tested in laboratory studies, no. 3 N. Manitoba Tough wheat induced quickest development, followed by sultanas, American yellow corn and almonds. Of four types of wheat, Australian was more suitable than no. I N. Manitoba or U.S. Northern Spring; English wheat was the least suitable. Milo (N. American sorghum) was as good as no. I N. Manitoba and U.S. Northern Spring wheats, and Plate maize was comparable to English wheat. Groundnuts were less satisfactory and maize meal gave poorer results than any other food.The main period of emergence of adults was short on those foods which induced the most rapid development but prolonged on those on which the development period was longer. The life cycle was unusually long in a proportion of individuals which were reared on American yellow corn, no. I N. Manitoba wheat and almonds. In these examples the fully grown larvae underwent a long period of rest within the cocoon, suggesting a facultative diapause. Mortality of pre‐adult stages appeared to be higher when the period of development was longer.
Population increase of Ditylenchus dipsaci (Kühn) in the narcissus and the spread of the nematode through the soil
Authors: WEBSTER J. M. 
Published: February 2008

SUMMARYA bioassay technique, using forty onion seedlings per pot, was used to determine the soil population of the narcissus race of Ditylenchus dipsaci.In experiments with narcissus, a progressive increase of D. dipsaci populations was shown, reaching a peak at the end of the growing season. This rise in population in May/June was associated with a rise in temperature. Increase in inoculum gave a significantly larger population in the foliage but not in the bulbs. Nematodes moved actively and were transported passively both up and down within the host plant. The presence of spikkels was associated with nematodes in the active intercalary meristem.Migration from the plant into the soil and back into the plant, mostly via the base of the bulb, was continuous throughout the growing season and related to the population increase within the plant. Migration of nematodes from wetted dried leaf tissue continued over 60 days. Spread of the nematode through the soil was slow in the absence of external agencies, such as water run‐off and methods of cultivation.
Sugar and fructosan accumulation in virus‐infected plants: rapid testing by circular‐paper chromatography
Authors: GOODMAN P. J. , WATSON M. A. , HILL A. R. C. 
Published: February 2008

SUMMARYThe effects of virus infection on the sugar and fructosan contents of plants were studied by circular‐paper chromatography. Fructose and glucose in sugar‐beet leaves were greatly increased, and sucrose slightly, by infection with beet yellows virus (BYV): sugar content was increased more by an avirulent than by a virulent strain. Yellow‐net virus decreased the sugar concentration, whereas yellow‐net mild yellows virus increased it. Sugar accumulated in leaves of magnesium‐deficient plants, which also showed symptoms resembling virus yellows.Carrot motley dwarf virus increased fructose, glucose and sucrose concentrations in carrot leaves, but in petioles and roots sucrose increased while fructose and glucose decreased: more sugar accumulated in plants infected late than early. Applying menazon to the seed to control aphids increased the sucrose concentration of the roots.Cereal yellow dwarf virus (CYDV) increased fructose, glucose, sucrose and four fructosans in leaves of oats, an avirulent strain more than a virulent one. Virulent strains of BYV and CYDV apparently decrease photosynthesis more than avirulent ones.
Studies of pelargonium leaf curl virus
Authors: HOLLINGS M. , STONE OLWEN M. 
Published: February 2008

SUMMARYPelargonium leaf curl virus (PLCV) was compared with nine other viruses with isometric particles: broad bean mottle, carnation mottle, carnation Italian ringspot (CIRV), cymbidium ringspot, raspberry ringspot, tobacco necrosis, tomato bushy stunt (TBSV), turnip crinkle and a virus from Trifolium repens.PLCV was serologically related to CIRV and TBSV, although cross‐reactions between the latter two viruses occurred only with sera from rabbits given one more injection of antigen than usual. Considerable antigenic differences were found among seven isolates of PLCV, and between these isolates and CIRV and TBSV.Cymbidium ringspot virus was serologically closely related to the virus from Trifolium repens, and both were similar but serologically unrelated to the PLCV‐CIRV‐TBSV group. No other serological relationships were found among the ten viruses. Serologically related viruses gave similar zones after centrifugation in sucrose density‐gradients and, usually similar sedimentation coefficients.The different viruses infected twenty‐three to forty‐four out of sixty plant species tested. Carnation mottle and turnip crinkle viruses were not eliminated from plants grown at 37d̀C. for 4–6 weeks, whereas the other viruses usually were. The properties of the viruses in vitro were broadly similar.
The control of Alternaria species on leaves of sugar beet infected with yellowing viruses
Authors: RUSSELL G. E. 
Published: February 2008

SUMMARYSpraying the foliage with copper or captan increased the sugar yield of beet plants inoculated with two yellowing viruses but did not increase the yield of uninoculated plants. The severity of leaf‐necrosis symptoms, resulting from virus‐inoculation, was decreased by spraying with fungicides. These results could be attributed to a partial control of Alternaria spp. which invariably attack the older leaves of beet plants infected with beet yellows virus (BYV) and beet mild yellowing virus (BMYV). Alternaria infection also apparently affected the processing quality of the roots by lowering the sugar content and increasing the sodium content. It seems, therefore, that Alternaria spp. may have caused much of the damage previously attributed directly to virus infection. Spraying virus‐infected plants with copper or captan caused smaller yield increases in an experimental, virus‐tolerant, variety than in a commercial variety. The virus‐tolerant variety showed a useful degree of inherited resistance to Alternaria and this gave yield increases comparable with those obtained by fungicide treatment of the commercial variety.These preliminary experiments suggest that Alternaria‐induced necrosis is of considerable economic importance in beet crops infected with yellowing viruses. The losses due to the disease can be reduced by growing resistant varieties and by spraying with fungicides, although the need for further experimentation, using different strains of BYV and BMYV and also different fungicides, is emphasized.
Tomato leaf curl diseases in the Sudan and their relation to tobacco leaf curl
Authors: YASSIN A. M. , NOUR M. A. 
Published: February 2008

SUMMARYThe viruses causing two tomato leaf‐curl diseases, tomato leaf curl without vein thickening (TLCV) and tomato leaf curl with vein thickening (TVTV), were both transmissible (to tomato and other hosts) by the aleurodid Bemisia tabaci (=B. gossypiperda M. & L.) and by grafting, but not by mechanical inoculation of expressed sap. A third virus, which arrested growth of the shoot apices and caused a disease referred to as tomato condensed top (CT), was transmissible only by grafting and was not studied in detail.Both TLCV and TVTV belong to the complex of tobacco leaf‐curl viruses described by other workers, but the different effects of the two and their failure to interfere with one another in plants suggest that they are not strains of one virus.TLCV and TVTV were not transmissible to cotton nor was cotton leafcurl virus transmissible to tobacco, tomato or Datura stramonium L. Virus transmitted from okra with leaf curl caused leaf curl both in cotton and tobacco, suggesting that the okra was infected with a mixture of viruses or with a virus having a new combination of properties. TVTV was transmitted with difficulty to okra, causing vein thickening.
Studies on resistance and tolerance to cocoa viruses in Ghana
Authors: ATTAFUAH ALEX. , GLENDINNING D. K. 
Published: February 2008

SUMMARYCuttings from fifty T17 seedling trees derived from an open‐pollinated pod from the Iquitos selection no. 53 were each infested with fifty infective mealybugs (Planococcus njalensis) carrying either the severe New Juaben strain of cocoa swollen shoot virus or the Kpeve strain of cocoa mottle leaf virus.All but forty‐seven out of 1000 cuttings treated with CSSV became infected. All Amelonado beans treated at the same time as these cuttings with thirty insects each became infected. There was no evidence of variation in susceptibility to infection with CSSV in the T17 progeny. The infected plants were scored for tolerance; one clone seemed more tolerant and five less tolerant than the remainder. Deposition of mixed pollen in the natural pollination is suggested as the cause of this variation in tolerance in the progeny. There was no evidence of rcsistance and tolerance being associated. Tolerance to CSSV was much higher in the T17 progeny than in Amelonado.Transmission rates of CMLV were much lower than of CSSV both to the T17 cuttings and to the Amelonado beans, Conditions at the time of infestation clearly affected the transmission rates. No evidence of variation in susceptibility to infection with CMLV was found in the T17 progeny. Plants infected with CMLV were scored for tolerance in only one replicate; there was little evidence of variation and none of an association between resistance and tolerance.
The spread of yellows viruses in sugar beet
Authors: KERSHAW W. J. S. 
Published: February 2008

SUMMARYIn 1963 and 1964 single sugar‐beet plants (infectors) growing in commercial root crops were infected with either beet yellows virus (BYV), beet mild yellowing virus (BMYV), or both viruses, by viruliferous Myzus persicae (Sulz.). Virus‐free aphids were put on other beet plants. All the M. persicae were then removed, but in 1964 additional ones, either virus‐free or viruliferous, were put on half the plots. More plants subsequently became infected with yellows viruses in plots containing infectors than in those without.In 1963 more virus spread from BYV than from BMYV infectors; in 1964 the reverse happened. Usually less of either virus spread from plants with dual infection than from those singly infected. In 1964 more virus spread in plots where additional viruliferous apterae of M. persicae were set free on infector plants than in others where the aphids were removed.The greater spread of BYV than of BMYV in 1963 is attributed to transmission by Aphis fabae Scop., which was exceptionally abundant.The greater spread of BMYV than of BYV in 1964 is attributed to differences in the virus‐vector relationships of the two viruses when transmitted by M. persicae only.
Influence of steam/air mixtures, when used for heating soil, on biological and chemical properties that affect seedling growth
Authors: DAWSON J. R. , JOHNSON R. A. H. , ADAMS P. , LAST F. T. 
Published: February 2008

SUMMARYAn apparatus for heating small quantities of soil with steam/air mixtures, at temperatures from 50 to 100d̀ C., is described.Heating naturally infested soils at 60d̀ C. for 10–30 min. eliminated attack by Rhizoctonia solani Kuhn and pathogens causing brown root rot, so increasing survival and growth of lettuce and tomato seedlings respectively.Growth in soils heated at temperatures above 80d̀ C. was often less, however, than in soils heated at 60–75d̀ C. Decreases were associated with relatively high soil concentrations of (1) soluble and exchangeable manganese and (2) nitrite. Amounts of ammonia were greatly increased at 52d̀ C., compared with the unheated controls, but those of manganese (water‐soluble and exchangeable) and nitrite were not significantly increased at temperatures less than 65d̀ C.The damage done to lettuce by R. solani when inoculated to preheated soils usually increased with increasing treatment temperatures. Fewer seedlings survived in soils preheated at 60d̀ C. than in the unheated controls but usually more than in soils preheated at 100d̀ C.
The suppression of ascospore production to facilitate the control of apple scab (Venturia inaequalis (Cke.) Wint.)
Authors: BURCHILL R. T. , HUTTON K. E. 
Published: February 2008

SUMMARYUsing phenylmercuric chloride (PMC) as the experimental fungicide it has been shown that spraying trees once in autumn at 0.05% and again just before bud‐burst at 0.01% reduced scab infection on blossom truss leaves by over 99% in the following spring. In another orchard 0.01% PMC sprays in autumn and just before bud‐burst, followed by fungicide sprays in spring and early summer, gave complete control of scab. In a third orchard, which was subject to contamination by ascospores from non‐treated apple trees, infection was reduced by 56.9% by one autumn and one pre‐bud‐burst spray of 0.01% PMC without subsequent anti‐scab sprays.
Studies on the aphid, Cavariella aegopodii Scop
Authors: DUNN J. A. 
Published: February 2008

SUMMARYThe important aphid pest of carrots, Cavariella aegopodii Scop., overwintered in the egg stage on all the common willows (Salix spp.) found in the English Midlands, and showed no host preference between willows on the same site. The eggs were found more frequently on Salix alba and S. fragilis, however, probably because these trees, being larger and generally growing in less sheltered conditions than other species of willow, provide obvious targets for the migrating aphid. Neither eggs nor fundatrices were found on Salix babylonica.The spring migration from willow to carrot started in May, reached its peak about the beginning of June and was over before July. April‐sown carrots were the most severely attacked and high, damaging aphid populations sometimes developed on these within 6–7 weeks from the onset of immigration.The number of aphids on carrots declined in July when winged forms developed among the second and third alienicolae generations and dispersed. Some of these winged alienicolae flew to later‐sown carrots, where they did little colonizing but might have furthered the spread of motley dwarf virus.Natural enemies did not check aphid multiplication: years of highest aphid numbers were those with low rainfall over the first half of the spring migration period.Seasons when motley dwarf virus disease was most troublesome were those in which C. aegopodii apterae survived on overwintered carrot crops.
Some interactions of kinetin and temperature on tobacco leaves infected with tomato aucuba mosaic virus
Authors: DAFT M. J. 
Published: February 2008

SUMMARYKinetin stimulated production of tomato aucuba mosaic virus in detached tobacco leaves kept at 18 and 28°C., both in newly infected leaves and in those infected a week previously. Kinetin counteracted the ageing effect of exposing leaves at 28°C. In attached leaves kinetin either stimulated or inhibited virus synthesis, depending on the quantity applied and the age of the leaves. Kinetin increased fresh weights, soluble proteins and chlorophyll content of leaves.In an individual comparison of leaves treated with kinetin and with water, infectivity of extracts and ribonuclease activity were correlated in leaves treated differently at the same temperature, but not otherwise.
The epidemiology of tomato mosaic VIII. Virus infection through tomato roots
Authors: BROADBENT L. 
Published: February 2008

SUMMARYOnly a small percentage of tomato plants became infected when grown in soil that contained TMV‐infected debris from a previous crop, whether they were set out into this soil or into a layer of partially sterilized soil overlying it. In one experiment, half the plants were infected when grown in sand containing infected tomato debris, and treating the sand–debris mixture with metham‐sodium greatly increased the proportion of plants infected. When shoots were separated from each other virus was not transmitted from adjacent infectors through roots of plants growing in uninfested soil.When roots were inoculated with TMV, virus was detected in young shoots after periods varying from 3 weeks in seedlings to 6 months in older plants, the average periods being between 10 and 16 weeks. Virus was detected in the roots of many plants, but not in their shoots, when experiments ceased 4–6 months after root inoculation. Plants infected in their roots often showed severe fruit defects in the lower trusses several weeks before mosaic showed in the foliage.
Early‐season control of hop downy mildew, Pseudoperonospora humuli (Miy. and Tak.) Wilson, with streptomycin and protectant fungicides in severely infected plantings
Authors: COLEY‐SMITH J. R. 
Published: February 2008

SUMMARYApplications of streptomycin sulphate or protectant fungicides reduced numbers of secondary infections in severely infected hop plantings. When primary infected shoots treated with streptomycin were left on plants for 3 weeks no significant increase in secondary disease resulted. Streptomycin, which was absorbed rapidly by hop plants, could not be detected in expressed shoot sap by early June and had no effect on crop yield or quality.
Effects of photoperiod in the glasshouse on the growth of leaves and tillers in three perennial grasses
Authors: RYLE G. J. A. 
Published: February 2008

SUMMARYLeaf and tiller development in vegetative plants of S.37 cocksfoot (Dactylis glomerata L.), S.215 meadow fescue (Festuca pratensis Huds.) and S.24 perennial rye‐grass (Lolium perenne L.) were measured in photoperiods varied by extending a basic period of natural light with low‐intensity artificial illumination so that all plants received approximately the same amount of light each day. Increasing the photoperiod usually increased leaf length and sometimes leaf width, but decreased rate of production of leaves. However, the rate of production of new leaf surface increased with photoperiod. Increasing the photoperiod generally decreased the rate of tillering; thus, plants grown in long days had few tillers with large leaves and sheaths, in short days, plants developed more but smaller tillers.
Breeding for resistance to infection with yellowing viruses in sugar beet
Authors: RUSSELL G. E. 
Published: February 2008

SUMMARYDifferences in resistance to infection with beet yellows virus (BYV) and beet mild yellowing virus (BMYV) have been observed in virus‐tolerant sugar‐beet breeding material. The results of glasshouse virus‐susceptibility tests usually agreed well with those of field experiments in which plants were exposed to artificial, or natural, infestation with viruliferous aphids. Breeding lines and varieties, which showed resistance to BYV when Myzus persicae Sulz, was used as vector, generally showed a similar resistance to this virus when Aphis fabae Scop. was used. Varieties which were resistant to infection with one virus were not necessarily resistant to the other, although some showed resistance to both BYV and BMYV. Preliminary results suggest that resistance to infection may be controlled by recessive genes which occur widely in sugar‐beet cultivars. The mechanism of this form of resistance is not understood, but it does not appear to be closely associated with resistance to the aphid vectors of the viruses.The observed differences in resistance to infection demonstrate the possibility of breeding a sugar‐beet variety in which two forms of resistance to virus yellows, tolerance and resistance to infection, are combined.
The influence of increased CO2 concentration and supplementary illumination on growth of tomato seedlings during the winter months
Authors: NEWTON PETER 
Published: February 2008

SUMMARYDuring the period November to March a threefold increase in CO2 concentration had only a small effect on the growth rate of tomato seedlings, variety Eurocross B. Although net assimilation rates were increased, some inhibitory effects of increased CO2 concentration on leaf growth were found when the seedlings were very small. The increase in dry weight was equivalent to that made in a few days by plants grown with naturally occurring amounts of CO2. There was no increase in the rate of flower initiation. Using supplementary illumination for 17 hr. per day with high‐pressure mercury vapour lamps made it possible to produce in November‐December seedlings similar to those grown during March‐April with natural illumination.
Translocation of photosynthetic assimilates in wheat
Authors: LUPTON F. G. H. 
Published: February 2008

SUMMARYWhen 14CO2 was supplied to three varieties of wheat in the field translocation of carbohydrates took place freely throughout young plants, but after the stems elongated the tillers became autotrophic.The efficiency with which carbohydrate was translocated to the grain increased during the first 4 weeks after anthesis and then fell. Translocation from the glumes and flag leaves was almost entirely towards the grain; that from the second and third leaves was partly towards the grain and partly downward, with evidence of varietal differences in behaviour.
Interactions of crop density of field beans, abundance of Aphis fabae Scop., virus incidence and aphid control by chemicals
Authors: WAY M. J. , HEATHCOTE G. D. 
Published: February 2008

SUMMARYThe number of Aphis fabae Scop. per plant and per acre developing on field beans (Vicia faba L.) was inversely related to seeding rate (i.e. plant density) except sometimes at very low rates; with equal numbers of plants per acre, fewer aphids developed on plants in rows 11 in. than 22 in. apart.Plots sown in mid‐March with more than about 150,000 plants per acre were more attractive than less dense stands to colonizing alate A. fabae, but established colonies multiplied most on the sparsest and least on the densest plots.The number of plants per acre infected by pea leaf‐roll virus was inversely related to planting density. There were more virus‐infected plants on II in. than on 22 in. spaced rows‐in contrast to the numbers of A. fabae. A single spray with demeton‐methyl, timed to control A. fabae, did not significantly decrease virus incidence.Grain yields of sprayed plots were little altered by increasing the seed rate above a critical minimum, except in one year when the densest crops lodged. Increased yields from spraying were closely related to the numbers of A. fabae on unsprayed plots. Dense planting (more than 400,000 plants per acre) prevented or greatly decreased losses caused by A. fabae in unsprayed plots except in one year when the aphids were exceptionally abundant.