bluuebunny/crossref_metadata_2025_split huggingface dataset:
The predaceous activity of nematode‐trapping fungi added to soil
Authors: COOKE RODERIC C. 
Published: February 2008

SUMMARYPredaceous activity of different species of nematode‐trapping fungi introduced into non‐sterile soil varies in both intensity and duration. In some cases free‐living nematode populations increase after the addition of mycelium of these fungi to the soil and in other cases decrease.Evidence suggests that fungi forming the constricting ring type of trap are more efficient in reducing soil nematode populations than fungi forming adhesive reticulate traps,
Populations of stem‐boring Diptera in leys and in subsequent winter wheat and the effects of aldrin and phorate
Authors: HEARD A. J. , HOPPER M. J. 
Published: February 2008

SUMMARYIn 1957‐61 stem‐boring larvae were removed for identification from grasses shortly before ploughing in October and from the subsequent crop of wheat. At Hurley populations of up to 700 larvae per sq.yd. including up to 400 Meromyxa spp., 270 Oscinella vastator and 250 O. frit agg. were found in the leys and up to forty larvae per sq.yd. of all species were found in the wheat. Migration of the larvae from the buried grasses into the wheat was associated with soil temperatures above 7·2°C. at 4 in. depth. The larvae occurred in the wheat mainly in February and March.A survey of twenty‐nine leys in the southern half of England gave an average of eighty larvae, including twenty‐three larvae of O. frit agg., per sq.yd. In wheat grown after the leys there was an average of only two larvae per sq.yd.Attempts were made to kill the migrating larvae by applying aldrin and phorate dusts to the grassland before ploughing and by applying aldrin granules to the soil surface after establishing the wheat. To ensure different levels of infestation the larval population was doubled on some plots by ploughing in a double layer of turf. The aldrin dust treatment of the grassland killed 70% of the migrating larvae. The aldrin granules and the phorate were less, if at all, effective.
Withertip disease of limes (Citrus aurantifolia) in Zanzibar
Authors: ROBERTS MARGARET F. , MARTIN J. T. 
Published: February 2008

SUMMARYLime leaves (Citrus aurantifolia) of different ages were examined chemically to ascertain the relationship between cuticle development and susceptibility to withertip disease. Marked differences were found in the contents of waxes and cutin between the young susceptible and the older resistant leaves. The rapid rate of deposition of cutin, and the exceptionally high level of deposition attained, indicated that cuticle development was an important factor in the resistance of the older leaves to infection.
Further studies on the biological activity of bulbiformin
Authors: VASUDEVA R. S. , SINGH PRITAM , GUPTA P. K. SEN , MAHMOOD M. , BAJAJ B. S. 
Published: February 2008

SUMMARYAmendment of soil with roots of certain leguminous crops, molasses and oil cakes markedly increased the antibiotic production by Bacillus subtilis. A soil amendment consisting of a combination of groundnut cake and molasses was about five times more effective than a dextrose amendment in increasing the production of bulbiformin and also favoured its persistence in the soil. The antibiotic was found to act systemically and to be non‐phytotoxic when taken up by the roots of pigeon pea (Cajunus cajan).In a pot experiment, inoculation of B. subtilis into autoclaved soil amended with molasses, sweet clover roots and groundnut cake brought about a reduction of 88% in the incidence of pigeon pea wilt caused by Fusarium udum.
The uptake of copper by fungal cells
Authors: SOMERS E. 
Published: February 2008

SUMMARYUsing 64Cu a quantitative study has been made of the factors influencing the uptake of copper, from buffered solutions of pH 5·6, by conidia of Neurospora crassa. The initial uptake is probably an ion‐exchange reaction which is followed by permeation throughout the cell; there was no evidence of an adsorption process. Copper is considered to be accumulated passively by the spores by unspecific reaction with cell constituents; the process is complicated by the high uptake of dead cells which results in a variable response by the spore population. The apparent activation energy of the initial exchange has been calculated and the competitive effect of other metal ions shown. A small proportion of the copper uptake was inhibited by respiratory poisons whilst increased copper uptake was observed under anaerobic conditions.The distribution of accumulated copper in disrupted conidia of Alternaria tenuis, N. crassa, and Penicillium italicum has been found to vary with fungal species. Cell walls, particularly of A. tenuis and P. italicum, had a much greater avidity for copper than has been previously supposed. The copper‐binding sites on A. tenuis were more accessible to acid washing, chelation by EDTA, and to radioactive exchange than those on N. crassa. High levels of copper uptake are required for fungicidal action against both these species of fungi and it is suggested that there are different sites of action for the fungistatic and fungicidal processes.
Investigations on fungicides
Authors: WAIN R. L. , SOBÓTKA W. , SPENCER D. M. 
Published: February 2008

SUMMARYA series of thiocarbamoylthionitroparaffins of the general formula XC(S)SCH(CCl3)CHRNO2 (where X is a secondary amino grouping and R is hydrogen or methyl), together with other related compounds, were prepared and examined for their ability to inhibit the germination of spores of Botrytis cinerea in vitro. Some of these compounds were notably fungistatic and the two most active were selected for further examination in tests against six other fungi. Their protectant fungicidal activity was also assessed against B. fabae and Uromyces fabae on broad bean and against Erysiphe graminis on wheat and compared with that of two established commercial fungicides. They were found to possess low phytotoxicity and good fungicidal properties and may find specific uses in crop protection.
Changes in the capsule of Papaver somniferum between flowering and maturity
Authors: BUNTING E. S. 
Published: February 2008

SUMMARYThe changes occurring during ripening in the seed and capsule of Papaver somniferum were examined at Oxford in each of the years 1948‐60.The percentage content of dry material in the seed increases at a fairly uniform rate and in average seasons reaches a maximum of 85–90 about 7 weeks after flowering. The dry weight of the seed and the content of oil and protein are maximal at least a fortnight before a minimum water content is attained.The capsule increases very rapidly in size and weight during the first 2 weeks and the volume, fresh weight and dry weight are maximal within 3 weeks of flowering. Subsequently, there is a significant reduction, not only in volume and fresh weight but also in dry weight. When the capsule has a minimum water content the dry weight is 10–15% below the previously recorded maximum. The percentage dry matter content of the capsule shows little increase until 4–6 weeks after flowering; it then falls very rapidly and the maximum percentage value of 80–85 is reached at the same time as in the seed.The dry and ripe capsule readily absorbs or loses water with changes in ambient conditions, whereas the contained ripe seed exhibits little such variation.Morphine is accumulated in the capsule until about 6 weeks after flowering but later the content declines. When conditions during ripening are warm and dry the water content of the seed and capsule is nearly minimal when the morphine content in the capsule is maximal. In wet seasons, more than half of the morphine previously accumulated in the capsule may be lost by the time a minimum water content is reached.Different varieties behave similarly during ripening, but there are marked variations from year to year in the maximum amount of morphine accumulated in the capsule. Although morphine content is usually greater when warm, dry conditions prevail during ripening, there are exceptions, and the complex interrelationships between environment and morphine production need further elucidation.
Post‐treatment effects of sublethal doses of dieldrin on the mosquito Aedes aegypti L
Authors: DUNCAN JOHN 
Published: February 2008

SUMMARYSublethal doses of dieldrin were topically applied to individuals of the mosquito Aedes aegypti L., and the effects on feeding, egg laying and mortality observed. The highest dose of dieldrin (0·0075 μg./insect) stopped the feeding of 2‐ to 3‐day‐old blood‐fed females. Egg laying continued up to 96 hr. after treatment but then dwindled and finally stopped. Lower doses induced diminished responses and the lowest amount of insecticide applied (0·0016 μg./insect) had no effect.Females (1–2 days old) were treated with 0·0060 μg./insect. Of the survivors, very few fed on subsequent days and only a small number of eggs were laid by them. Dieldrin apparently had no effects on the viability of the progeny from the treated adults.It is concluded that the insecticide primarily affects feeding; egg laying and longevity suffer as a consequence.
Toxicological studies on a beetle, Alphitobius laevigatus (F.)
Authors: HEWLETT P. S. , GOSTICK K. G. 
Published: February 2008

SUMMARYThe influence on the toxicity of insecticides of the site of topical application on the insect's body has been studied, with Alphitobius laevigatus beetles as the test insects. Four toxicants, n‐valone (2‐n‐valeryl 1,3‐indandione), DDT, dieldrin, and allethrin were used in solution in a non‐volatile mineral oil, Shell Risella 17 (R17).To facilitate the interpretation of the results of the toxicity tests, the spread of oil after application to different sites was followed. R 17 oil was marked with a fluorescent material and its spread over beetles was observed under ultra‐violet light. Doses of 0·05 μl. spread over considerable areas of cuticle from most of the sites of application, though doses of 0·02 μl. spread rather less. The greatest spread occurred after dosage between the front coxae, and the least after that on the pronotum. Although the areas of wetted cuticle overlapped following application to different sites, there were possibly quantitative differences in distribution not detectable with the method used. For experimental work applications to the mesoscutellum and hind coxae were the easiest.Toxicity tests for nine sites of application were done, using fixed doses. During and after treatment on the pronotum, elytron, or tarsi, beetles were held in wire loops to prevent their shedding any of the dose. After treatment on the other sites, the beetles were kept in groups running freely within containers. The site of application influenced slightly but significantly the toxicity of n‐valone DDT, and allethrin, but scarcely at all that of dieldrin. Generally the first three toxicants were most toxic when applied on or near the prothorax.The toxicities of the applications made to the mesoscutellum and hind coxae were examined in more detail, varying the doses. Pairs of parallel probit‐log‐dose lines fitted satisfactorily responses for the two sites, concentration of toxicant and volume of solution being varied in respective experiments with each toxicant. Combining these results with those from the first paper of this series indicates that the respective probit planes in log‐concentration and log‐volume for the two sites were parallel.From the toxicity experiments as a whole, it appeared that the toxicant was at most about 1·9 times as effective on the ‘most sensitive’ site as on the ‘least sensitive’.
Field tests of experimental and commercial soil sterilants against the potato‐root eel worm, Heterodera rostochiensis Woll
Authors: PEACHEY J. E. , RAO G. N. , CHAPMAN MARGARET R. 
Published: February 2008

SUMMARYFive experiments were made on sandy loam containing 12% clay, infested with potato‐root eelworm. Methyl bromide at 89 g./10 sq.ft. killed most eelworms, induced most increase of ammonia‐nitrogen and gave the largest yield of ware potatoes. Metham‐sodium diluted and mixed into the soil at normal dose (35 ml. active material/10 sq.ft.) and half dose, dazomet at 29 g. active material/10 sq.ft. mixed into the soil and methyl isothiocyanate injected at 23 ml. active material/10 sq.ft. were more effective than injected metham‐sodium or D‐D, except when D‐D was applied at 70 ml./10 sq.ft. to soil at 20° C. Methyl bromide, metham‐sodium, dazomet and methyl isothiocyanate controlled weeds in the weeks immediately following treatment.Assays of live eggs, hatched larvae, larvae in roots or cysts formed on the root‐mat of potato indicator plants and counts of nematodes free in the soil all selected the same treatment as the most effective. More new cysts formed in the treated plots than in untreated controls because intensive eelworm attack in untreated plots limited root growth and prevented larvae developing into cysts. To produce a good yield of ware potatoes it was necessary to reduce the eelworm population by 90%.None of the commercial treatments damaged the haulms or tainted the tubers, though spring treatment 7 weeks before planting may have depressed yields slightly. Of many experimental compounds tested, only 1,2,3,‐tribromopropane and chloro‐bromopropene (CBP‐55) were promising.
Fruit‐spot (‘speckle’) of Jamaican bananas caused by Deightoniella torulosa (Syd.) Ellis
Authors: MEREDITH D. S. 
Published: February 2008

SUMMARYThe severity of banana fruit‐spot (‘speckle’), caused by Deightoniella torulosa, in plantations having abundant leaf trash was greater than in relatively trash‐free plantations. Experimental de‐trashing reduced disease severity to a level at which it ceased to be of commercial importance. Aerial application of fungicides did not control disease, but direct spraying of bunches was effective. Plastic bags put on bunches shortly after ‘shooting’ also provided good control of speckling. Relative costs of various control measures are discussed and associated practical difficulties pointed out. De‐trashing two or three times a year appears to be the cheapest and most practical method.
Stump protection against Fomes annosus
Authors: RISHBETH J. 
Published: February 2008

SUMMARYInoculation of pine stumps with oidia of Peniophora gigantea directly after felling gives good protection against Fomes annosus. With the largest inoculum of F. annosus spores likely to occur naturally, a dosage of 1 × 104oidia suffices for stumps having a wood‐diameter of 16 cm. P. gigantea enters the lateral roots of inoculated stumps and tends to check advance of F. annosus in any tissues infected at the time of felling; it also replaces this fungus to some extent, Lignin is rapidly decomposed and sporophores are generally produced within a year. Suspensions may conveniently be applied by a compressed air sprayer. Owing to the selectivity of freshly cut stumps, contamination of the suspension is not a serious hazard.If widely used, the method would necessitate large‐scale production of suitable inoculum sources. For most of the experimental work undertaken the inoculum was derived from wood‐block cultures of P. gigantea stored in polythene bags, but for routine use a more compact source would be preferable. A method is described for preparing tablets which, when dissolved in IOO ml. water, yield suspensions containing up to 1 × 106viable oidia per ml.: if kept at 10° C. they should each provide inoculum for more than a hundred stumps over a storage period of 10–20 weeks.The relative merits of inoculation and chemical treatment for control of F. annosus in pine stumps are briefly discussed and other possible applications of stump inoculation are outlined.
Bacterial canker of stone‐fruits
Authors: CROSSE J. E. 
Published: February 2008

SUMMARYMost leaf‐scar infections of cherry trees are caused by bacteria washed from the leaf surfaces in rain. In estimates made from three young orchards in four different seasons the numbers of Pseudomonas mors‐prunorum on the leaf surfaces of the cherry variety Napoleon during the autumn were consistently higher than those on the more resistant variety Roundel, the ratio on occasion exceeding three to one. The amount of leaf surface inoculum and the number of cankers on each variety increased progressively with the age of the trees, but both were unrelated to the severity of leaf‐spot infection, which fluctuated widely from year to year. The possibility of epiphytic growth by the pathogen and the relationship between inoculum potential and ‘field’ resistance of the varieties are discussed.
The effects of nitrogen, phosphorus, potassium and gibberellic acid on leaf area and cell division in Majestic potato
Authors: HUMPHRIES E. C. , FRENCH S. A. W. 
Published: February 2008

SUMMARYPotato plants in a factorial experiment with nitrogen, phosphorus and potassium were sprayed with gibberellic acid. Leaf areas were determined at a‐week intervals and cell numbers in some leaves determined. Total leaf area of main‐stem leaves was affected more by nitrogen than by gibberellic acid. The effects of nitrogen and gibberellic acid on maximum size of main‐stem leaves increased acropetally. Mineral nutrients affected lateral‐stem leaves more than main‐stem leaves, because laterals developed after the soil had been depleted of nutrients.Leaf discs from main‐stem leaves nos. 7, 11 and 15 were macerated with pectinase and ethylene‐diamine‐tetraacetic acid and cells counted. Cell size decreased from leaf to leaf up the stem. Gibberellic acid but none of the mineral nutrients increased cell size. Cell size accounts for only part of the increase in leaf area caused by gibberellic acid, because cell number also increased.In contrast to its effect in an earlier experiment, gibberellic acid increased dry matter of tubers, perhaps because larger pots were used. Potassium increased total dry matter and net assimilation rate.In absence of nitrogen gibberellic acid increased the integral of leaf area and time (the leaf‐area duration) but this increase was not associated with increase in yield. With nitrogen most of the difference in leaf‐area duration caused by mineral nutrition was associated with lateral‐stem leaves. There was a linear relationship between leaf‐area duration and dry‐matter yield, and regression coefficients indicated that I g. dry matter was produced by a leaf‐area duration of 3 or 4 dm.2weeks.
Weed populations on arable land after four‐course rotations and after short leys
Authors: HEARD A. J. 
Published: February 2008

SUMMARYUsing a point‐quadrat, measurements were made of the frequency of the weeds in the stubbles of winter wheat grown after various 3 1/2‐year leys and after two four‐course arable rotations barley, fodder‐beet and barley undersown with a 1‐year ley. The most frequent broad‐leaved weeds were Matricaria maritima var. inodora, Stellaria media and Polygonum aviculare. The total frequency of broad‐leaved weeds was 10% after the arable rotations and 18% after the 3 1/2‐year leys. The corresponding figures for Poa annua were 16 and 25%. These differences probably occurred because the weeds were abundant and set seed during the years of establishment of the 3 1/2year leys.Some grasses and clovers sown in the leys were common weeds of the wheat. Lolium multiflorum, Trifolium pratense and T. repens showed frequencies of 14–30% after leys in which they had seeded. Lolium perenne re‐established vegetatively; its average frequency was 15% after ryegrass leys. Dactylis glomerata was more easily killed by ploughing.Defoliation and nitrogen manuring treatments of the leys affected the control of S. media, P. aviculare, T. repens, L. perenne, P. annua and Agropyron repens. The frequency of A. repens was 15% after the arable rotation, whereas after 34‐year leys it was 15% after hayed leys and only 4% after cut leys not receiving nitrogen and after some grazed leys.
The epidemiology of tomato mosaic III. Cleaning virus from hands and tools
Authors: BROADBENT L. 
Published: February 2008

SUMMARY10% Teepol, 2% citric acid, 1% tannic acid, 3% NaH2PO4, 3% Na2HPO4, 0·1%, 0·5%, 1 and 3% Na3PO4 and Diversol (a chlorinated Na,PB, plus bromine) solutions were mixed with tomato sap infected with tomato mosaic virus (TMV) and inoculated to Nicotiana glutinosa, after standing for different lengths of time. Fewest lesions were caused by mixtures with tri‐sodium orthophosphate or Diversol at concentrations over 1%.It was found difficult to free sap‐cngrained hands from TMV: the best treatment was to wash in a 3% solution of tri‐sodium orthophosphate and then to scrub well with soap and water, but this did not always free under the nails from virus.The best way to prevent contamination from TMV‐infected tools, other than heat sterilization, was to dip them in 3% tri‐sodium orthophosphate solution and not to rinse this off.
The use of nematicides to control the spread of arabis mosaic virus by Xiphinema diversicaudatum (Micol.)
Authors: HARRISON B. D. , PEACHEY J. E. , WINSLOW R. D. 
Published: February 2008

SUMMARYField experiments on three soil types in southern Britain showed that applying dichloropropane‐dichloropropene (D‐D) or methyl bromide at 2 lb./100 sq.ft. in summer killed over 99% of X. diver sicaudatum in soil and almost stopped the infection of strawberry crops with arabis mosaic virus (AMV). Both chemicals killed X. diversicaudatum down to 28 in., the greatest depth sampled. D‐D at 1 lb./100 sq.ft. gave variable results when applied in summer but was more effective when left in the soil through the winter. At the doses used, dazomet, methyl isothiocyanate, metham‐sodium, dibromochloropropane and tetramethyl thiuram disulphide killed too few X. diversicaudatum to control the spread of AMV.Incidence of AMV in crops planted on treated land was closely related to the number of surviving X. diversicaudatum. Larvae and adults seemed equally susceptible to the chemicals. In some experiments, other species of plant‐parasitic nematodes were sometimes less affected by D‐D than X. diversicaudatum.In untreated soil planted with strawberries, numbers of X. diversicaudatum tripled in 2 years, most of the increase coming in the second year. In D‐D treated soil, the few survivors appeared to increase even more slowly than this. A nematicidal treatment that brings the X. diversicaudatum population to fewer than one nematode per 2 1. of soil should not need repeating for several years.
The effect of three organo‐phosphorus insecticides on certain arthropods which infest livestock
Authors: BEESLEY W. N. 
Published: February 2008

SUMMARYThe organo‐phosphorus compounds fenchlorphos, trichlorphon and coumaphos, used at 0·25%, killed Dermanyssus gallinne on poultry and perches, and Leiognathus (Liponyssus) sylziarum on poultry: both showed persistent acaricidal value without avian toxicity.Fenchlorphos at 100 mg./kg. and trichlorphon at 20–100 mg./kg. were systemically effective against larvae of Lucilia sericata on sheep. Coumaphos was non‐insecticidal, but toxic to sheep, when given orally at 15–20 mg./kg. Sprzying with 0·25% coumaphos protected sheep against L. sericata larvae for 8–10 weeks.Fenchlorphos administered orally at 110 nig./kg. killed larvae of Hypoderma boris which had been implanted into calves. Trichlorphon (2·0%) applied externally killed all larvae within 28 days: coumaphos (2·0%) similarly applied was larvicidal within about 15 days.The toxic dose of fenchlorphos for calves was 500 mg./kg.; trichlorphon at 300 mg./ kg. and coumaphos at 20 mg./kg. were toxic to sheep.