bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experiments on the value of stupefying and lethal substances in the control of harmful birds
Authors: RIDPATH M. G. , THEARLE R. J. P. , McCOWAN D. , JONES F. J. S. 
Published: February 2008

SUMMARYLaboratory experiments and field trials in town and country were carried out with four reputedly narcotic substances (pentobarbital sodium, dithiobiuret, tri‐orthocresyl phosphate and chloralose) and four poisons (picrotoxin, nicotine, parathion and sodium fluoroacetate) to investigate their value in the control of pigeons, corvids and sparrows.The alpha isomer of chloralose was the most satisfactory material tested; it normally produces narcosis from 15 to 30 min. after ingestion on wheat or maize and this lasts from 10 to 20 hr. Its potency was assessed using treated grain, gelatine capsules and flour pills, administered with and without food, and also from field data. It was most effective on grain and least effective in gelatine capsules. The flour pill method was the most satisfactory for obtaining an LD 50 figure which for alpha‐chloralose used against feral pigeons was about 131 mg./kg. live weight. The pure beta isomer of chloralose was ineffective.Using alpha‐chloralose, urban populations of feral pigeons were reduced from 48 to 83% in three to seven treatments. In fifty‐two trials in towns 1544 feral pigeons were disabled, only five of the 1409 picked up being found at a greater distance than 500 yards from the baiting point. With five different concentrations between 2.5 and 0.5% by weight in bait, the lower concentrations produced lower mortality without affecting the size of the catch. Bait containing chloralose at 1.5% by weight gave the greatest efficiency with a mortality of less than 50% and this concentration is recommended for practical control operations.In towns the risk of accidentally affecting legally protected species is negligible, whereas in rural districts it is much higher, at any rate when grain baits are used. The use of maize greatly reduces the risk to small birds which cannot swallow the large grains.Four series of field trials in Kent and East Anglia in autumn and winter caught only seven wood‐pigeons and one stock‐dove during a total of 72 baiting days. This disregard for cereals is discussed and is thought to be due to changing ‘feeding images’.In four field trials to catch corvids, using alpha‐chloralose on maize, only fourteen were narcotized. Two field trials using alpha‐chloralose against house‐sparrows were unsuccessful, but eighty house‐sparrows were captured incidentally during four of the trials on feral pigeons. With the possible exception of nicotine none of the other substances tested showed promise for controlling birds. The use of blue‐coloured baits, as a warning to the public, reduced takes by feral pigeons but did not prevent feeding altogether.The value of alpha‐chloralose as a control agent and the hazards it presents to wildlife are discussed; its use probably offers a better means of controlling feral pigeons in towns than any existing method.
Verticillium wilt of tomatoes—the role of pectic and cellulolytic enzymes
Authors: WOOD R. K. S. 
Published: February 2008

SUMMARYAn isolate of Verticillium albo‐atrum, highly pathogenic to tomato plants, secreted polygalacturonase (PG) on a variety of synthetic media. Particularly active filtrates were obtained from cultures on media containing mineral salts, casamino acids and pectin or polypectate. Pectates were degraded more rapidly than pectin. None of the filtrates had high cellulase or pectinesterase activity; the most active were from cultures with carboxymethyl cellulose or pectin as carbon sources.The fungus made little growth in exudates from xylem sap unless carbon sources were added, and then culture filtrates had appreciable PG and cellulase activity but very little pectinesterase activity. Saps from susceptible and resistant varieties gave similar results.The fungus was also grown on a synthetic sap based upon an analysis of xylem exudate. Results similar to those for xylem sap were obtained.Filtrates from cultures on dead stems of both varieties had little pectinesterase activity and a definite but relatively low PG and cellulase activity.Extracts from diseased plants had no PG or cellulase activity but had a considerably higher pectinesterase activity on fresh and dry weight bases. Exudates from xylem of diseased plants had no PG or cellulase activity but had a low pectinesterase activity which was slightly higher than that from healthy plants.The effects of different culture filtrates on cuttings is described. Filtrates with high PG activity produced some of the symptoms found in naturally diseased plants.Solutions of pectin, polypectate and carboxymethyl cellulose caused cuttings to wilt in very low concentrations; much higher concentrations were needed after solutions of these substances had been degraded by PG or cellulase.
Studies on silvering disease of red beet
Authors: KEYWORTH W. G. , HOWELL J. SHEILA 
Published: February 2008

SUMMARYObservations and experiments were made on silvering disease of red beet during the period 1952–59. The disease is most prevalent on seed crops of the variety Cheltenham Green Top, but also affects other cultivars of Beta vulgaris, often only mildly. The causal organism is Corynebacterium betae sp.nov. which can be found in the tap‐roots, stems and leaves of systemically affected plants causing veinal or uniform silvering of the leaves followed by wilting and death of the plant. External leaf infection gives rise to silvered lesions on the laminae or leaf margins.About 1% of the seeds from infected plants contain the pathogen and these seeds give rise to plants showing systemic symptoms. The bacteria spread from such plants in the seedling bed during the autumn and winter, probably entering other plants through their leaf edges. Such spread can occur to distances of at least 50 yards, and the planted out seed crop may be up to 75% infected. The disease is readily transmitted on knives which have cut infected roots.Seed treatment with streptomycin or erythromycin (200–400 g/ml.) gives almost complete control of the disease. Mercurial dusts are less effective but have been found of some value in practice.
Investigations on fungitoxic derivatives of salicylaldehyde
Authors: SMITH R. J. , READ W. H. 
Published: February 2008

SUMMARYA number of halogenated derivatives of salicylideneaniline were synthesized, several of which showed high eradicative activity against cucumber powdery mildew when sprayed on to young pot plants. The two most promising compounds were 3‐bromo‐and 3‐chloro‐salicylideneaniline. These were subjected to commercial‐scale trial, but, although more effective (at 0.08–0.10%) than standard 2:4‐dinitro‐6‐(1‐methyl‐heptyl)phenyl crotonate (‘Karathane’) sprays in controlling severe mildew infection, they showed phytotoxic effects on mature cucumber plants.Their toxicity to certain other fungi is outlined in the appendix.
Effect of nitrogen supply on the response of Majestic potato to gibberellic acid
Authors: HUMPHRIES E. C. , FRENCH S. A. W. 
Published: February 2008

SUMMARYPotato plants sprayed with gibberellic acid (GA) were given extra nitrogen either through the soil (as ammonium nitrate) or through the leaves (as urea). GA increased the initial production of dry matter but the effect did not persist, even with additional N. The number of leaves on lateral branches was decreased by GA partly because leaf production on laterals at lower nodes was inhibited. N increased the rate leaves were produced on lateral branches; the soil application doubled the leaf number and the urea increased it by 50%. GA, but not N, increased the area of a main‐stem or lateral‐stem leaf; however, nitrogen produced the largest total leaf area because it produced more leaves. There was no evidence for any interaction between GA and N either in the effect on leaf number or total leaf area. The fall in total N content per unit area caused by GA found in an earlier experiment was confirmed and additional N did not arrest this decline. Loss of efficiency of GA‐sprayed plants is unlikely to result from indirect deficiency caused by rapid leaf expansion.
Some isolates of virus causing swollen‐shoot disease of cacao in Nigeria and their interrelationships
Authors: THRESH J. M. 
Published: February 2008

SUMMARYMany symptomatically distinct virus isolates were made from cacao trees infected with swollen‐shoot disease in Nigeria. The symptoms caused by typical viruses from six different localities were studied on seedling Amelonado cacao inoculated as beans. Two isolates caused swellings as the only permanent symptom and another caused only leaf chlorosis. The others caused both swellings and chloroses of different type and severity. Two atypical isolates were much less virulent than the others and caused only transient and very inconspicuous leaf symptoms.Isolates from the same or from adjacent trees usually protected against each other, whereas those from dissimilar areas did not. This suggests that the isolates are not all closely related and they may be grouped according to the results of plant protection tests.
Witchweed (Striga hermonthica) on rain‐grown pearl millet in nitrogen‐deficient sandy soil of the central Sudan
Authors: TARR S. A. J. 
Published: February 2008

SUMMARYSpraying with 1 lb./acre of 80% sodium 2,4‐D 2 weeks after sowing reduced incidence of the phanerogamic root parasite Striga hermonthica (Scrophulariaceae, ‘witchweed’) attacking rain‐grown pearl millet (Pennisetum typhoides) in sandy soil of the Central Sudan, but this control resulted in increased yields only on land very deficient in available nitrogen and not when ammonium sulphate fertilizer was added. Nitrogen deficiency may be more important than Striga attack in limiting yields of millet in these sandy soils, although in inherently fertile clay soils elsewhere in the Central Sudan Striga has been reported to cause heavy crop losses to sorghum (Sorghum vulgare) before signs of soil exhaustion appear.
The growth requirements of Phoma violacea, with reference to its disfiguration of painted surfaces
Authors: EVELEIGH D. E. 
Published: February 2008

SUMMARYGrowth requirements of Phoma violacea in comparison with the commoner paint‐attacking fungi Pullularia pullulans and Cladosporium herbarum were determined. In liquid culture media, growth occurred over a range of pH values from 3 to 8, double optimal pH values being noted. A wide range of carbohydrates supported good growth. Lipolysis was not marked. Phoma violacea strains were autotrophic for vitamins. Zinc oxide exhibited fungistatic properties at 5% in agar medium, but was not fungicidal. White lead caused slight fungistasis while titanium dioxide had no marked effect on fungal growth.
Effects of time and temperature on the fungistatic action of mercury‐containing and other compounds on conidia of Botrytis fabae Sardiña
Authors: McINTOSH A. H. 
Published: February 2008

SUMMARYThe in vitro fungistatic action of nineteen compounds was measured on conidia of two strains of Botrytis fabae Sardiña in slide‐germination tests, at two or three incubation temperatures in the range 10–25° C.; the effects were assessed at intervals up to 14 days from the start of each test.In general, the ED 50's increased as incubation time passed, finally approaching or reaching steady values. With each compound, an increase in incubation temperature increased the speed of action (i.e. decreased the time taken for the ED 50 to reach a steady value), and increased the ultimate toxicity. Temperature coefficients were calculated as ratios of ED 50's and were ‘positive’ or ‘negative’ according to whether the toxic action was greater or less at the higher temperature.The conidia of the two strains of B. fabae behaved similarly, but the temperature coefficients were larger with one strain (A) than the other (B).Mercuric cyanide, chloride, bromide, acetate and thiocyanate gave positive coefficients which increased in size as incubation time passed. In these tests, which lasted for only 3 days, the largest 10:25° C. coefficient (+ 35) was given by the cyanide after 3 days (strain A); the corresponding figures for the chloride and bromide were + 10.5 and +6.0. Phenyl mercury acetate, methyl mercury nitrile, silver nitrate, copper sulphate, 8‐hydroxyquinoline, acetamide, p‐nitrophenol, 2,4‐dinitrophenol and pentachlorophenol gave coefficients which were usually small and positive (about + 1.3), and changed only slightly in size as incubation time passed. t‐Butyl alcohol, pyridine, 3‐picoline, phenol and p‐chlorophenol gave coefficients which changed from negative (‐ 3.9 to ‐1.5) to positive (+1.3 to +3.2) after 2–7 days (strain B).There was little evidence that spores are more resistant to fungicides at their optimum temperature for germination, i.e. the temperature at which maximum germination is reached soonest (15–20° C. for B. fabae).Mercuric cyanide, chloride and bromide, which are scarcely ionized in aqueous solution, also resembled non‐electrolytes in that the sizes of their positive temperature coefficients were inversely related to their solvent: water partition coefficients, i.e. the temperature coefficients increased with decrease in the presumed rates at which lipoid membranes are penetrated by diffusion. This correlation did not extend to other compounds.
Strains of Botrytis allii resistant to chlorinated nitrobenzenes
Authors: PRIEST D. , WOOD R. K. S. 
Published: February 2008

SUMMARYWhen Botrytis allii was grown in nutrient agar in the presence of vapour of penta‐chloronitrobenzene (PCNB), or isomers of tetrachloronitrobenzene (TCNB), a slow‐growing mycelium of distorted hyphae was produced on which sporulation was much reduced or suppressed. After periods which differed with the different fungicides, variants were produced which in the absence of fungicide closely resembled the parent but which, in the presence of fungicide, grew much more rapidly than the parent, and produced hyphae of normal appearance. A strain produced in response to one fungicide was more resistant than the parent to each of the other three fungicides, but the extent of this resistance depended on the origin of the strain. The most resistant was the 2,3,4,6‐TCNB‐resistant strain, followed in turn by the 2,3,5,6‐TCNB‐, 2,3,4,5‐TCNB‐, and PCNB‐resistant strains.In liquid culture, apart from the fact that fungistatic effects were less pronounced, the results were similar to those obtained on agar; the resistant strains utilized carbohydrate more efficiently than did the parent strain in the presence of each of the fungicides.The strains resistant to PCNB and TCNB were also resistant, in varying degrees, to diiodo‐, dibromo‐ and dichloronitrobenzenes. The diiodo‐ and dibromo‐ compounds were less active against B. allii than was TCNB, whereas the dichloro‐ compounds were more active and in certain conditions killed inocula. Resistant strains were also resistant to benzene, to 2,3,5,6‐tetrachloronitroaniline, and to 2,6‐dichloro‐4‐nitro‐aniline, the active principle of ‘Allisan’. Resistant strains retained their resistance for at least 18 months under ordinary conditions of laboratory subculturing, and were as pathogenic to onions as was the parent strain.
The poison baiting of corn‐ricks with particular reference to the control of house‐mice
Authors: ROWE F. P. , TAYLOR E. J. , CHUDLEY A. H. J. 
Published: February 2008

SUMMARYExperimental warfarin treatments designed to reduce house‐mouse (Mus musculus) and common rat (Rattus norvegicus) populations in corn‐ricks are described. Baiting rick bases at permanent poison points or in rat holes was found not to be completely successful in controlling either rats or mice. Bait placed 1 ft. inside ricks in containers or wrapped in paper was effective in reducing the level of mouse infestation. In ricks treated after erection, baits wrapped in paper were more easily applied.Samples of threshed grain taken from each sack showed that ricks baited internally contained fewer mouse droppings but more poison bait residues than ricks baited at ground level only.
The effect of paracrinkle virus on the growth of King Edward potato at different temperatures and daylengths
Authors: KASSANIS B. , SCHWABE W. W. 
Published: February 2008

SUMMARYThe growth of King Edward potatoes of a stock freed from paracrinkle virus was slightly but consistently superior to that of an infected stock, when grown in controlled environments. Although the leaves of the infected plants showed no evident symptoms, their lower water content suggested incipient N‐deficiency. Changes in daylength and night temperature affected virus‐free and infected plants similarly. Long days and high night temperature decreased tuber formation, and the higher tuber and total dry weights in short days probably resulted from increased leaf area and reduced stem growth.
Experiments on the dispersion of Lycopodium and Podaxis spores in the air
Authors: SREERAMULU T. , RAMALINGAM A. 
Published: February 2008

SUMMARYIn twelve experiments known quantities of Lycopodium spores (in five with spores of Podaxis) were liberated into the open air artificially from a point source, under different meteorological conditions, and trapped on ‘Vaseline’‐coated slides, placed horizontally at: 2.5, 5.0, 10.0, 15.0, 20.0, 25.0 and 30.0 m. from the source, along from five to thirteen radii (20° apart in some experiments, and 5° or 10° apart in others).The size of spore had little effect on the relative numbers of Lycopodium and Podaxis spores deposited at different distances (the deposition gradient), but from a cloud containing ten times as many Podaxis as Lycopodium spores over twice as many Lycopodium were deposited per unit area as were Podaxis spores. The rate of deposition is thus approximately proportional to the volume of the individual spore.Estimated percentage recovery, within the sampling area, of Lycopodium spores liberated varied from 5.4% (afternoon in wind of 4.4 m./sec.) to 91.6% (night in wind of 0.8 m./sec). Recovery of Podaxis varied from 0.3 % by day to 1.6% by night.The results of these experiments are examined in the light of the statistical theories of W. Schmidt and O. G. Sutton, which formulate atmospheric diffusion by eddies, and are found to be in closer agreement with the latter. The values of the parameters ‘m’ in Sutton's equation agree excellently with his theoretical values, but the values of the parameter ‘C’ are more variable.
Wilt of lucerne caused by species of Verticillium
Authors: ISAAC IVOR , HEALE J. B. 
Published: February 2008

SUMMARYResting mycelium of V. albo‐atrum in moribund lucerne remains viable at room temperature for 13 months but is not viable after 2 years, whereas conidia on lucerne seed kept at room temperature fail to germinate after 7 months.The fungicide, Orthocide (captan) is toxic both to the conidia of V. albo‐atrum on seed coats of lucerne and to infected plant material carried with seed. Dressed seeds inoculated with Rhizobium mellelotus developed into healthy seedlings bearing normal root nodules, although the Orthocide is toxic to the bacterium in culture.Dressing of seeds with Orthocide, Agrosan‐GN (containing mercury) and Fernasan (thiram) after inoculation gives slightly higher yields of lucerne than where dressing is done before inoculation, but this is not sufficient to recommend a change in the normal commercial procedure of dressing before inoculation.Methyl bromide, used commercially as a fumigant to control Ditylenchus dipsaci, has no effect on Verticillium. However, allyl alcohol, allyl bromide, chloropicrin and formaldehyde are shown to be useful fumigants to control Verticillium carried with seed, since at exposures which kill the resting mycelium and conidia of V. albo‐atrum, they do not affect the viability of lucerne seed.
The effect of vernalization on embryos of field‐resistant wheat varieties infected by loose smut (Ustilago tritici)
Authors: MANTLE P. G. 
Published: February 2008

SUMMARYThe occurrence of an incompatible host/parasite reaction between winter wheat varieties infected with three Cambridge loose smut races was observed following vernalization of inoculated seed. This led to a re‐investigation of certain embryo‐susceptible field‐resistant combinations and the incompatibility reaction was found to be usual. Other unusual reactions were also observed. Whereas it was previously thought that loose smut mycelium failed to penetrate the plumular bud of embryo‐susceptible field‐resistant wheat varieties, it is shown that in fact the plumular bud may be infected with a subsequent serious effect on the host's development. Consequently a modified scheme for determining varietal reaction to loose smut infection is suggested.
Investigations on fungicides
Authors: BATES ANGELA N. , SPENCER D.M. , WAIN R.L. 
Published: February 2008

SUMMARYThe in vitro fungicidal activity of 2‐methyl‐4,6‐dinitrophenol (DNC) and fifteen of its esters was determined in mycelial growth tests. The aliphatic esters possessed similar activity to that of DNC and the aromatic esters were much less fungitoxic. The benzoic ester was only weakly active against mycelial growth and in preventing spore germination but as a protectant fungicide in vivo it was very effective. It was established that DNC‐benzoate is stable in light, under conditions of high humidity and in the presence of fungal spores, but it was shown that some degree of hydrolysis occurs on the leaves of broad bean to yield the parent cresol. This hydrolysis does not lead to phytotoxicity but the small quantities of DNC produced could account for the protectant fungicidal activity of this compound.
Studies of the fungitoxicity of captan
Authors: RICHMOND D.V. , SOMERS E. 
Published: February 2008

SUMMARYA study has been made of the factors controlling the uptake of captan from aqueous solution by conidia of Neurospora crassa. The uptake process has been found to deviate from normal diffusion in the effects of captan concentration, temperature, salts, oxygen supply, and metabolic poisons. It is suggested that the captan absorbed by the spores is decomposed on or within the cell protoplast by a process requiring cell metabolic energy. Pre‐treatment of the spores with thiol reagents such as iodoacetic acid and p‐chloromercuribenzoate markedly decreased the uptake of captan without affecting spore viability or captan toxicity. This suggests that much of the high level of captan uptake required to inhibit spore germination is in fact being decomposed by cell thiols before reaching its site of toxic action.
Studies on the chemical control of Phytophthora palmivora (Butl.) Butl. on Theobroma cacao L. in Nigeria
Authors: Hislop E.C. , Park P.O. 
Published: February 2008

SUMMARYA technique is described whereby detached cocoa pods can be inoculated with zoospores of Phytophthora palmivora to produce multiple lesions. The number of lesions developing can be correlated with the concentration and efficiency of protectant fungicides applied to the pod before inoculation. A number of fungicides have been tested by this method and the results are in general agreement with those obtained from field trials.
Studies on the chemical control of Phytophthora palmivora (Butl.) Butl. on Theobroma cacao L. in Nigeria
Authors: Hislop E.C. , Park P. O. 
Published: February 2008

SUMMARYTwo field trials of fungicides for the control of Phytophthora palmivora on cocoa in Nigeria are described. The results obtained during two harvest periods have been subjected to two methods of analysis and are compared and discussed. The field results have been correlated with the results of laboratory bio‐assays and a close agreement is demonstrated. Possible reasons for the poor control of P. palmivora in the field trials are considered in the light of results obtained from laboratory tests of fungicides (Hislop & Park, 1962a, b).
Dry‐rot disease of the potato
Authors: McKEE R.K. , BOYD A.E.W. 
Published: February 2008

SUMMARYThe effect of diphenyl on potato dry‐rot infection was investigated in laboratory tests and field trials. Diphenyl reduced infection in the laboratory but failed to give consistent control in the field, where such treatments as were effective also proved phytotoxic. Treated tubers were also tainted.