bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE ACTION OF DRUGS ON THE NERVOUS SYSTEM OF THE LOCUST (LOCUSTA MIGRATORIA)
Authors: HARLOW P. ANNE 
Published: February 2008

Two preparations of the hind‐leg of the locust have been used to investigate the physiological effect of chemicals on nerve muscle and on the central nervous system.In the first preparation, the isolated hind‐leg is made to kick regularly by electrical stimulation of the crural nerve. Test chemicals are perfused in saline solution through the femur.The second preparation makes use of a reflex synapsing in the metathoracic ganglion. A reflex retraction of the tibia of the hind‐leg is initiated by stimulating the tarsus by heat at regular intervals; the chemicals are applied in agar or paraffin blocks directly to the ganglion. In both cases the movements of the tibia or of the extensor or flexor tibialis muscles separately are recorded mechanically on a smoked drum.Acetylcholine has no action on the nervous system except for an unusual action on the nerve muscle preparation. Acetyl β‐methylcholine, carbamylcholine and benzoylcholine have no action on either preparation except at high concentration.Decamethonium and d‐tubocurarine had no effect on either preparation, while nicotine and eserine, after initial excitation, caused a simple reversible block in both preparations, the ganglion being affected at a lower concentration.Adrenalin and adrenergic drugs have no effect on either preparation.The organo‐phosphorus insecticides, parathion, paraoxon and TEPP, acted on the ganglion only and at low concentrations. Their main site of action is on the central nervous system.DDT affected ganglionic and nerve muscle preparations, whereas γ‐BHC acted rather similarly on the ganglion but had no effect on nerve muscle.There is no evidence for a cholinergic mechanism at the neuromuscular junction in the leg muscles. The ganglion, on the other hand, was markedly affected by the anticholinesterases tested, but acetylcholine and related cholinesterase substrates, and drugs which interfere with the action of acetylcholine in mammals, had no effect. Acetylcholine was still without effect when injected through the membrane sheathing the ganglion. On the other hand, micro injection experiments show that the sheath is relatively impermeable to prostigmine.
THE CONTROL OF CERTAIN PLANT DISEASES WITH SULPHONAMIDES
Authors: CROWDY S. H. , ELIAS R. S. , JONES D. RUDD 
Published: February 2008

In in vitro tests, sulphanilamide was more toxic to plant pathogenic fungi than to bacterial plant pathogens, but sulphadiazine and other heterocyclic‐ring substituted compounds were more toxic to plant pathogenic bacteria than to fungi. When tested in vivo against a number of facultative plant parasites the sulphonamides were without effect except in providing slight control of Pseudomonas coronafaciens on oats. Against a number of obligate parasites including Uromyces fabae on broad beans and Puccinia triticina on wheat, the sulphonamides gave effective control when applied either through the roots or leaves. The minimal effective concentrations in the leaves of the more active compounds varied between 100–200 μg./g. fresh weight of leaf tissue.The sulphonamides are also toxic to higher plants and both the fungitoxic and phytotoxic effects could be reversed with p‐aminobenzoic acid.A number of sulphanilamides with acyl substituents on the p‐amino‐group were tested against P. triticina and were shown to control the disease with very slight phytotoxic damage. Control could be attributed to the release of ‘free’ sulphanilamide by hydrolysis within the plant.Two factors appear to control the systemic action of sulphonamides: first, the movement in the plant which results in the accumulation of effective concentrations in the leaves, and secondly, the specificity of a sulphonamide for a particular host‐parasite association.
FUNGICIDAL ACTIVITY AND CHEMICAL CONSTITUTION
Authors: BYRDE R. J. W. , CLIFFORD D. R. , WOODCOCK D. 
Published: February 2008

A series of 5‐n‐alkyl oxines was tested against the mycelium of Aspergillus niger. As non‐chelated molecules, they showed maximum fungistatic activity at a chain length of 5–6 carbon atoms. Values of Ferguson's thermodynamic activity coefficient, obtained from spore germination tests with Sclerotinia laxa, indicated that the mechanism of toxicity of the lower homologues is predominantly chemical, whilst that of the n‐amyl and higher members is mainly physical.The ED 50 value of 5‐n‐amyl‐6‐hydroxyquinoline, which is incapable of chelation, was found to be eighty times greater than that of 5‐n‐amyl oxine (in the non‐chelated form). The optimum initial pH for fungistatic activity of the latter was 5.4–5.6.In the presence of metals the pattern of fungistatic activity was markedly altered: maximum activity in the presence of Cu2+, Fe2+and Zn2+was found with oxine and 5‐methyloxine.
FACTORS AFFECTING INFECTION GRADIENTS FROM A POINT SOURCE OF PUCCINIA POLYSORA IN A PLOT OF ZEA MAYS
Authors: CAMMACK R. H. 
Published: February 2008

Two plots of Zea mays were planted in April and September, respectively, at Ibadan, Nigeria during 1956. A point source of inoculum consisting of potted maize plants heavily infected with the American corn rust, Puccinia polysora Underw., was introduced at pre‐arranged times before the plots became naturally infected. Disease gradients from these point sources of infection were assessed by the number of pustules subsequently appearing on plants along the circumferences of concentric circles around the source of infection. ‘Control’ plots were planted at the same time as the main trial and the pattern of natural infection was observed in an attempt to assess the degree of contamination in the main experiment.In the centre of the main experiment a volumetric spore trap gave continuous records of the uredospore content of the atmosphere immediately above the crop during both plantings for periods of 2 weeks before planting until 2 weeks after the last assessment of infection.The forms of the disease gradients were considerably altered by several factors—principally contamination by inoculum from outside sources, the method of assessment and the time at which the assessments were made.
STUDIES ON THE TRANSMISSION OF CASSAVA MOSAIC VIRUS BY BEMISIA SPP. (ALEYRODIDAE)
Authors: CHANT S. R. 
Published: February 2008

Whiteflies, which had originated from a mixed culture of Bemisia spp. collected from cassava (Manihot utilissima Pohl.) in the field, needed to feed for at least 4 hr. on the young leaves of a cassava plant with mosaic before they acquired the virus. Whiteflies that acquired virus in 4–6 hr. required another 4 hr. to become viruliferous. Once viruliferous they could infect healthy plants in a feeding period of 15 min., but longer periods gave more infections. Adult whiteflies remained infective for more than 48 hr. after ending their infection feed. Cassava fed upon by only one viruliferous fly sometimes became infected.The virus‐vector relationships of cassava mosaic virus resemble those of cotton leaf‐curl virus but the first could not be transmitted to cotton or the second to cassava.
RASPBERRY YELLOW DWARF, A SOIL‐BORNE VIRUS
Authors: HARRISON B. D. 
Published: February 2008

An apparently undescribed virus, provisionally named raspberry yellow dwarf virus (RYDV), was isolated from naturally infected raspberry, strawberry, blackberry and several weed species by mechanical inoculation of sap to Chenopodium amaranticolor. The severe disease it caused in Malling Exploit raspberry usually occurred patchily in otherwise normal plantations: these patches increased in size from year to year. RYDV was differentiated from raspberry ringspot and tomato black ring viruses by the symptoms produced in C. amaranticolor, tobacco and Petunia hybrida. RYDV lost infectivity when sap was heated for 10 min. at 61° C., diluted 10‐5or kept for 15 days at 18° C. RYDV was precipitated without inactivation by acetone and by ammonium sulphate.Isolates of RYDV from different plants and localities, and of different virulence, were identified by plant‐protection and serological tests. Such tests gave no evidence that RYDV was related to raspberry ringspot, tobacco ringspot, tomato black ring or cucumber mosaic viruses.Raspberry and sugar‐beet plants became systemically infected with RYDV when grown under glass in soil from a field where the disease had occurred in raspberry plants, and where the virus persisted in the soil for 3 years after the raspberry plants were removed. RYDV seems to be widely disseminated in England but recently introduced and rare in eastern Scotland.Like raspberry ringspot and tomato black ring viruses, RYDV causes symptoms of the ringspot type in tobacco, has a wide natural and experimental host range, is soil‐borne and of local importance. Such features seem characteristic of ringspot viruses as a group.
‘BULBIFORMIN’, AN ANTIBIOTIC PRODUCED BY BACILLUS SUBTILIS
Authors: VASUDEVA R. S. , SUBBAIAH T. V. , SASTRY M. L. N. , RANGASWAMY G. , IYENGAR M. R. S. 
Published: February 2008

The antimicrobial spectrum of the antibiotic produced by Bacillus subtilis has indicated that it is chiefly antifungal. In the presence of the antibiotic, a characteristic bulb formation has been observed in the spores and hyphae of the test fungi. The active principle has been shown to be thermolabile. The importance of magnesium in relation to growth and antibiotic production has been indicated. Large quantities up to 30 p.p.m. are required for maximum production of the antibiotic which is not intracellular, but is secreted into the medium.The data presented suggest that the antibiotic under consideration is different from those of B. subtilis previously described, therefore the name proposed for this antibiotic is ‘bulbiformin’.
A COMPARISON OF HIGH AND LOW VOLUME SPRAYS FOR CONTROL OF THE BEAN APHID, APHIS FABAE SCOP. ON FIELD BEANS
Authors: WAY M. J. , BARDNER R. , van BAER R. , AITKENHEAD P. 
Published: February 2008

Insecticides were sprayed in different amounts of water to control Aphis fabae Scop. attacking spring‐sown field beans. The single application of each insecticide was timed to coincide with the end of aphid migration from the winter host to the crop. A tractor‐mounted row‐crop hydraulic sprayer was used.In one experiment seven different insecticide sprays were compared at high volume (in 140 gal. of water per acre); the most effective were nicotine at 22.4 oz. of active constituent per acre, demeton at 5.6 oz. and demeton‐methyl at 11.2 oz.A further comparison was made of five insecticides for each of which a selected dose of active ingredient was applied in 60 gal. (medium volume) and in 10 gal. of water per acre (low volume). The amount of insecticide retained on the plant following the low‐volume application was not less than that from the medium‐volume spray; the efficiency of A. fabae control was not affected by the volume sprayed except with malathion which did better at the medium volume. The systemic insecticides demeton‐methyl at 6 oz. of active constituents per acre, the related compound 4741 at 3 oz. and fluoroacetamide at 3 oz. stopped the aphid numbers from rising above a peak of eight per plant compared with 230 per plant for malathion (low volume) at 12 oz. 2400 per plant for lindane at 6 oz. and 3550 per plant for check treatments sprayed with wetter only. Grain yields ranged from around 4 cwt. per acre on check treatments to around 27 cwt. per acre on plots sprayed once with the systemic insecticides. There was a curvilinear relationship between grain yield and log number of A. fabae per plant.
STUDIES ON SOIL POPULATION OF CONTARINIA PISI WINN. IN 1957 IN YORKSHIRE AND LANCASHIRE
Authors: BEVAN W. J. , UNCLES J. J. 
Published: February 2008

For studying the population of pea‐midge cocoons, larvae and pupae in the soil, a new method of examining the ‘float’ obtained from washing soil through the wet‐extraction apparatus is described.Examination of soil samples in the summer of 1957 from fields which carried heavily attacked pea crops in 1956 indicated that pupae were present at depths of 0–3, 3–6, 6–9 in., respectively, from 18 June onwards, and that the peak emergence of midges was in the period 28 June‐2 July; observations on adult activity in pea fields confirmed this. Small numbers of pupae were recovered throughout July.Similar studies on pea fields in 1957 showed the build‐up of the cocoon population and the rate of pupation of this generation of larvae. The first flight of 1957 was composed of individuals from the 1956 generation and was far larger than the second flight, which was composed of some 1956 generation and part of the first 1957 generation.There were indications that increases of temperature might accelerate pupation with a resulting earlier emergence of adults.The size of midge populations recorded from soil from green pea and dry‐harvesting pea fields tended to be similar and appeared to be related to sowing date.
STRIATE MOSAIC OF CEREALS IN EUROPE AND ITS TRANSMISSION BY DELPHACODES PELLUCIDA (FAB.)*
Authors: SLYKHUIS JOHN T. , WATSON MARION A. 
Published: February 2008

A virus disease that resembles wheat striate mosaic was found affecting up to 5% of the plants in English wheat fields in 1956. Symptoms on wheat included fine chlorotic striae, followed by stunting, general chlorosis, and death of plants. Other hosts included oats, barley, rye, perennial rye grass and Italian rye grass.The virus was transmitted by Delphacodes pellucida (Fabricius) (Homoptera, Delphacidae). A few of the insects were already infective when caught in the field. The percentage of infective individuals was increased by feeding the insects for 24 hr. or longer on diseased plants, and up to 56% became infective after feeding on diseased plants for 3 days. Non‐infective insects were unable to transmit the virus until from 8 to 36 days after they first fed on diseased plants, but they frequently remained infective for the remainder of their lives, up to 10 weeks after feeding on a diseased plant. Infective insects seldom transmitted the virus during test feeds as short as 30 min. When fed for 1 or more days on each test plant, some insects infected many plants in succession, others seldom infected test plants even if they fed as long as 7 days on each. The virus was transmitted through the eggs to as many as 88% of the progeny of infective females, and to some of the progeny of a few females that had failed to infect wheat test plants.
THE DISTRIBUTION OF VIRUSES IN LEAVES AND THEIR INACTIVATION BY ULTRA‐VIOLET IRRADIATION
Authors: HITCHBORN J. H. 
Published: February 2008

The infectivity of sap expressed from the lower epidermis stripped from leaves systemically infected with potato virus Y, henbane mosaic virus or tobacco mosaic virus was compared with that of sap from the underlying mesophyll. Results suggested that the concentration of virus in each of the two tissues was about the same.Ultra‐violet irradiation of leaves infected with potato virus Y or henbane mosaic virus greatly reduced the infectivity of sap expressed from subepidermal tissues.
CROOK ROOT OF WATERCRESS
Authors: TOMLINSON J. A. 
Published: February 2008

Zinc, used as zinc sulphate at 0.5 p.p.m., was found to inhibit the growth of Spongospora subterranea (Wallr.) Lagerh., f.sp. nasturtii Tomlinson, the cause of crook‐root disease of watercress. A relatively insoluble finely powdered glass frit containing zinc oxide (zinc frit) largely prevented infection by this fungus when added, at 0.2 g./350 ml., to water in which watercress was growing.In field trials made in 1955‐56 on brown watercress at Bere Regis, Dorset, and on green watercress at Greatford, Lincolnshire, zinc frit was applied at two rates of 1 and 1/2 lb. per sq.yd. After 4–8 weeks, plants in the treated beds grew more strongly and root infection was reduced considerably. Untreated control beds remained heavily infected from September to April but, in the treated beds, the disease was greatly reduced from November to January though, by April, this effect had largely disappeared. Disease control at both places was associated with increases in total crop and individual plant weight. Field trials in 1956‐57 gave similar results.When zinc frit was shaken with distilled water for 24 hr. a solution containing 0.21 p.p.m. zinc was obtained, but if watercress plants had been grown in the water before it was shaken with the frit the solution contained 2.82 p.p.m. zinc. The treated water was found to contain 16 p.p.m. CO2 which had a solvent action on the frit. Field tests showed that plants in watercress beds liberated sufficient CO2 into the water to bring into solution a fungitoxic concentration of zinc. Observations on the crook‐root fungus showed that the suppression of the disease by zinc was caused by the killing of the zoospores.The zinc content of watercress in beds treated with zinc frit was at a safe level for human consumption and the zinc content of the outflow water from such beds was non‐toxic to trout (Salmo gairdnerii Richardson).A previous theory on the release of metals from glass by plants is discussed in relation to the experiments described on the release of zinc from zinc frit.
THE ADAPTATION OF FUNGI TO FUNGICIDES: ADAPTATION TO THIRAM, ZIRAM, FERBAM, NABAM AND ZINEB
Authors: PARRY K. E. , WOOD R. K. S. 
Published: February 2008

The concentrations of thiram preventing germination of spores of Botrytis cinerea in drops of a 1% solution of sucrose, and on the surface of a sucrose‐nitrate agar have been determined. Thiram had much less effect on germination in the agar medium, even when a purified agar was used. There was no growth on sucrose‐nitrate agar if the concentration of thiram exceeded 31 p.p.m. Attempts to obtain strains able to grow at higher concentrations were unsuccessful.Similar results were obtained with ziram, nabam and zineb.Ferbam also was more effective in preventing spore germination in spore drops than on agar media; this effect was obtained with ordinary and with purified agar.On a sucrose‐nitrate agar generally there was no growth if the concentration of ferbam exceeded 125 p.p.m., but in one of forty‐eight plates containing 250 p.p.m. ferbam, five slowly growing colonies were produced, and from these colonies arose mycelium which grew and sporulated rapidly on 500 p.p.m. ferbam agar. Agar disk inocula were transferred from these cultures to agar containing higher concentrations of ferbam and in this way, and by repeating the process, a strain was obtained which grew slowly but continuously, and sporulated on agar containing 5000 p.p.m. ferbam. However, the poor solubility of this fungicide made it difficult to assess quantitatively the degree of adaptation.A proportion of the spores from this strain germinated in drops containing about twice the concentration of ferbam which prevented germination of parent spores.The resistance of the mycelium of the resistant strain was not lost after repeated subculture on fungicide‐free agar. The resistant strain was as susceptible as the parent strain to thiram, ziram, nabam and zineb.Attempts to obtain strains of Venturia inaequalis resistant to thiram, ferbam, ziram and zineb were unsuccessful.
SAPROPHYTIC BEHAVIOUR OF SOME CEREAL ROOT‐ROT FUNGI: IV. SAPROPHYTIC SURVIVAL IN SOILS OF HIGH AND LOW FERTILITY
Authors: BUTLER F. C. 
Published: February 2008

In southern New South Wales the resumption of ley land for wheat growing has been accompanied by an increase in take‐all (Ophiobolus graminis) and Fusarium root rot (Fusarium culmorum). No such increase has been observed in foot and root rots of wheat caused by Helminthosporium sativum and Curvularia ramosa.It is shown experimentally that these differences are related to the relative capacity of the causal fungi to persist in wheat straw buried in each of two unsterilized soils which, because of past cultural treatments, differed in their organic carbon and total nitrogen content. While the saprophytic survival of O. graminis and F. culmorum was promoted by high soil fertility that of H. sativum was markedly depressed. The survival of C. ramosa was little affected by soil fertility. F. culmorum, H. sativum and C. ramosa each remained viable under the soil conditions best suited to their survival in one‐third to one‐half of the test straws for 2 years but O. graminis was not recovered after the 52nd week of sampling.
THE EFFECT OF INORGANIC MANURES, MOISTURE AND INOCULUM ON THE INCIDENCE OF ROOT DISEASE CAUSED BY RHIZOCTONIA SOLANI KUHN IN CULTIVATED SOIL
Authors: DAS A. C. , WESTERN J. H. 
Published: February 2008

An account is given of experiments designed to study the effect of inorganic manures, both singly and in combination, soil moisture and available inoculum on the development of root disease in glasshouse soils.Growth of Rhizoctonia solani Kuhn in sterilized soil was increased by applications of balanced fertilizer, by moderate doses of potassium and by the highest rate of phosphates applied. It was decreased by the higher applications of nitrogen and the highest rate of potassium. In unsterilized soil growth was poor in all treatments.Fresh weights of lettuce seedlings were increased by moderate applications of balanced fertilizer but decreased by the higher levels of this and of the individual ingredients. Most disease was found in the balanced (basic) and nitrogen series: potassium and phosphatic amendments had comparatively little effect.Mycelium of R. solani grew best, and produced most disease, in the relatively drier soils. It was found to need a minimum supply of nutriment (food base) to establish itself in soil but high concentrations of inoculum reduced pathogenicity. Its survival in artificially inoculated soils was shown to be little affected by soil fertility.A description is given of a method to demonstrate the persistence and rate of spread of a parasite under relatively natural conditions.
STUDIES IN THE BACTERIAL DISEASES OF SUDAN CROPS: II. BACTERIAL LEAF BLIGHT DISEASE OF CASTOR (RICINUS COMMUNIS L.)
Authors: SABET K. A. 
Published: February 2008

The bacterial disease of castor in the Sudan has been reinvestigated. Typically the disease symptoms are brown or black, round or angular lesions on leaves; occasionally the thin succulent branches are attacked, but not the vascular tissue.The bacterium responsible for the disease was previously thought to be Pseudomonas solanacearum E.F.Sm. but comparative studies show that the Sudan species differs in pathogenicity and physiology from P. solanacearum. It closely resembles Xanthomonas ricinicola (Elliott) Dowson (=Bacterium ricini Yoshi and Takimoto) in characters, host range and pathogenic effects. In culture on solid media the growth of X. ricinicola is typically yellow, while that of the Sudan species is dirty white; but this difference is not considered sufficient to justify the establishment of a new species.The author proposes the specific name ricini originally adopted by Archibald (1927) and Yoshi & Takimoto (1928), for the species of Xanthomonas causing the leaf blight disease of castor, and considers that the causal organism in the Sudan is an atypical strain of this species.