bluuebunny/crossref_metadata_2025_split huggingface dataset:
TOPICAL APPLICATION OF MOBILE LIQUIDS TO INSECTS BY MEANS OF MICRO‐CAPILLARY TUBES
Authors: HEWLETT P. S. , LLOYD C. J. 
Published: February 2008

A method is described for topical application of mobile liquids, whether volatile or not, to insects. The principle is that of the self‐filling micro‐pipette, the ‘pipettes’ being calibrated lengths of fine, thin‐walled glass capillary tube; for use a micro‐capillary tube is mounted in a special holder. The doses delivered were shown to be adequately reproducible for mean doses of 0.03 μl. upwards. Precautions in use are: (1) in filling the capillary, its tip is dipped into the reservoir of liquid no more deeply than is necessary: (2) the dose is applied to the insect in such a way that the liquid is carried rapidly away from the delivery tip; and (3) pressure for expulsion of the dose from the capillary is maintained until after the delivery tip is removed from the insect.A convenient apparatus for keeping a batch of insects under anaesthesia during their dosage is described.
THE TOXICITY OF SOME INSECTICIDES TO FIFTH‐INSTAR NYMPHS OF THE DESERT LOCUST
Authors: MacCUAIG R. D. 
Published: February 2008

The toxicities of the insecticides γ‐BHC, diazinon, dieldrin, DNC, heptachlor and parathion to fifth‐instar hoppers of the desert locust were determined. Parathion and dieldrin were the most toxic, followed in descending order by heptachlor, γ‐BHC, diazinon and DNC. The resistance of the hoppers to γ‐BHC and DNC changed appreciably with age within the instar.The effects of some factors which might influence the resistance of the insects were examined and are discussed.
APHID BEHAVIOUR ON HEALTHY AND ON YELLOWS‐VIRUS‐INFECTED SUGAR BEET
Authors: BAKER PETER F. 
Published: February 2008

Myzus persicae Sulz., M. ascalonicus Doncaster, Aphis fabae Scop, and Aulacorthum solani Kalt., when caged on sugar‐beet leaves in the glasshouse preferred yellows‐virus‐infected leaves to healthy ones; they chose those with the most severe symptoms on which they bred more rapidly and lived longer than on green leaves. M. persicae behaved similarly on whole plants in the glasshouse. The previous host influenced the aphid's preference. Differences between the multiplication rates of aphids on healthy plants of inbred sugar‐beet varieties were eliminated or reversed by infection with yellows virus.Spraying healthy plants with either sugar solutions or hydrolysate of casein increased the multiplication rate of M. persicae, but much less than did virus infection.
STUDIES ONGLOEOSPORIUM MUSARUMCKE. AND MASSEE CAUSING STORAGE ROTS OF JAMAICAN BANANAS
Authors: MEREDITH D. S. 
Published: February 2008

Experimental inoculations indicate that several factors may influence the extent to which anthracnose, caused byGloeosporium musarum, develops on bananas following wound‐infection. Severity of disease increases with increasing ‘grade’ of maturity, ‘full’ fruit being more seriously affected than ‘thin’ fruit. The evidence suggests that Gros Michel fruit is less susceptible to this form of rot than fruit of the Lacatan or Robusta varieties. The amount ofGloeosporium‐rot on fruit imported into the United Kingdom undergoes marked seasonal variation, being greatest during autumn and winter.The presence of perforated ‘Polythene’ bags during cold storage (55° F.) appears to favour slightly the development of disease. Bagging had no significant effect on rotting during the subsequent ripening period. After wound‐inoculation, disease incidence and severity decreased appreciably with increasing periods of storage at tropical temperatures (76–87° F.). Such a decrease was evident even when the humidity at the surface of the fruit was maintained at a high level (92–100%).In several shipping trials, a post‐harvest fruit‐dip treatment with nystatin (200–400 p.p.m.) effected 40–70% control of anthracnose.
INVESTIGATION OF FIRE‐BLIGHT OF PEAR IN ENGLAND
Authors: CROSSE J. E. , BENNETT MARGERY , GARRETT CONSTANCE M. E. 
Published: February 2008

Outbreaks of fire‐blight, caused by Erwinia amylovora, in Kentish orchards during 1957 constitute the first authenticated record of the disease in Europe. The origin of the disease is unknown, but evidence suggests that it was not present in the orchards prior to 1957.The seasonal development and symptoms of the disease are described in detail. Fire‐blight attacked trees only during the growing season; infection began in the blossoms, particularly summer blossoms, and spread into the branches forming cankers, in many of which the pathogen remained viable during the winter 1957–8. In the orchards examined there was a higher incidence of new infections by July 1958 on trees attacked the previous year than on those which were then healthy, and this is discussed in relation to overwintering sources of inoculum. The distribution of the disease in orchards during 1957 and 1958 was consistent with spread by pollinating insects rather than rain.The outstanding susceptibility of the variety Laxton's Superb in all localities was attributed partly to its tendency to produce abundant secondary blossom. Inoculations of blossoms, fruits, shoots and branches showed it also to have less inherent resistance than the varieties Williams's Bon Chrétien and Conference, neither of which has been seriously affected in the field. The progress of symptoms following inoculation of pear and infection experiments with apple, Cotoneaster sp., Pyracantha sp., and other hosts, are described.A comparison of climatic conditions favouring the disease in the U.S.A., i.e. high temperatures and high humidity, with meteorological records at East Malling, suggests that epidemic infection of spring blossom would be exceptional in this country.
COMPARISON OF TWO BARLEY YELLOW‐DWARF VIRUSES IN GLASSHOUSE AND FIELD EXPERIMENTS
Authors: WATSON MARION A. , MULLIGAN T. E. 
Published: February 2008

Comparisons were made of the host ranges, interactions in infected plants, and effects on yields of cereals of two isolates of barley yellow‐dwarf virus, one avirulent, RV, obtained from Rothamsted farm (Watson & Mulligan, 1956) and the other virulent, KV, obtained from Kent. They resembled each other and the American yellow‐dwarf viruses in their ability to infect wild grasses but differences were found when the infection tests were made using inbred lines of the same grass species. KV infected one variety each of rice, rye and maize, and caused symptoms in each.When plants were first infected with RV and later, when symptoms had fully developed, with KV, they suffered the same loss of yield from KV as did plants infected for the same length of time with KV alone. Therefore plants infected with RV were not protected against infection with KV. Similarly, aphids (Rhopalosiphum padi L.), fed first on sources of RV and then on KV, transmitted mainly KV so there was no evidence of protection in the insect vectors.Effects on yield of cereals were related to the time of appearance and intensity of symptoms. The effect of RV was not only less than that of KV but was also more variable.
THE USE OF SOIL INSECTICIDES TO CONTROL POTATO APHIDS AND VIRUS DISEASES
Authors: BURT P. E. , BROADBENT L. , HEATHCOTE G. D. 
Published: February 2008

A replicated trial was done to find whether the insecticides Thimet and Rogor applied in the soil affected the spread of aphid‐transmitted viruses from infected to healthy plants with potato crops. The insecticides were applied at planting as activated carbon formulations at rates equal in cost to three sprays with DDT emulsion at 2 lb. DDT per acre. The infected plants were removed (rogued) in late June.Thimet applied along the furrows with the fertilizer, and Rogor applied in individual doses beneath each tuber, kept the plants free from aphids from a week after the plants emerged until early August. Thimet in individual doses was less effective but greatly decreased the aphid infestation. All treatments prevented or greatly decreased the spread of leaf‐roll virus, but they only slightly decreased the spread of virus Y. No treatment damaged the plants or depressed yields significantly.Tubers harvested from the plots treated with insecticides contained only very small quantities of the insecticides, but shoots from them, when infested with adult Myzus persicae (Sulz.), carried fewer aphids a week after infestation than did shoots from control tubers. Shoots of tubers from treated plots also grew more slowly than those from the controls.The aphicidal efficiency of Thimet applied as individual doses separated from the tubers by distances of up to 6 in., decreased as the distance increased, but the effect of distance became less as time passed.Reasons for the differences in the behaviour of the insecticides are discussed, and the possibilities that the method offers to control virus diseases. The application of insecticides to soil promises to be a useful way of controlling the spread of viruses, provided the harvested crop is free from toxic residues.
THE EFFECTS OF FUNGICIDE‐INSECTICIDE SEED TREATMENTS ON EMERGENCE, GROWTH AND YIELD OF IRRIGATED COTTON IN THE SUDAN GEZIRA
Authors: TARR S. A. J. 
Published: February 2008

Fungicide‐insecticide seed treatment, particularly with methoxyethylmercuriacetate (MEMA) and dieldrin, often improved emergence, growth and yield of irrigated Egyptian‐type cotton (Gossypium barbadense) in the Gezira area of the Sudan. Such treatment reduced post‐emergence wilting and death of seedlings resulting from termite attack, and also reduced pre‐emergence mortality probably caused primarily by soil insects, but appeared to have little effect on the incidence of termite damage to tap‐roots of mature plants at the end of the season. Termite attack tended to be worse in close rotations, and the beneficial effects of fungicide‐insecticide seed treatment were greater in three‐course than in four‐course rotation plots. In one experiment treatment improved growth and yield of cotton plants in the apparent near‐absence of insect pests and diseases, this effect perhaps deriving from control of minor root damage caused by soil insects and/or fungi.Certain seed treatments, notably those containing MEMA and γ‐BHC, were slightly phytotoxic, but at the levels applied—0.043% mercury/seed and 0.12—0.24% insecticide/seed—this aspect, although needing further investigation, seems unlikely to be of serious practical significance in the Sudan Gezira where high sowing rates are the rule; any slight phytotoxicity would probably be outweighed by the protective effects of the treatment. Phytotoxicity tended to become more pronounced with increasing number of seeds per sowing hole.
EXPERIMENTS ON THE HERBICIDAL ACTION OF 1,1‘‐ETHYLENE‐2,2’‐DIPYRIDYLIUM DIBROMIDE
Authors: MEES G. C. 
Published: February 2008

Light was shown to increase the rate of kill obtained with 1,1′‐ethylene‐2,2′‐dipyridylium dibromide, without being essential for herbicidal action. The light effect, which was observed only in green tissues, increased with intensity up to about 10 k‐lux, and was inhibited by N‐(4‐chlorophenyl)‐N,N'‐dimethyl urea or the absence of oxygen, but not by potassium cyanide or in a carbon‐dioxide‐free atmosphere. The herbicide was also shown to stimulate and inhibit respiration. The stimulation was transitory, and appeared to depend on a continuous supply to the tissues, while the inhibition did not.These observations are interpreted, consistently with chemical evidence, to show that the reduction of the herbicide to its free radical form is an essential step in the sequence of toxic reactions. It is supposed that energy for reduction comes from the photolysis of water in the light, and from respiration in the dark. Once formed, the radical may initiate chain reactions in the presence of oxygen which end in the degradation of essential cytoplasmic components.
METABOLISM OF PLANT GROWTH REGULATORS
Authors: LUCKWILL L. C. , LLOYD‐JONES C. P. 
Published: February 2008

2,4‐Dichlorophenoxyacetic acid (2,4‐D) labelled with 14C in either the carboxyl or methylene group was fed through the transpiration stream into detached leaves of black currant, which is sensitive to this herbicide, and of red currant which is highly resistant. The leaves were then kept in darkness and the evolution of 14CO2 was followed; subsequently the leaves were extracted and the metabolic products examined by chromatography and radioassay.The chief difference between the species is the ability of the red‐currant leaf to oxidize approximately 50% of the carboxyl and 20% of the methylene carbon from the side chain of the 2,4‐D over a period of 1 week: in the black‐currant leaf only about 2% of the 2,4‐D is broken down in this way in the same period. The red‐currant leaf can metabolize in a similar manner the side chains of 2,4,5‐trichlorophenoxyacetic acid (2,4,5‐T), 4‐chlorophenoxyacetic acid (4‐CPA) and 2‐methyl‐4‐chlorophenoxyacetic acid (MCPA), but not of 2‐chlorophenoxyacetic acid (2‐CPA).In both species 5–10% of the 2,4‐D taken up by the leaves is converted to water‐soluble compounds which are biologically inactive in the oat mesocotyl and Coleus abscission tests and which yield 2,4‐D on hydrolysis with 2N sulphuric acid. The failure of 2‐CPA to produce growth responses in currants, and probably in other plants, is attributable to the conversion of 70–80% of the applied chemical to water‐soluble inactive compounds. A further 5–10% of the 2,4‐D entering the leaf is metabolized to a biologically active, non‐acidic neutral compound. Analogous compounds were formed in leaves treated with 2,4,5‐T or 2‐CPA.In both species a variable proportion (10–30%) of 2,4‐D, 2,4,5‐T and 2‐CPA are bound in the leaf tissue and cannot be removed by aqueous or organic solvents or by mild hydrolysis.The red currant is killed by low concentrations of 2,4,5‐T even though this compound is broken down in the leaf as rapidly as 2,4‐D. It is noteworthy that death is delayed and there is an absence of the epinastic reactions normally associated with damage by phenoxy‐acid herbicides.
THE MANNER OF TRANSMISSION OF SOME BARLEY YELLOW‐DWARF VIRUSES BY DIFFERENT APHID SPECIES
Authors: WATSON MARION A. , MULLIGAN T. 
Published: February 2008

Some barley yellow‐dwarf (BYD) viruses isolated from cereal crops in Great Britain were transmitted by Rhopalosiphum padi, L. and others were not. Sitobion fragariae (Walker), S. avenae (Fabricius), and Metopolophium dirhodum (Walker) all transmitted viruses of both types, but they usually transmitted those of which Rhopalosiphum was a vector less readily than did R. padi. The transmissibility of a virus by a given aphid species was not affected by transmission with another, less efficient, vector species. Neomyzus circumflexus (Buckt.) and Rhopalosiphum maidis (Fitch) transmitted the few viruses with which they were tested.A few R. padi acquired virus from infected leaves during 30 min. feeding and inoculated healthy seedlings during 15 min. feeding, but the minimum total time taken to acquire and transmit was 10 hr. and 32 hr. were needed for about half the aphids that were able to acquire and transmit virus to do so. This may indicate the existence of a short latent period of the virus in the vector, although the evidence is not conclusive. The times spent on infected plants influenced the results more than those spent on healthy ones; many transmissions occurred with short feeding times on healthy plants so long as the time spent on infected leaves was long, but the reverse was not true. Nymphs of R. padi that moulted after they left infected plants on which they fed long enough to become infective, infected slightly fewer plants than adults fed for the same times.
RED CLOVER MOTTLE VIRUS
Authors: SINHA R. C. 
Published: February 2008

A virus, provisionally named red clover mottle virus (RCMV), isolated from red clover plants in England, seems distinct from any previously described. It was transmitted by mechanical inoculation of sap to many legumes and to Gomphrena globosa L., but it was not transmitted by six aphid species, or through soil or through seeds.RCMV is inactivated in 10 min. between 60 and 63°C., and in 8 days at 18°C., but survives for long periods at ‐20; sap was not infective when diluted more than 1/1000. The virus is soluble in the pH range (4–7) in which it is stable. It was precipitated without inactivation by 50% saturated ammonium sulphate solution, but it was inactivated by ethanol or acetone. Partially purified preparations contained polygonal particles about 28 mμ in diameter. Serological tests showed no antigens in common with broad bean mottle, true broad bean mosaic or lucerne mosaic viruses.
THE ACTION OF COPPER IN ANTIFOULING PAINTS
Authors: CRISP D. J. , AUSTIN A. P. 
Published: February 2008

Experiments on the number of barnacle cyprids found on plane surfaces and on the surface of small pits coated with compositions containing different amounts of cuprous oxide show that the presence of copper does not deter the cyprids from attempting to settle. Copper‐oxide paints do not inhibit settlement appreciably; their efficiency as antifouling agents is caused by the toxic action of copper on cyprids and young spat after initial attachment.The cementing of the shell to the substratum in young barnacles which have survived metamorphosis appears to be hindered by the presence of copper paints so that they are easily dislodged.
THE INFLUENCE OF GROWTH STAGE ON THE RESPONSE OF RED CLOVER (TRIFOLIUM PRATENSE L.) TO GIBBERELLIC ACID
Authors: STODDART J. L. 
Published: February 2008

The response of seedling and first harvest year plants of red clover (Trifolium pratense L.) to treatment with gibberellic acid (GA) at various growth stages is described.Seedlings sprayed before the seventh leaf stage developed into single‐stemmed plants; treatment with GA at the third‐ or fourth‐tiller stage resulted in final stem numbers similar to those of controls. Emergence was earliest, and the number of heads per plant greatest where sprayings were delayed until the third‐ or fourth‐tiller stage.In first harvest year plants significant increases in the number of heads per stem were obtained with certain treatments, especially those which had two applications of 0.5 mg. GA per plant during the elongation of the first four internodes. This was related in all treatment groups to modifications of the branching pattern, and also to the increased incidence of multiple heading. Earlier emergence resulted from treatment at all growth stages, the effect being maximal where three well‐spaced sprayings were applied during active stem extension.
STUDIES ON GLOEOSPORIUM MUSARUM CKE. & MASSEE CAUSING STORAGE ROTS OF JAMAICAN BANANAS
Authors: MEREDITH D. S. 
Published: February 2008

Gloeosporium musarum Cke. & Massee is the most important fungus associated with finger‐stalk rot of Jamaican Lacatan bananas, Fusarium spp. being of minor importance. Sodium salicylanilide (Shirlan WS), at concentrations of 0.5, 1.0 and 1.5%, provided approximately 30, 50 and 65% control, respectively, when inoculated fruit was dipped for 1 min. in the compound: severe phytotoxic effects were caused by all concentrations. When Shirlan WS treatment was followed by rinsing in water, there were no phytotoxic effects and approximately 15, 35 and 40% control of finger‐stalk rot, respectively, was obtained. 1.0 and 1.5% Shirlan WS also effected good control of anthracnose (G. musarum), both with and without post‐treatment washing.Moderate to poor control of Gloeosporium rot was obtained when Shirlan WS/washing treatment was delayed for more than 24 hr. after inoculation. A 2 min. immersion period in Shirlan WS was more effective than shorter periods: a momentary dip was ineffective.The antibiotic nystatin (200 and 400 p.p.m.) had no significant effect on the incidence of finger‐stalk rot: also, the severity of main‐stalk rot was not reduced appreciably.Practical considerations arising from the possibility of commercial‐scale treatment with Shirlan WS are discussed.
Field trials on the control of club root in Brassicae
Authors: WIGGELL P. , HAWKEN R. H. , WIGGELL D. , COCK L. J. , BANT J. H. 
Published: February 2008

SUMMARYExperiments were made in 1957‐59 on the fungicidal control of club root in cauliflowers (summer and winter), brussels sprouts, summer cabbages and savoys. Plants were treated immediately before setting out or in their final position.Pure (100%) calomel used in suspension at 1 and 2 oz. per pint gave best control of the disease: the 4% calomel paste method was effective but treated plants suffered an initial check from which they only slowly recovered. Formulations of pentachloro‐nitrobenzene and of aldrin did not give satisfactory control.Several methods of applying metham‐sodium were tried but gave poor control of the disease.
Saprophytic colonization of wheat straw by Cercosporella herpotrichoides Fron and other fungi
Authors: MACER R. C. F. 
Published: February 2008

SUMMARYIn liquid cultures Cercosporella herpotrichoides utilized both organic and inorganic sources of nitrogen and showed an absolute requirement for thiamin. On nutrient agar and through sterilized straw, C. herpotrichoides grew more slowly than other facultative fungal parasites of cereal roots and stem‐bases.The competitive saprophytic ability of C. herpotrichoides was found to be very limited. The observation that saprophytic colonization of straw tissue by Ophiobolus graminis declined as invasion progressed inwards was confirmed and found to occur also with C. herpotrichoides and Helminthosporium sativum but not with Fusarium culmorum.It is concluded that C. herpotrichoides exhibits a low competitive saprophytic ability and is therefore unlikely to colonize straw in the soil.
The survival of Cercosporella herpotrichoides Fron in wheat straw
Authors: MACER R. C. F. 
Published: February 2008

SUMMARYThe saprophytic survival of Cercosporella herpotrichoides in naturally infected and artificially infested wheat straw has been investigated. Test pieces of straw containing the fungus were buried both in unsterilized soil in laboratory containers and in the field. Survival of the fungus was assessed by its ability to produce viable and infective spores on the surface of the recovered pieces of straw when incubated in a moist chamber. It was found that C. herpotrichoides survived, virtually undiminished in vitality, in straw buried for 3 years, the maximum period tested. Straw colonized by C. herpotrichoides was observed to decompose more slowly in the soil than did uninoculated straw; this suggests a mechanism whereby C. herpotrichoides may be enabled to survive for such long periods in the presence of competitors.