bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on poly(acrylic acid) induced resistance to viral and non‐viral plant pathogens
Authors: Cassells Alan C. , Flynn Theresa 
Published: November 2006

AbstractStudies on polymer size, concentration and mode of application, either as foliar spray or soil drench, in relation to the induction of resistance to tobacco mosaic virus (TMV) in Nicotiana tabacum cv xanthi‐nc by poly(acrylic acid) (PA) are reported. PA also induced resistance to TMV in N. glutinosa, to pelargonium leaf curl virus in Datura stramonium, to cucumber mosaic virus in Vigna sinensis and to tobacco ring‐spot virus in N. tabacum cv White Burley. No TMV was detected in PA‐treated tomato cv Virocross 11 days after inoculation; but the susceptible cultivar Craigella became infected. PA treatment had no effect on TMV replication in White Burley tobacco but resistance was induced to Peronospora tabacina, a fungal pathogen of N. tabacum cv xanthi‐nc. The potential of PA‐induced resistance as a control measure for viruses and fungi is discussed.
Controlling pests of tropical legumes; current recommendations and future strategies
Authors: Gerard Brian M. 
Published: November 2006

AbstractLegumes have evolved effective defences against many pests by accumulating high levels of poisonous or indigestible compounds, pubescence and vigorous growth. These defences are greatly reduced in many cultivars of cowpea and common bean, which are susceptible to a succession of pest complexes. Stem pests and defoliators may kill seedlings but well‐established plants tolerate heavy insect damage to leaves, flowers and green pods before pod or grain yields are reduced; virus vectors and root‐knot nematode may be of greater importance. Generally, pod‐borers, pod‐sucking bugs and seed beetles are the main key pests. Control programmes are based on post‐flowering treatments with broad spectrum insecticides. Battery‐powered, controlled‐droplet application machines are ousting knapsack sprayers in small‐scale farming and competing with tractors and aircraft in larger units; subsistence cropping is still predominant and most legume crops remain unsprayed. Consequently, current emphasis is placed on developing cultivars with high yield potential and multiple pest and disease resistance. Insect infestations are lower in most other major legume crops largely due to pubescence (e.g. soybean, blackgram, greengram), fruiting in the dry season (e.g. pigeonpea, chickpea) or geocarpy (e.g. groundnut). Future entomological research will presumably concentrate on assessing the status of pests on resistant cultivars and introducing integrated control methods for the key pests.
Pesticide usage on bananas with special references to fungicides
Authors: Waller James 
Published: November 2006

AbstractBananas (including plantains) are widely grown throughout the tropics both for local consumption and for export. Pesticide usage is confined largely to the export crop because of its value and the susceptibility to diseases of varieties suitable for the export market. Most of the bananas grown for export are produced in Latin America and the Caribbean. Weed control with herbicides is particularly valuable in young banana plantations before a mature canopy is produced and when weeds compete with the shallow rooting system. Insecticides are used to control high populations of the banana weevil and may be used against fruit thrips. Nematicides are used extensively to control the banana root nematode and granular applications are now replacing soil injections. Fungicidal control of Sigatoka leaf diseases and fruit diseases has been practised for many years and is essential for the production of high quality, exportgrade fruit. Changes in the chemicals used and in application techniques have brought important benefits in recent years and genetic resistance is likely to play a large part in disease control in the future.
Permethrin as a residual insecticide against cockroaches
Authors: Carter Stuart W. , Chadwick Peter R. 
Published: November 2006

AbstractThe pyrethroid permethrin was shown to be active against Blattella germanica, Periplaneta americana and Blatta orientalis. In laboratory tests on plywood panels the best formulation was a 25% wettable powder which showed an initial LC50 of 10 mg m−2 against B. germanica and lost activity at the weekly rate of 1.9 mg m−2. An initial deposit of 108 mg m−2 gave 50% kill after one year. The synergist piperonyl butoxide diminished residual performance. In one field trial, good control was maintained for more than four months with an initial deposit of 50 mg m−2, the smallest dose used. From this and other trials, the recommended rate of application for general use in long‐term control is 100 mg m−2. A distinctive slow expellent action against B. germanica was seen in field trials.
Degradation of the herbicide flamprop‐isopropyl in soil under laboratory conditions
Authors: Hitchings Eric J. , Roberts Terry R. 
Published: November 2006

AbstractThe degradation of the wild‐oat herbicide flamprop‐isopropyl, [isopropyl (±)‐N‐benzoyl‐N‐(3‐chloro‐4‐fluorophenyl)alaninate], in four soils has been examined under laboratory conditions with sampling times of up to 45 weeks after treatment. The major degradation product of [14C]flamprop‐isopropyl in all soils at up to 10 weeks after treatment was the carboxylic acid (±)‐N‐benzoyl‐N‐(3‐chloro‐4‐fluorophenyl)alanine. This compound in turn underwent degradation by loss of the benzoyl group and the propionic acid moiety, with evolution of [14C]carbon dioxide to form 3‐chloro‐4‐fluoroaniline (CFA). The CFA was formed slowly in soil and occurred mainly as a bound form. There was evidence to show that the CFA was subsequently converted into other polar products. The time for depletion of 50% of the applied herbicide was approximately 10 weeks in sandy loam and medium loam soils, 11 weeks in a clay loam soil and 23 weeks in a peat soil.
Direct observation of the distribution of radiolabelled ethirimol in soil by resin impregnation and autoradiography
Authors: Collier Graham F. , Graham‐Bryce Ian J. , Knight Brian A. G. , Coutts John 
Published: November 2006

AbstractA procedure for examining the distribution of ethirimol in soil is described. Soil samples containing ethirimol are initially freeze‐dried at −5 to −10°C, impregnated with Araldite resin and hardeners under vacuum and then maintained for 16 h at room temperature followed by 24 h at 100°C, to complete curing. The impregnated soils may then be sectioned and the radiolabelled pesticide located by autoradiography. The distribution of ethirimol within the soil was found to be unaffected by either freeze‐drying or impregnation. The method enables the distribution to be determined on a small scale directly in undisturbed soil sections from both the laboratory and the field. It was used to investigate the effects of soil type on the movement of ethirimol. Structural and textural factors appear to have an important influence on the redistribution of this fungicide and may override the effects of adsorption.
Effect of pH on the degradation of atrazine, dichlorprop, linuron and propyzamide in soil
Authors: Hance Raymond J. 
Published: November 2006

AbstractThe rates of disappearance of atrazine, dichlorprop, linuron and propyzamide were measured in two soils incubated at 22°C and 80% water holding capacity. Observations were made at four pH levels in each soil. Atrazine degradation was relatively insensitive to pH; it increased slightly with increasing pH in one soil and decreased in the other. The other compounds all degraded more slowly at low pH in both soils although dichlorprop had essentially disappeared in 14 days under all conditions, so that the effect of pH is not unlikely to be of practical interest. The ratios of the degradation rates of atrazine, linuron, and propyzamide varied with the soil and the pH.
Action of pesticides on earthworms. Part II: Elimination of parathion by the earthworm Eisenia foetida (Savigny)
Authors: Stenersen Jørgen 
Published: November 2006

AbstractThe earthworm, Eisenia foetida, eliminated parathion and carbofuran at first order rates when continually rinsed in water after treatment with the pesticides. This experiment was also carried out on Lumbricus rubellus for comparison. Carbofuran which is more soluble in water, was eliminated quicker than parathion. The later rate of elimination was very similar for the two species, but immediately after injection the rate was much higher in E. foetida. The metabolism of 1‐ethyl14C labelled parathion and paraoxon (diethyl 4‐nitrophenyl phosphate) was studied in E. foetida. The worm was able to convert parathion to paraoxon by a rather slow process although this metabolite could not be detected in the worms due to its rapid transformation to diethyl hydrogen phosphate. Indirectly, paraoxon can be postulated as a parathion metabolite because of a progressive depression of cholinesterase level observed after treatment with parathion. Small amounts of diethyl hydrogen phosphate were detected as a metabolite of parathion; this is also an indication of paraoxon formation. During the 30 h following injection of parathion, only 4.4% of the applied dose was recovered as water‐soluble metabolites (2.8% in the worms and 1.6% in the sand surrounding them), while 52% was recovered as unmetabolised parathion. Because of inefficient injection, only 70‐59% of the dose thought to be injected was recovered. Therefore the part of the actual applied dose that remained unmetabolised was probably even greater (88%). Five days after injection of parathion, 15 and 9.3 % of the recovered radioactivity in the surrounding sand and in the worm extracts, respectively, was identified as O,O‐diethyl O‐hydrogen phosphorothioate, 3.7 and 7.0% as diethyl hydrogen phosphate, 8.8 and 3.3% as O‐ethyl O‐4‐nitrophenyl O‐hydrogen phosphorothioate (desethylparathion) and/or O‐4‐aminophenyl O,O‐diethyl phosphorothioate, while 70.3 and 80.4% was unmetabolised parathion. Paraoxon was very quickly hydrolysed to diethyl hydrogen phosphate in vivo and in vitro. The in‐vitro hydrolysis was associated with a microsomal fraction and was not inhibited by ethylenediaminetetra‐acetic acid or 4‐(chloromercuri)benzoic acid, and incompletely by aldicarb. Cholinesterase and arylesterase were therefore excluded as enzymes responsible for the activity.
Action of pesticides on earthworms. Part III: Inhibition and reactivation of cholinesterases in Eisenia foetida (Savigny) after treatment with cholinesterase‐inhibiting insecticides
Authors: Stenersen Jørgen 
Published: November 2006

AbstractThe degree of inhibition and the rate of recovery of total cholinesterase level were investigated after in‐vivo treatment of the earthworm Eisenia foetida (Savigny) with aldicarb, carbaryl, carbofuran, oxamyl, and the O‐analogues of bromophos (bromo‐phosoxon), parathion (paraoxon), parathion‐methyl (paraoxon‐methyl), and trichloronate (trichloronatoxon). The results can be explained by the presence of two cholinesterases (E1 and E2), which were demonstrated by in‐vitro inhibition studies. E1 was the most sensitive to all the inhibitors tested. The in‐vivo reactivation rate after inhibition with paraoxon was very high for E1 and very low for E2. Therefore, pretreatment with paraoxon probably increased the toxicity of carbaryl. It was concluded that the toxicity towards E. foetida can be explained in terms of cholinesterase inhibition, provided that the action on the two cholinesterases and the worms' tolerance for a transient but almost total cholinesterase depression are taken into account. Data are given showing that two other species of earthworms also contain different types of cholinesterases with respect to reactions with inhibitors.
Sites of action of photosynthetic inhibitor herbicides; Experiments with trypsinated chloroplasts
Authors: Pallett Kenneth E. , Dodge Alan D. 
Published: November 2006

AbstractThe effect of four photosynthetic inhibitor herbicides, bromacil, ioxynil, metribuzin and monuron, on chloroplast electron transport was investigated. All four compounds completely inhibited electron flow with tripotassium hexacyanoferrate as oxidant, but the inhibition caused by bromacil, metribuzin and monuron was almost totally reversed by trypsin treatment. With ioxynil, only a partial degree of reversability was shown. With a molybdosilicate as oxidant, electron transport was not completely inhibited by any of the herbicides. Whereas the partial inhibition was reversed by tryptic digestion in the presence of bromacil, metribuzin and monuron, there was virtually no reversal in the presence of ioxynil. The results suggest a common site of action for all four herbicides and an additional site for ioxynil nearer to photosystem II.
Synthesis, spectral properties and insecticidal, acaricidal and ovicidal activities of some O‐(1,5‐disubstituted‐ 6‐oxo‐12H‐pyridazin‐4‐yl) phosphorothioates
Authors: Konec̆ný Václav , Kovác̆ Štefan , Varkonda Štefan , Šustek Ján 
Published: November 2006

AbstractA synthesis of O,O‐dialkyl, O‐alkyl O‐2‐chloroethyl (or O‐2‐ethoxyethyl) O‐(1,5‐disubstituted‐6‐oxo‐1H‐pyridazin‐4‐yl) phosphorothioates is described. Infrared, Raman and ultraviolet spectra of the compounds prepared are interpreted. The wave‐numbers of the v(CC) bands were correlated with substituent constants. Good linear correlations of v(CO) with σ, σF, σI and σR were observed for compounds containing various substituents in the neighbourhood of the keto group of the pyridazinone ring. The insecticidal, acaricidal and ovicidal activities of O‐(ethyl or isopropyl), O‐(alkyl, 2‐chloroethyl, or 2‐ethoxyethyl) O‐(5‐methoxy‐1‐methyl‐6‐oxo‐1H‐ pyridazin‐4‐yl) phosphorothioates, O‐ethyl O‐isopropyl O‐(5‐methoxy‐1‐substituted‐6‐oxo‐1H‐pyridazin‐4‐yl) phosphorothioates and O‐ethyl O‐isopropyl O‐(1‐methyl‐5‐substitutedd‐oxo‐1H‐pyridazin‐4‐yl) phosphorothioates are reported together with the toxicity of some of these compounds to rats.
Use of the scanning electron microscope and cathodoluminescence in studying the application of pesticides to plants
Authors: Hart Clifford A. 
Published: November 2006

AbstractThe efficacy of a pesticidal formulation is in part affected by the surface to which it is applied. During the drying process, spray drops can interact with the complex microenvironment of trichomes, secretory glands, stomata, epicuticular wax and cuticle of the leaf epidermis. The subsequent uptake and persistence of the deposit can be further influenced by the action of the microclimate, including humidity, temperature, rain and dew. The scanning electron microscope (SEM), which is an instrument ideally suited for the study of the surface of bulk specimens, has been used to show the spreading and distribution of pesticides applied as sprays and individual drops to leaf surfaces. Particle size, crystal growth and co‐precipitation of the active ingredient with surfactants and other adjuvants have also been investigated. The SEM can also show how some pesticides and their adjuvants continue to be taken up by the leaf long after the drops have visibly dried. Phytotoxicity, sometimes associated with the penetration of active ingredient or formulation adjuvant, can also be demonstrated using the microscope, especially if either specifically emits cathodoluminescence. These images can also supply complementary information concerning the persistence of deposits, provided that interpretation of the results is carried out with care and, if possible, in conjunction with residue and biological assays.
Mechanisms of DDT resistance in larvae of the mosquito Aedes aegypti L
Authors: McDonald Alan E. , Wood Roger J. 
Published: November 2006

AbstractLarvae of eight strains of Aedes aegypti were exposed to DDT and compared for resistance, DDT uptake, in‐vivo breakdown of DDT and residual unmetabolised DDT. Resistance varied widely between strains, three being fully susceptible, two almost immune and three of intermediate resistance. Breakdown of DDT by dehydrochlorination to 1,1‐dichloro‐2,2‐bis(4‐chlorophenyl)ethylene (pp'‐DDE) occurred in all strains and was greater in the five resistant types, but there was no significant correlation between the extent of breakdown in the resistant strains and the level of resistance. Moreover the overall difference between susceptible and resistant strains disappeared when they were compared at a low, almost sublethal, concentration of DDT. Larvae of resistant strains carried a greater absolute quantity of unmetabolised DDT in the body and were able to tolerate levels of DDT that were lethal to susceptible larvae. However the two most resistant strains (T8 and B51) contained significantly less DDT plus pp'‐DDE than strains of intermediate resistance (T30 and BSJ) from which they had been derived. Addition of the synergist chlorfenethol to DDT increased its knockdown effect on all resistant strains, suggesting that dehydrochlorination was a factor in resistance. Three strains, two DDT‐resistant and one DDT‐susceptible, were tested with 1,1‐bis(4‐ethoxyphenyl)‐2,2‐dimethylpropane (I), an insecticide that cannot be dehydrochlorinated. All the strains were relatively tolerant to it although the DDT‐susceptible strains were less tolerant. Addition of the synergist sesamex decreased the level of tolerance to I in all strains which suggested that microsomal oxidation made some contribution to it. It is concluded that three factors contribute to larval DDT resistance in A. aegypti; (a) increased metabolism to pp'‐DDE; (b) increased tolerance to unmetabolised internal DDT; and (c) reduced content of DDT+pp'‐DDE (only in the most resistant strains and due either to reduced absorption or increased excretion). These factors are discussed in relation to known larval resistance genes RDDT1 and y.
The structural rearrangement of iprodione in ethanolic solution
Authors: Cooke Barry K. , Loeffler R. S. Thomas , Pappas Athanasios C. 
Published: November 2006

AbstractIprodione, in ethanolic solution, was found to undergo structural rearrangement over a period of days to give a solid product which was shown by mass spectrometry to be an isomer. Mechanistic considerations led to a proposed structure, which was verified by synthesis of an authentic specimen by an unambiguous route. The biological implications of these findings are discussed.
Measurement of petroleum oil deposits on citrus leaves by gas‐liquid chromatography
Authors: Furness Geoffrey O. , Howard Rex T. , Smith Peter J. 
Published: November 2006

AbstractThe quantity of oil deposited on citrus leaves when sprayed with oil‐in‐water emulsions was determined by gas‐liquid chromatography of a diethyl ether extract of the leaves. Recovery of oil diminished rapidly as the time interval between spraying and extraction increased; this effect must be recognised when the method is applied.
The extraction and assay of thiabendazole in strongly adsorbing soils
Authors: Cayley George R. , Lord K. Alan 
Published: November 2006

AbstractThiabendazole is strongly adsorbed on soils, and is not readily extracted by conventional solvents. two‐phase solvent system consisting of a mixture of aqueous ammonium chloride solution (pH 10), ethanol and chloroform was developed which extracted thiabendazole from a range of soils including high‐organic fen peat soils and mushroom compost. Subsequent partition of the extract between organic solvents and acid or alkaline solutions provided sufficient clean‐up for assay by ultraviolet or fluorescence spectroscopy, of concentrations of less than 1 mg thiabendazole kg−1 of soil. Investigation of the adsorption of thiabendazole from aqueous solution by soils indicated the importance of both soil organic and mineral matter and the adsorption of both neutral and protonated molecules.
Stability of insecticide resistance in the peach‐potato aphid, Myzus persicae (Sulzer)
Authors: Sawicki Roman M. , Devonshire Alan L. , Payne Roger W. , Petzing Stephanie M. 
Published: November 2006

AbstractAnholocyclic Myzus persicae (Sulz.) from the glasshouse and field can be classified into six variants, each with a characteristic carboxylesterase activity and consequent resistance to carbamate and organophosphorus insecticides. Overlapping activity distributions prevent unequivocal identification of an individual from measurements of its enzyme activity, but this may be done by cloning and measuring the frequency distribution of the enzyme activity in its progeny. Although each of the four lowest esterase variants has a frequency distribution with a single peak, only the susceptible (USLL) is best described by a single Normal distribution. Those of the other three clones (MSIG, French R and T1V) correspond better with two Normally‐distributed components. However, these are not well separated and the lower component accounts for only 10‐25% of the individuals. The very resistant clones from glasshouses have higher mean activities but with very broad distributions covering the whole range observed in this aphid. These broad distributions have peaks corresponding to those of the less resistant variants and arise from the appearance at each generation of a small proportion of individuals with much less active enzyme than their parents. Careful monitoring of the changes in activity between parents and offspring of the most resistant variant (clone G6) showed that complete loss of resistance can occur either in a single step or over several generations, and that below a threshold value, reversion to higher levels is very rare. Such reversion could only be detected by selection, with insecticide, of large clonal populations from an individual that had lost activity. High esterase activity was not stabilised by breeding for 16 generations only from individuals with high esterase activity, and is probably maintained in glasshouses by continuous exposure to insecticides. Spontaneous loss of esterase activity and resistance was observed only in glasshouse populations.
The bromination of highly halogenated chrysanthemic acid analogues
Authors: Bentley Philip D. , Cheetham Rex , Huff Roger K. , Swanborough Joe 
Published: November 2006

Abstract(Z)‐cis‐ and (Z)‐trans‐3‐(2‐chloro‐3,3,3‐trifluoroprop‐1‐enyl)‐2,2‐dimethylcyclo‐propanecarboxylic acids react with bromine under radical conditions predominantly to open the cyclopropane ring; the stereochemistry and reactions of the dibromides thus formed are described.
Recent topics in the chemistry of synthetic pyrethroids containing certain secondary alcohol moieties
Authors: Matsuo Takashi , Nishioka Toshio , Hirano Masachika , Suzuki Yukio , Tsushima Kazunori , Itaya Nobushige , Yoshioka Hirosuke 
Published: November 2006

AbstractFour important classes of synthetic pyrethroids containing certain secondary alcohol moieties, namely the α‐cyano‐3‐phenoxybenzyl esters, the analogous α‐ethynyl esters, 1‐(3‐phenoxyphenyl)prop‐2‐ynyl esters and 2‐methyl‐4‐oxo‐3‐(prop‐2‐ynyl)‐cyclopent‐2‐enyl esters and their most active isomers, are introduced with essential descriptions of synthetic pathways, optical resolution and determination of absolute configuration. The relationship between stereochemistry and the biologically active enantiomers of esters formed from the major secondary alcohols is discussed.
The vinylogous relationship in some pyrethroids
Authors: Farooq Saleem 
Published: November 2006

AbstractAttention is drawn to a vinylogous relationship between the structure of certain biologically‐active pyrethroids. A series of racemic α‐cyano‐3‐phenoxybenzyl 2‐(2,2‐dichlorovinyl)‐1‐phenylcyclopropanecarboxylates, based on this relationship, were synthesised and were found to be only moderately toxic to Musca domestica, Spodoptera littoralis and Leptinotarsa decemlineata.