bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of fungal and plant esterases on the fungicidal activity of nitrophenyl esters
Authors: Clifford Derek R. , Hislop Eric C. , Shellis Claire 
Published: November 2006

AbstractAryl esterases, present within leaves and fungal spores and on their surfaces, hydrolysed 2‐naphthyl, 4‐nitrophenyl and 4‐(1‐substituted alkyl)‐2, 6‐dinitrophenyl esters at rates which appeared to be determined by the nature of the ester group and by the alkyl substituents in the molecule. No simple relationship was found between partitioning (as measured by Rm values from reverse‐phase t.l.c.) and susceptibility to hydrolysis by esterases. The most readily hydrolysed alkyldinitrophenyl esters are not those derived from parent nitrophenols with the greatest fungitoxicity in vivo or in vitro and the highly active 4‐(1‐cyclobutylalkyl)‐2, 6‐dinitrophenyl crotonates are amongst the least easily hydrolysed. It is suggested that alkyldinitrophenyl esters may have their own mode of action as powdery mildew fungicides which complements, and may even supplant, that resulting from hydrolysis to the parent alkyldinitrophenol. The proposed mechanism is disruption of the fungal cell membrane (as a result of surfactant properties) leading to leakage of essential cell components.
Deposition and drift of ulv and vlv insecticide sprays applied to cotton by hand applicator in northern nigeria
Authors: Johnstone Donald R. , Huntington Kathryn A. 
Published: November 2006

AbstractExperiments have been carried out in northern Nigeria to study the deposition and drift of the small spray droplets (70–130 μ v.m.d.), utilised in the application of carbaryl plus an indicating dye, to cotton, at very low volume rates (6–12 litre/ha) using water‐based formulations and at ultralow volume rates (3 litre/ha) using waterless formulations. The character of the deposition and extent of drift have been shown to relate to spray droplet size, formulation and a combination of meteorological factors. Practical recommendations have been evolved for very low volume and ultralow volume techniques in which the time of application is restricted to those periods of the day which favour high recovery.
Penetration of bean leaves by aminotriazole as influenced by adjuvants and humidity
Authors: Cook Gordon T. , Babiker Abdel G. T. , Duncan Henry J. 
Published: November 2006

AbstractPenetration of bean leaves (Phaseolus vulgaris var. Canadian Wonder) by aminotriazole (3‐amino‐1,2,4‐triazole) was greatly enhanced under high humidity conditions (ca 10% in 17 h at the low humidity level (LHL) compared with ca 80% in 2 h at the high humidity level (HHL)). The addition of polyoxyethylene 20 sorbitan monolaurate (polysorbate 20) to the spray fluid increased penetration on all occasions at the LHL. The increase obtained was found to be dependent on the concentration of polysorbate 20. The inclusion of polysorbate 20 at the HHL resulted in an increase in aminotriazole penetration at low polysorbate 20 concentrations 0.2–12.8 g/litre and a non‐significant decrease over the aqueous control at a concentration of 40 g/litre. With additions of glycerol to the spray fluid, aminotriazole penetration was increased on all occasions at the LHL while at the HHL no concentration of glycerol was found to enhance penetration. The addition of polysorbate 20 (< 0.1 to 40 g/litre) to a spray solution containing glycerol (0.3 ml/litre) enhanced penetration at the HHL compared with the aqueous and glycerol controls. A polysorbate 20 plus glycerol combination (6.4 g+0.6 ml/litre) gave the same order of penetration (98.4 and 94.0%) at the HHL and LHL respectively. In both cases penetration exceeded that obtained with the corresponding polysorbate 20 and glycerol controls. Some of the practical implications of these findings are discussed.
Analytical method for traces of hexachlorobenzene in formulations of other pesticides
Authors: Alam Mumtaz 
Published: November 2006

AbstractA method is described for the analysis of trace levels of hexachlorobenzene in pesticide formulations. The method involves the conversion of hexachlorobenzene to pentachlorophenol which is converted to the acetate and analysed on a gas chromatograph using microcoulometric detection. This technique allows separation of hexachlorobenzene from most constituents of the pesticide formulations.
Hydrolysis and photolysis of the fungicide triforine
Authors: Darda Siegfried , Darskus Rolf L. , Eichler Dietrich , Ost Walter , Wotschokowsky Manfred 
Published: November 2006

AbstractThe main decomposition products formed from triforine by hydrolysis in solution and by photolysis were isolated and identified. In aqueous solution at 21°, hydrolysis proceeds rapidly by formation of chloride ions and, through several intermediates, 1‐(dihydroxyacetyl)piperazine and piperazine. Photolysis by ultraviolet light in the absence of water leads preferentially to the removal of one side chain, the second side chain being attacked more slowly. In aqueous solution, triforine is rapidly destroyed by ultraviolet light. N‐(2,2‐Dichlorovinyl)formamide was isolated as an intermediate photodecomposition product.
Toxicity of pyrethroids to larvae of the egyptian cotton leafworm, Spodoptera littoralis (Boisd.). I. Relative toxicities and knockdown activities of benzyl, and 5‐benzyl‐3‐furylmethyl, cyclopropanecarboxylates
Authors: Ford Martyn G. , Reay Richard C. , Pert David , Ellis Peggy E. , McVeigh Lawrence J. 
Published: November 2006

AbstractThe contact toxicity of ten pyrethroids to larvae of Spodoptera littoralis (Boisd.) was investigated by topical application, and symptoms observed for different combinations of dose and time. Several compounds were sufficiently active to suggest that they may prove useful for the control of populations in the field. Structure and activity are discussed with particular reference to time‐dose‐response relationships: speed of action is related to both chemical structure and applied dose.
Stability of thiophanate‐methyl in aqueous dispersion
Authors: Courtney Graham F. 
Published: November 2006

AbstractThis paper reports chemical evidence on the fate of the systemic fungicide thio‐phanate‐methyl dissolved in methanol, chloroform and ethyl acetate0, and in aqueous dispersions from pH 1 to pH 13. It is shown that thiophanate‐methyl is unstable when dissolved in ethyl acetate and that it is stable in aqueous dispersions from pH 1 to pH 9.
Transparent emulsions of pyrethroids
Authors: Brown Bernard B. , Jaus Joseph B. , Calsetta Douglas R. 
Published: November 2006

AbstractWhen the absence of organic solvents or halogenated/hydrocarbon propellants are desirable or mandatory in applying pyrethroids for typical institutional or household disinsection, emulsifiable concentrates are available that permit aqueous dilution in all proportions to provide transparent, indefinitely stable compositions suitable for non‐pressurised delivery. The system is equally applicable to synergised natural pyrethrins and typical synthetic pyrethroids. The compositions can accommodate additives to provide economic residual action against crawling insects when desirable. Typical products registered in the United States will be discussed as will development activities on the new long residual pyrethroids.
The evaluation of permethrin for wood preservation
Authors: Berry Roger W. 
Published: November 2006

AbstractThe toxicity of the synthetic pyrethroid permethrin (NRDC 143) to a range of wood destroying insects has been investigated. In tests using Hylotrupes bajulus, Anobium punctatum, Lyctus brunneus and Reticulitermes santonensis permethrin showed a similar order of toxicity to that of gamma‐BHC. Although the toxicity of permethrin to adult A. punctatum was of the same order as that of gamma‐BHC, the toxicity to larvae was rather lower. The implications of these results are discussed and it is concluded that, subject to further field evaluation, permethrin could provide an alternative to gamma‐BHC and dieldrin in wood preservatives.
Substituted 3‐furamides with specific activity against basidiomycetes
Authors: Pommer Ernst‐Heinrich , Zeeh Bernd 
Published: November 2006

AbstractSubstituted furanilides and furamides show very good activity against Basidiomycetes. Whilst N‐cyclohexyl‐x‐methyl‐3‐furamides (where x‐ is one or more of the vacant positions in the furan ring) further substituted on the amide nitrogen have specific activity against Basidiomycetes (e.g. Ustilago nuda, U. scitaminea, Tilletia tritici and Rhizoctonia solani), N‐cyclohexyl‐N‐methoxy‐2,5‐dimethyl‐3‐furamide also gives good control of other classes of fungi (e.g. Fusarium nivale and Helminthosporium gramineum). This compound is to be developed under the Code Number BAS 389 F as a mercury‐free seed dressing alone or in combination with other fungicides.
Confirmation of perfluidone residues in rice by gas‐liquid chromatography following the formation of derivatives
Authors: Tafuri Francesco , Businelli Mario , Patumi Maurizio , Marucchini Cesare 
Published: November 2006

AbstractA simple and sensitive method for the confirmation of perfluidone residues in rice grains is described. The procedure involves extraction, purification on an anionexchange resin, chlorination, methylation and gas‐chromatographic analysis with electron capture detection. The recoveries from fortified rice grains varied from 84.0 to 92.4% in the range 0.01–0.20 mg/kg. The sensitivity was such that perfluidone could be detected down to a level of 0.005 mg/kg. The method can be used for confirmation of perfluidone quantitatively as well as qualitatively.
Routine methods for analysis of organophosphorus and carbamate insecticides in soil and ryegrass
Authors: Holland Patrick T. 
Published: November 2006

AbstractThe organophosphate insecticides dichlorvos, trichlorphon and isofenphos have been extracted from soil and ryegrass by blending with acetone+ benzene (19+1, v/v) and charcoal. After filtering, water and waxes were precipitated from the extract at − 78°. The extracts were analysed for insecticide by gas chromatography using alkali flameionisation detection. Trichlorphon was converted to the acetate by on‐column acetylation. Recoveries ranged from 73 to 93% for levels of insecticide from 0.1 to 10mg/kg. The carbamate insecticides methomyl and carbofuran plus the metabolite 2,3‐dihydro‐3‐hydroxy‐2,2‐dimethylbenzofuran‐7‐yl methylcarbamate have been extracted from soil and ryegrass samples by shaking with acidified ammonium acetate. Following filtration and neutralisation, the aqueous phase was extracted with dichloromethane. The carbamates in the extracts were determined by gas chromatography using on‐column trans‐esterification to methyl methylcarbamate. Recoveries ranged from 79 to 97% for levels of insecticide from 0.1 to 10 mg/kg.
A farmer's approach to the socio‐economic aspects of crop protection
Authors: Fell Henry R. 
Published: November 2006

AbstractThe period since 1945 has been one of extraordinary development in British agriculture. A period during which the science of Crop Protection has advanced from practically nothing to where it is today—an accepted and essential part of everyday farming. The speed of these developments has put pressure on the industry and on the individual farmer. At the same time the economic climate of the 1960's has sharpened the search for efficient, low‐cost production. The farmer has no choice but to use every weapon in his armoury. Safeguards against misuse of chemicals seem to be basically satisfactory up to the point of sale. There is, however, the basic point of whether the food producer has grown to be too dependent on chemical control, whilst neglecting good husbandry, which may be both cheaper and more effective.
The metabolism of the herbicide flamprop‐methyl in wheat
Authors: Roberts Terry R. 
Published: November 2006

AbstractThe metabolism of the wild oat herbicide flamprop‐methyl, methyl (±)‐2‐[N‐(3‐chloro‐4‐fluorophenyl)benzamido]propionate, in spring wheat grown to maturity has been studied under glasshouse and outdoor conditions. [14C]‐Flamprop‐methyl labelled separately in the halophenyl ring and the carbonyl of the benzoyl group was used. The major metabolite formed in plants was the corresponding carboxylic acid, II, which also occurred as conjugates. Other minor metabolites detected under glasshouse conditions only were the 3‐ and 4‐hydroxybenzoyl analogues of flamprop‐methyl and 3′‐chloro‐4′‐fluorobenzanilide. The soil in which the plants were grown contained residues comprising mainly flamprop‐methyl and II together with smaller amounts of unidentified polar material.
An equation for computing concentration‐time products of 1, 2‐dibromoethane (EDB) gas during fumigation
Authors: Swaine Gordon , Corcoran Robert J. , Pepper Patricia M. , Cranny Anne E. , Davey Marguerite A. 
Published: November 2006

AbstractThe concentration of 1, 2‐dibromoethane (EDB) gas in the air space during fumigation can be expressed by the empirical equation c = exp [k(t+ I)b]. In this equation c is the concentration of EDB in g/m3 and t is the lapsed time in minutes; k is the natural log of the nominal dosage and b is a parameter which depends on the contents of the fumigation chamber. The b value is obtained from the linear relationship In [(In c)/k] = b In (t+1). The concentration‐time product is obtained from the integral
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DDT‐resistant mosquito strains with cross‐resistance to pyrethroids
Authors: Prasittisuk Chusak , Busvine James R. 
Published: November 2006

AbstractVarious DDT‐resistant strains of mosquito, comprising 8 strains of Aedes aegypti from the Neotropics (tropical and South America) and one each of Anopheles gambiae and An. quadrimaculatus were tested for resistance to pyrethroids. Susceptibility was measured by LT50 values, after exposure to impregnated papers in the cylinders used in the WHO standardised test for adult mosquitoes. DDT‐resistance levels (by comparison with susceptible strains) ranged from × 2 to × 73, with simultaneous low resistance to permethrin (× 1.4 to × 3.4) except in one strain from Guyana which reached × 30. Further comparisons were made with this Guyana strain and one from Salvador with similar DDT‐resistance (about × 70) but low permethrin‐resistance. Tests with methoxychlor and I,I‐di‐(4‐chlorophenyl)‐2‐nitropropane and with the synergist I,I‐di‐(4‐chlorophenyl)‐2,2,2‐trifluoroethanol suggested that a considerable part of the DDT‐resistance of both strains was due to a dehydrochlorination mechanism. Tests with the synergist piperonyl butoxide (PB) suggested that microsomal oxidase systems were also involved, especially in the Guyana strain. The cross‐resistance in both strains extended to 3 other pyrethroids. Addition of the synergist PB had little effect on the Salvador strain, but substantially reduced permethrin‐resistance in the Guyana strain. It is concluded that an unknown mechanism associated with DDT‐resistance confers a low level cross‐tolerance to pyrethroids; this can be substantially augmented by the development of a microsomal oxidase mechanism, as in the Guyana strain.
An Example of Cross‐resistance to Pyrethroids in DDT‐resistant Aedes aegypti
Authors: Chadwick Peter R. , Invest John F. , Bowron Marcus J. 
Published: November 2006

AbstractComparisons of the susceptibility of several strains of adult Aedes aegypti were made. Mosquitoes from Bangkok and Jakarta were found to be highly resistant to DDT and resistant to pyrethroids relative to a laboratory strain. A strain from Singapore, where less DDT has been used, was susceptible to DDT and pyrethroids. Two strains from the Caribbean had LC50 values to DDT 3 times that of the reference strain while the LC50 values against bioresmethrin synergised with piperonyl butoxide were 1 1/2 times raised. Another two strains from central Africa were 2 times tolerant of DDT and 1 1/2 times tolerant of bioresmethrin plus piperonyl butoxide. Agents which block DDT‐dehydrochlorinase, esterases and oxidases each caused small increases in the mortality of the Bangkok strain due to DDT and bioresmethrin as well as augmenting toxicity to the susceptible reference strain. It is tentatively suggested that resistance in the Bangkok strain is due to a combination of the actions of these and perhaps other resistance mechanisms.
Studies on the control of groundkeeper potatoes with the soil‐applied herbicides chlorpropham, propyzamide and trifluralin
Authors: Lutman Peter J. W. 
Published: November 2006

AbstractChlorpropham, propyzamide and trifluralin were assessed in several trials, to test their potential for the control of groundkeeper potatoes (Solanum tuberosum L.). Chlorpropham was insufficiently active, but trifluralin and propyzamide at doses of 4 kg a.i./ha, or more, reduced and delayed the emergence of potato plants in the summer, after autumn/winter or spring applications. The highest dose (12 kg a.i./ha) prevented many tubers producing plants. Greatest activity was attained when the herbicides completely surrounded the tubers when active growth started in the spring. However, both residue and crop tolerance data indicated that the doses of trifluralin and propyzamide required to control the potatoes were so high that appreciable residues remained in the following summer. These damaged vegetable crops drilled in April and May, and affected cereals planted 12 months after application. Thus there is insufficient margin of selectivity between the doses required to control the potatoes and those tolerated by subsequent crops.
The action of pyrethroids in the insect central nervous system. I. Features of molecular structure associated with toxicity to cockroaches and to their giant fibre axons
Authors: Burt Paul E. , Goodchild Ralph E. 
Published: November 2006

AbstractTo investigate relationships between the molecular structure of pyrethroids and their mode of action, toxicities to adult male Periplaneta americana by topical application and injection were compared with toxicities to their giant fibre nerve axons. From the tests against intact insects it was concluded that: (i) although ED50S ranged from 0.04 to 65 μg/insect, each compound was equally toxic, with one exception, when administered by either route; (ii) esters of (1 R)‐cis‐ were more toxic than esters of the corresponding (1 R)‐trans‐3‐substituted‐2, 2‐dimethylcyclopropanecarboxylic acids; (iii) α‐cyano‐3‐phenoxybenzyl esters were more toxic than the corresponding 3‐phenoxybenzyl esters; (iv) changes in the alcoholic component of some compounds (particularly trans‐isomers of esters of 5‐benzyl‐3‐furylmethanol and esters of α‐cyano‐3‐phenoxybenzyl alcohol) affected a recovery phase in their ED50/time curves more than changes in the acid component; (v) the amount of recovery was positively correlated with molecular polarity. The concentration required to decrease the amplitude of the action potential of giant fibres by 30% in 1 h ranged from 0.26 μM for the most active compound to 100 μM for the least active. There was no clear relationship between neurotoxicity and toxicity to whole insects and little association between neurotoxicity and features of molecular structure. Neurotoxicity was, however, positively correlated with polarity. Giant fibre axons seem unlikely to be critical sites of action of pyrethroids.
The action of (S)‐3‐allyl‐2‐methyl‐4‐oxocyclopent‐2‐enyl (1 R)‐trans‐chrysanthemate, (S)‐bioallethrin, on single neurones in the central nervous system of the leech, Hirudo medicinalis
Authors: Leake Lucy D. 
Published: November 2006

AbstractIntracellular recordings from identifiable neurones in the leech segmental ganglion in high (20 mM) magnesium Ringer solution showed that (S)‐3‐allyl‐2‐methyl‐4‐oxocyclopent‐2‐enyl (1 R)‐trans‐chrysanthemate, (S)‐bioallethrin, induced three phases of activity: (1) hyperexcitability; (2) repeated depolarisations accompanied by trains of action potentials; and (3) block of action potentials. A linear relation between log (time to onset) of both depolarisations and block and the log (applied dose) was observed over the range 3.44 × 10−7–1.10 × 10−3M. (S)‐Bioallethrin was toxic to leeches at similar concentrations to those effective on isolated ganglia. The possible role of repeated depolarisations in the poisoning process is discussed.
Eradication of apple powdery mildew (Podosphaera leucotricha) with dormant‐season sprays of surface‐active agents
Authors: Hislop Eric C. , Clifford Derek R. , Holgate Margaret E. , Gendle Peter 
Published: November 2006

AbstractOf twenty non‐ionic surfactant formulations tested in 1974–75 several were successful as eradicants of overwintering apple mildew as were two ionic materials. The incidence of Nectria canker was increased by sprays applied in October but less so by the same materials applied in January or February when phytoxicity measured in terms of fruit yield was also less. PP 222, a non‐ionic surfactant introduced in 1975, proved to be an efficient eradicant of mildew in 1976. Although the yield of fruit from most sprayed trees was greater than from controls, the best mildew eradicants did not produce greatest yields in the same year, perhaps indicating adverse effects of treatments on the trees. However, significantly better yields of fruit obtained in the year following the dormant season eradication of primary mildew, suggest long term beneficial effects of these treatments.
Distribution and metabolic fate of [14C]‐daminozide injected into silver maple and american sycamore seedlings
Authors: Domir Subhash C. , Brown Galen K. 
Published: November 2006

AbstractThe distribution and metabolic fate of [14C]‐daminozide in silver maple and American sycamore seedlings were studied by use of autoradiography, ion‐exchange chromatography, thin‐layer chromatography (t.l.c.), and liquid scintillation spectrometry. Within one day after treatment with [14C]‐daminozide, radioactivity was detected in all parts of the plant. The 14C concentrated in meristematic regions of the leaves. Ion‐exchange and thin‐layer chromatographic analyses of the 50% methanol extracts indicated that no detectable metabolites of daminozide were formed in any of the plant parts but approximately 20% of the applied 14C, most of it in the stem tissue, was not extractable by aqueous methanol.
Inhibition of the hill reaction of isolated chloroplasts by herbicidal phenylureas
Authors: Dicks John W. 
Published: November 2006

AbstractI50 values have been determined for inhibition of the Hill reaction of lettuce chloroplasts by thirteen phenylurea herbicides, all of which are potent inhibitors. The compounds fall into two groups on the basis of the relationship between pI50 and log (water solubility).
The algaecidal activity of some substituted 1,3‐diphenylureas, 1‐phenyl‐3‐(2‐pyridyl)ureas and the corresponding thioureas
Authors: Goulding Kenneth H. , Badami Nasi V. , Cremlyn Richard J. W. 
Published: November 2006

AbstractTwelve ureas and thioureas with 1,3‐diphenyl‐ and 1‐phenyl‐3‐(2‐pyridyl) were tested as potential herbicides in a simple screen against two species of algae Chlorella fusca and Anabaena variabilis. Several were shown to inhibit growth at 100 mg litre−1 but only 1‐[2,4‐bis(azidosulphonyl)phenyl]‐3‐(2‐pyridyl)urea and 1,3‐bis(4‐isopropyl‐ idenehydrazinosulphonylphenyl)thiourea showed any activity at 1 mg litre−1. This compares with the well‐established urea herbicide diuron which, in identical tests, gives similar inhibition of growth at concentrations as low as 0.01 mg litre−1.