bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of diflubenzuron upon larvae of the geometrid Boarmia (Ascotis) selenaria on avocado leaves
Authors: Ascher K. R. Simon , Wysoki Manes , Nemny Nadia E. , Gur‐Telzak Leah 
Published: November 2006

AbstractSmall (70 mg) Boarmia selenaria larvae fed for 4 days on avocado leaves or alfalfa dipped in aqueous diflubenzuron suspensions suffered from severe developmental disturbances. Similar results were obtained with leaves sprayed in an avocado orchard, with which, in addition, the considerable persistence of diflubenzuron under field conditions could be demonstrated. The substance was also active by topical application against large (500–600 mg) B. selenaria larvae, whereas by contact it was only moderately toxic. Some other non‐conventional control agents, viz., the antifeedant AC‐24055 and several juvenile hormone analogues, were of medium and negligible activity, respectively, against this insect.
Procedures and potentialities in sugar beet production
Authors: Hull Raymond 
Published: November 2006

AbstractCultivation procedures for the sugar beet crop continue to change considerably in England. The average contract per grower has increased from 3.4 in 1936 to 8.2 ha in 1973. Within the last decade the use of genetic monogerm seed has extended to 65% of the area sown, and pelleted seed to 90%. Seed spacing has doubled and the hand work needed to establish the crop drastically decreased. Much of the crop is now sown in March, instead of April or even May. The average yield of sugar has increased since 1936 from less than 3.6 to over 6 t ha−1. These changes have been associated with routine usage of fungicide and insecticide on seed and chemical weed control on 90% of the crop in recent years; insecticide, mainly organophosphorus, has been used to control aphids and virus on 36 000 to 125 000 ha of crop annually on the basis of spray warnings; sporadic pesticide control has been used against an abundance of seedling, leaf‐ and root‐eating pests and fungi. The changes in cultural practices have been paralleled by changes in the relative importance of the various pests and diseases—for instance, wide seed spacing and the use of herbicide have intensified seedling pest problems. The extent to which crop losses from weeds, pests and diseases have been assessed as a basis for recommendations for control is discussed, as well as the economics of control by pesticides.
The effects of diflubenzuron on the growth of insect cuticle
Authors: Ker Robert F. 
Published: November 2006

AbstractCuticle consists of chitin microfibrils embedded in a matrix composed largely of hydrated proteins. The effect of diflubenzuron, an inhibitor of chitin synthetase, on the deposition of both these components is reviewed. The polymerisation reaction is but one step in the pathway leading to chitin microfibrils. Possibly interactions to other steps in the pathway serve to enhance the consequences of the inhibition. Such enhancement could help to explain the abrupt changes in the rate of chitin synthesis that can be observed as diflubenzuron is cleared from epidermal cells. Cuticle proteins differ widely in their ability to form a stable layer when chitin is largely absent. In the most stable regions, diflubenzuron has no effect on the amount or nature of the proteins deposited. In contrast, there are many regions where the deposition of solid cuticle is stopped, presumably because the proteins involved cannot form a coherent layer. Intermediate degrees of stability are found. There is an association between the regions of stability and those of high sclerotisation; though sclerotisation often takes place long after deposition. Even when the protein layer is fairly stable it may not be deposited in a regular manner. This statement is illustrated by electron micrographs of cuticle from the hind tibiae of adult locusts. These micrographs also show that diflubenzuron can affect epidermal cells. In normal cells the plaques are in contact with the newly secreted cuticle; they are still present but this contact is not maintained after treatment with diflubenzuron.
The prospects of pest control by disruption of arthropod development
Authors: Busvine James R. 
Published: November 2006

AbstractDisruption of arthropod development is considered under the action of juvenoids (synthetic analogues of juvenile hormone), ecdysones (a class of compounds interacting with the hormone), diflubenzuron and its analogues and, finally, compounds with an anti‐hormone action. The compound's action is classified empirically by the symptoms produced in mosquito larvae.
Photodecomposition of piperazine in water by ‘sunlight’ ultraviolet radiation
Authors: Rouchaud Jean , Moons Chantal , Decallonne Jacques R. , Meyer Joseph A. 
Published: November 2006

AbstractA solution of piperazine in water was photochemically oxidised by the dissolved oxygen when irradiated with ‘sunlight’ ultraviolet radiation obtained with a Hanau Q‐300 lamp, or with RUL‐300 nm lamps. Sensitisers (riboflavin, acetone and benzophenone) did not increase the rate of the oxidation induced by the RUL‐300 nm lamps; however, they (especially riboflavin) accelerated the oxidation induced by the Hanau Q‐300 lamp. A large number of products were observed in the sensitised oxidation but they were not analysed further. The irradiation mixture of the non‐sensitised photo‐oxidation, when 65% of the initial piperazine had been transformed, contained piperazine (35%), glycine (approximately 25%) and three unidentified compounds in equal amounts (approximately 13% each); the same products were obtained with both irradiation systems. The photo‐oxidation of piperazine, a metabolite of the fungicide triforine, 1,4‐bis(2,2,2‐trichloro‐l‐formamidoethyl)piperaerazine, could thus be a way for the latter's biodegradation at a surface, or in plant tissues, this biodegradation having already been observed.
Identification of the photochemical decomposition product of chlorothalonil by 13C n.m.r. spectroscopy
Authors: Loeffler R. S. Thomas 
Published: November 2006

AbstractThe light‐induced decomposition of chlorothalonil (2,4,5,6‐tetrachloroisophthalonitrile) in benzene and toluene was found to give rise to one and three products respectively. These were shown by gas chromatography‐mass spectrometry to be trichlorodicyanobiphenyls and the benzene adduct was fully identified by 13C n.m.r. spectroscopy as 2,4‐dicyano‐3,5,6‐trichlorobiphenyl.
A multiresidue analytical method for determining organochlorine, organophosphorus, dinitrophenyl and carbamate pesticides in apples
Authors: Johansson Carl E. 
Published: November 2006

AbstractA multiresidue analytical method for the simultaneous extraction of organochlorine, organophosphorus, dinitrophenyl and carbamate pesticides from apples is presented. Extraction is performed with a mixture of toluene and hexane. After clean‐up on a Florisil column, and in some cases conversion to derivatives, quantitative determination is performed by electron‐capture gas chromatography. Qualitative verification is performed by thin‐layer chromatography or gas chromatography‐mass spectrometry.
The degradation of methazole in soil. I. Effects of soil type, soil temperature and soil moisture content
Authors: Walker Allan 
Published: November 2006

Abstract[14C]‐Labelled methazole was incubated in six soils at 25°C and with soil moisture at field capacity. Under these conditions, methazole was unstable, the concentration declined following first‐order kinetics with half‐life values in the soils ranging from 2.3 to 5.0 days. The main degradation product was 1‐(3,4‐dichlorophenyl)‐3‐methylurea (DCPMU) which was more stable than the parent compound. After about 160 days, DCPMU accounted for 30 to 45% of the initial methazole concentration. Degradation of methazole and DCPMU was affected by soil temperature and moisture content. With methazole, half‐lives in one soil at field capacity moisture content and temperatures of 25, 15 and 5°C were 3.5, 8.7 and 31.1 days respectively. The half‐life at 25°C was increased to 5.0 days at 50% of field capacity and 9.6 days at 25% of field capacity. A proportion of the initial radioactivity added to the soil could not be extracted and this proportion increased with time. After 160 days this unextractable radioactivity accounted for up to 70% of the amount applied.
The metabolism of cis‐2,5‐dimethylpyrrolidine‐1‐carboxanilide in rodents
Authors: Mitchell Stephen C. , Waring Rosemary H. 
Published: November 2006

AbstractThe metabolism of cis‐2,5‐dimethylpyrrolidine‐1‐carboxanilide was studied in rats, rabbits, guinea‐pigs and mice. The major metabolite in all species was cis‐4′‐hydroxy‐2,5‐dimethylpyrrolidine‐1‐carboxanilide, both free and as glucuronide and sulphate conjugates. About 95% of the compound was absorbed from the gut; over a 3‐day period, about 50% of the administered dose was excreted in urine and about 27% in faeces.
Pest control for cotton production: Present practice and trends for the future
Authors: Johnstone Donald R. 
Published: November 2006

AbstractCotton—the world's major fibre crop—is perhaps unique in the broad nature of the insect attack to which it is subjected, and the control of cotton insect pests remains an unabated challenge. In attempting a worldwide review of pest control practices in cotton production it is the diversity of all aspects of the problem which is immediately apparent. A variety of pest control solutions has evolved. This paper attempts to generalise the types of solution and at the same time point out how regional differences and the degree of capitalisation and management control have influenced the chosen approach.
The control of Plasmopara viticola with the 1:1 complex of zineb with 2‐(2‐aminoethylamino)ethanol and the potential effect of the use of this complex on ethylenethiourea residues
Authors: Clifford David P. , Bruyns‐Haylett John P. 
Published: November 2006

AbstractZineb 1:1 complex with 2‐(2‐aminoethylamino)ethanol was shown to be more active than zineb in glasshouse and field trials against Plasmopara viticola. The effects of this increase in efficacy on the potential reduction of ethylenethiourea residues are discussed.
Photolysis, metabolism and other factors influencing the performance of triadimefon as a powdery mildew fungicide
Authors: Clark Terence , Clifford Derek R. , Deas Adrian H. B. , Gendle Peter , Watkins David A. M. 
Published: November 2006

AbstractTriadimefon, 1‐(4‐chlorophenoxy)‐3,3‐dimethyl‐1‐( 1,2,4‐triazol‐1‐yl)butanone, applied at low dosage rates to leaves of marrow, apple or barley plants gave effective control of the appropriate powdery mildew fungi. The compound appeared to be systemic and to have considerable vapour‐phase activity. In marrow plants, up to 56% of triadimefon was metabolised to a mixture of two corresponding diastereoisomeric secondary alcohols. The mixture was identical with that obtained by chemical reduction of triadimefon. This mixture was also a very effective systemic fungicide and active in the vapour‐phase. Triadimefon was also reduced when incubated with Aspergillus niger but this was important only in shake culture. In replacement culture experiments, mycelial mats of this fungus converted the compound into a different metabolite, its isopropyl analogue. This may have resulted from participation of triadimefon in the C‐4 demethylation processes involved in fungal biosynthesis of ergosterol. Photolysis caused cleavage of the C‐1 to triazole bond liberating 1,2,4‐triazole, 4‐chlorophenol and 4‐chlorophenyl methyl carbonate, all of which were non‐fungitoxic. The importance of this photolysis in the in‐vivo situation is discussed.
Inhibition of ergosterol biosynthesis by triadimenol in Ustilago avenae
Authors: Buchenauer Heinrich 
Published: November 2006

AbstractIn Ustilago avenae sporidia, following the first doubling period of about 4 h, triadimenol (2 μg ml−1) affected sporidial multiplication more severely than other growth processes; daughter cells failed to separate from the parent sporidia resulting in chains of interconnected cells. Triadimenol incubated with the fungus for 8 h interfered neither with respiration nor with protein and nucleic acid synthesis but after 6 h the toxicant had induced a higher content of free fatty acids. Triadimenol markedly altered, both quantitatively and qualitatively, the sterols in sporidia of U. avenae. Incorporation of [14C]acetate (in the form of sodium acetate) into lipid fractions for a period of 2 h revealed that the toxicant powerfully inhibited the synthesis of the 4‐demethyl sterol fraction (predominantly ergosterol), whilst the 4,4‐dimethyl sterol fraction rapidly accumulated. This was confirmed by g.1.c. analysis of the sterols after 6 and 8 h incubation which showed that the amount of ergosterol, the major sterol in untreated sporidia, was diminished while simultaneously 4,4‐dimethyl, 4‐methyl and 14‐methyl sterols increased. The accumulation of 14‐methyl sterols suggests that triadimenol acts as a potent inhibitor of one of the metabolic steps involved in the demethylation at the 14‐position during ergosterol biosynthesis.
Further studies on the genetics of the carboxylesterase regulatory system involved in resistance to organophosphorus insecticides in Myzus persicae (Sulzer)
Authors: Blackman Roger L. , Devonshire Alan L. 
Published: November 2006

AbstractLevels of carboxylesterase activity in F1 clones of Myzus persicae, obtained by crossing sexuales from a resistant, high esterase clone with those from a susceptible, low esterase clone, fell into two distinct groups intermediate between the levels of carboxylesterase in the parent clones. When sexuales of F1 clones of the lower of these two intermediate levels of carboxylesterase activity were crossed, segregation ratios in the F2 generation indicated that this lower intermediate activity level (about 0.4 μmol mg−1 h−1). which is about twice the level in susceptible clones, is due to mutation at a single regulatory locus. The results obtained with backcrosses, between sexuales of an F1 clone having the higher intermediate level of carboxylesterase activity and a parent susceptible, low esterase clone, suggest that a second locus may be involved in the expression of higher levels of esterase activity.
Laboratory studies with antifeedants against larvae of Boarmia (Ascotis) selenaria on alfalfa
Authors: Ascher K. R. Simon , Nemny Nadia E. , Wysoki Manes , Gur‐Telzak Leah 
Published: November 2006

AbstractThe antifeedant effect of five organotin compounds (fentin acetate, fentin hydroxide, fentin chloride, cyhexatin and fenbutatin oxide) and of three other compounds known to possess antifeeding activity (guazatine triacetate, 4′‐chloroacetophenone isobutyrylhydrazone and thiram) was investigated by feeding treated alfalfa to larvae of Boarmia selenaria. The three fentins and cyhexatin were highly active at 0.1 g litre−1, the order of activity at this concentration being fentin chloride > fentin hydroxide > fentin acetate ⩾ cyhexatin, whereas the other compounds were practically inactive at either this or a somewhat higher concentration (0.5 g litre−1). Guazatine triacetate had a concentration‐independent antifeedant effect at much higher concentrations (5–20 g litre−1).
Contact activity of synthetic pyrethroids against adult grass grub, Costelytra zealandica (white)
Authors: Henzell Ronald F. , Lauren Denis R. 
Published: November 2006

AbstractThe field life for contact activity of cypermethrin and permethrin, applied to pasture, was similar for all of five application rates between 0.25 and 1.5 kg ha−1. Laboratory bioassays with grass grub beetles, Costelytra zealandica (White), showed that the insecticides lost their activity after about 4–9 days on pasture. Microencapsulation significantly increased the active field life of permethrin.
Quantitative structure‐activity relationships of pyrethroid insecticides
Authors: Ford Martyn G. 
Published: November 2006

AbstractThe structure‐activity relationships of two congeneric series of pyrethroid insecticides, the methylbenzyl (1RS)‐cis,trans‐chrysanthemates tested against Musca domestica (houseflies) and Phaedon cochleariae (mustard beetles), and the (E)‐4‐aryl‐3‐chlorobut‐2‐enyl chrysanthemates and their corresponding 2,2,3,3‐tetramethylcyclo‐propanecarboxylates tested against M. domestica only, have been examined using multiple regression analyses and substituent constants. With M. domestica, different optimum partition values (π) were indicated for knockdown and toxicity; with P. cochleariae, an optimum π value for toxicity, similar to that for M. domestica, was obtained 24 h after application, but at later times the more lipophilic compounds were more effective. For the methylbenzyl chrysanthemates, a steric constraint associated with 3,5‐dimethyl substitution reduced toxicity approximately five‐fold. The influence on toxicity of geometrical isomerism and electronic effects are briefly discussed. Differences between the required polarities for knockdown and toxicity are attributed to variations in the binding affinities of pyrethroid molecules at the sites of action.
Neurophysiological studies of the effects of permethrin upon pyrethroid resistant (kdr) and susceptible strains of dipteran larvae
Authors: Osborne Michael P. , Hart Richard J. 
Published: November 2006

AbstractPermethrin at concentrations as high as 10−6 had no detectable effect upon neuromuscular transmission at 20‐21°C in the body‐wall muscles of susceptible larvae of Lucilia sericata and susceptible and resistant (kdr) strains of larvae of Musca domestica. At the higher concentrations of 5 × 10−6M, muscle cells in all strains and species of larva were slowly depolarised, resulting in failure of neuromuscular transmission when the level of depolarisation corresponded with the peak height of the postsynaptic potentials. Multiple postsynaptic potentials were sometimes obtained in response to a single electrical stimulus to the motor axon. Neither of these effects is considered to result from interference with release of the neurotransmitter or its binding to the postsynaptic receptors. Spontaneous activity in sensory nerve fibres from susceptible larvae was increased followed by intermittent bursting and block at concentrations of permethrin as low as 10−9M at 20‐21°C and 10−10 at 26°C. Resistant larvae of M. domestica were 1000 times less sensitive, needing concentrations of permethrin as high as 10−6M at 20‐21°C and 10−7M at 26°C to affect sensory discharge. The results are discussed in relationship to the cause of knockdown by pyrethroid insecticides and to possible changes in the nervous system which may be brought about by the kdr resistance factor.
Toxicodynamics of insecticidal action: An introduction
Authors: Welling Wim 
Published: November 2006

AbstractAs an introduction to insecticide toxicodynamics, a description is given of the elementary processes with their interactions that are essential to an understanding of the dynamic behaviour; these include penetration, binding, biochemical conversions and reactions with the target. Points of ignorance or controversy are emphasised. method is discussed for integrating existing knowledge quantitatively by using mathematical models.
Uptake of iprodione and control of diseases on potato stems
Authors: Cayley George R. , Hide Geoffrey A. 
Published: November 2006

AbstractWhen applied to the roots of potato plants growing in different soils iprodione became systemic in the plants. Although iprodione was adsorbed on the soils tested, sufficient fungicide was present in potato stems to prevent infection by Phoma exigua var. foveata on all plants except those grown in peat soils. The amount of fungicide present in the aerial parts of the plant was related to the soil/water distribution coefficients. Application of iprodione to the sprouts of seed potato tubers prior to planting decreased the incidence and severity of infection by Rhizoctonia solani (stem canker) and Polyscytalum pustulans on stem bases.
Pesticide volatilisation rates: A new measurement of the vapour pressure of pentachlorophenol at room temperature
Authors: Dobbs Anthony J. , Grant Colin 
Published: November 2006

AbstractThe rates of volatilisation of pentachlorophenol, gamma‐HCH and HEOD have been measured under the same conditions. The rates found indicate that the vapour pressure of pentachlorophenol at ambient temperatures is ∽ 10−6 mmHg, significantly lower than the widely quoted value ∽ 10−1 mmHg. This lower value accounts for the behaviour of pentachlorophenol better than the existing value, which was obtained by extrapolation of the results of high temperature experiments. It is suggested that the direct measurement of relative loss rates is a simpler method of measuring volatile loss than the measurement of vapour pressure and that the method may prove a useful alternative to vapour pressure measurements in the assessment of the environmental effects of chemicals, particularly for compounds of moderate volatility.
Studies on low‐volume application of plant growth substances; Part 1: Ethylene production, induced by 1‐naphthylacetic acid, as a means of evaluating spray parameters
Authors: Crabtree Garvin D. , Bukovac Martin J. 
Published: November 2006

AbstractThe evolution of ethylene, induced by 1‐naphthylacetic acid (NAA), was studied as a means of evaluating spray parameters using cowpea [Vigna sinensis (Torner) Savi] under defined conditions as a test system. The dose‐response curve was linear over the range of 1.4‐14 μg per leaf. The marked production of ethylene following treatment with an active auxin, 2,4‐D (2,4‐dichlorophenoxyacetic acid), and the absence of its production following treatment with an inactive analogue (3,5‐dichlorophenoxyacetic acid), established that ethylene production was hormonally induced. The effect of application volumes of 10‐100 μ1 and of droplet sizes of 1‐10 μ1 were evaluated using a constant dose (5 μg NAA per leaf); NAA was more effective when delivered to the leaf in the larger volumes but in the smaller droplet sizes.
Quantitative structure—activity relationships for nicotinanilide molluscicides
Authors: Dunlop Robert W. , Duncan John , Ayrey Geoffrey 
Published: November 2006

AbstractStructure‐activity correlations for the toxicity of nicotinanilides to Biomphalaria glabrata have been studied in terms of partitioning, charge transfer and steric properties. Partition coefficients or πNA values (substituent constants for nicotinanilides, reflecting the influence on the partition coefficient of a substituent on the parent molecule) have been shown to contain a significant electronic component and to be related to chromatographically determined RM values (derived from a relationship between the partition coefficient and RF value for liquid‐liquid chromatographic systems). There was no overall correlation between LC50 values and partitioning, electronic or steric effects. However, for ten 4′‐substituted nicotinanilides, the LC50 values correlated significantly with partitioning, an increase in lipophilic character leading to an increase in biological activity. The greater activity of the unsubstituted parent compound could not be explained by purely advantageous steric effects but the 4′‐position may be an important metabolic site. Use of compounds labelled with deuterium failed to clarify this point because no isotope effects were observed.