摘要:

AbstractSeveral series of alkyl‐substituted amino‐, bromo‐, chloro‐, fluoro‐ and hydroxy‐1, 4‐naphthoquinones, as well as some 6‐alkylaminoquinoline‐5, 8‐diones and 7‐alkyl‐6‐hydroxyquinoline‐5, 8‐diones were prepared and tested as protectant fungicides against apple powdery mildew (caused byPodosphaera leucotricha). While most of the compounds did not reduce infection when applied at 10−3M, several 3‐alkyl‐2‐bromo‐and 3‐alkyl‐2‐chloro‐1, naphthoquinones

ISSN:0031-613X    

DOI:10.1002/ps.2780120102

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA description is given of the synthesis, acetylcholinesterase inhibition, insecticidal activity and field trial results with 2‐diethylamino‐4‐nitrophenyl dimethylcarbamate and related comp

ISSN:0031-613X    

DOI:10.1002/ps.2780120103

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe residues and metabolism of methidathion [S‐(2, 3‐dihydro‐5‐methoxy‐2‐oxo‐1, 3, 4‐thiadiazol‐3‐ylmethyl)O, O‐dimethyl phosphorodithioate] and its secondary metabolites: demethyl‐methidathion [S‐(2, 3‐dihydro‐5‐methoxy‐2‐oxo‐1, 3, 4‐thiadiazol‐3‐ylmethyl)O‐methylO‐hydrogen phosphorodithioate] (IV), the sulphide (2,3‐dihydro‐5‐methoxy‐3‐methylthiomethyl‐1,3,4‐thiadiazol‐2‐one) (I), tsulphoxide(2,3‐dihydro‐5‐methoxy‐3‐ methylsulphinylmethyl‐1,3,4‐thiadiazol‐2‐one) (II) and the sulphone (2,3‐dihydro‐5‐methoxy‐3‐methylsulphonylmethyl‐1,3,4‐thiadiazol‐2‐one (III) were studied in laboratory‐treated tomato fruit. The metabolites and residues of methidathion were determined for the applied doses of 1, 7 and 14 mg of methidathion kg−1of fruit. Methidathion was metabolised extensively over a 14‐day period. The amount of metabolites formed was a function of both the applied dose as well as the time after application. Major water‐soluble metabolites were found to beIVand the cysteine conjugateS‐(2,3‐dihydro‐5‐methoxy‐2‐oxo‐1,3,4‐thiadiazol‐3‐ylmethyl)‐L‐cysteine (VI). The chloroform‐soluble metabolites were identified as the oxygen analogue of methidathion [S‐(2,3‐dihydro‐5‐methoxy‐2‐oxo‐1,3,4‐thiadiazol‐3‐ylmethyl)O, O‐dimethyl phosphorothioate] (V), the sulphoxideII, and the hydroxy compound 2,3‐dihydro‐3‐hydroxymethyl‐5‐methoxy‐1,3,4‐thiadiazol‐2‐one. The oxygen analogue of methidathion (V) was found in small amounts, corresponding to<5% of the added methidathion. Demethyl‐methidathion (IV) appeared

ISSN:0031-613X    

DOI:10.1002/ps.2780120104

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA rat, given a single oral dose of [14C] cymoxanil, 1‐(2‐cyano‐2‐methoxyimino‐[2‐14C]‐acetyl)‐3‐ethylurea, eliminated 91% of the radioactivity within 72 h. The urine contained 71%, the faeces 11%, and the expired air about 7% of the radiolabel; no14C residue was found in the internal organs. Greater than 70% of the radioactivity in the urine was identified. The major metabolite was characterised as glycine, both free and conjugated, as hippuric acid and phenylaceturic acid [N‐(phenylacetyl)‐glycine], and probably in the form of polypeptides of low molecular weight. The other metabolites identified included 2‐cyano‐2‐methoxyiminoacetic acid, 2‐cyano‐2‐hydroxyiminoacetic acid and 1‐ethylimidazolidine‐2, 4, 5‐trione. The minor metabolites included succinic acid and 2‐oxoglutaric acid which indicated reincorporation of metabolic14C. Cymoxani

ISSN:0031-613X    

DOI:10.1002/ps.2780120105

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA laboratory model system for the determination of the volatility of non‐ionic pesticides from soil surfaces is presented. The pesticides examined were the insecticides methidathion, diazinon, and isazophos, the herbicide metolachlor, and the fungicide metalaxyl. The rates of volatilisation of these compounds from soil increased with increasing pesticide concentration, temperature and air flow rate and with decreasing soil organic matter content. The volatilities of the same pesticides were also calculated by using their vapour pressure, water solubility and soil adsorption data. The excellent correlation between calculated and experimental results showed that information on the volatility of a chemical can be obtained simply by calculation. Such calculations allow the classification of each pesticide according to its volatility, and therefore represent a useful alternative for volatility studies in laboratory model system

ISSN:0031-613X    

DOI:10.1002/ps.2780120106

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe determination of rate constants and the calculation of the activation parameters [activation energy (Ea), free energy of activation(ΔG≠)and entropy of activation (ΔS≠)] demonstrated the identity of the reaction kinetics of chemical hydrolysis of the chlorinated triazine herbicides simazine, atrazine, propazine and terbuthylazine. Persistence in soil could be estimated, from the hydrolytic half‐life time, only in pH regions where these compounds were also sensitive to chemical hydrolysis. In general, the rate of hydrolysis increased in the presence of soil as the result of a catalysing effect of the soil in their breakdown. When half‐lives in soil of these triazine herbicides were compared with adsorption constants, a functional relationship was observed in both soil types; as adsorption increased the half‐life in soil als

ISSN:0031-613X    

DOI:10.1002/ps.2780120107

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractNew pyrethroids containing heterocyclic rings in the alcohol moieties were synthesised and their insecticidal activities were studied. Of these new pyrethroids, 3‐benzylpyrrol‐1‐ylmethyl (1RS‐cis, trans‐3(2,2‐dichlorovinyl)‐2,2‐dimethylcyclopropanecarboxylate was found to be the most effective, having higher activity than permethrin againstMusca domesticaby a topical application method. In addition,para‐substituted analogues of the 3‐benzylpyrrol‐1‐ylmethyl ester were also synthesised to study the substituent effects on insecticidal activities; the residual effects of these compounds againstBlattella germ

ISSN:0031-613X    

DOI:10.1002/ps.2780120108

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractEphestia elutellalarvae in diapause were exposed at 25°C to methyl bromide at 12 mg litre−1for 3.5 or 7.5 h and then immediately exposed to a lower concentration. The minimum effective concentration (that at which Haber's rule, concentration × time =k, a constant for mortality, still applied) was about 3 mg litre−1in tests with no previous exposure toa high concentration, but it was about 2.5 mg litre−1for individuals surviving a 3.5 h exposure to 12 mg litre−1, and was about 1.6 mg litre−1for those surviving a 7.5 h exposure to 12 mg litre−1. These exposures to 12 mg litre−1, respectively, killed 2–20% and 50–75% of larvae exposed, and hence the smaller the proportion of survivors of exposure to a high concentration, the lower the minimum effective concentration needed against them. Thus the low concentration persisting at the end of a practical fumigation should contribute significantly to the success of the treatment and be much more effective than any similar low concentration present soon after the

ISSN:0031-613X    

DOI:10.1002/ps.2780120109

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractMethods have been developed for the analysis by gas‐liquid chromatography and thin‐layer chromatography of mecarbam and a number of its degradation products which result from oxidation and/or partial hydrolysis. In acid solution, mecarbam was found to be relatively stable but it decomposed more readily under alkaline conditions to giveO, O‐diethylhydrogen phosphorodithioate by fission of thesulphur‐carbon bond. At pH 9.2, the half‐life at room temperature was about 44 h. For residue analysis, a clean‐up procedure with Florisil was found to be preferable to one which employed alumina, as the latter caused cleavage of the ethoxycarbonyl group under certain conditions. Field trials with olives, oranges and pears showed that the parent pesticide, mecarbam, was the only significant detectable residue at any stage from treatment to harvesting, and that it tended to concentrate in the oil‐containing portion of the crop. Low levels ofO, O‐diethylS‐methylcarbamoylmethyl phosphorodithioate were also detected in residues from lucerne and from bean plants, and it was shown that this samemetabolite could be formed photolytically on filter paper or (morerapidly) on dock leaves.S‐(N‐Ethoxycarbonyl‐N‐methylcarbamoylmethyl)O, O‐diethyl phosphorothioate was detected only in bean plants and then, at a lev

ISSN:0031-613X    

DOI:10.1002/ps.2780120110

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractWettable powder formulations of the organophosphorus insecticides, fenitrothion and pirimiphos‐methyl, and the pyrethroids, permethrin and deltamethrin, have been compared for persistence and activity on woven polypropylene fabric; the residues produced in maize kept under the test sheets have also been measured. The test insects wereSitophilus oryzue(L.) andTribolium custuneum(Herbst). Permethrin at 41 and 83 mg m−2was completely effective for the full 12 weeks of the experiment. Deltamethrin at 6.2 and 12.5 mg m−2was almost equally effective but after 4 weeks the deposit was slower acting againstS. oryzae. The organophosphorus compounds were effective only up to 2 weeks at 250 mg m−2and up to 4 weeks at 500 mg m−2. No residues could be detected under the pyrethroids but the organophosphorus insecticides gave residues of 2–4 mg kg−1on a thin layer of grain. This residue was biologically effective against the

ISSN:0031-613X    

DOI:10.1002/ps.2780120111

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY