摘要:

AbstractThe photodecomposition of pendimethalin (N‐(l‐ethylpropyl)‐2,6‐dinitro‐3,4‐xylidine, l) in solution, as a thin film, and on soil surfaces under ultraviolet light and sunlight was investigated. Irradiation of pendimethalin in methanol yielded, in addition to the minor dealkylated product, the major products 2‐amino‐6‐nitro‐N‐(l‐ethylpropyl)‐3,4‐xylidine and 2‐nitroso‐6‐nitro‐3,4‐xylidine. Pendimethalin was found to degrade rapidly through reductive cyclisation of a nitro group and an adjacent N‐ethylpropyl group to give a cyclised benzimidazole product. The photodecomposition of pendimethalin involves oxidative dealky

ISSN:0031-613X    

DOI:10.1002/ps.2780250202

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractAn epithelial cell‐line from Chironomus tentans, able to synthesise chitin in considerable amounts, was used as a test system to study the influence of tunicamycin (I20=750 nM), the benzoylphenylurea derivative SIR 8514 (I50=100 nM), oligomycin (I50=200 nM), avermectin (I50=5 μM) and nikkomycin Z (I50,=50 μM) on the rate of glucosamine incorporation into chitin. Chitin synthesis was diminished by application of 20‐hydroxyecd

ISSN:0031-613X    

DOI:10.1002/ps.2780250203

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractWhile the parts played by synthesis chemists, biologists and toxicologists in the discovery and development of fungicides are well established, the role of the biochemist is generally less well appreciated. Biochemistry does, however, have an important contribution to make, the principal activities being: mode of action studies; generation of data on the intrinsic activities of molecules; biorational design of novel inhibitors; fungicide resistance; and molecular biology and its applications. The background to each of these areas and relevance to fungicide discovery and development are described. Examples from studies on ergosterol biosynthesis inhibitors are used to illustrate the discussion.

ISSN:0031-613X    

DOI:10.1002/ps.2780250204

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractPhosphonic acid analogues of phenylalanine, tyrosine and 3,4‐dihydroxyphenylalanine exhibited interesting plant growth regulatory properties when tested on Cucumis sativus L. Depending on the chemical structure, they slightly inhibited or strongly promoted the growth of C. sativus roots, while their influence on hypocotyls was negligible. Phosphono peptides based on these acids showed less significant plant growth regulating activit

ISSN:0031-613X    

DOI:10.1002/ps.2780250205

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

Abstract[14C]metalaxyl applied to seeds, roots and leaves of cowpea was readily taken up by all plant parts and a major fraction of it was retained within the treated leaves and seeds but not in the roots. The fungicide exhibited ambimobility inside the plant. When applied to the middle of leaflets, metalaxyl mobilised towards proximal and distal parts of the leaflet. Intraleaflet movement seemed to result from translocation through veins and diffusion through cell walls and intercellular spaces. Accumulation of metalaxyl at tips and margins of primary leaves followed application to roots. Metalaxyl was readily extracted from most plant parts except cotyledons and only 0.8% of the fungicide applied as a seed treatment was recovered from 50‐day‐old pla

ISSN:0031-613X    

DOI:10.1002/ps.2780250206

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractTransesterification andN‐methylation of carbetamide was carried out usingN,N,N‐trimethylanilinium hydroxide as an alkylation reagent. The final product of the on‐column methylation appeared as the dimethyl derivative of carbetamide which was qualitatively identified and quantitatively determined by means of gas‐liquid chromatography. The standard methyl N‐methylcarbanilate was analytically identified by a mass spectrometr

ISSN:0031-613X    

DOI:10.1002/ps.2780250207

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThirty 6‐trifluoromethylpyrazolo[3,4‐d]pyrimidines were synthesised and tested for antifungal activity in vitro against ten phytopathogenic fungi of different taxonomic classes. Six of the compounds had noteworthy activity against Sclerotinia minor, Corticium solani and Phoma betae. The relationships between structure and activity are discussed on the basis of the present and previous stud

ISSN:0031-613X    

DOI:10.1002/ps.2780250208

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractPhosphonic acid (phosphorous acid), H — PO(OH)2, the active breakdown product in plant tissues of the systemic anti‐oomycete fungicide fosetyl‐aluminium was investigated in order to assay the stability of the labelled compound. There is a strong and fast isotopic exchange in unbuffered aqueous solutions of2H — PO(OH)2, and therefore3H — PO(OH)2, so that Fenn and Coffey's experiments must be reinterpreted because these authors used a stock solution of pure labelled phosphonic acid. However, it is possible to use this last compound for biological experiments under the following conditions: (1) Keeping the dry sodium salt3H — PO(ONa)2. 5H2O in small flasks (100 mg, 37 MBq each) in a vacuum desiccator for individual use without fractionation; (2) using the compound at neutral or slightl

ISSN:0031-613X    

DOI:10.1002/ps.2780250209

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA trial was carried out to investigate the efficacy of methacrifos against susceptible and multi‐resistant strains of four species of insect and three species of mite. Methacrifos was applied to two separate 20‐tonne loads of English wheat which were then stored under ambient conditions for 24 weeks. The efficacy of methacrifos was assessed using established bioassay techniques which showed complete control for 24 weeks of all susceptible insects except S. oryzae, where there were survivors at week 24. Methacrifos also gave 100% mortality of resistant O. surinamensis for 24 weeks. There was>95% mortality for 16 weeks of resistant strains of T. castaneum and of resistant S. granarius and S. oryzae for 20 weeks. After S. granarius and S. oryzae were removed, the grain was incubated for 10 weeks. Subsequent F1emergence was considerably less from the treatments than from the controls. Methacrifos produced 100% mortality for T. longior for 24 weeks, but control of G. destructor fluctuated and was<100% at week 24. There were survivors of A. siro from wee

ISSN:0031-613X    

DOI:10.1002/ps.2780250210

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA model for the transport of pesticides in non‐structured arable soil has been tested under field conditions. Three classes of sorption site are distinguished in the model. Sorption at class 1 sites is assumed to be at equilibrium whereas sorption at class 2 and class 3 sites is calculated using rate equations. Class 2 sites equilibrate on a time scale of days and class 3 sites equilibrate on a time scale of hundreds of days. In the model, the liquid phase is assumed to be homogeneous and completely mobile. The model was validated in two field experiments on a loamy sand soil using the herbicides cyanazine and metribuzin and using bromide ion as a tracer of liquid flow in soil. Ignoring sorption at class 3 sites resulted in large discrepancies between calculated and measured concentration profiles. Calculated concentration profiles were sensitive to the desorption rate constant for class 3 site

ISSN:0031-613X    

DOI:10.1002/ps.2780250211

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY