摘要:

AbstractWhole plants of Ricinus communis var. Gibsonii were used to study the mobility of some xenobiotics in the phloem. Solutions of14C‐ or35S‐labelled test compounds were introduced directly into the hollow petiole of a leaf that was exporting assimilates. Translocation was monitored by collecting phloem exudate from an incision in the stem bark beneath the treated leaf. Using [3H]sucrose as an internal standard, qualitative and quantitative results were obtained for a variety of model compounds, including herbicides, fungicides and a nematic

ISSN:0031-613X    

DOI:10.1002/ps.2780150102

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA study was conducted of the behaviour of oxamyl in Israeli soils of varying clay and organic matter contents. The adsorption isotherms for oxamyl were linear, and the adsorption coefficient (Kd) could be correlated to the clay content of the soils, as well as to the organic matter content of the soil. Oxamyl adsorption was underestimated by using published correlations between the adsorption and the chemical properties of pesticides, such as their solubility or octan‐1‐ol‐water partition coefficient. The decomposition of oxamyl in soils followed first‐order kinetics. The half‐life ranged from 4 to 33 days in a Bet Dagan soil. The reaction rate increased with increasing moisture content of the soil until field capacity was reached, at which point it levelled off. The Arrhenius relationship was followed, with degradation proceeding more rapidly at higher temperatures. In several soils of varying composition, which were kept at field capacity, no difference in the degradation rates was observed. Oxamyl was applied to a Bet Dagan soil from a point source in a single pulse, as a split application, and on a continuous basis. The distribution patterns of oxamyl under the various treatments differed significantly. After the single‐pulse application, oxamyl was leached out of the emitter zone. While the split application decreased the oxamyl‐free zone, the best results were obtained by continuous application, which gave a nearly uniform distribution of oxamy

ISSN:0031-613X    

DOI:10.1002/ps.2780150103

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractDroplets were released from an ‘instantaneous line source’ perpendicular to the wind at heights of 4 and 7 m above the ground. Droplets were collected by rotating samplers at three heights; sets of samplers were positioned in a line parallel to the wind, downwind of the line source. Trials were carried out in moderately unstable conditions during the day, and under stable conditions shortly after dark, both over short rough stubble and over mature cotton. A substantial proportion of the small droplets were found to travel as far as 500 m over cotton; over grass, few of even the smallest droplets were collected 250 and 500 m downwind of the line source. Collection at the distant samplers was on average slightly, but not significantly, more when the spray was released at the greater hei

ISSN:0031-613X    

DOI:10.1002/ps.2780150104

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractSome symmetrical and unsymmetrical 2, 3‐bis(arylthio)‐1, 4‐naphthoquinones have been synthesised and assayed against Botrytis cinerea, Cladosporium fulvum and Venturia inaequalis. With the surprising exception of the 2, 3‐bis(4‐chlorophenylthio) derivative, the compounds were essentially inactive. The 2‐phenylthio and lower 2‐alkylthio derivatives showed a high level of activity, which was absent in the 2‐pentylthio and hi

ISSN:0031-613X    

DOI:10.1002/ps.2780150105

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractQuantitative structure‐activity relationship (QSAR) studies have been carried out on oral rat LD50values, for 129 herbicidal (trifluoromethyl)benzimidazoles, by multiple regression analyses, using computer‐generated descriptors to represent chemical structure, at several levels of specificity. The results permit rationalisation of the structure‐toxicity relationship, particularly the effect of substituent interactions, and allows reliable ‘rough estimate’ prediction of toxicity. However, reliable predictions of high accuracy are not feasible, even from analysis of this large, consistent, congeneric set of data, thus casting doubt on the suitability of the LD50as a biological end‐point

ISSN:0031-613X    

DOI:10.1002/ps.2780150106

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractOver the past 15 years, an increasing number of ergosterol biosynthesis inhibitors (EBIs) have been introduced in crop protection as fungicides, and in medicine as fungicides and bactericides. Their spectrum of activity and their systemic properties vary widely, depending on structural elements. By their high protective and curative activity the EBIs have greatly improved the level of disease control, both in plants and in man. However, the chemical and biological potential of this group has not yet been fully explored, particularly in the field of growth regulation.

ISSN:0031-613X    

DOI:10.1002/ps.2780150107

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe metabolism of triforine, chloraniformethan, the α‐(pyrimidin‐5‐yl)benzhydryl alcohols (fenarimol, nuarimol and triarimol), the trityl‐azoles (fluotrimazole and clotrimazole), and the morpholine types of sterol inhibitors is reviewed; the metabolism of the azolyl‐alkane derivatives (mainly triadimefon and triadimenol) is discussed in detail. Redox and hydrolytic reactions are of primary importance. Enzymic inactivation may be one factor influencing fungicide selectivity. Metabolism is the dominant factor of selectivity if it represents the activation process, as with triadimefon. Transformations in higher plants do not differ significantly from those occurring in fungi, except that factors such as the formation of conjugates with natural compounds of plant tissues also play a role, as with triforine and triadimenol. The selectivity of fungitoxic action may be influenced by metabolism both in the host plant and th

ISSN:0031-613X    

DOI:10.1002/ps.2780150108

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractPhthalimide fungicides (captafol, captan and folpet) enhanced the accumulation of fenarimol by the mycelium of a wild‐type strain and a fenarimol‐resistant strain ofAspergillus nidulans. The accumulation is ascribed to inhibition of active efflux of fenarimol from the mycelium. It is assumed that the synergistic action observed between the phthalimide fungicides and fenarimol with respect to fungitoxicity, was caused by the increased accumulation of fenari

ISSN:0031-613X    

DOI:10.1002/ps.2780150109

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractBotrytis cinerea, grown in shake culture in a liquid nutrient medium containing different amounts of triadimefon (4–40 mg litre−1), produced triadimenol as the sole major metabolite. Analysis by gas‐liquid chromatography (g.l.c.) showed the presence of (1R,2S) and (1S,2S)‐triadimenol, but no (1S,2R) or (1R,2R)‐enantiomer. The proportion of (1R,2S) to (1S,2S)‐triadimenol decreased over the period 6 to 168 h and with increased amounts of applied triadimefon. The implications of these patterns of metabolism are discussed in terms of overall fungitoxicity, the stereospecificity of the reduction process and the shortcomings of conventional, non‐chiral analysis of diastereoisomers by g.l.c. for assessing the sensitivity of fungi to such fungicides a

ISSN:0031-613X    

DOI:10.1002/ps.2780150110

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe fungiCoriolus versicolor, Cladosporium cucumerinum, Botrytis cinereaandFusarium culmorum, in shake culture, metabolised triadimefon to triadimenol. Analyses by gas–‐liquid chromatography of the triadimenol showed that the fungi produced different qualitative and quantitative combinations of the four possible enantiomers, and that these differences were reproducible. The relationship between the enantiomeric composition of the triadimenol produced and the sensitivity of the test fungi to triadimefon, is discussed in the light of published data on the differences in antifungal activity shown by these enantiom

ISSN:0031-613X    

DOI:10.1002/ps.2780150111

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY