摘要:

AbstractThe effects of two herbicides, glyphosate (as a 359 g litre−1SL) and hexazinone (as a 50gkg−1granule) on soil microbial population, carbon dioxide evolution, and in‐vitro growth of five species of ectomycorrhizal fungi were investigated. Glyphosate at 0–54 and 3.23 kg a.i. ha−1and hexazinone at 1. 2 and 8 kg a.i. ha−1did not reduce soil microbial population or carbon dioxide evolution in the long term (6 months). However, there was a significant short‐term (2 months) effect of glyphosate on both fungal and bacterial counts at the 0.54 kg ha−1treatment. In in‐vitro tests, Cenococcum graniforme. Hebeloma crustuliniformeandLaccaria laccatawere more susceptible to both herbicides than wasSuillus tomentosus.which was, in turn, more susceptible thanPaxillus involutus.The growth of all five ectomycorrhizal fungi was significantly reduced when subjected to concentrations above 50 μl formulation litre−1(glyphosate) or 50 μg formulatio

ISSN:0031-613X    

DOI:10.1002/ps.2780280302

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe effects of the herbicide glyphosate[N‐(phosphonomethyl)glycine]on seedling growth ofPinus resinosaand on the ectomycorrhizal development of the symbiotic fungusPaxillus involutuswere investigated under greenhouse and field conditions. Glyphosate at 0–54 and 3–23 kg ha−1did not reduce seedling growth or ectomycorrhizal development under greenhouse conditions. There was no seedling mortality due to glyphosate treatment at either rate. Under field conditions, seedling growth ofP. resinosaand ectomycorrhizal development ofP. involutuswere not affected by the above rates. Seedlings (46–48%) failed to survive in non‐glyphosate‐treated plots, presumably because of weed competition, whereas all survived in glyphosate‐treated plots. All the non‐mycorrhizal seedlings were colonized bv indigenous mvcorrhizal fungi within 2 months after planting in both control and glyphosate‐treated plots. The injection rates

ISSN:0031-613X    

DOI:10.1002/ps.2780280303

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA genetic analysis revealed that the resistance to diazinon of the bulb mite, Rhizoglyphus robiniClaparède. lacked sex linkage, and was based on the operation of a dominant allele. Synergism of diazinon by eight inhibitors of detoxifying enzymes in susceptible and resistant strains of the bulb mite was determined. Esterases were shown to play an important role in detoxification against diazinon. S.S.S‐tributyl phosphorotrithioate, an esterase inhibitor, was the only synergist which obviously synergized diazinon. The others, including the inhibitors of glutathione‐S‐transferases, carboxylesterase and mixed function oxidases, showed obscure or even antagonistic

ISSN:0031-613X    

DOI:10.1002/ps.2780280304

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractIn laboratory studies, Colorado potato beetle (CPB) (Leptinotarsa decemlineataSay) reared on eggplant were significantly more susceptible to permethrin than CPB reared on tomato. Field studies conducted in 1984 and 1985 showed that the percentage reduction of CPB larvae reared on eggplant due to foliar applications of fenvalerate was significantly greater than the percentage reduction of CPB larvae reared on either potato or tomato. Plant defoliation was greater on eggplant and potato than on tomato. Eggplant and potato yields increased as the dose of fenvalerate increased and the potato beetle population decreased, but tomato yields were unaffected by fenvalerate treatments. The effects and biological activity of individual plant chemical compounds(i.e., glvcoalkaloids) in variousSolanumspecies need to be examined in detail before the full significance of the role of these compounds in host‐plant resistance and their interaction with CPB insecticide resistance are understoo

ISSN:0031-613X    

DOI:10.1002/ps.2780280305

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe effect of the fungicide, diclobutrazol, on the germination, growth, chloroplast pigment and sterol content of winter wheat seedlings has been studied. At 250 μEm it retards their germination and growth, producing smaller, darker green and apparently healthy young plants. This is largely due to the 2S,3S–enantiomeric component. The increased greenness is not due to a direct effect on chloroplast pigments. It inhibits sterol 14—demethylation, causing an increase in the content of 4α,14α–dimethyl sterols, and also increases the proportion of campesterol, a 24—methyl sterol, relative to that of the 24—ethyl sterols, stigmasterol and sitosterol. Both the 2R,3R– and 2S,3S–enantiomers appear to be able to cause these changes i

ISSN:0031-613X    

DOI:10.1002/ps.2780280306

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe molecular action of herbicides with a triazine structure, such as atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐1,3,5‐triazine) and metribuzin (4‐amino‐6‐tert‐butyl‐3‐methylthio‐1,2,4‐triazin‐5(4H)‐one), has been related to their inhibition of the electron carrier system between chloroplastic photosystems II and I.This report provides evidence that 4‐amino‐6‐methyl‐3‐phenylamino‐1,2,4‐triazin‐5(4H)‐one, a recently synthesised triazine, structurally analogous to metribuzin, causes a powerful inhibition of the cell‐wall lignification catalysed by peroxidase from lupin. The two reactions involved in this lignification process are: oxidative polymerisation of coniferyl alcohol and the generation

ISSN:0031-613X    

DOI:10.1002/ps.2780280307

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractSubstitution of silicon for carbon was explored in etofenprox and MTI‐800, primarily to establish the suitability of silicon for pesticide construction and to probe steric effects. It was shown that silicon is an effective building block for insecticides with subtle qualitative and quantitative differences relative to the carbon analogs. The silanes were slightly less toxic to insects than the carbon analogs (relative potency of 0.2‐0.6) but the silane analog of MTI‐800 was considerably less toxic to fish (0% mortality at ≥50 mg liter−1) than MTI‐800 itself (LC50= 3 mg liter−1). The mode of action of both carbon and silicon compounds was similar in the intact, electrode‐implanted cockroach and involved repetitive firing of a sensory nerve; potency measurements were also made using an in‐vitro nerve assay. The possible metabolic and physicochemical contributions to the observed insecticide potencies were explored using synergism studies, physical chemistry measurements and quantum mechan

ISSN:0031-613X    

DOI:10.1002/ps.2780280308

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractSilicon effectively substitutes for quaternary carbon in etofenpr ox‐type insecticides; the resulting dimethyl‐4‐ethoxyphenyl‐3‐(4‐fluoro‐3‐phenoxyphenyl)propylsilane is a broad‐spectrum insecticide with extremely low toxicity to fish. Four regions of this new silane insecticide have been systematically altered. The methyl groups on silicon appear to be critical for activity. Replacement of the fluorine with hydrogen results in a substantial loss of activity. The aromatic rings of the phenoxyphenyl fragment are best tethered by oxygen or carbonyl, the methylene and nitrogen analogs being of very low toxicity to the test species. The activity ranking of the methylene and carbonyl tethers is opposite to that found for ester pyrethroids. The relationship of insecticidal activity to the aromatic substituentparato the silicon atom has been found to correlate with the molar refractivity of the substituent. Replacement of a tetra‐substituted carbon atom with a silicon atom can simplify construction of test compounds and thus be advantageously used in the exploration of structure—activity relationships. A novel method for preparing allylbenzenes from aromatic aldehyd

ISSN:0031-613X    

DOI:10.1002/ps.2780280309

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe passage of a14C‐labeled carbamate, 2‐(2‐chloro‐1‐methoxy‐' ethoxy)phenyl N‐methylcarbamate, or its labeled metabolites through the alimentary system of the grey garden slugDeroceras reticulatumwas examined by autoradiographic studies and scintillation counting. It was demonstrated that, in a first step, the molluscicide penetrated the cells of the oesophagus and the crop. It was quickly transported by the hemolymph to the periphery of the body and re‐entered the cells of the digestive tract and the mid‐gut gland in a second step from the hemolymph side. The crypt cells of the mid‐gut gland are discussed as cells involved in detoxification, and connective tissue cells as the major storage sites of the labeled material. Excretion in feces and secretion in mucus are thought to be the rout

ISSN:0031-613X    

DOI:10.1002/ps.2780280310

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractNematicidal activity of the essential oils of different plant species belonging to the families Labiatae(Ocimum basilicum, Ocimum sanctumandMentha piperata),Myrtaceae(Callistemon lanceolatusandEugenia caryophyllata)and Gramineae(Cymbopogon caesius)and their major monoterpenoidal constituents, linalool, eugenol, menthol, cineole and geraniol was determined against second‐stage juveniles of seed‐gall nematode(Anguina tritici),citrus nematode(Tylenchulus semipenetrans),root‐knot nematode(Meloidogyne javanica)and pigeon‐pea cyst‐nematode(Heterodera cajani).The essential oil ofE. caryophyllataand its major constituent eugenol, as well as linalool and geraniol, exhibited non‐specific activity against all the four nemat

ISSN:0031-613X    

DOI:10.1002/ps.2780280311

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY