Diclofop methyl

Other auxin-like herbicides (2,48) include the chlorobenzoic acids, eg, dicamba and chloramben, and miscellaneous compounds such as picloram, a substituted picolinic acid, and naptalam (see Table 1). Naptalam is not halogenated and is reported to function as an antiauxin, competitively blocking lAA action (199). TIBA is an antiauxin used in receptor site and other plant growth studies at the molecular level (201). Diclofop-methyl and diclofop are also potent, rapid inhibitors of auxin-stimulated response in monocots (93,94). Diclofop is reported to act as a proton ionophore, dissipating cell membrane potential and perturbing membrane functions. 

In addition to the use of 2,4-dichlorophenol in the synthesis of 2,4-D herbicides (acid 2,4-D, acid 2,4-DP, acid 2,4-DB), it is also found in the selective post-emergence herbicide, diclofop-methyl [51338-27-3] (61) and as a selective pre-emergence herbicide, oxadia2on [19666-30-9] (62). A postemergence herbicide is appHed between the emergence of a seedling and the maturity of a crop plant. 

Using a simple solvent extraction procedure to minimize matrix effects, a diclofop-methyl immunoassay was developed for milk, a number of edible plant products, and other matrices. Gas chromatography (GC) and liquid scintillation counting (LSC) of a C-labeled analyte were used as reference methods to compare with enzyme immunoassay (EIA) results. The methods were well correlated, with comparison of EIA... 

Diclofop-methyl is an early post-emergence herbicide applied to cereals, oil seeds and a variety of other crops for the control of annual grasses. Both Diclofop-methyl and its hydrolysis product, diclofop, are herbicidal [200] therefore, analysis for Diclofop-methyl in soil includes the determination of both chemicals. 

The next stage is hydrolysis to Diclofop-methyl in the extract to diclofop. This is achieved by heating the residue obtained by removal of hexane with methanoic potassium hydroxide at 60°C, then acidification and extraction... 

This reaction occurs in soils amended with Flamprop-methyl [205], Benzoyl-prop-ethyl, and Diclofop-methyl [206]. As the names of these pesticides indicate, R is CH3 or CH2CH3, respectively. The second product of the conversion is presumably the non-toxic alcohol [R -OH]. 

Diclofop-methyl [51338-27-3] bobwhite quail LDso" 3.64 Hamburg et al., 1989... 

CASRN 51338-27-3 molecular formula C16H14CI2O4 FW 341.20 Biological. Based on the first-order biotic and abiotic rate constants of diclofop-methyl in estuarine water and sediment/water systems, the estimated biodegradation half-lives were 0.24-12.4 and 0.11-2.2 d, respectively (Walker et al., 1988). 

Soil Under aerobic conditions, diclofop-methyl decomposes in soil forming diclofop-acid (Smith, 1977, 1979a Hartley and Kidd, 1987 Humburg et al., 1989) which degraded to 4-(l4-di-chlorophenoxy)phenol (Smith, 1979), 4-(2,4-dichlorophenoxy)ethoxybenzene (Smith, 1977, 1979a), and hydroxylated free acids (Hartley and Kidd, 1987 Humburg et al, 1989). The half-lives in sandy soils and sandy clay soils were reported to be 10 and 30 d, respectively (Ashton and Monaco, 1991). 

Smith, A.E. Degradation of the herbicide diclofop-methyl in prairie soils, J. Agric. Food Chem., 25(4) 893-898,1977. 

Other herbicides are selectively inactivated by the target crop whilst the weeds that they control either do not metabolise them or they do it so slowly that the weed is killed before it can inactivate the herbicide. There are a number of key plant enzymes that are used in the inactivation of herbicides. Microsomal mixed function oxidases are able to hydroxylate a wide range of herbicides such as bentazone and diclofop-methyl (Figure 2.30). It is often the case that these hydroxylated metabolites are subsequently glucosylated by sugars in the tissue and these conju-gants can be stored in the cell vacuole where they can have no phytotoxic effects. 

Diclofop-methyl, diclofop Methanobwater ethylacetate acetic acid (40 40 19 1) Conversion to pentafluo-robenzyl bromide derivative then gas chromatography [476]... 

In 2001, Llewellyn and Powles reported a survey of fields in the Western Australian Wheat Belt, conducted to determine the extent of rigid ryegrass resistance to commonly used herbicides (i.e., diclofop-methyl, clethodim, chlorsulfuron, and sulfometuron). Of the randomly collected populations, 46% exhibited resistance to diclofop-methyl and 64% to chlorsulfuron, with 37% exhibiting resistance to both herbicides. 

Cotterman, J.C. and F.F. Saari (1992). Rapid metabolic inactivation is the basis for cross-resistance to chlorsulfuron in diclofop-methyl-resistant rigid ryegrass (Lolium rigidum) biotype SR4/84. Pestic. Biochem. Physiol., 43 182-192. 

McCarty, L.B. (1989). Goosegrass control and turfgrass tolerance to diclofop-methyl. Proc. South. Weed Sci. Soc., 42 144. 

Enantiomer separation of various compounds such as barbituric acids, benzoin, MTH-proline, glutethimide, a-methyl-oc-phenyl-succinimide, y-phenyl-y-butyrolac-tone, methyl-mandelate, l-(2-naphthyl)ethanol, mecoprop methyl, diclofop methyl and fenoxaprop methyl by pressure supported CEC on a permethyl-P-cyclodextrin modified stationary phase was described by Wistuba and Schurig [42-44]. Three different separation beds were used (i) permethyl-P-cyclodextrin was covalently attached via a thioether to silica (Chira-Dex-silica) [42], permethyl-P-cyclodextrin was linked to a dimethylpolysiloxane and thermally immobilized (ii) on silica (Chirasil-Dex-silica) [43] or (iii) on a silica monolith (Chirasil-Dex-monolith) [44], respectively. 

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