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Other herbicides

Several other herbicides (for example, triazines) have been found to inhibit acyl lipid synthesis, but their effects may be due to secondary effects following a more acute action elsewhere in metabolism. For further details of such compounds, the reader is referred to previous reviews. [Pg.90]

Other significant groups of herbicides include polysubstituted benzenes, e.g. Trifluralin carbamates, e.g. Asulam acetamides, e.g. Propachlor and the triazoles, e.g. Amitrole. [Pg.263]


Degradation of a herbicide by abiotic means may be divided into chemical and photochemical pathways. Herbicides are subject to a wide array of chemical hydrolysis reactions with sorption often playing a key role in the process. Chloro-j -triazines are readily degraded by hydrolysis (256). The degradation of many other herbicide classes has been reviewed (257,258). [Pg.48]

Miscellaneous Other Herbicides. The herbicides in this group are not readily included in any of the preceding groups. Acrolein [107-02-8] (2-propenal) is used as a contact, aquatic herbicide. Sethoxydim, clethodim, and tridiphane are used for selective, post-emergence weed control. [Pg.54]

The complexity of the metabolism of alachlor, acetochlor, butachlor, and propachlor has led to the development of degradation methods capable of hydrolyzing the crop and animal product residues to readily quantitated degradation products. Alachlor and acetochlor metabolites can be hydrolyzed to two major classes of hydrolysis products, one which contains aniline with unsubstituted alkyl groups at the 2- and 6-positions, and the other which contains aniline with hydroxylation in the ring-attached ethyl group. For alachlor and acetochlor, the nonhydroxylated metabolites are hydrolyzed in base to 2,6-diethylaniline (DBA) and 2-ethyl-6-methylaniline (EMA), respectively, and hy-droxylated metabolites are hydrolyzed in base to 2-ethyl-6-(l-hydroxyethyl)aniline (HEEA) and 2-(l-hydroxyethyl)-6-methylaniline (HEMA), respectively. Butachlor is metabolized primarily to nonhydroxylated metabolites, which are hydrolyzed to DEA. Propachlor metabolites are hydrolyzed mainly to A-isopropylaniline (NIPA). The base hydrolysis products for each parent herbicide are shown in Eigure 1. Limited interference studies have been conducted with other herbicides such as metolachlor to confirm that its residues are not hydrolyzed to the EMA under the conditions used to determine acetochlor residues. Nonhydroxylated metabolites of alachlor and butachlor are both hydrolyzed to the same aniline, DEA, but these herbicides are not used on the same crops. [Pg.347]

Electrospray mass spectrometry has been used to characterise triazine, phenylurea, and other herbicides in estuarine water [391]. [Pg.425]

The recommended field application rates for terrestrial weed control usually range between 0.28 and 1.12 kg paraquat cation/ha (0.25 and 1.0 pounds/acre), between 0.56 and 2.24 kg paraquat dichloride/ha (0.5 and 2.0 pounds/acre) — both applied as an aerosol — and between 0.1 and 2.0 mg/L for aquatic weed control, although sensitive aquatic plants may be affected between 0.019 and 0.372 mg/L (Ross etal. 1979 Summers 1980 Bauer 1983 Dial and Bauer 1984). Paraquat is frequently used in combination with other herbicides (Fletcher 1974 Summers 1980). Water solutions of the dichloride salt, which usually contain 240 g/L, have been successfully mixed with 2,4-D, substituted ureas, dalapon, amitrol, and various triazines (Anonymous 1963, 1974). [Pg.1160]

The degradation rate of paraquat in certain soils can be slow, and the compound can persist for years — reportedly in a form that is biologically unavailable. But data are missing or incomplete on flux rates of paraquat from soil into food webs and on interaction dynamics of paraquat with other herbicides frequently applied at the same time. It seems prudent at this time to keep under close surveillance the residues of paraquat in soils in situations where repeated applications have been made over long periods of time (Summers 1980). [Pg.1183]

Toxicokinetics of mixtures of paraquat and other herbicides applied concomitantly... [Pg.1186]

O Donovan, J.T. and P.A. O Sullivan. 1986. Annual weed control with paraquat in combination with other herbicides. Can. Jour. Plant Sci. 66 153-160. [Pg.1190]

Abbott et al. [163] described a pyrolysis unit for the determination of Picloram and other herbicides in soil. The determination is effected by electron capture-gas chromatography following thermal decarboxylation of the herbicide. Hall et al. [164] reported further on this method. The decarboxylation products are analysed on a column (5mm i.d.) the first 15cm of which is packed with Vycor chips (2-4mm), the next 1.05m with 3% of SE-30 on Chromosorb W (60-80 mesh) and then 0.6m with 10% of DC-200 on Gas Chrom Q (60-80 mesh). The pyrolysis tube, which is packed with Vycor chips, is maintained at 385°C. The column is operated at 165°C with nitrogen as carrier gas (110ml min-1). The method when applied to ethyl ether extracts of soil gives recoveries of 90 5%. Dennis et al. [165] have reported on the accumulation and persistence of Picloram in bottom deposits. [Pg.255]

Many changes are occurring in the cultivation of tropical crops, and it is difficult to make any predictions in a field which is undergoing rapid changes. However, the present trend in the use of herbicides appears to be away from the use of single chemicals. Usually the combination of chemicals involves 2,4-D with some other herbicide, although TCA combined with a contact herbicide has been widely used. Some of the newer chemicals, such as TCA and CMU, will probably be used more in the future, especially if the cost can be reduced. [Pg.94]

Strong acids include battery acid, murintic acid, and hydrochloric acid. Weak acids include acetic acid, toilet bowl cleaner, and lactic acid. Banned pesticides include Silvex, Mirex, Aldrin, Chlordane, DDT, and Heptachlor. Caustics include oven cleaner and drain cleaner. Flammables include alcohol, acetone, turpentine, lacquer, and paint thinner. Pesticides include rodent poisons, insecticides, weed killer, and other herbicides and fungicides. Pesticide containers should be triple-rinsed, and the contents sprayed on crops or yard, before discarding. [Pg.81]

A number of other herbicides have specific uses. The amide herbicides, of which propanil is typical, are used in large quantities. Propanil is made by the reaction of propionyl chloride and 3,4-dichloroaniline. [Pg.386]

Glyphosate is a significant eye and skin irritant. It has caused lethal outcomes, although it is far less potent than the bipyridyl herbicides. Although the pure chemical seems to have little persistence and lower toxicity than other herbicides, the commercial formulations of glyphosate often contain surfactants and other active compounds that complicate the toxicity of the product. No specific treatment is available for glyphosate toxicity. [Pg.1222]

There are a number of other herbicides that affect photosynthesis indirectly. Pyrazole herbicides such as benzofenap, pyrazolynate and pyrazoxyfen interfere with chlorophyll biosynthesis and have found commercial application for the control of annual and perennial weeds in paddy rice and maize (Figure 2.4). [Pg.25]

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. [Pg.38]

Other herbicidal phenoxyacetic and phenoxypropionic acids have some properties similar to those of (2,4-dichlorophenoxy)acetic acid, but often have quite different species selectivity. Some of the differences can be explained on the basis of molecular stability, persistence, or mobility in the toxic form, as well as on the basis of differences in solubility and in absorption through leaves or roots. [Pg.397]

Many other herbicides and compounds having growth-alteration properties are known, and new ones appear annually from commercial screening. It has been quite evident so far that no correlation has been demonstrated between chemical structure or physical properties and biological activity. The empirical search continues for new structures having biological properties, and basic research studies continue with newer instrumental techniques for investigating the mechanisms of activity. [Pg.408]

Two groups of sucrose derivatives of herbicidal acids have been reported. The herbicidal properties of the sucrose esters of (2,4-dichlorophenoxy)-acetic acid and other analogs differed somewhat from the salts of the free herbicide acids. This could be accounted for as being due to differences in solubility and penetration, since it is unlikely, by analogy to the fatty acid esters, that the sucrose esters would remain intact in the plant. 0 The second set of sucrose esters were water-soluble sirups, having surfactant properties, prepared from reaction products of hydroxyethyl ethers of sucrose or diglycidyl ethers of poly(oxyetbylene glycol) with (2,4,5-tri-chlorophenoxy) acetic acid or other herbicidal acids. 1... [Pg.416]

Herbicides. The use of herbicides (qv) based on iodine compounds has its main market in Western Europe. In Canada and the United States these compounds are used only to a small extent. The only significant iodine-containing herbicide is ioxynil [1689-85 4] (4,-hydroxy-3,5,-diiodobenzoic acid). This compound, often used in combination with other herbicides, is formulated for controlling many annual broad-leaved weeds, especially black-bindweed, knotgrass, mayweeds, and com marigold post-emergence in wheat, barley, oats, rye, and triticale (142). Annual consumption of iodine in relation to ioxynils is considered to be about 300—500 t (66). [Pg.367]

Kubo et al. [122] have covered the sensing area of a gold electrode lattice with a polyimide layer which supports an atrazine selective MIP prepared with MAA and EDMA and functional monomer and cross linker, respectively. The detection limit was 50 nM (11 ppb) with a working range up to 15 pM atrazine. Other herbicides... [Pg.156]

Fig. 6 Detection frequency for pesticides targeted at 50 or more sites, in 127 studies conducted between 1958 and 1993. The relative agricultural use of each pesticide is shown in the left half of each graph. 2,4,5-T use percentage is based on a 1971 use estimate values for all other herbicides are based on 1989 use estimates. Organochlorine use percentage is based on 1966 use estimates values for other pesticides are based on 1990 use estimates. Numbers to the right of the bars represent the number of sites at which the chemical was targeted (T, triazines A, acetanilides P, phenoxys O, others OC, organochlorines CA, carbamates OP, organophosphates). From [12]... Fig. 6 Detection frequency for pesticides targeted at 50 or more sites, in 127 studies conducted between 1958 and 1993. The relative agricultural use of each pesticide is shown in the left half of each graph. 2,4,5-T use percentage is based on a 1971 use estimate values for all other herbicides are based on 1989 use estimates. Organochlorine use percentage is based on 1966 use estimates values for other pesticides are based on 1990 use estimates. Numbers to the right of the bars represent the number of sites at which the chemical was targeted (T, triazines A, acetanilides P, phenoxys O, others OC, organochlorines CA, carbamates OP, organophosphates). From [12]...
Air samples collected in the Canadian Prairies showed the presence of several currently used herbicides such as triallate, 2,4-D, dicamba, bromoxynil, MCPA, and trifluralin. While triallate was identified to be influenced by local sources, the other herbicides identified in air were thought to be due to regional atmospheric transport [88]. [Pg.179]


See other pages where Other herbicides is mentioned: [Pg.34]    [Pg.39]    [Pg.40]    [Pg.44]    [Pg.367]    [Pg.143]    [Pg.616]    [Pg.298]    [Pg.747]    [Pg.16]    [Pg.256]    [Pg.513]    [Pg.236]    [Pg.384]    [Pg.354]    [Pg.78]    [Pg.747]    [Pg.156]    [Pg.41]    [Pg.143]    [Pg.203]    [Pg.34]    [Pg.198]   


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