Herbicides benzoic acid derivatives

Chloramben, a benzoic acid derivative introduced by Amchem in 1958, is a selective preemergence herbicide (Fig. 3). It is used principally in soybeans, corn, and peanuts. 

Substituted phenols Chlorophenoxy compounds Substituted acetic and propionic acids Amides and thioamides Substituted ureas Carbamates and dithiocarbamates Symmetrical triazines Benzoic acid derivatives Miscellaneous herbicides... 

Chloramben is a synthetic benzoic acid derivative acting as an auxin. It is selective because some plants (soya beans) detoxicate it by making stable N-glucosides of it. It has low adsorbtion in soil and may be active in the soil for several weeks. Picloram is an example of a pyridinecarboxylic acid, which has been widely used alone or mixed with other herbicides. It is taken up by the roots, has a long action time, and leakage from the site of application may occur. It was marketed since 1963 by the Dow Chemical Company. 

Various chemical classes of auxin herbicides with different weed spectra and types of selectivity have been synthesized and commercially introduced over the years. They include phenoxycarboxylic acids, benzoic acids, pyridine carboxylic acids, aromatic carboxymethyl derivatives and a relatively new category, the quinolinecarboxylic acids (Figure 1). These compounds basically act as synthetic mimics of indole-3-acetic acid (lAA), which is the principal natural auxin in higher plants [2,3,5,7]. 

The Pesticide Manual describes 5 pyridine carboxylic acid derivatives, 3 benzoic acids, and 10 aryloxyalkanoic acids in current use as herbicides. 2,4,5-T seems to be banned worldwide and is not included in the current issue (Tomlin, 2000) but is described in earlier issues (e.g., Worthing, 1979). It was first registered in 1948 by Amchem Products, Inc., Pennsylvania, and the Dow Chemical Company, and was mainly used to control shrubs and trees, for example, in forests and along railways. Although the content of dioxin was eventually controlled, with a limit of <0.05 mg/kg in the preparation, it was banned soon after the termination of its use in Vietnam. Other products with 2,4,5-trichlorophenol were also banned or restricted after the Seveso accident (see Hay, 1978a, 1978b). 2,4-D is also produced from a chlo-rophenol and may contain dioxins, but of the much less toxic congeners. It... 

The Pesticide Manual describes 5 pyridine carboxylic acid derivatives, 3 benzoic acids, and 10 aryloxyalkanoic acids in current use as herbicides. 

Benzoic derivatives pesticides, those based on the fungicide benzoic acid (65-85-0), such as tricamba, a herbicide. 

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