2,4-Dichlorophenoxyacetic acid plants

Yasuda, T., Yajima, Y., and Yamada, Y., Induction of DNA synthesis and callus formation from tuber tissue of Jerusalem artichoke by 2,4-dichlorophenoxyacetic acid, Plant Cell Physiol., 15, 321-329, 1974. Yeoman, M.M., Tissue Culture and Plant Science, Street, H.E., Ed., Blackwell s, Oxford, 1974, pp. 1-17. Zubr, J. and Pedersen, H.S., Characteristics of growth and development of different Jerusalem artichoke cultivars, in Inulin and Inulin-containing Crops, Fuchs, A., Ed., Elsevier, Amsterdam, The Netherlands, 1993, pp. 11-19. 

Herbicide Glasses and Databases. Herbicides can be classified as selective and nonselective. Selective herbicides, like 2,4-D (2,4-dichlorophenoxyacetic acid), metolachlor [51218-45-2] and EPTC [759-94 ] are more effective against some types of plants than others, eg, broadleaved plants vs grasses. Glyphosate [1071 -83-6] is representative of the nonselective herbicides used for total vegetable control. 

Of agricultural importance is the plant-growth regulating activity of 6,8-dichloro-2-methyl-3-carboxymethyl-4(3H) quinazolinone which was as potent as 2,4-dichlorophenoxyacetic acid in the Lepidium test. 4-Hydroxy-5,6,7,8-tetrahydroquinazoline has been patented with reference to fungicidal activity. 

So far as the author is aware, the first statement of the herbicidal action of 2,4-dichlorophenoxyacetic acid, made in the United States, was in a publication by Hamner and Tukey (14) in 1944. They sprayed 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid on bindweed and obtained a complete kill down to the root tips. At about the same time Hamner and Tukey (13) and Marth and Mitchell (24) demonstrated the effect of 2,4-dichlorophenoxyacetic acid as a differential herbicide on lawns. All plants growing on the lawns (except the grasses) were destroyed with apparently no noticeable ill effect on the grasses. 

Kraus and Mitchell have published an interesting paper (20) on the effects of a variety of substances including 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid on plant growth their experiments were carried out in 1943. 

These results show that the 2,4-dichlorophenoxyacetic acid can remain stable, and exert its herbicidal effects, only during the initial lag phase before the rapid logarithmic phase of destruction takes place. This initial lag phase depends upon the previous treatment of the soil, particularly on whether it has already been exposed to 2,4-dichlorophenoxyacetic acid. Clearly, once a soil is enriched with 2,4-dichlorophenoxyacetic acid destroying organisms, the herbicide, if added to the soil, will have little or no value in the control of plants growing there. 

Bronsema FBF, Vanuvustveen WJF, Pinsen E, Van Lammeren AAM. Distribution of [14C] dichlorophenoxyacetic acid in cultured zygotic embryos of Zea mays L. J Plant Growth Regul 1998 17 81-88. 

Ordin, L., M. J. Garber, and J. I. Kindinger. Effect of 2,4-dichlorophenoxyacetic acid on growth and on /1-glucan synthetases of peroxyacetyl nitrate pretreated Avena coleoptile sections. Physiol. Plant. 26 17-23, 1972. 

Feung. C. S., Hamilton. R.H., Witham. F.H., and Mumma, R.O. The relative amounts and identification of some 2,4-dichlorophenoxyacetic acid metabolites isolated from soybean cotyledon callus cultures. Plant Physiol., 50 80-86, 1972. 

Dicblorophenol, hexagonal ndls (from benz), mp 43°, bp 2o6-08°at 753 mm press, vol with steam forms some unstable salts most important use is in the manuf of 2,4 D (2,4-dichlorophenoxyacetic acid), a powerful plant-growth regulator (Refs 2 6)... 

Audus, L.J. (1949). The biological detoxification of 2,4-dichlorophenoxyacetic acid in soil. Plant Soil, 2 31-36. 

Chlorophenoxy acid herbicides are also widely used to control broadleaf weeds and grass plants. Several immunoassays have been reported for 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T).246 247 Several immunosensors have been described using a transducing principle similar to the RIANA system already described in this chapter. Thus, Meusel et al.248 reported the use of monoclonal antibodies in a sensor chip to analyze river and lake water samples, obtaining detection limits of 0.1 ig L 1. Moreover, monoclonal antibodies, produced by Cuong et al.,249 were used in a dipstick immunoassay format to analyze pond water samples. When applied to the 2,4-D compound, this semiquantitative method yielded for an IC50 of 6 ug I. and an LOD of 0.5 pg L-1. 

Verma, D.C., Tarvares, I, and Loewus, F.A., 1976, Effect of benzyladenine, 2,4-dichlorophenoxyacetic acid, and D-glucose in myo-inositol metabolism in Acer pseudoplatanus L. cells grown in suspension culture. Plant Physiol. 37 241-244. 

There are other herbicides in use which cannot be discussed in detail here, but one particular pair of chemicals should be mentioned. These are 2,4-D and 2,4,5-T, which are abbreviations of 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid. These chemicals act like plant growth hormones but cause excessive growth. They are selectively toxic against weeds. Although these herbicides have low toxicity to animals they can be contaminated with the most toxic type of dioxin (2,3,7,8-TCDD), as a result of the manufacturing process. The mixture of 2,4-D and 2,4,5-T was... 

Dichlorophenol, hexagonal ndls (from benz), mp 43° bp 2o6-08°at 753 mm press, vol with steam forms some unstable salts most important use is in the manuf of 2,4" D (2,4-dichlorophenoxyacetic acid), a powecful plant-growth regulator (Refs 2 6) 2,5-Dichlorophenol, crysts (from benz), mp 59° bp 209 11° volatile with steam of no coml importance (Refs 3 6) 2,6 Dichlorophenol, crysts (from petr eth), mp 66-68°, bp 220°, volatile with steam no Coml application (Refs 4 8c 6) 3,4 f it hloropkenol, ndls (from petr eth) mp 64-66°, bp 145-46° volatile with steam no coml utility (Refs 5 6)... 

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