Herbicides dalapon

Buchananwollaston, V., Snape, A., and Cannon, F. 1992. A plant selectable marker gene based on the detoxification of the herbicide dalapon. Plant Cell Rep., 11, 627-631. 

Reichert, J. Gemikeites, T Winkler, M. Application of HPLC with fluorescence detection to environmental analysis exemplified with the herbicide dalapon. Vom Wasser 1994,82, 37 8. 

Senior, E., A. T. Bull, and J. M. Slater. 1976. Enzyme evolution in a microbial community growing on the herbicide dalapon. Nature 263 476-479. 

Aliphatic-Garboxylics. There are only two herbicides present in this class, trichloroacetate [76-03-9] (TCA) and dalapon [75-99-0]. These are used primarily for the selective control of annual and perennial grass weeds in cropland and noncropland (2,299). Dalapon is also used as a selective aquatic herbicide (427). Dalapon and TCA are acidic in nature and are not strongly sorbed by sods. They are reported to be rapidly degraded in both sod and water by microbial processes (2,427). However, the breakdown of TCA occurs very slowly when incubated at 14—15°C in acidic sods (428). Timing not only accelerates this degradation but also increases the numbers of TCA-degrading bacteria. An HA has been issued for dalapon, but not TCA (269). 

Dalapon 0.2 0.2 Minor kidney changes Runoff from herbicide used on rights of way... 

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). 

Tsukioka et al. [187] determined these contact herbicides in soil by mass fragmentography. The method is based on the reaction of l-benzyl-3-p-polytriazene with an extract of Frenock and Dalapon from strongly acidified sample solutions to form benzylated species. In the analysis of soil samples, steam distillation was applied prior to extraction. Recoveries were >92% and precision <5%. 

Smith and Fitzpatrick [252] have also described a thin layer method for the detection in water and soil of herbicide residues, including Atrazine, Barban, Diuron, Linuron, Monuron, Simazine, Trifluralin, Bromoxynil, Dalapon, Dicamba, MCPB, Mecoprop, Dicloram, 2,4-D, 2,4-DB, Dichloroprop, 2,4,5-T, and 2,3,6-trichlorobenzoic acid. 

Herbicides 2,4-D, MCPA, Mecoprop, 4-(2,4-DB), TCA, Amitrole, Dalapon, Monuron, Chlorpropham, Endothal, Pyrazon, and DNOC. 

Figure 2 shows a simplified process flow diagram for halogenated aliphatic acid production facilities [8]. Halogenated aliphatic acids include chlorinated aliphatic acids and their salts, for example, TCA, Dalapon, and Fenac herbicides. Chlorinated aliphatic acids can be prepared by nitric acid oxidation of chloral (TCA) or by direct chlorination of the acid. The acids can be sold as mono- or dichloro acids, or neutralized to an aqueous solution with caustic soda. The neutralized solution is generally fed to a dryer from which the powdered product is packaged. 

Chlorinated phenoxypropanoic acid herbicides have been very widely used following the introduction of products such as Dalapon in the 1950s. More recently Mecoprop and... 

Two aliphatic acids possess, for grasses, many of the growth-distortion and toxicity effects associated with the synthetic auxins on dicotyledonous plants. Trichloroacetic acid and 2,2-dichloropropionic acid (dalapon), as the sodium salts, have been called grass "hormones or auxins, although Wilkinson184 could find no growth stimulation at low concentrations, and described dalapon as an antiauxin from its interference with indole-3-acetic acid effects. The herbicidal properties of trichloroacetate do not depend on its protein-denaturing ability, and those of 2,2-dichloropropionic acid involve, at least indirectly, the synthesis of pantothenic acid. 

Aliphatic-Carboxylics. These are used primarily lor the selective control of annual and perennial grass weeds in cropland and noncropland. Dalapon is also used as a seleclive aquatic herbicides. 

Many chemicals are regulated by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and their properties are as diverse as the properties of ecosystems. In forestry, however, relatively few herbicides are used very much. In fiscal year 1981, for instance, the USDA Forest Service used more than 25 different herbicides in the National Forests, but 2,4-D and picloram alone and in combination accounted for 70% of the total amount of herbicide applied. Atrazine, glyphosate, dalapon, simazine, fosamine, and hexazinone accounted for an additional 18% (2). 

Getzendaner s method [199] for determining Dalapon (2,2 dichloropropionic acids is applicable to plant tissues and body fluid and doubtlessly to water samples. The sample was extracted with ethyl ether and the residue was analysed by gas chromatography on a glass column (1.2mx 2mm) of 4% LAC-2R plus 0.5% of phosphoric acid on Gas Chrom S (60-80 mesh) at 100°C with nitrogen as carrier gas (85mL min-1) and electron capture detection. Recoveries of about 90% were obtained for lOppm of the herbicide. 

The Frank and Demint [200] method is directly applicable to water samples. After addition of sodium chloride (340g IT1) and aqueous hydrochloric acid (1 1) to bring the pH to 1, the sample was extracted with ethyl ether and the organic layer was then extracted with 0.1M sodium bicarbonate (saturated with sodium chloride and adjusted with sodium hydroxide to pH8). The aqueous solution adjusted to pHl with hydrochloric acid was extracted with ether and after evaporation of the ether to a small volume, Dalapon was esterified at room temperature by addition of diazomethane (0.5% solution in ether) and then applied to a stainless steel column (1.5m/3mm) packed with Chromosorb P (60-80 mesh) pretreated with hexamethyldisilazane and then coated with 10% FFAP. The column was operated at 140°C, with nitrogen carrier gas (30mL muT1) and electron capture detection. The recovery of Dalapon ranged from 91 to 100% the limit of detection was O.lng. Herbicides of the phenoxyacetic acid type did not interfere trichloroacetic acid could be determined simultaneously with Dalapon. 

Kaufman, D.D. (1966) Microbial degradation of herbicide combinations Amitrole and dalapon. Weeds 14, 130-134. 

The acute oral LD50 of dalapon for male rats is as high as 9,330 mg/kg, and for female rabbits is 3,860 mg/kg, suggesting that rabbits are more susceptible to the herbicide. The sodium salt of dalapon (in a dry powder formulation) to rabbit eyes produced pain and irritation, followed by severe conjunctivitis and comeal injury, which healed after several days. A 10% solution produced slight pain and conjunctivitis. Repeated or prolonged exposure to dalapon caused irritation to the mucous membrane linings of the mouth, nose, throat, lungs, and eyes. 

Figure 3. Relationship between the number of moles of ethylene oxide in octylphenol (%), nonylphenol ( ), or laurylphenol ( J) polyoxyethylene glycol ether surfactant molecules and the toxicity index of these surfactants in mixtures with (a) paraquat, (b) dalapon, and (c) amitrole on corn plants. Herbicides applied at 1/64, 10, and 5 lb./ acre, respectively surfactant concentration was 0.005M in all cases. Toxicity index calculated by expressing fresh weight for each treatment as percentage of untreated control and subtracting this value from 100 (58)...

Bipyridyl herbicides include alachlor, amitrole, atrazine, bromacil, bromoxynil, butylate, cyanazine, dalapon, dicamba, diuron, linuron, fluometuron, hexazinone, molinate, metolachlor, oryzalin, pendimethalin pronamide, propanil, propazine, simazine, terbacil, triallate, and triclopyr. In addition to these herbicides, the most common bipyridyls are diquat and paraquat. Paraquat is more toxic than diquat and produces chronic abnormal cell growth in the lungs, cornea and lens of the eye, nasal mucosa, skin, and fingernails. Diquat affects the eye lens and intestinal tract lining, but does not usually produce the frequently fatal lung changes characteristic of paraquat. 

Preferred Name Dalapon sodium salt Synonyms Basfapon Basfapon B Basfapon/ Basfapon N BH Dalapon Basinex Crisapon Dalapon 85 Ded-Weed Devipon 2,2-Dicloro-propionic acid a-Dichloropropionic acid a,a-Dichloropropionic acid Dowpon Dowpon M Gramevin Kenapon Kyselina Liropon Proprop Radapon Revenge Unipon Chemical/Pharmaceutical/Other Class Chlorinated aliphatic herbicide Chemical Structure ... 

Synthetic organic contaminants including pesticides and herbicides such as the following 2,4-D, 2,4,5-TP (Silvex), acrylamide, Alachlor, atrazine, benzoapyrene, carbofuran, Chlordane, dalapon, di-2-ethylhexyl adipate, di-2-ethylhexyl phtha-late, dibromochloropropane, Dinoseb, dioxin (2,3,7,8-TCDD), Diquat, Endothall, Endrin, epic-hlorohydrin, ethylene dibromide, glyphosate, He-ptachlor, Heptachlor epoxide, hexachlorobenzene. 

Eight of the nine compounds are chlorinated phenoxyadds dalapon is a chlorinated aliphatic acid. The positive ion thermospray mass spectra of these pesticides are summarized in Table I. The base peak in all cases is the (M+NH4)+ ion for 2,4-DB the (M+H) ion is present No ions were detected for dalapon. Since the protonated molecule is present for 2,4-DB this compound has the highest apparent proton affinity among these herbicides. 

Over the past years since the extensive use of modern herbicides began, cases of intraspecific resistance to a few other herbicides have developed, and there have been many examples of evolution toward interspecific herbicide tolerance (i.e., the more tolerant species gradually take over, such as 2,4-D tolerant broadleaf weeds and dalapon tolerant grasses). Within the last two years, there... 

Selective herbicides Pre-plan ting Na arsenite, H2S04, 2,4-D, MCPA, dalapon, IPC, CIPC, sesone, Sesin, Natrin,... 

The herbicidal activity of 2,2-dichloropropionic acid was described by Barrons (1963). Its approved common name is dalapon (3). 

Dalapon, like TCA, is a contact selective herbicide for the control of grassy weeds. It is used for selective weed killing at a rate of 0.8-10 kg acid equivalent/ha, and for total weed control on non-crop areas at a rate of 10-25 kg/ha. 

As does TCA, dalapon reduces the leaf wax synthesis of peas and cabbages, thereby increasing the sensitivity of the plants to contact herbicides (Pfeiffer et al., 1960). 

Erbon is a translocatable herbicide absorbed through roots and foliage, applied pre- or postemergence as a total herbicide. Its action lasts over one season. It is converted in the soil and in the plant into 2,4,S-trichlorophenoxyacetic acid and dalapon with herbicidal action. 

Oxyfluorfen is applied as a preemergence herbicide in soybeans, cotton, tomatoes, tobacco and green pepper at a rate of 0.2-0.4 kg active ingredient/ha. Grassy weeds are not well controlled by oxyfluorfen, but in the case of heavy grass weed infestation it can be tank—mixed with thiocarbamates, dinitroanilines, chloroacetamides, dalapon and paraquat. Oxyfluorfen is also recommended in tree fruits, vineyards and in conifer nurseries as an early postemergence treatment. 

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