Agricultural uses

The 1-phenylpyrazole core has been shown to bestow pharmacological activity in a number of areas in the pharmaceutical and agrochemical industries. In the latter field, select examples of biological activities include insecticidal, miticidal, and herbicidal. More specifically, 1-phenylpyrazoles with alkyl, acyl, thioalkyl, or cyano substituents at the 4-position exhibit potent insecticidal activity. In particular, 5-amino-I-(2,6-dichloro-4-trifluoro-methylphenyl)-4-trifluoromethanesulfinyl-l//-pyrazole-3-carbonitrile (Fipronil ) is one of the most commercially successful insecticides. In fleas, ticks, and other arthropods, it acts as a gamma-aminobutyric acid (GABA)-gated 

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Some of the chemical derivatives, especially those tied to agricultural uses, tend to experience some cycHcal demand. However, because of the speciali2ed nature of many of the fluorinated chemicals, these products are positioned in strong, high performance market areas having above average growth rates. 

Between 1979 and 1991, the amounts of herbicide apphed in the United States have remained constant, but the expenditures on herbicides have increased 54%. Agricultural costs accounted for ah. of this increase and more, since herbicide user expenditures in the government/commercial and home sectors combined dropped 3 to 4% during that period. Increased weed control costs related to crop protection have also contributed to the 37% increase, since 1988, in total annual user expenditures for pesticides in general, ie, herbicides, fungicides, and insecticides. In the United States, agricultural uses (ca 1993) account for more than 67% of total pesticide user expenses and 75% of the quantity used annually. Herbicides are now the lea ding type of pesticides in terms of both user expenditures and volumes used (1). 

Agricultural Uses. Pesticides represent the second largest commercial market for hydrazine. Hundreds of hydrazine derivatives have been patented for a wide range of agricultural appHcations. Table 13 presents a sampling of the 50—60 that are commercially available or developmental products. These compounds are made from hydrazine, MMH, and UDMH and are for the most part heterocycHc nitrogen compounds (see Insect control technology). 

Rubber chemicals, primarily antioxidants (qv), stabiLhers, and antio2onants (qv), account for 12% of the demand for aniline woddwide. Important agricultural uses for aniline derivatives include fungicides, insecticides, animal repellents, and defoHants. It is estimated that less than 5% of the aniline produced in 1988 was consumed for agricultural chemicals. 

Table 3. Pesticides in Groundwater from Normal Agricultural Use ...

Alcosorb 400 Water-Retaining Polymer," undated product Hterature, AHied CoUoids describes agricultural uses of cross-linked polyacrylamide gels. 

Agricultural uses for ammonium thiosulfate take advantage of both the sulfur and ammonium content by blending with other nitrogen fertilizers such as urea (71). Some foHar-spray fertilizers contain ammonium thiosulfate together with other metal micronutrients (72,73). Ammonium thiosulfate or mixtures with ammonium nitrate can also be used as desiccants and defoHants ia crop-beariag plants such as cotton (qv), soybean, alfalfa, rice, and peppers (74,75). 

The influence of human activities in a stream drainage basin can be relatively simple and direct, as in the disposal of soluble organic and inorganic waste, or more subtie and complex, as in the conversion of prairie or forest land to agricultural use. Such effects can be expected to increase as population density and agricultural, industrial, and mining activities increase. 

Avemiectin is the most effective of the averniectia family of natural products against agriculturally important insects and mites (14). It has been commercialized for agricultural use under the nonproprietary name abamectin. This mixture of avermectins contains at least 80% of avermectin (C4gH 20 and not more than 20% of avermectin B Abamectin for use in foHar spray appHcations is formulated as an emulsiftable... 

The second most important (3%) use of sodium chlorate in 1990 was as an intermediate in the production of other chlorates and of perchlorates. The use of sodium chlorate as in agricultural appHcation amounted to about 7000 metric tons in 1990. The agricultural use of sodium chlorate is as a herbicide, as a defoHant for cotton (qv). Magnesium chlorate is used as a desiccant for soybeans to remove the leaves prior to mechanical picking (see Desiccants). 

Agricultural Use. Citric acid and its ammonium salts are used to form soluble chelates of iron, copper, magnesium, manganese, and zinc micronutrients in Hquid fertilizers (97—103). Citric acid and citrate salts are used in animal feeds to form soluble, easily digestible chelates of essential metal nutrients, enhance feed flavor to increase food uptake, control gastric pH and improve feed efficiency. 

For agricultural uses, a fully hydrated calcium cyanamide powder containing 2% oil is used for dusting appHcations for general fertilizer use, the hydrated material is granulated with water in rotary dmms and dried giving a 2.38 x 0.32 mm (8 x 48 mesh) product. 

Nearly 95% of the sodium chlorate produced ia North America is used to produce chlorine dioxide [10049-04-4] CIO2, for pulp (qv) bleaching (see Bleaching AGENTS, pulp and paper) (37). Minor amounts are used to produce other chemicals such as KCIO, NaC102, NaClO, etc, to recover uranium [7440-61-17, U (see Uraniumand uranium compounds) and for agricultural uses as a defoHant or herbicide (see Herbicides). 

Atrazine and simazine arose principally as a result of their use in amenity situations but, since their ban for non-agriciiltiiral purposes, concentrations are generally declining. Fiowever, atrazine and simazine still have some agricultural uses (atrazine on maize and simazine on a wide range of crops), so the risk of pollution still exists when these pesticides are applied in either groundwater or surface water drinking water supply catchments. 

The Stretham steam pumping engine (Fig. 16.8) was built in 1831 as part of an extensive project to drain the Fens for agricultural use. In its day it was one of the largest beam engines in the Fens, having a maximum power of 105 horsepower at 15 rpm (it could... 

Ref 11). The pH of a satd soln in w was measured with a glass electrode and found to be 0.6 (Ref 25, p 2) CA Registry No 517-25-9. The Hercules Powder Co of Wil-mington, Del has been granted a trademark for Nitroform , a synthetic w-insoluble compd for controlled release of N for agricultural use (Ref 40). This should not be confused with TNMe... 

Kubasova [963] has reviewed the chemistry of the ammonium salts of polyphosphoric acids. Much interest in the field derives from the agricultural uses of these substances as fertilizers. Both NH3 and H20 tend to be eliminated simultaneously on heating, but dehydration alone may be achieved in an atmosphere of NH3 [963], e.g. 

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