Fungicides in agriculture

Thirugnanam, M. and A.J. Forgash. 1977. Environmental impact of mosquito pesticides toxicity and anticholinesterase activity of chlorpyrifos to fish in a salt marsh habitat. Arch. Environ Contam, Toxicol. 5 415-425. Tsuda, T., S. Aoki, T. Inoue, and M. Kojima. 1994. Accumulation and excretion of pesticides used as insecticides or fungicides in agricultural products by the willow shiner Gnathopogon caerulescens. Comp. Biochem. Physiol. 107C 469-473. 

Various mixtures of simple copper compounds with one another or with other compounds have been, and in some cases still are, of great importance as fungicides in agriculture. The range of plants on which they can be used and the diseases they control are too numerous to mention here and the literature should be consulted.60 Table 2 gives the compositions of these mixtures and the more common trade names under which they are known. 

With the success of Qo inhibitors as fungicides in agriculture, inhibitor resistance has become a possible threat for both farmers and chemists. After a short time of... 

Penicillamine (D-(3,(3-dimethylcysteine) is an effective chelator of copper, mercury, zinc and lead which promotes the excretion of these metals in the urine. It is clinically used in patients with Wilson s disease, with rheumatoid arthritis and with heavy-metal intoxications. Ziram and ferbam are the zinc and the iron salts respectively of dimethyl-dithiocarbamic acid (Figure 20.44). They are widely used as selective fungicides in agriculture. Pyrithione (1 -hydroxy-2(l//)-pyridinethione), as its zinc salt is used in dermatology as antiseborrheic. 

Ethers may have a cyclic structure, such as ethylene oxide and tetrahydrofurane. Ethylene oxide is a gas at room temperature and is used as a disinfectant for foods and a fungicide in agriculture. 

Since water is perhaps the most environmentally friendly solvent available at high purity and low cost, it has been exploited for the extraction of avoparcin in animal tissue (53), fungicides in agricultural commodities (54), fragrances from clove (55), antioxidative compounds from sage (56), anthocyanins and total phenolics from dried red grape skin (48), and other bioactive compounds from plants (57). See also chapters 5 and 6 in this book uid a few review articles (51,58). 

Janssen, M. J. and Kaars Sijpesteijn, A. (1961) In Fungicides in Agriculture and Horticulture. Society of Chemical Industry Monograph, IS, 40. 

Klimmer, 0. R., Applications of organotin fungicides in agriculture with regard to toxicity, Pflanzenschutzberichte 3i 57 66 (I966) CA 18227. 

Other chelating antimicrobials have been found that, while having a totally different structure, mimic the action of oxine by being active only in the presence of a variable-valence metal, and hence show concentration quenching. Such a substance is i-hydroxypyridine-2-thione (pyrithione), (2.2j) (Albert, Rees, and Tomlinson, 1956), which is much used in the dermatology of the scalp. Another example is dimethyldithiocarbamic acid (2.2 ), whose salts are widely used as selective fungicides in agriculture. 

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