Triphenyltin, potatoes

Triphenyltin has been determined in potatoes in amounts down to 0.1 ng/1 by extraction with ethanolic potassium hydroxide, derivatisation with sodium tetraethyl boron and solid-phase microextraction gas chromatography IC-PMS [5]. 

Triphenyltin hydroxide (Fentin) and triphenyltin acetate (Brestan) are used to combat potato blight, leaf spot on celery and sugar beet, rice blast, and coffee leaf rust. Tricyclo-hexyltin hydroxide (Plictran), bis(trineophyltin) oxide (Vendex or Torque), and 1-tricyclohexylstannyl-l,2,4-triazole (Peropal) have also been used for the contol of mites on apples, pears, and citrus fruits. 

This active substance, appearing as white, odourless crystals, was developed by Van der Kerk and Luijten (1954,1956). It hydrolyses rapidly in aqueous medium to form triphenyltin hydroxide. Although of the organotin compounds it is the one best tolerated by plants, it is used mainly for the protection of field crops (sugar beet, potato). In certain cases, it causes phytotoxic damage, even in potatoes. This phytotoxicity can be reduced by combination with maneb, and a synergistic effect has even been detected between the two active substances (Hartel, 1964). The combination is marketed under the name Brestan . 

Of the butyltin derivatives the active substances dibutyltin disalicylate (17) and bis (tri-/i-butyltin) oxide (18) are effective against potato blight, but have only about one-tenth the effect of triphenyltin compounds (McIntosh, 1970). 

Du-Ter . [Griffin] Triphenyltin hydroxide flowable fungicide for pecans, potatoes, sugar beets. 

Pro-Tex. [Griffin] Maneb (32.63%) and triphenyltin hy xide (4.72%) sol n. flowable fungicide for potatoes and sugar beets. 

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