Bordeaux mixture toxicity

Early in the history of plant chemotherapy the differential toxicity of the therapeutic chemical was related to the limitation of its aqueous solubility. A case in point was the 19th century discovery of the grape fungicide, Bordeaux mixture. 

Bordeaux mixture and other copper salts owe their toxicity to the ions ability to make one-electron exchanges (Cu+ D Cu++ + e ) (Figure 3.10). An electron is taken up from the electron transport chain and delivered to 02 to form the superoxide anion. The anion radical is further transformed to H202 by superoxide dismutase catalysing. 

Activation analysis has also been used to determine other toxic elements in agricultural materials. Arsenic has been determined in vegetables by Kirchmann and Roderbourg (473) and Lenihan and Smith (543). Shibuya (842) has determined the effects of copper from mine-water wastes upon rice oryza saliva), while Fourcy (283,285) has analyzed the leaves of vitis vinifera vines for copper residues from Bordeaux mixture treatments. 

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